1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/thread.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,4686 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "classfile/classLoader.hpp"
1.30 +#include "classfile/javaClasses.hpp"
1.31 +#include "classfile/systemDictionary.hpp"
1.32 +#include "classfile/vmSymbols.hpp"
1.33 +#include "code/scopeDesc.hpp"
1.34 +#include "compiler/compileBroker.hpp"
1.35 +#include "interpreter/interpreter.hpp"
1.36 +#include "interpreter/linkResolver.hpp"
1.37 +#include "interpreter/oopMapCache.hpp"
1.38 +#include "jvmtifiles/jvmtiEnv.hpp"
1.39 +#include "memory/gcLocker.inline.hpp"
1.40 +#include "memory/metaspaceShared.hpp"
1.41 +#include "memory/oopFactory.hpp"
1.42 +#include "memory/universe.inline.hpp"
1.43 +#include "oops/instanceKlass.hpp"
1.44 +#include "oops/objArrayOop.hpp"
1.45 +#include "oops/oop.inline.hpp"
1.46 +#include "oops/symbol.hpp"
1.47 +#include "prims/jvm_misc.hpp"
1.48 +#include "prims/jvmtiExport.hpp"
1.49 +#include "prims/jvmtiThreadState.hpp"
1.50 +#include "prims/privilegedStack.hpp"
1.51 +#include "runtime/arguments.hpp"
1.52 +#include "runtime/biasedLocking.hpp"
1.53 +#include "runtime/deoptimization.hpp"
1.54 +#include "runtime/fprofiler.hpp"
1.55 +#include "runtime/frame.inline.hpp"
1.56 +#include "runtime/init.hpp"
1.57 +#include "runtime/interfaceSupport.hpp"
1.58 +#include "runtime/java.hpp"
1.59 +#include "runtime/javaCalls.hpp"
1.60 +#include "runtime/jniPeriodicChecker.hpp"
1.61 +#include "runtime/memprofiler.hpp"
1.62 +#include "runtime/mutexLocker.hpp"
1.63 +#include "runtime/objectMonitor.hpp"
1.64 +#include "runtime/osThread.hpp"
1.65 +#include "runtime/safepoint.hpp"
1.66 +#include "runtime/sharedRuntime.hpp"
1.67 +#include "runtime/statSampler.hpp"
1.68 +#include "runtime/stubRoutines.hpp"
1.69 +#include "runtime/task.hpp"
1.70 +#include "runtime/thread.inline.hpp"
1.71 +#include "runtime/threadCritical.hpp"
1.72 +#include "runtime/threadLocalStorage.hpp"
1.73 +#include "runtime/vframe.hpp"
1.74 +#include "runtime/vframeArray.hpp"
1.75 +#include "runtime/vframe_hp.hpp"
1.76 +#include "runtime/vmThread.hpp"
1.77 +#include "runtime/vm_operations.hpp"
1.78 +#include "services/attachListener.hpp"
1.79 +#include "services/management.hpp"
1.80 +#include "services/memTracker.hpp"
1.81 +#include "services/threadService.hpp"
1.82 +#include "trace/tracing.hpp"
1.83 +#include "trace/traceMacros.hpp"
1.84 +#include "utilities/defaultStream.hpp"
1.85 +#include "utilities/dtrace.hpp"
1.86 +#include "utilities/events.hpp"
1.87 +#include "utilities/preserveException.hpp"
1.88 +#include "utilities/macros.hpp"
1.89 +#ifdef TARGET_OS_FAMILY_linux
1.90 +# include "os_linux.inline.hpp"
1.91 +#endif
1.92 +#ifdef TARGET_OS_FAMILY_solaris
1.93 +# include "os_solaris.inline.hpp"
1.94 +#endif
1.95 +#ifdef TARGET_OS_FAMILY_windows
1.96 +# include "os_windows.inline.hpp"
1.97 +#endif
1.98 +#ifdef TARGET_OS_FAMILY_bsd
1.99 +# include "os_bsd.inline.hpp"
1.100 +#endif
1.101 +#if INCLUDE_ALL_GCS
1.102 +#include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
1.103 +#include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
1.104 +#include "gc_implementation/parallelScavenge/pcTasks.hpp"
1.105 +#endif // INCLUDE_ALL_GCS
1.106 +#ifdef COMPILER1
1.107 +#include "c1/c1_Compiler.hpp"
1.108 +#endif
1.109 +#ifdef COMPILER2
1.110 +#include "opto/c2compiler.hpp"
1.111 +#include "opto/idealGraphPrinter.hpp"
1.112 +#endif
1.113 +#if INCLUDE_RTM_OPT
1.114 +#include "runtime/rtmLocking.hpp"
1.115 +#endif
1.116 +
1.117 +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.118 +
1.119 +#ifdef DTRACE_ENABLED
1.120 +
1.121 +// Only bother with this argument setup if dtrace is available
1.122 +
1.123 +#ifndef USDT2
1.124 +HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
1.125 +HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
1.126 +HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
1.127 + intptr_t, intptr_t, bool);
1.128 +HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
1.129 + intptr_t, intptr_t, bool);
1.130 +
1.131 +#define DTRACE_THREAD_PROBE(probe, javathread) \
1.132 + { \
1.133 + ResourceMark rm(this); \
1.134 + int len = 0; \
1.135 + const char* name = (javathread)->get_thread_name(); \
1.136 + len = strlen(name); \
1.137 + HS_DTRACE_PROBE5(hotspot, thread__##probe, \
1.138 + name, len, \
1.139 + java_lang_Thread::thread_id((javathread)->threadObj()), \
1.140 + (javathread)->osthread()->thread_id(), \
1.141 + java_lang_Thread::is_daemon((javathread)->threadObj())); \
1.142 + }
1.143 +
1.144 +#else /* USDT2 */
1.145 +
1.146 +#define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_PROBE_START
1.147 +#define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_PROBE_STOP
1.148 +
1.149 +#define DTRACE_THREAD_PROBE(probe, javathread) \
1.150 + { \
1.151 + ResourceMark rm(this); \
1.152 + int len = 0; \
1.153 + const char* name = (javathread)->get_thread_name(); \
1.154 + len = strlen(name); \
1.155 + HOTSPOT_THREAD_PROBE_##probe( /* probe = start, stop */ \
1.156 + (char *) name, len, \
1.157 + java_lang_Thread::thread_id((javathread)->threadObj()), \
1.158 + (uintptr_t) (javathread)->osthread()->thread_id(), \
1.159 + java_lang_Thread::is_daemon((javathread)->threadObj())); \
1.160 + }
1.161 +
1.162 +#endif /* USDT2 */
1.163 +
1.164 +#else // ndef DTRACE_ENABLED
1.165 +
1.166 +#define DTRACE_THREAD_PROBE(probe, javathread)
1.167 +
1.168 +#endif // ndef DTRACE_ENABLED
1.169 +
1.170 +
1.171 +// Class hierarchy
1.172 +// - Thread
1.173 +// - VMThread
1.174 +// - WatcherThread
1.175 +// - ConcurrentMarkSweepThread
1.176 +// - JavaThread
1.177 +// - CompilerThread
1.178 +
1.179 +// ======= Thread ========
1.180 +// Support for forcing alignment of thread objects for biased locking
1.181 +void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
1.182 + if (UseBiasedLocking) {
1.183 + const int alignment = markOopDesc::biased_lock_alignment;
1.184 + size_t aligned_size = size + (alignment - sizeof(intptr_t));
1.185 + void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
1.186 + : AllocateHeap(aligned_size, flags, CURRENT_PC,
1.187 + AllocFailStrategy::RETURN_NULL);
1.188 + void* aligned_addr = (void*) align_size_up((intptr_t) real_malloc_addr, alignment);
1.189 + assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
1.190 + ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
1.191 + "JavaThread alignment code overflowed allocated storage");
1.192 + if (TraceBiasedLocking) {
1.193 + if (aligned_addr != real_malloc_addr)
1.194 + tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
1.195 + real_malloc_addr, aligned_addr);
1.196 + }
1.197 + ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
1.198 + return aligned_addr;
1.199 + } else {
1.200 + return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
1.201 + : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
1.202 + }
1.203 +}
1.204 +
1.205 +void Thread::operator delete(void* p) {
1.206 + if (UseBiasedLocking) {
1.207 + void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
1.208 + FreeHeap(real_malloc_addr, mtThread);
1.209 + } else {
1.210 + FreeHeap(p, mtThread);
1.211 + }
1.212 +}
1.213 +
1.214 +
1.215 +// Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
1.216 +// JavaThread
1.217 +
1.218 +
1.219 +Thread::Thread() {
1.220 + // stack and get_thread
1.221 + set_stack_base(NULL);
1.222 + set_stack_size(0);
1.223 + set_self_raw_id(0);
1.224 + set_lgrp_id(-1);
1.225 +
1.226 + // allocated data structures
1.227 + set_osthread(NULL);
1.228 + set_resource_area(new (mtThread)ResourceArea());
1.229 + DEBUG_ONLY(_current_resource_mark = NULL;)
1.230 + set_handle_area(new (mtThread) HandleArea(NULL));
1.231 + set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
1.232 + set_active_handles(NULL);
1.233 + set_free_handle_block(NULL);
1.234 + set_last_handle_mark(NULL);
1.235 +
1.236 + // This initial value ==> never claimed.
1.237 + _oops_do_parity = 0;
1.238 +
1.239 + // the handle mark links itself to last_handle_mark
1.240 + new HandleMark(this);
1.241 +
1.242 + // plain initialization
1.243 + debug_only(_owned_locks = NULL;)
1.244 + debug_only(_allow_allocation_count = 0;)
1.245 + NOT_PRODUCT(_allow_safepoint_count = 0;)
1.246 + NOT_PRODUCT(_skip_gcalot = false;)
1.247 + _jvmti_env_iteration_count = 0;
1.248 + set_allocated_bytes(0);
1.249 + _vm_operation_started_count = 0;
1.250 + _vm_operation_completed_count = 0;
1.251 + _current_pending_monitor = NULL;
1.252 + _current_pending_monitor_is_from_java = true;
1.253 + _current_waiting_monitor = NULL;
1.254 + _num_nested_signal = 0;
1.255 + omFreeList = NULL ;
1.256 + omFreeCount = 0 ;
1.257 + omFreeProvision = 32 ;
1.258 + omInUseList = NULL ;
1.259 + omInUseCount = 0 ;
1.260 +
1.261 +#ifdef ASSERT
1.262 + _visited_for_critical_count = false;
1.263 +#endif
1.264 +
1.265 + _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
1.266 + _suspend_flags = 0;
1.267 +
1.268 + // thread-specific hashCode stream generator state - Marsaglia shift-xor form
1.269 + _hashStateX = os::random() ;
1.270 + _hashStateY = 842502087 ;
1.271 + _hashStateZ = 0x8767 ; // (int)(3579807591LL & 0xffff) ;
1.272 + _hashStateW = 273326509 ;
1.273 +
1.274 + _OnTrap = 0 ;
1.275 + _schedctl = NULL ;
1.276 + _Stalled = 0 ;
1.277 + _TypeTag = 0x2BAD ;
1.278 +
1.279 + // Many of the following fields are effectively final - immutable
1.280 + // Note that nascent threads can't use the Native Monitor-Mutex
1.281 + // construct until the _MutexEvent is initialized ...
1.282 + // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
1.283 + // we might instead use a stack of ParkEvents that we could provision on-demand.
1.284 + // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
1.285 + // and ::Release()
1.286 + _ParkEvent = ParkEvent::Allocate (this) ;
1.287 + _SleepEvent = ParkEvent::Allocate (this) ;
1.288 + _MutexEvent = ParkEvent::Allocate (this) ;
1.289 + _MuxEvent = ParkEvent::Allocate (this) ;
1.290 +
1.291 +#ifdef CHECK_UNHANDLED_OOPS
1.292 + if (CheckUnhandledOops) {
1.293 + _unhandled_oops = new UnhandledOops(this);
1.294 + }
1.295 +#endif // CHECK_UNHANDLED_OOPS
1.296 +#ifdef ASSERT
1.297 + if (UseBiasedLocking) {
1.298 + assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
1.299 + assert(this == _real_malloc_address ||
1.300 + this == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
1.301 + "bug in forced alignment of thread objects");
1.302 + }
1.303 +#endif /* ASSERT */
1.304 +}
1.305 +
1.306 +void Thread::initialize_thread_local_storage() {
1.307 + // Note: Make sure this method only calls
1.308 + // non-blocking operations. Otherwise, it might not work
1.309 + // with the thread-startup/safepoint interaction.
1.310 +
1.311 + // During Java thread startup, safepoint code should allow this
1.312 + // method to complete because it may need to allocate memory to
1.313 + // store information for the new thread.
1.314 +
1.315 + // initialize structure dependent on thread local storage
1.316 + ThreadLocalStorage::set_thread(this);
1.317 +}
1.318 +
1.319 +void Thread::record_stack_base_and_size() {
1.320 + set_stack_base(os::current_stack_base());
1.321 + set_stack_size(os::current_stack_size());
1.322 + if (is_Java_thread()) {
1.323 + ((JavaThread*) this)->set_stack_overflow_limit();
1.324 + }
1.325 + // CR 7190089: on Solaris, primordial thread's stack is adjusted
1.326 + // in initialize_thread(). Without the adjustment, stack size is
1.327 + // incorrect if stack is set to unlimited (ulimit -s unlimited).
1.328 + // So far, only Solaris has real implementation of initialize_thread().
1.329 + //
1.330 + // set up any platform-specific state.
1.331 + os::initialize_thread(this);
1.332 +
1.333 +#if INCLUDE_NMT
1.334 + // record thread's native stack, stack grows downward
1.335 + address stack_low_addr = stack_base() - stack_size();
1.336 + MemTracker::record_thread_stack(stack_low_addr, stack_size(), this,
1.337 + CURRENT_PC);
1.338 +#endif // INCLUDE_NMT
1.339 +}
1.340 +
1.341 +
1.342 +Thread::~Thread() {
1.343 + // Reclaim the objectmonitors from the omFreeList of the moribund thread.
1.344 + ObjectSynchronizer::omFlush (this) ;
1.345 +
1.346 + EVENT_THREAD_DESTRUCT(this);
1.347 +
1.348 + // stack_base can be NULL if the thread is never started or exited before
1.349 + // record_stack_base_and_size called. Although, we would like to ensure
1.350 + // that all started threads do call record_stack_base_and_size(), there is
1.351 + // not proper way to enforce that.
1.352 +#if INCLUDE_NMT
1.353 + if (_stack_base != NULL) {
1.354 + address low_stack_addr = stack_base() - stack_size();
1.355 + MemTracker::release_thread_stack(low_stack_addr, stack_size(), this);
1.356 +#ifdef ASSERT
1.357 + set_stack_base(NULL);
1.358 +#endif
1.359 + }
1.360 +#endif // INCLUDE_NMT
1.361 +
1.362 + // deallocate data structures
1.363 + delete resource_area();
1.364 + // since the handle marks are using the handle area, we have to deallocated the root
1.365 + // handle mark before deallocating the thread's handle area,
1.366 + assert(last_handle_mark() != NULL, "check we have an element");
1.367 + delete last_handle_mark();
1.368 + assert(last_handle_mark() == NULL, "check we have reached the end");
1.369 +
1.370 + // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
1.371 + // We NULL out the fields for good hygiene.
1.372 + ParkEvent::Release (_ParkEvent) ; _ParkEvent = NULL ;
1.373 + ParkEvent::Release (_SleepEvent) ; _SleepEvent = NULL ;
1.374 + ParkEvent::Release (_MutexEvent) ; _MutexEvent = NULL ;
1.375 + ParkEvent::Release (_MuxEvent) ; _MuxEvent = NULL ;
1.376 +
1.377 + delete handle_area();
1.378 + delete metadata_handles();
1.379 +
1.380 + // osthread() can be NULL, if creation of thread failed.
1.381 + if (osthread() != NULL) os::free_thread(osthread());
1.382 +
1.383 + delete _SR_lock;
1.384 +
1.385 + // clear thread local storage if the Thread is deleting itself
1.386 + if (this == Thread::current()) {
1.387 + ThreadLocalStorage::set_thread(NULL);
1.388 + } else {
1.389 + // In the case where we're not the current thread, invalidate all the
1.390 + // caches in case some code tries to get the current thread or the
1.391 + // thread that was destroyed, and gets stale information.
1.392 + ThreadLocalStorage::invalidate_all();
1.393 + }
1.394 + CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
1.395 +}
1.396 +
1.397 +// NOTE: dummy function for assertion purpose.
1.398 +void Thread::run() {
1.399 + ShouldNotReachHere();
1.400 +}
1.401 +
1.402 +#ifdef ASSERT
1.403 +// Private method to check for dangling thread pointer
1.404 +void check_for_dangling_thread_pointer(Thread *thread) {
1.405 + assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
1.406 + "possibility of dangling Thread pointer");
1.407 +}
1.408 +#endif
1.409 +
1.410 +
1.411 +#ifndef PRODUCT
1.412 +// Tracing method for basic thread operations
1.413 +void Thread::trace(const char* msg, const Thread* const thread) {
1.414 + if (!TraceThreadEvents) return;
1.415 + ResourceMark rm;
1.416 + ThreadCritical tc;
1.417 + const char *name = "non-Java thread";
1.418 + int prio = -1;
1.419 + if (thread->is_Java_thread()
1.420 + && !thread->is_Compiler_thread()) {
1.421 + // The Threads_lock must be held to get information about
1.422 + // this thread but may not be in some situations when
1.423 + // tracing thread events.
1.424 + bool release_Threads_lock = false;
1.425 + if (!Threads_lock->owned_by_self()) {
1.426 + Threads_lock->lock();
1.427 + release_Threads_lock = true;
1.428 + }
1.429 + JavaThread* jt = (JavaThread *)thread;
1.430 + name = (char *)jt->get_thread_name();
1.431 + oop thread_oop = jt->threadObj();
1.432 + if (thread_oop != NULL) {
1.433 + prio = java_lang_Thread::priority(thread_oop);
1.434 + }
1.435 + if (release_Threads_lock) {
1.436 + Threads_lock->unlock();
1.437 + }
1.438 + }
1.439 + tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
1.440 +}
1.441 +#endif
1.442 +
1.443 +
1.444 +ThreadPriority Thread::get_priority(const Thread* const thread) {
1.445 + trace("get priority", thread);
1.446 + ThreadPriority priority;
1.447 + // Can return an error!
1.448 + (void)os::get_priority(thread, priority);
1.449 + assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
1.450 + return priority;
1.451 +}
1.452 +
1.453 +void Thread::set_priority(Thread* thread, ThreadPriority priority) {
1.454 + trace("set priority", thread);
1.455 + debug_only(check_for_dangling_thread_pointer(thread);)
1.456 + // Can return an error!
1.457 + (void)os::set_priority(thread, priority);
1.458 +}
1.459 +
1.460 +
1.461 +void Thread::start(Thread* thread) {
1.462 + trace("start", thread);
1.463 + // Start is different from resume in that its safety is guaranteed by context or
1.464 + // being called from a Java method synchronized on the Thread object.
1.465 + if (!DisableStartThread) {
1.466 + if (thread->is_Java_thread()) {
1.467 + // Initialize the thread state to RUNNABLE before starting this thread.
1.468 + // Can not set it after the thread started because we do not know the
1.469 + // exact thread state at that time. It could be in MONITOR_WAIT or
1.470 + // in SLEEPING or some other state.
1.471 + java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
1.472 + java_lang_Thread::RUNNABLE);
1.473 + }
1.474 + os::start_thread(thread);
1.475 + }
1.476 +}
1.477 +
1.478 +// Enqueue a VM_Operation to do the job for us - sometime later
1.479 +void Thread::send_async_exception(oop java_thread, oop java_throwable) {
1.480 + VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
1.481 + VMThread::execute(vm_stop);
1.482 +}
1.483 +
1.484 +
1.485 +//
1.486 +// Check if an external suspend request has completed (or has been
1.487 +// cancelled). Returns true if the thread is externally suspended and
1.488 +// false otherwise.
1.489 +//
1.490 +// The bits parameter returns information about the code path through
1.491 +// the routine. Useful for debugging:
1.492 +//
1.493 +// set in is_ext_suspend_completed():
1.494 +// 0x00000001 - routine was entered
1.495 +// 0x00000010 - routine return false at end
1.496 +// 0x00000100 - thread exited (return false)
1.497 +// 0x00000200 - suspend request cancelled (return false)
1.498 +// 0x00000400 - thread suspended (return true)
1.499 +// 0x00001000 - thread is in a suspend equivalent state (return true)
1.500 +// 0x00002000 - thread is native and walkable (return true)
1.501 +// 0x00004000 - thread is native_trans and walkable (needed retry)
1.502 +//
1.503 +// set in wait_for_ext_suspend_completion():
1.504 +// 0x00010000 - routine was entered
1.505 +// 0x00020000 - suspend request cancelled before loop (return false)
1.506 +// 0x00040000 - thread suspended before loop (return true)
1.507 +// 0x00080000 - suspend request cancelled in loop (return false)
1.508 +// 0x00100000 - thread suspended in loop (return true)
1.509 +// 0x00200000 - suspend not completed during retry loop (return false)
1.510 +//
1.511 +
1.512 +// Helper class for tracing suspend wait debug bits.
1.513 +//
1.514 +// 0x00000100 indicates that the target thread exited before it could
1.515 +// self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
1.516 +// 0x00080000 each indicate a cancelled suspend request so they don't
1.517 +// count as wait failures either.
1.518 +#define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
1.519 +
1.520 +class TraceSuspendDebugBits : public StackObj {
1.521 + private:
1.522 + JavaThread * jt;
1.523 + bool is_wait;
1.524 + bool called_by_wait; // meaningful when !is_wait
1.525 + uint32_t * bits;
1.526 +
1.527 + public:
1.528 + TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
1.529 + uint32_t *_bits) {
1.530 + jt = _jt;
1.531 + is_wait = _is_wait;
1.532 + called_by_wait = _called_by_wait;
1.533 + bits = _bits;
1.534 + }
1.535 +
1.536 + ~TraceSuspendDebugBits() {
1.537 + if (!is_wait) {
1.538 +#if 1
1.539 + // By default, don't trace bits for is_ext_suspend_completed() calls.
1.540 + // That trace is very chatty.
1.541 + return;
1.542 +#else
1.543 + if (!called_by_wait) {
1.544 + // If tracing for is_ext_suspend_completed() is enabled, then only
1.545 + // trace calls to it from wait_for_ext_suspend_completion()
1.546 + return;
1.547 + }
1.548 +#endif
1.549 + }
1.550 +
1.551 + if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
1.552 + if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
1.553 + MutexLocker ml(Threads_lock); // needed for get_thread_name()
1.554 + ResourceMark rm;
1.555 +
1.556 + tty->print_cr(
1.557 + "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
1.558 + jt->get_thread_name(), *bits);
1.559 +
1.560 + guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
1.561 + }
1.562 + }
1.563 + }
1.564 +};
1.565 +#undef DEBUG_FALSE_BITS
1.566 +
1.567 +
1.568 +bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits) {
1.569 + TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
1.570 +
1.571 + bool did_trans_retry = false; // only do thread_in_native_trans retry once
1.572 + bool do_trans_retry; // flag to force the retry
1.573 +
1.574 + *bits |= 0x00000001;
1.575 +
1.576 + do {
1.577 + do_trans_retry = false;
1.578 +
1.579 + if (is_exiting()) {
1.580 + // Thread is in the process of exiting. This is always checked
1.581 + // first to reduce the risk of dereferencing a freed JavaThread.
1.582 + *bits |= 0x00000100;
1.583 + return false;
1.584 + }
1.585 +
1.586 + if (!is_external_suspend()) {
1.587 + // Suspend request is cancelled. This is always checked before
1.588 + // is_ext_suspended() to reduce the risk of a rogue resume
1.589 + // confusing the thread that made the suspend request.
1.590 + *bits |= 0x00000200;
1.591 + return false;
1.592 + }
1.593 +
1.594 + if (is_ext_suspended()) {
1.595 + // thread is suspended
1.596 + *bits |= 0x00000400;
1.597 + return true;
1.598 + }
1.599 +
1.600 + // Now that we no longer do hard suspends of threads running
1.601 + // native code, the target thread can be changing thread state
1.602 + // while we are in this routine:
1.603 + //
1.604 + // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
1.605 + //
1.606 + // We save a copy of the thread state as observed at this moment
1.607 + // and make our decision about suspend completeness based on the
1.608 + // copy. This closes the race where the thread state is seen as
1.609 + // _thread_in_native_trans in the if-thread_blocked check, but is
1.610 + // seen as _thread_blocked in if-thread_in_native_trans check.
1.611 + JavaThreadState save_state = thread_state();
1.612 +
1.613 + if (save_state == _thread_blocked && is_suspend_equivalent()) {
1.614 + // If the thread's state is _thread_blocked and this blocking
1.615 + // condition is known to be equivalent to a suspend, then we can
1.616 + // consider the thread to be externally suspended. This means that
1.617 + // the code that sets _thread_blocked has been modified to do
1.618 + // self-suspension if the blocking condition releases. We also
1.619 + // used to check for CONDVAR_WAIT here, but that is now covered by
1.620 + // the _thread_blocked with self-suspension check.
1.621 + //
1.622 + // Return true since we wouldn't be here unless there was still an
1.623 + // external suspend request.
1.624 + *bits |= 0x00001000;
1.625 + return true;
1.626 + } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
1.627 + // Threads running native code will self-suspend on native==>VM/Java
1.628 + // transitions. If its stack is walkable (should always be the case
1.629 + // unless this function is called before the actual java_suspend()
1.630 + // call), then the wait is done.
1.631 + *bits |= 0x00002000;
1.632 + return true;
1.633 + } else if (!called_by_wait && !did_trans_retry &&
1.634 + save_state == _thread_in_native_trans &&
1.635 + frame_anchor()->walkable()) {
1.636 + // The thread is transitioning from thread_in_native to another
1.637 + // thread state. check_safepoint_and_suspend_for_native_trans()
1.638 + // will force the thread to self-suspend. If it hasn't gotten
1.639 + // there yet we may have caught the thread in-between the native
1.640 + // code check above and the self-suspend. Lucky us. If we were
1.641 + // called by wait_for_ext_suspend_completion(), then it
1.642 + // will be doing the retries so we don't have to.
1.643 + //
1.644 + // Since we use the saved thread state in the if-statement above,
1.645 + // there is a chance that the thread has already transitioned to
1.646 + // _thread_blocked by the time we get here. In that case, we will
1.647 + // make a single unnecessary pass through the logic below. This
1.648 + // doesn't hurt anything since we still do the trans retry.
1.649 +
1.650 + *bits |= 0x00004000;
1.651 +
1.652 + // Once the thread leaves thread_in_native_trans for another
1.653 + // thread state, we break out of this retry loop. We shouldn't
1.654 + // need this flag to prevent us from getting back here, but
1.655 + // sometimes paranoia is good.
1.656 + did_trans_retry = true;
1.657 +
1.658 + // We wait for the thread to transition to a more usable state.
1.659 + for (int i = 1; i <= SuspendRetryCount; i++) {
1.660 + // We used to do an "os::yield_all(i)" call here with the intention
1.661 + // that yielding would increase on each retry. However, the parameter
1.662 + // is ignored on Linux which means the yield didn't scale up. Waiting
1.663 + // on the SR_lock below provides a much more predictable scale up for
1.664 + // the delay. It also provides a simple/direct point to check for any
1.665 + // safepoint requests from the VMThread
1.666 +
1.667 + // temporarily drops SR_lock while doing wait with safepoint check
1.668 + // (if we're a JavaThread - the WatcherThread can also call this)
1.669 + // and increase delay with each retry
1.670 + SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
1.671 +
1.672 + // check the actual thread state instead of what we saved above
1.673 + if (thread_state() != _thread_in_native_trans) {
1.674 + // the thread has transitioned to another thread state so
1.675 + // try all the checks (except this one) one more time.
1.676 + do_trans_retry = true;
1.677 + break;
1.678 + }
1.679 + } // end retry loop
1.680 +
1.681 +
1.682 + }
1.683 + } while (do_trans_retry);
1.684 +
1.685 + *bits |= 0x00000010;
1.686 + return false;
1.687 +}
1.688 +
1.689 +//
1.690 +// Wait for an external suspend request to complete (or be cancelled).
1.691 +// Returns true if the thread is externally suspended and false otherwise.
1.692 +//
1.693 +bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
1.694 + uint32_t *bits) {
1.695 + TraceSuspendDebugBits tsdb(this, true /* is_wait */,
1.696 + false /* !called_by_wait */, bits);
1.697 +
1.698 + // local flag copies to minimize SR_lock hold time
1.699 + bool is_suspended;
1.700 + bool pending;
1.701 + uint32_t reset_bits;
1.702 +
1.703 + // set a marker so is_ext_suspend_completed() knows we are the caller
1.704 + *bits |= 0x00010000;
1.705 +
1.706 + // We use reset_bits to reinitialize the bits value at the top of
1.707 + // each retry loop. This allows the caller to make use of any
1.708 + // unused bits for their own marking purposes.
1.709 + reset_bits = *bits;
1.710 +
1.711 + {
1.712 + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1.713 + is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
1.714 + delay, bits);
1.715 + pending = is_external_suspend();
1.716 + }
1.717 + // must release SR_lock to allow suspension to complete
1.718 +
1.719 + if (!pending) {
1.720 + // A cancelled suspend request is the only false return from
1.721 + // is_ext_suspend_completed() that keeps us from entering the
1.722 + // retry loop.
1.723 + *bits |= 0x00020000;
1.724 + return false;
1.725 + }
1.726 +
1.727 + if (is_suspended) {
1.728 + *bits |= 0x00040000;
1.729 + return true;
1.730 + }
1.731 +
1.732 + for (int i = 1; i <= retries; i++) {
1.733 + *bits = reset_bits; // reinit to only track last retry
1.734 +
1.735 + // We used to do an "os::yield_all(i)" call here with the intention
1.736 + // that yielding would increase on each retry. However, the parameter
1.737 + // is ignored on Linux which means the yield didn't scale up. Waiting
1.738 + // on the SR_lock below provides a much more predictable scale up for
1.739 + // the delay. It also provides a simple/direct point to check for any
1.740 + // safepoint requests from the VMThread
1.741 +
1.742 + {
1.743 + MutexLocker ml(SR_lock());
1.744 + // wait with safepoint check (if we're a JavaThread - the WatcherThread
1.745 + // can also call this) and increase delay with each retry
1.746 + SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
1.747 +
1.748 + is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
1.749 + delay, bits);
1.750 +
1.751 + // It is possible for the external suspend request to be cancelled
1.752 + // (by a resume) before the actual suspend operation is completed.
1.753 + // Refresh our local copy to see if we still need to wait.
1.754 + pending = is_external_suspend();
1.755 + }
1.756 +
1.757 + if (!pending) {
1.758 + // A cancelled suspend request is the only false return from
1.759 + // is_ext_suspend_completed() that keeps us from staying in the
1.760 + // retry loop.
1.761 + *bits |= 0x00080000;
1.762 + return false;
1.763 + }
1.764 +
1.765 + if (is_suspended) {
1.766 + *bits |= 0x00100000;
1.767 + return true;
1.768 + }
1.769 + } // end retry loop
1.770 +
1.771 + // thread did not suspend after all our retries
1.772 + *bits |= 0x00200000;
1.773 + return false;
1.774 +}
1.775 +
1.776 +#ifndef PRODUCT
1.777 +void JavaThread::record_jump(address target, address instr, const char* file, int line) {
1.778 +
1.779 + // This should not need to be atomic as the only way for simultaneous
1.780 + // updates is via interrupts. Even then this should be rare or non-existant
1.781 + // and we don't care that much anyway.
1.782 +
1.783 + int index = _jmp_ring_index;
1.784 + _jmp_ring_index = (index + 1 ) & (jump_ring_buffer_size - 1);
1.785 + _jmp_ring[index]._target = (intptr_t) target;
1.786 + _jmp_ring[index]._instruction = (intptr_t) instr;
1.787 + _jmp_ring[index]._file = file;
1.788 + _jmp_ring[index]._line = line;
1.789 +}
1.790 +#endif /* PRODUCT */
1.791 +
1.792 +// Called by flat profiler
1.793 +// Callers have already called wait_for_ext_suspend_completion
1.794 +// The assertion for that is currently too complex to put here:
1.795 +bool JavaThread::profile_last_Java_frame(frame* _fr) {
1.796 + bool gotframe = false;
1.797 + // self suspension saves needed state.
1.798 + if (has_last_Java_frame() && _anchor.walkable()) {
1.799 + *_fr = pd_last_frame();
1.800 + gotframe = true;
1.801 + }
1.802 + return gotframe;
1.803 +}
1.804 +
1.805 +void Thread::interrupt(Thread* thread) {
1.806 + trace("interrupt", thread);
1.807 + debug_only(check_for_dangling_thread_pointer(thread);)
1.808 + os::interrupt(thread);
1.809 +}
1.810 +
1.811 +bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
1.812 + trace("is_interrupted", thread);
1.813 + debug_only(check_for_dangling_thread_pointer(thread);)
1.814 + // Note: If clear_interrupted==false, this simply fetches and
1.815 + // returns the value of the field osthread()->interrupted().
1.816 + return os::is_interrupted(thread, clear_interrupted);
1.817 +}
1.818 +
1.819 +
1.820 +// GC Support
1.821 +bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
1.822 + jint thread_parity = _oops_do_parity;
1.823 + if (thread_parity != strong_roots_parity) {
1.824 + jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
1.825 + if (res == thread_parity) {
1.826 + return true;
1.827 + } else {
1.828 + guarantee(res == strong_roots_parity, "Or else what?");
1.829 + assert(SharedHeap::heap()->workers()->active_workers() > 0,
1.830 + "Should only fail when parallel.");
1.831 + return false;
1.832 + }
1.833 + }
1.834 + assert(SharedHeap::heap()->workers()->active_workers() > 0,
1.835 + "Should only fail when parallel.");
1.836 + return false;
1.837 +}
1.838 +
1.839 +void Thread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
1.840 + active_handles()->oops_do(f);
1.841 + // Do oop for ThreadShadow
1.842 + f->do_oop((oop*)&_pending_exception);
1.843 + handle_area()->oops_do(f);
1.844 +}
1.845 +
1.846 +void Thread::nmethods_do(CodeBlobClosure* cf) {
1.847 + // no nmethods in a generic thread...
1.848 +}
1.849 +
1.850 +void Thread::metadata_do(void f(Metadata*)) {
1.851 + if (metadata_handles() != NULL) {
1.852 + for (int i = 0; i< metadata_handles()->length(); i++) {
1.853 + f(metadata_handles()->at(i));
1.854 + }
1.855 + }
1.856 +}
1.857 +
1.858 +void Thread::print_on(outputStream* st) const {
1.859 + // get_priority assumes osthread initialized
1.860 + if (osthread() != NULL) {
1.861 + int os_prio;
1.862 + if (os::get_native_priority(this, &os_prio) == OS_OK) {
1.863 + st->print("os_prio=%d ", os_prio);
1.864 + }
1.865 + st->print("tid=" INTPTR_FORMAT " ", this);
1.866 + osthread()->print_on(st);
1.867 + }
1.868 + debug_only(if (WizardMode) print_owned_locks_on(st);)
1.869 +}
1.870 +
1.871 +// Thread::print_on_error() is called by fatal error handler. Don't use
1.872 +// any lock or allocate memory.
1.873 +void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
1.874 + if (is_VM_thread()) st->print("VMThread");
1.875 + else if (is_Compiler_thread()) st->print("CompilerThread");
1.876 + else if (is_Java_thread()) st->print("JavaThread");
1.877 + else if (is_GC_task_thread()) st->print("GCTaskThread");
1.878 + else if (is_Watcher_thread()) st->print("WatcherThread");
1.879 + else if (is_ConcurrentGC_thread()) st->print("ConcurrentGCThread");
1.880 + else st->print("Thread");
1.881 +
1.882 + st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
1.883 + _stack_base - _stack_size, _stack_base);
1.884 +
1.885 + if (osthread()) {
1.886 + st->print(" [id=%d]", osthread()->thread_id());
1.887 + }
1.888 +}
1.889 +
1.890 +#ifdef ASSERT
1.891 +void Thread::print_owned_locks_on(outputStream* st) const {
1.892 + Monitor *cur = _owned_locks;
1.893 + if (cur == NULL) {
1.894 + st->print(" (no locks) ");
1.895 + } else {
1.896 + st->print_cr(" Locks owned:");
1.897 + while(cur) {
1.898 + cur->print_on(st);
1.899 + cur = cur->next();
1.900 + }
1.901 + }
1.902 +}
1.903 +
1.904 +static int ref_use_count = 0;
1.905 +
1.906 +bool Thread::owns_locks_but_compiled_lock() const {
1.907 + for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
1.908 + if (cur != Compile_lock) return true;
1.909 + }
1.910 + return false;
1.911 +}
1.912 +
1.913 +
1.914 +#endif
1.915 +
1.916 +#ifndef PRODUCT
1.917 +
1.918 +// The flag: potential_vm_operation notifies if this particular safepoint state could potential
1.919 +// invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
1.920 +// no threads which allow_vm_block's are held
1.921 +void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
1.922 + // Check if current thread is allowed to block at a safepoint
1.923 + if (!(_allow_safepoint_count == 0))
1.924 + fatal("Possible safepoint reached by thread that does not allow it");
1.925 + if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
1.926 + fatal("LEAF method calling lock?");
1.927 + }
1.928 +
1.929 +#ifdef ASSERT
1.930 + if (potential_vm_operation && is_Java_thread()
1.931 + && !Universe::is_bootstrapping()) {
1.932 + // Make sure we do not hold any locks that the VM thread also uses.
1.933 + // This could potentially lead to deadlocks
1.934 + for(Monitor *cur = _owned_locks; cur; cur = cur->next()) {
1.935 + // Threads_lock is special, since the safepoint synchronization will not start before this is
1.936 + // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
1.937 + // since it is used to transfer control between JavaThreads and the VMThread
1.938 + // Do not *exclude* any locks unless you are absolutly sure it is correct. Ask someone else first!
1.939 + if ( (cur->allow_vm_block() &&
1.940 + cur != Threads_lock &&
1.941 + cur != Compile_lock && // Temporary: should not be necessary when we get spearate compilation
1.942 + cur != VMOperationRequest_lock &&
1.943 + cur != VMOperationQueue_lock) ||
1.944 + cur->rank() == Mutex::special) {
1.945 + warning("Thread holding lock at safepoint that vm can block on: %s", cur->name());
1.946 + }
1.947 + }
1.948 + }
1.949 +
1.950 + if (GCALotAtAllSafepoints) {
1.951 + // We could enter a safepoint here and thus have a gc
1.952 + InterfaceSupport::check_gc_alot();
1.953 + }
1.954 +#endif
1.955 +}
1.956 +#endif
1.957 +
1.958 +bool Thread::is_in_stack(address adr) const {
1.959 + assert(Thread::current() == this, "is_in_stack can only be called from current thread");
1.960 + address end = os::current_stack_pointer();
1.961 + // Allow non Java threads to call this without stack_base
1.962 + if (_stack_base == NULL) return true;
1.963 + if (stack_base() >= adr && adr >= end) return true;
1.964 +
1.965 + return false;
1.966 +}
1.967 +
1.968 +
1.969 +bool Thread::is_in_usable_stack(address adr) const {
1.970 + size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0;
1.971 + size_t usable_stack_size = _stack_size - stack_guard_size;
1.972 +
1.973 + return ((adr < stack_base()) && (adr >= stack_base() - usable_stack_size));
1.974 +}
1.975 +
1.976 +
1.977 +// We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
1.978 +// However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
1.979 +// used for compilation in the future. If that change is made, the need for these methods
1.980 +// should be revisited, and they should be removed if possible.
1.981 +
1.982 +bool Thread::is_lock_owned(address adr) const {
1.983 + return on_local_stack(adr);
1.984 +}
1.985 +
1.986 +bool Thread::set_as_starting_thread() {
1.987 + // NOTE: this must be called inside the main thread.
1.988 + return os::create_main_thread((JavaThread*)this);
1.989 +}
1.990 +
1.991 +static void initialize_class(Symbol* class_name, TRAPS) {
1.992 + Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
1.993 + InstanceKlass::cast(klass)->initialize(CHECK);
1.994 +}
1.995 +
1.996 +
1.997 +// Creates the initial ThreadGroup
1.998 +static Handle create_initial_thread_group(TRAPS) {
1.999 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
1.1000 + instanceKlassHandle klass (THREAD, k);
1.1001 +
1.1002 + Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
1.1003 + {
1.1004 + JavaValue result(T_VOID);
1.1005 + JavaCalls::call_special(&result,
1.1006 + system_instance,
1.1007 + klass,
1.1008 + vmSymbols::object_initializer_name(),
1.1009 + vmSymbols::void_method_signature(),
1.1010 + CHECK_NH);
1.1011 + }
1.1012 + Universe::set_system_thread_group(system_instance());
1.1013 +
1.1014 + Handle main_instance = klass->allocate_instance_handle(CHECK_NH);
1.1015 + {
1.1016 + JavaValue result(T_VOID);
1.1017 + Handle string = java_lang_String::create_from_str("main", CHECK_NH);
1.1018 + JavaCalls::call_special(&result,
1.1019 + main_instance,
1.1020 + klass,
1.1021 + vmSymbols::object_initializer_name(),
1.1022 + vmSymbols::threadgroup_string_void_signature(),
1.1023 + system_instance,
1.1024 + string,
1.1025 + CHECK_NH);
1.1026 + }
1.1027 + return main_instance;
1.1028 +}
1.1029 +
1.1030 +// Creates the initial Thread
1.1031 +static oop create_initial_thread(Handle thread_group, JavaThread* thread, TRAPS) {
1.1032 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
1.1033 + instanceKlassHandle klass (THREAD, k);
1.1034 + instanceHandle thread_oop = klass->allocate_instance_handle(CHECK_NULL);
1.1035 +
1.1036 + java_lang_Thread::set_thread(thread_oop(), thread);
1.1037 + java_lang_Thread::set_priority(thread_oop(), NormPriority);
1.1038 + thread->set_threadObj(thread_oop());
1.1039 +
1.1040 + Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
1.1041 +
1.1042 + JavaValue result(T_VOID);
1.1043 + JavaCalls::call_special(&result, thread_oop,
1.1044 + klass,
1.1045 + vmSymbols::object_initializer_name(),
1.1046 + vmSymbols::threadgroup_string_void_signature(),
1.1047 + thread_group,
1.1048 + string,
1.1049 + CHECK_NULL);
1.1050 + return thread_oop();
1.1051 +}
1.1052 +
1.1053 +static void call_initializeSystemClass(TRAPS) {
1.1054 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1.1055 + instanceKlassHandle klass (THREAD, k);
1.1056 +
1.1057 + JavaValue result(T_VOID);
1.1058 + JavaCalls::call_static(&result, klass, vmSymbols::initializeSystemClass_name(),
1.1059 + vmSymbols::void_method_signature(), CHECK);
1.1060 +}
1.1061 +
1.1062 +char java_runtime_name[128] = "";
1.1063 +char java_runtime_version[128] = "";
1.1064 +
1.1065 +// extract the JRE name from sun.misc.Version.java_runtime_name
1.1066 +static const char* get_java_runtime_name(TRAPS) {
1.1067 + Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1.1068 + Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1.1069 + fieldDescriptor fd;
1.1070 + bool found = k != NULL &&
1.1071 + InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
1.1072 + vmSymbols::string_signature(), &fd);
1.1073 + if (found) {
1.1074 + oop name_oop = k->java_mirror()->obj_field(fd.offset());
1.1075 + if (name_oop == NULL)
1.1076 + return NULL;
1.1077 + const char* name = java_lang_String::as_utf8_string(name_oop,
1.1078 + java_runtime_name,
1.1079 + sizeof(java_runtime_name));
1.1080 + return name;
1.1081 + } else {
1.1082 + return NULL;
1.1083 + }
1.1084 +}
1.1085 +
1.1086 +// extract the JRE version from sun.misc.Version.java_runtime_version
1.1087 +static const char* get_java_runtime_version(TRAPS) {
1.1088 + Klass* k = SystemDictionary::find(vmSymbols::sun_misc_Version(),
1.1089 + Handle(), Handle(), CHECK_AND_CLEAR_NULL);
1.1090 + fieldDescriptor fd;
1.1091 + bool found = k != NULL &&
1.1092 + InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
1.1093 + vmSymbols::string_signature(), &fd);
1.1094 + if (found) {
1.1095 + oop name_oop = k->java_mirror()->obj_field(fd.offset());
1.1096 + if (name_oop == NULL)
1.1097 + return NULL;
1.1098 + const char* name = java_lang_String::as_utf8_string(name_oop,
1.1099 + java_runtime_version,
1.1100 + sizeof(java_runtime_version));
1.1101 + return name;
1.1102 + } else {
1.1103 + return NULL;
1.1104 + }
1.1105 +}
1.1106 +
1.1107 +// General purpose hook into Java code, run once when the VM is initialized.
1.1108 +// The Java library method itself may be changed independently from the VM.
1.1109 +static void call_postVMInitHook(TRAPS) {
1.1110 + Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_PostVMInitHook(), THREAD);
1.1111 + instanceKlassHandle klass (THREAD, k);
1.1112 + if (klass.not_null()) {
1.1113 + JavaValue result(T_VOID);
1.1114 + JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
1.1115 + vmSymbols::void_method_signature(),
1.1116 + CHECK);
1.1117 + }
1.1118 +}
1.1119 +
1.1120 +static void reset_vm_info_property(TRAPS) {
1.1121 + // the vm info string
1.1122 + ResourceMark rm(THREAD);
1.1123 + const char *vm_info = VM_Version::vm_info_string();
1.1124 +
1.1125 + // java.lang.System class
1.1126 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
1.1127 + instanceKlassHandle klass (THREAD, k);
1.1128 +
1.1129 + // setProperty arguments
1.1130 + Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
1.1131 + Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
1.1132 +
1.1133 + // return value
1.1134 + JavaValue r(T_OBJECT);
1.1135 +
1.1136 + // public static String setProperty(String key, String value);
1.1137 + JavaCalls::call_static(&r,
1.1138 + klass,
1.1139 + vmSymbols::setProperty_name(),
1.1140 + vmSymbols::string_string_string_signature(),
1.1141 + key_str,
1.1142 + value_str,
1.1143 + CHECK);
1.1144 +}
1.1145 +
1.1146 +
1.1147 +void JavaThread::allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS) {
1.1148 + assert(thread_group.not_null(), "thread group should be specified");
1.1149 + assert(threadObj() == NULL, "should only create Java thread object once");
1.1150 +
1.1151 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
1.1152 + instanceKlassHandle klass (THREAD, k);
1.1153 + instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
1.1154 +
1.1155 + java_lang_Thread::set_thread(thread_oop(), this);
1.1156 + java_lang_Thread::set_priority(thread_oop(), NormPriority);
1.1157 + set_threadObj(thread_oop());
1.1158 +
1.1159 + JavaValue result(T_VOID);
1.1160 + if (thread_name != NULL) {
1.1161 + Handle name = java_lang_String::create_from_str(thread_name, CHECK);
1.1162 + // Thread gets assigned specified name and null target
1.1163 + JavaCalls::call_special(&result,
1.1164 + thread_oop,
1.1165 + klass,
1.1166 + vmSymbols::object_initializer_name(),
1.1167 + vmSymbols::threadgroup_string_void_signature(),
1.1168 + thread_group, // Argument 1
1.1169 + name, // Argument 2
1.1170 + THREAD);
1.1171 + } else {
1.1172 + // Thread gets assigned name "Thread-nnn" and null target
1.1173 + // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
1.1174 + JavaCalls::call_special(&result,
1.1175 + thread_oop,
1.1176 + klass,
1.1177 + vmSymbols::object_initializer_name(),
1.1178 + vmSymbols::threadgroup_runnable_void_signature(),
1.1179 + thread_group, // Argument 1
1.1180 + Handle(), // Argument 2
1.1181 + THREAD);
1.1182 + }
1.1183 +
1.1184 +
1.1185 + if (daemon) {
1.1186 + java_lang_Thread::set_daemon(thread_oop());
1.1187 + }
1.1188 +
1.1189 + if (HAS_PENDING_EXCEPTION) {
1.1190 + return;
1.1191 + }
1.1192 +
1.1193 + KlassHandle group(this, SystemDictionary::ThreadGroup_klass());
1.1194 + Handle threadObj(this, this->threadObj());
1.1195 +
1.1196 + JavaCalls::call_special(&result,
1.1197 + thread_group,
1.1198 + group,
1.1199 + vmSymbols::add_method_name(),
1.1200 + vmSymbols::thread_void_signature(),
1.1201 + threadObj, // Arg 1
1.1202 + THREAD);
1.1203 +
1.1204 +
1.1205 +}
1.1206 +
1.1207 +// NamedThread -- non-JavaThread subclasses with multiple
1.1208 +// uniquely named instances should derive from this.
1.1209 +NamedThread::NamedThread() : Thread() {
1.1210 + _name = NULL;
1.1211 + _processed_thread = NULL;
1.1212 +}
1.1213 +
1.1214 +NamedThread::~NamedThread() {
1.1215 + if (_name != NULL) {
1.1216 + FREE_C_HEAP_ARRAY(char, _name, mtThread);
1.1217 + _name = NULL;
1.1218 + }
1.1219 +}
1.1220 +
1.1221 +void NamedThread::set_name(const char* format, ...) {
1.1222 + guarantee(_name == NULL, "Only get to set name once.");
1.1223 + _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
1.1224 + guarantee(_name != NULL, "alloc failure");
1.1225 + va_list ap;
1.1226 + va_start(ap, format);
1.1227 + jio_vsnprintf(_name, max_name_len, format, ap);
1.1228 + va_end(ap);
1.1229 +}
1.1230 +
1.1231 +// ======= WatcherThread ========
1.1232 +
1.1233 +// The watcher thread exists to simulate timer interrupts. It should
1.1234 +// be replaced by an abstraction over whatever native support for
1.1235 +// timer interrupts exists on the platform.
1.1236 +
1.1237 +WatcherThread* WatcherThread::_watcher_thread = NULL;
1.1238 +bool WatcherThread::_startable = false;
1.1239 +volatile bool WatcherThread::_should_terminate = false;
1.1240 +
1.1241 +WatcherThread::WatcherThread() : Thread(), _crash_protection(NULL) {
1.1242 + assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
1.1243 + if (os::create_thread(this, os::watcher_thread)) {
1.1244 + _watcher_thread = this;
1.1245 +
1.1246 + // Set the watcher thread to the highest OS priority which should not be
1.1247 + // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
1.1248 + // is created. The only normal thread using this priority is the reference
1.1249 + // handler thread, which runs for very short intervals only.
1.1250 + // If the VMThread's priority is not lower than the WatcherThread profiling
1.1251 + // will be inaccurate.
1.1252 + os::set_priority(this, MaxPriority);
1.1253 + if (!DisableStartThread) {
1.1254 + os::start_thread(this);
1.1255 + }
1.1256 + }
1.1257 +}
1.1258 +
1.1259 +int WatcherThread::sleep() const {
1.1260 + MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1.1261 +
1.1262 + // remaining will be zero if there are no tasks,
1.1263 + // causing the WatcherThread to sleep until a task is
1.1264 + // enrolled
1.1265 + int remaining = PeriodicTask::time_to_wait();
1.1266 + int time_slept = 0;
1.1267 +
1.1268 + // we expect this to timeout - we only ever get unparked when
1.1269 + // we should terminate or when a new task has been enrolled
1.1270 + OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
1.1271 +
1.1272 + jlong time_before_loop = os::javaTimeNanos();
1.1273 +
1.1274 + for (;;) {
1.1275 + bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag, remaining);
1.1276 + jlong now = os::javaTimeNanos();
1.1277 +
1.1278 + if (remaining == 0) {
1.1279 + // if we didn't have any tasks we could have waited for a long time
1.1280 + // consider the time_slept zero and reset time_before_loop
1.1281 + time_slept = 0;
1.1282 + time_before_loop = now;
1.1283 + } else {
1.1284 + // need to recalulate since we might have new tasks in _tasks
1.1285 + time_slept = (int) ((now - time_before_loop) / 1000000);
1.1286 + }
1.1287 +
1.1288 + // Change to task list or spurious wakeup of some kind
1.1289 + if (timedout || _should_terminate) {
1.1290 + break;
1.1291 + }
1.1292 +
1.1293 + remaining = PeriodicTask::time_to_wait();
1.1294 + if (remaining == 0) {
1.1295 + // Last task was just disenrolled so loop around and wait until
1.1296 + // another task gets enrolled
1.1297 + continue;
1.1298 + }
1.1299 +
1.1300 + remaining -= time_slept;
1.1301 + if (remaining <= 0)
1.1302 + break;
1.1303 + }
1.1304 +
1.1305 + return time_slept;
1.1306 +}
1.1307 +
1.1308 +void WatcherThread::run() {
1.1309 + assert(this == watcher_thread(), "just checking");
1.1310 +
1.1311 + this->record_stack_base_and_size();
1.1312 + this->initialize_thread_local_storage();
1.1313 + this->set_active_handles(JNIHandleBlock::allocate_block());
1.1314 + while(!_should_terminate) {
1.1315 + assert(watcher_thread() == Thread::current(), "thread consistency check");
1.1316 + assert(watcher_thread() == this, "thread consistency check");
1.1317 +
1.1318 + // Calculate how long it'll be until the next PeriodicTask work
1.1319 + // should be done, and sleep that amount of time.
1.1320 + int time_waited = sleep();
1.1321 +
1.1322 + if (is_error_reported()) {
1.1323 + // A fatal error has happened, the error handler(VMError::report_and_die)
1.1324 + // should abort JVM after creating an error log file. However in some
1.1325 + // rare cases, the error handler itself might deadlock. Here we try to
1.1326 + // kill JVM if the fatal error handler fails to abort in 2 minutes.
1.1327 + //
1.1328 + // This code is in WatcherThread because WatcherThread wakes up
1.1329 + // periodically so the fatal error handler doesn't need to do anything;
1.1330 + // also because the WatcherThread is less likely to crash than other
1.1331 + // threads.
1.1332 +
1.1333 + for (;;) {
1.1334 + if (!ShowMessageBoxOnError
1.1335 + && (OnError == NULL || OnError[0] == '\0')
1.1336 + && Arguments::abort_hook() == NULL) {
1.1337 + os::sleep(this, 2 * 60 * 1000, false);
1.1338 + fdStream err(defaultStream::output_fd());
1.1339 + err.print_raw_cr("# [ timer expired, abort... ]");
1.1340 + // skip atexit/vm_exit/vm_abort hooks
1.1341 + os::die();
1.1342 + }
1.1343 +
1.1344 + // Wake up 5 seconds later, the fatal handler may reset OnError or
1.1345 + // ShowMessageBoxOnError when it is ready to abort.
1.1346 + os::sleep(this, 5 * 1000, false);
1.1347 + }
1.1348 + }
1.1349 +
1.1350 + PeriodicTask::real_time_tick(time_waited);
1.1351 + }
1.1352 +
1.1353 + // Signal that it is terminated
1.1354 + {
1.1355 + MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
1.1356 + _watcher_thread = NULL;
1.1357 + Terminator_lock->notify();
1.1358 + }
1.1359 +
1.1360 + // Thread destructor usually does this..
1.1361 + ThreadLocalStorage::set_thread(NULL);
1.1362 +}
1.1363 +
1.1364 +void WatcherThread::start() {
1.1365 + assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1.1366 +
1.1367 + if (watcher_thread() == NULL && _startable) {
1.1368 + _should_terminate = false;
1.1369 + // Create the single instance of WatcherThread
1.1370 + new WatcherThread();
1.1371 + }
1.1372 +}
1.1373 +
1.1374 +void WatcherThread::make_startable() {
1.1375 + assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
1.1376 + _startable = true;
1.1377 +}
1.1378 +
1.1379 +void WatcherThread::stop() {
1.1380 + {
1.1381 + MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1.1382 + _should_terminate = true;
1.1383 + OrderAccess::fence(); // ensure WatcherThread sees update in main loop
1.1384 +
1.1385 + WatcherThread* watcher = watcher_thread();
1.1386 + if (watcher != NULL)
1.1387 + watcher->unpark();
1.1388 + }
1.1389 +
1.1390 + // it is ok to take late safepoints here, if needed
1.1391 + MutexLocker mu(Terminator_lock);
1.1392 +
1.1393 + while(watcher_thread() != NULL) {
1.1394 + // This wait should make safepoint checks, wait without a timeout,
1.1395 + // and wait as a suspend-equivalent condition.
1.1396 + //
1.1397 + // Note: If the FlatProfiler is running, then this thread is waiting
1.1398 + // for the WatcherThread to terminate and the WatcherThread, via the
1.1399 + // FlatProfiler task, is waiting for the external suspend request on
1.1400 + // this thread to complete. wait_for_ext_suspend_completion() will
1.1401 + // eventually timeout, but that takes time. Making this wait a
1.1402 + // suspend-equivalent condition solves that timeout problem.
1.1403 + //
1.1404 + Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1.1405 + Mutex::_as_suspend_equivalent_flag);
1.1406 + }
1.1407 +}
1.1408 +
1.1409 +void WatcherThread::unpark() {
1.1410 + MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ? NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1.1411 + PeriodicTask_lock->notify();
1.1412 +}
1.1413 +
1.1414 +void WatcherThread::print_on(outputStream* st) const {
1.1415 + st->print("\"%s\" ", name());
1.1416 + Thread::print_on(st);
1.1417 + st->cr();
1.1418 +}
1.1419 +
1.1420 +// ======= JavaThread ========
1.1421 +
1.1422 +// A JavaThread is a normal Java thread
1.1423 +
1.1424 +void JavaThread::initialize() {
1.1425 + // Initialize fields
1.1426 +
1.1427 + // Set the claimed par_id to UINT_MAX (ie not claiming any par_ids)
1.1428 + set_claimed_par_id(UINT_MAX);
1.1429 +
1.1430 + set_saved_exception_pc(NULL);
1.1431 + set_threadObj(NULL);
1.1432 + _anchor.clear();
1.1433 + set_entry_point(NULL);
1.1434 + set_jni_functions(jni_functions());
1.1435 + set_callee_target(NULL);
1.1436 + set_vm_result(NULL);
1.1437 + set_vm_result_2(NULL);
1.1438 + set_vframe_array_head(NULL);
1.1439 + set_vframe_array_last(NULL);
1.1440 + set_deferred_locals(NULL);
1.1441 + set_deopt_mark(NULL);
1.1442 + set_deopt_nmethod(NULL);
1.1443 + clear_must_deopt_id();
1.1444 + set_monitor_chunks(NULL);
1.1445 + set_next(NULL);
1.1446 + set_thread_state(_thread_new);
1.1447 +#if INCLUDE_NMT
1.1448 + set_recorder(NULL);
1.1449 +#endif
1.1450 + _terminated = _not_terminated;
1.1451 + _privileged_stack_top = NULL;
1.1452 + _array_for_gc = NULL;
1.1453 + _suspend_equivalent = false;
1.1454 + _in_deopt_handler = 0;
1.1455 + _doing_unsafe_access = false;
1.1456 + _stack_guard_state = stack_guard_unused;
1.1457 + (void)const_cast<oop&>(_exception_oop = NULL);
1.1458 + _exception_pc = 0;
1.1459 + _exception_handler_pc = 0;
1.1460 + _is_method_handle_return = 0;
1.1461 + _jvmti_thread_state= NULL;
1.1462 + _should_post_on_exceptions_flag = JNI_FALSE;
1.1463 + _jvmti_get_loaded_classes_closure = NULL;
1.1464 + _interp_only_mode = 0;
1.1465 + _special_runtime_exit_condition = _no_async_condition;
1.1466 + _pending_async_exception = NULL;
1.1467 + _thread_stat = NULL;
1.1468 + _thread_stat = new ThreadStatistics();
1.1469 + _blocked_on_compilation = false;
1.1470 + _jni_active_critical = 0;
1.1471 + _do_not_unlock_if_synchronized = false;
1.1472 + _cached_monitor_info = NULL;
1.1473 + _parker = Parker::Allocate(this) ;
1.1474 +
1.1475 +#ifndef PRODUCT
1.1476 + _jmp_ring_index = 0;
1.1477 + for (int ji = 0 ; ji < jump_ring_buffer_size ; ji++ ) {
1.1478 + record_jump(NULL, NULL, NULL, 0);
1.1479 + }
1.1480 +#endif /* PRODUCT */
1.1481 +
1.1482 + set_thread_profiler(NULL);
1.1483 + if (FlatProfiler::is_active()) {
1.1484 + // This is where we would decide to either give each thread it's own profiler
1.1485 + // or use one global one from FlatProfiler,
1.1486 + // or up to some count of the number of profiled threads, etc.
1.1487 + ThreadProfiler* pp = new ThreadProfiler();
1.1488 + pp->engage();
1.1489 + set_thread_profiler(pp);
1.1490 + }
1.1491 +
1.1492 + // Setup safepoint state info for this thread
1.1493 + ThreadSafepointState::create(this);
1.1494 +
1.1495 + debug_only(_java_call_counter = 0);
1.1496 +
1.1497 + // JVMTI PopFrame support
1.1498 + _popframe_condition = popframe_inactive;
1.1499 + _popframe_preserved_args = NULL;
1.1500 + _popframe_preserved_args_size = 0;
1.1501 +
1.1502 + pd_initialize();
1.1503 +}
1.1504 +
1.1505 +#if INCLUDE_ALL_GCS
1.1506 +SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
1.1507 +DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
1.1508 +#endif // INCLUDE_ALL_GCS
1.1509 +
1.1510 +JavaThread::JavaThread(bool is_attaching_via_jni) :
1.1511 + Thread()
1.1512 +#if INCLUDE_ALL_GCS
1.1513 + , _satb_mark_queue(&_satb_mark_queue_set),
1.1514 + _dirty_card_queue(&_dirty_card_queue_set)
1.1515 +#endif // INCLUDE_ALL_GCS
1.1516 +{
1.1517 + initialize();
1.1518 + if (is_attaching_via_jni) {
1.1519 + _jni_attach_state = _attaching_via_jni;
1.1520 + } else {
1.1521 + _jni_attach_state = _not_attaching_via_jni;
1.1522 + }
1.1523 + assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
1.1524 + _safepoint_visible = false;
1.1525 +}
1.1526 +
1.1527 +bool JavaThread::reguard_stack(address cur_sp) {
1.1528 + if (_stack_guard_state != stack_guard_yellow_disabled) {
1.1529 + return true; // Stack already guarded or guard pages not needed.
1.1530 + }
1.1531 +
1.1532 + if (register_stack_overflow()) {
1.1533 + // For those architectures which have separate register and
1.1534 + // memory stacks, we must check the register stack to see if
1.1535 + // it has overflowed.
1.1536 + return false;
1.1537 + }
1.1538 +
1.1539 + // Java code never executes within the yellow zone: the latter is only
1.1540 + // there to provoke an exception during stack banging. If java code
1.1541 + // is executing there, either StackShadowPages should be larger, or
1.1542 + // some exception code in c1, c2 or the interpreter isn't unwinding
1.1543 + // when it should.
1.1544 + guarantee(cur_sp > stack_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
1.1545 +
1.1546 + enable_stack_yellow_zone();
1.1547 + return true;
1.1548 +}
1.1549 +
1.1550 +bool JavaThread::reguard_stack(void) {
1.1551 + return reguard_stack(os::current_stack_pointer());
1.1552 +}
1.1553 +
1.1554 +
1.1555 +void JavaThread::block_if_vm_exited() {
1.1556 + if (_terminated == _vm_exited) {
1.1557 + // _vm_exited is set at safepoint, and Threads_lock is never released
1.1558 + // we will block here forever
1.1559 + Threads_lock->lock_without_safepoint_check();
1.1560 + ShouldNotReachHere();
1.1561 + }
1.1562 +}
1.1563 +
1.1564 +
1.1565 +// Remove this ifdef when C1 is ported to the compiler interface.
1.1566 +static void compiler_thread_entry(JavaThread* thread, TRAPS);
1.1567 +
1.1568 +JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
1.1569 + Thread()
1.1570 +#if INCLUDE_ALL_GCS
1.1571 + , _satb_mark_queue(&_satb_mark_queue_set),
1.1572 + _dirty_card_queue(&_dirty_card_queue_set)
1.1573 +#endif // INCLUDE_ALL_GCS
1.1574 +{
1.1575 + if (TraceThreadEvents) {
1.1576 + tty->print_cr("creating thread %p", this);
1.1577 + }
1.1578 + initialize();
1.1579 + _jni_attach_state = _not_attaching_via_jni;
1.1580 + set_entry_point(entry_point);
1.1581 + // Create the native thread itself.
1.1582 + // %note runtime_23
1.1583 + os::ThreadType thr_type = os::java_thread;
1.1584 + thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
1.1585 + os::java_thread;
1.1586 + os::create_thread(this, thr_type, stack_sz);
1.1587 + _safepoint_visible = false;
1.1588 + // The _osthread may be NULL here because we ran out of memory (too many threads active).
1.1589 + // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
1.1590 + // may hold a lock and all locks must be unlocked before throwing the exception (throwing
1.1591 + // the exception consists of creating the exception object & initializing it, initialization
1.1592 + // will leave the VM via a JavaCall and then all locks must be unlocked).
1.1593 + //
1.1594 + // The thread is still suspended when we reach here. Thread must be explicit started
1.1595 + // by creator! Furthermore, the thread must also explicitly be added to the Threads list
1.1596 + // by calling Threads:add. The reason why this is not done here, is because the thread
1.1597 + // object must be fully initialized (take a look at JVM_Start)
1.1598 +}
1.1599 +
1.1600 +JavaThread::~JavaThread() {
1.1601 + if (TraceThreadEvents) {
1.1602 + tty->print_cr("terminate thread %p", this);
1.1603 + }
1.1604 +
1.1605 + // By now, this thread should already be invisible to safepoint,
1.1606 + // and its per-thread recorder also collected.
1.1607 + assert(!is_safepoint_visible(), "wrong state");
1.1608 +#if INCLUDE_NMT
1.1609 + assert(get_recorder() == NULL, "Already collected");
1.1610 +#endif // INCLUDE_NMT
1.1611 +
1.1612 + // JSR166 -- return the parker to the free list
1.1613 + Parker::Release(_parker);
1.1614 + _parker = NULL ;
1.1615 +
1.1616 + // Free any remaining previous UnrollBlock
1.1617 + vframeArray* old_array = vframe_array_last();
1.1618 +
1.1619 + if (old_array != NULL) {
1.1620 + Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
1.1621 + old_array->set_unroll_block(NULL);
1.1622 + delete old_info;
1.1623 + delete old_array;
1.1624 + }
1.1625 +
1.1626 + GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
1.1627 + if (deferred != NULL) {
1.1628 + // This can only happen if thread is destroyed before deoptimization occurs.
1.1629 + assert(deferred->length() != 0, "empty array!");
1.1630 + do {
1.1631 + jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
1.1632 + deferred->remove_at(0);
1.1633 + // individual jvmtiDeferredLocalVariableSet are CHeapObj's
1.1634 + delete dlv;
1.1635 + } while (deferred->length() != 0);
1.1636 + delete deferred;
1.1637 + }
1.1638 +
1.1639 + // All Java related clean up happens in exit
1.1640 + ThreadSafepointState::destroy(this);
1.1641 + if (_thread_profiler != NULL) delete _thread_profiler;
1.1642 + if (_thread_stat != NULL) delete _thread_stat;
1.1643 +}
1.1644 +
1.1645 +
1.1646 +// The first routine called by a new Java thread
1.1647 +void JavaThread::run() {
1.1648 + // initialize thread-local alloc buffer related fields
1.1649 + this->initialize_tlab();
1.1650 +
1.1651 + // used to test validitity of stack trace backs
1.1652 + this->record_base_of_stack_pointer();
1.1653 +
1.1654 + // Record real stack base and size.
1.1655 + this->record_stack_base_and_size();
1.1656 +
1.1657 + // Initialize thread local storage; set before calling MutexLocker
1.1658 + this->initialize_thread_local_storage();
1.1659 +
1.1660 + this->create_stack_guard_pages();
1.1661 +
1.1662 + this->cache_global_variables();
1.1663 +
1.1664 + // Thread is now sufficient initialized to be handled by the safepoint code as being
1.1665 + // in the VM. Change thread state from _thread_new to _thread_in_vm
1.1666 + ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
1.1667 +
1.1668 + assert(JavaThread::current() == this, "sanity check");
1.1669 + assert(!Thread::current()->owns_locks(), "sanity check");
1.1670 +
1.1671 + DTRACE_THREAD_PROBE(start, this);
1.1672 +
1.1673 + // This operation might block. We call that after all safepoint checks for a new thread has
1.1674 + // been completed.
1.1675 + this->set_active_handles(JNIHandleBlock::allocate_block());
1.1676 +
1.1677 + if (JvmtiExport::should_post_thread_life()) {
1.1678 + JvmtiExport::post_thread_start(this);
1.1679 + }
1.1680 +
1.1681 + EventThreadStart event;
1.1682 + if (event.should_commit()) {
1.1683 + event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1.1684 + event.commit();
1.1685 + }
1.1686 +
1.1687 + // We call another function to do the rest so we are sure that the stack addresses used
1.1688 + // from there will be lower than the stack base just computed
1.1689 + thread_main_inner();
1.1690 +
1.1691 + // Note, thread is no longer valid at this point!
1.1692 +}
1.1693 +
1.1694 +
1.1695 +void JavaThread::thread_main_inner() {
1.1696 + assert(JavaThread::current() == this, "sanity check");
1.1697 + assert(this->threadObj() != NULL, "just checking");
1.1698 +
1.1699 + // Execute thread entry point unless this thread has a pending exception
1.1700 + // or has been stopped before starting.
1.1701 + // Note: Due to JVM_StopThread we can have pending exceptions already!
1.1702 + if (!this->has_pending_exception() &&
1.1703 + !java_lang_Thread::is_stillborn(this->threadObj())) {
1.1704 + {
1.1705 + ResourceMark rm(this);
1.1706 + this->set_native_thread_name(this->get_thread_name());
1.1707 + }
1.1708 + HandleMark hm(this);
1.1709 + this->entry_point()(this, this);
1.1710 + }
1.1711 +
1.1712 + DTRACE_THREAD_PROBE(stop, this);
1.1713 +
1.1714 + this->exit(false);
1.1715 + delete this;
1.1716 +}
1.1717 +
1.1718 +
1.1719 +static void ensure_join(JavaThread* thread) {
1.1720 + // We do not need to grap the Threads_lock, since we are operating on ourself.
1.1721 + Handle threadObj(thread, thread->threadObj());
1.1722 + assert(threadObj.not_null(), "java thread object must exist");
1.1723 + ObjectLocker lock(threadObj, thread);
1.1724 + // Ignore pending exception (ThreadDeath), since we are exiting anyway
1.1725 + thread->clear_pending_exception();
1.1726 + // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
1.1727 + java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1.1728 + // Clear the native thread instance - this makes isAlive return false and allows the join()
1.1729 + // to complete once we've done the notify_all below
1.1730 + java_lang_Thread::set_thread(threadObj(), NULL);
1.1731 + lock.notify_all(thread);
1.1732 + // Ignore pending exception (ThreadDeath), since we are exiting anyway
1.1733 + thread->clear_pending_exception();
1.1734 +}
1.1735 +
1.1736 +
1.1737 +// For any new cleanup additions, please check to see if they need to be applied to
1.1738 +// cleanup_failed_attach_current_thread as well.
1.1739 +void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1.1740 + assert(this == JavaThread::current(), "thread consistency check");
1.1741 +
1.1742 + HandleMark hm(this);
1.1743 + Handle uncaught_exception(this, this->pending_exception());
1.1744 + this->clear_pending_exception();
1.1745 + Handle threadObj(this, this->threadObj());
1.1746 + assert(threadObj.not_null(), "Java thread object should be created");
1.1747 +
1.1748 + if (get_thread_profiler() != NULL) {
1.1749 + get_thread_profiler()->disengage();
1.1750 + ResourceMark rm;
1.1751 + get_thread_profiler()->print(get_thread_name());
1.1752 + }
1.1753 +
1.1754 +
1.1755 + // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1.1756 + {
1.1757 + EXCEPTION_MARK;
1.1758 +
1.1759 + CLEAR_PENDING_EXCEPTION;
1.1760 + }
1.1761 + // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
1.1762 + // has to be fixed by a runtime query method
1.1763 + if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
1.1764 + // JSR-166: change call from from ThreadGroup.uncaughtException to
1.1765 + // java.lang.Thread.dispatchUncaughtException
1.1766 + if (uncaught_exception.not_null()) {
1.1767 + Handle group(this, java_lang_Thread::threadGroup(threadObj()));
1.1768 + {
1.1769 + EXCEPTION_MARK;
1.1770 + // Check if the method Thread.dispatchUncaughtException() exists. If so
1.1771 + // call it. Otherwise we have an older library without the JSR-166 changes,
1.1772 + // so call ThreadGroup.uncaughtException()
1.1773 + KlassHandle recvrKlass(THREAD, threadObj->klass());
1.1774 + CallInfo callinfo;
1.1775 + KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1.1776 + LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
1.1777 + vmSymbols::dispatchUncaughtException_name(),
1.1778 + vmSymbols::throwable_void_signature(),
1.1779 + KlassHandle(), false, false, THREAD);
1.1780 + CLEAR_PENDING_EXCEPTION;
1.1781 + methodHandle method = callinfo.selected_method();
1.1782 + if (method.not_null()) {
1.1783 + JavaValue result(T_VOID);
1.1784 + JavaCalls::call_virtual(&result,
1.1785 + threadObj, thread_klass,
1.1786 + vmSymbols::dispatchUncaughtException_name(),
1.1787 + vmSymbols::throwable_void_signature(),
1.1788 + uncaught_exception,
1.1789 + THREAD);
1.1790 + } else {
1.1791 + KlassHandle thread_group(THREAD, SystemDictionary::ThreadGroup_klass());
1.1792 + JavaValue result(T_VOID);
1.1793 + JavaCalls::call_virtual(&result,
1.1794 + group, thread_group,
1.1795 + vmSymbols::uncaughtException_name(),
1.1796 + vmSymbols::thread_throwable_void_signature(),
1.1797 + threadObj, // Arg 1
1.1798 + uncaught_exception, // Arg 2
1.1799 + THREAD);
1.1800 + }
1.1801 + if (HAS_PENDING_EXCEPTION) {
1.1802 + ResourceMark rm(this);
1.1803 + jio_fprintf(defaultStream::error_stream(),
1.1804 + "\nException: %s thrown from the UncaughtExceptionHandler"
1.1805 + " in thread \"%s\"\n",
1.1806 + pending_exception()->klass()->external_name(),
1.1807 + get_thread_name());
1.1808 + CLEAR_PENDING_EXCEPTION;
1.1809 + }
1.1810 + }
1.1811 + }
1.1812 +
1.1813 + // Called before the java thread exit since we want to read info
1.1814 + // from java_lang_Thread object
1.1815 + EventThreadEnd event;
1.1816 + if (event.should_commit()) {
1.1817 + event.set_javalangthread(java_lang_Thread::thread_id(this->threadObj()));
1.1818 + event.commit();
1.1819 + }
1.1820 +
1.1821 + // Call after last event on thread
1.1822 + EVENT_THREAD_EXIT(this);
1.1823 +
1.1824 + // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
1.1825 + // the execution of the method. If that is not enough, then we don't really care. Thread.stop
1.1826 + // is deprecated anyhow.
1.1827 + if (!is_Compiler_thread()) {
1.1828 + int count = 3;
1.1829 + while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
1.1830 + EXCEPTION_MARK;
1.1831 + JavaValue result(T_VOID);
1.1832 + KlassHandle thread_klass(THREAD, SystemDictionary::Thread_klass());
1.1833 + JavaCalls::call_virtual(&result,
1.1834 + threadObj, thread_klass,
1.1835 + vmSymbols::exit_method_name(),
1.1836 + vmSymbols::void_method_signature(),
1.1837 + THREAD);
1.1838 + CLEAR_PENDING_EXCEPTION;
1.1839 + }
1.1840 + }
1.1841 + // notify JVMTI
1.1842 + if (JvmtiExport::should_post_thread_life()) {
1.1843 + JvmtiExport::post_thread_end(this);
1.1844 + }
1.1845 +
1.1846 + // We have notified the agents that we are exiting, before we go on,
1.1847 + // we must check for a pending external suspend request and honor it
1.1848 + // in order to not surprise the thread that made the suspend request.
1.1849 + while (true) {
1.1850 + {
1.1851 + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1.1852 + if (!is_external_suspend()) {
1.1853 + set_terminated(_thread_exiting);
1.1854 + ThreadService::current_thread_exiting(this);
1.1855 + break;
1.1856 + }
1.1857 + // Implied else:
1.1858 + // Things get a little tricky here. We have a pending external
1.1859 + // suspend request, but we are holding the SR_lock so we
1.1860 + // can't just self-suspend. So we temporarily drop the lock
1.1861 + // and then self-suspend.
1.1862 + }
1.1863 +
1.1864 + ThreadBlockInVM tbivm(this);
1.1865 + java_suspend_self();
1.1866 +
1.1867 + // We're done with this suspend request, but we have to loop around
1.1868 + // and check again. Eventually we will get SR_lock without a pending
1.1869 + // external suspend request and will be able to mark ourselves as
1.1870 + // exiting.
1.1871 + }
1.1872 + // no more external suspends are allowed at this point
1.1873 + } else {
1.1874 + // before_exit() has already posted JVMTI THREAD_END events
1.1875 + }
1.1876 +
1.1877 + // Notify waiters on thread object. This has to be done after exit() is called
1.1878 + // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1.1879 + // group should have the destroyed bit set before waiters are notified).
1.1880 + ensure_join(this);
1.1881 + assert(!this->has_pending_exception(), "ensure_join should have cleared");
1.1882 +
1.1883 + // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1.1884 + // held by this thread must be released. A detach operation must only
1.1885 + // get here if there are no Java frames on the stack. Therefore, any
1.1886 + // owned monitors at this point MUST be JNI-acquired monitors which are
1.1887 + // pre-inflated and in the monitor cache.
1.1888 + //
1.1889 + // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
1.1890 + if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
1.1891 + assert(!this->has_last_Java_frame(), "detaching with Java frames?");
1.1892 + ObjectSynchronizer::release_monitors_owned_by_thread(this);
1.1893 + assert(!this->has_pending_exception(), "release_monitors should have cleared");
1.1894 + }
1.1895 +
1.1896 + // These things needs to be done while we are still a Java Thread. Make sure that thread
1.1897 + // is in a consistent state, in case GC happens
1.1898 + assert(_privileged_stack_top == NULL, "must be NULL when we get here");
1.1899 +
1.1900 + if (active_handles() != NULL) {
1.1901 + JNIHandleBlock* block = active_handles();
1.1902 + set_active_handles(NULL);
1.1903 + JNIHandleBlock::release_block(block);
1.1904 + }
1.1905 +
1.1906 + if (free_handle_block() != NULL) {
1.1907 + JNIHandleBlock* block = free_handle_block();
1.1908 + set_free_handle_block(NULL);
1.1909 + JNIHandleBlock::release_block(block);
1.1910 + }
1.1911 +
1.1912 + // These have to be removed while this is still a valid thread.
1.1913 + remove_stack_guard_pages();
1.1914 +
1.1915 + if (UseTLAB) {
1.1916 + tlab().make_parsable(true); // retire TLAB
1.1917 + }
1.1918 +
1.1919 + if (JvmtiEnv::environments_might_exist()) {
1.1920 + JvmtiExport::cleanup_thread(this);
1.1921 + }
1.1922 +
1.1923 + // We must flush any deferred card marks before removing a thread from
1.1924 + // the list of active threads.
1.1925 + Universe::heap()->flush_deferred_store_barrier(this);
1.1926 + assert(deferred_card_mark().is_empty(), "Should have been flushed");
1.1927 +
1.1928 +#if INCLUDE_ALL_GCS
1.1929 + // We must flush the G1-related buffers before removing a thread
1.1930 + // from the list of active threads. We must do this after any deferred
1.1931 + // card marks have been flushed (above) so that any entries that are
1.1932 + // added to the thread's dirty card queue as a result are not lost.
1.1933 + if (UseG1GC) {
1.1934 + flush_barrier_queues();
1.1935 + }
1.1936 +#endif // INCLUDE_ALL_GCS
1.1937 +
1.1938 + // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1.1939 + Threads::remove(this);
1.1940 +}
1.1941 +
1.1942 +#if INCLUDE_ALL_GCS
1.1943 +// Flush G1-related queues.
1.1944 +void JavaThread::flush_barrier_queues() {
1.1945 + satb_mark_queue().flush();
1.1946 + dirty_card_queue().flush();
1.1947 +}
1.1948 +
1.1949 +void JavaThread::initialize_queues() {
1.1950 + assert(!SafepointSynchronize::is_at_safepoint(),
1.1951 + "we should not be at a safepoint");
1.1952 +
1.1953 + ObjPtrQueue& satb_queue = satb_mark_queue();
1.1954 + SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1.1955 + // The SATB queue should have been constructed with its active
1.1956 + // field set to false.
1.1957 + assert(!satb_queue.is_active(), "SATB queue should not be active");
1.1958 + assert(satb_queue.is_empty(), "SATB queue should be empty");
1.1959 + // If we are creating the thread during a marking cycle, we should
1.1960 + // set the active field of the SATB queue to true.
1.1961 + if (satb_queue_set.is_active()) {
1.1962 + satb_queue.set_active(true);
1.1963 + }
1.1964 +
1.1965 + DirtyCardQueue& dirty_queue = dirty_card_queue();
1.1966 + // The dirty card queue should have been constructed with its
1.1967 + // active field set to true.
1.1968 + assert(dirty_queue.is_active(), "dirty card queue should be active");
1.1969 +}
1.1970 +#endif // INCLUDE_ALL_GCS
1.1971 +
1.1972 +void JavaThread::cleanup_failed_attach_current_thread() {
1.1973 + if (get_thread_profiler() != NULL) {
1.1974 + get_thread_profiler()->disengage();
1.1975 + ResourceMark rm;
1.1976 + get_thread_profiler()->print(get_thread_name());
1.1977 + }
1.1978 +
1.1979 + if (active_handles() != NULL) {
1.1980 + JNIHandleBlock* block = active_handles();
1.1981 + set_active_handles(NULL);
1.1982 + JNIHandleBlock::release_block(block);
1.1983 + }
1.1984 +
1.1985 + if (free_handle_block() != NULL) {
1.1986 + JNIHandleBlock* block = free_handle_block();
1.1987 + set_free_handle_block(NULL);
1.1988 + JNIHandleBlock::release_block(block);
1.1989 + }
1.1990 +
1.1991 + // These have to be removed while this is still a valid thread.
1.1992 + remove_stack_guard_pages();
1.1993 +
1.1994 + if (UseTLAB) {
1.1995 + tlab().make_parsable(true); // retire TLAB, if any
1.1996 + }
1.1997 +
1.1998 +#if INCLUDE_ALL_GCS
1.1999 + if (UseG1GC) {
1.2000 + flush_barrier_queues();
1.2001 + }
1.2002 +#endif // INCLUDE_ALL_GCS
1.2003 +
1.2004 + Threads::remove(this);
1.2005 + delete this;
1.2006 +}
1.2007 +
1.2008 +
1.2009 +
1.2010 +
1.2011 +JavaThread* JavaThread::active() {
1.2012 + Thread* thread = ThreadLocalStorage::thread();
1.2013 + assert(thread != NULL, "just checking");
1.2014 + if (thread->is_Java_thread()) {
1.2015 + return (JavaThread*) thread;
1.2016 + } else {
1.2017 + assert(thread->is_VM_thread(), "this must be a vm thread");
1.2018 + VM_Operation* op = ((VMThread*) thread)->vm_operation();
1.2019 + JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1.2020 + assert(ret->is_Java_thread(), "must be a Java thread");
1.2021 + return ret;
1.2022 + }
1.2023 +}
1.2024 +
1.2025 +bool JavaThread::is_lock_owned(address adr) const {
1.2026 + if (Thread::is_lock_owned(adr)) return true;
1.2027 +
1.2028 + for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1.2029 + if (chunk->contains(adr)) return true;
1.2030 + }
1.2031 +
1.2032 + return false;
1.2033 +}
1.2034 +
1.2035 +
1.2036 +void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
1.2037 + chunk->set_next(monitor_chunks());
1.2038 + set_monitor_chunks(chunk);
1.2039 +}
1.2040 +
1.2041 +void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
1.2042 + guarantee(monitor_chunks() != NULL, "must be non empty");
1.2043 + if (monitor_chunks() == chunk) {
1.2044 + set_monitor_chunks(chunk->next());
1.2045 + } else {
1.2046 + MonitorChunk* prev = monitor_chunks();
1.2047 + while (prev->next() != chunk) prev = prev->next();
1.2048 + prev->set_next(chunk->next());
1.2049 + }
1.2050 +}
1.2051 +
1.2052 +// JVM support.
1.2053 +
1.2054 +// Note: this function shouldn't block if it's called in
1.2055 +// _thread_in_native_trans state (such as from
1.2056 +// check_special_condition_for_native_trans()).
1.2057 +void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
1.2058 +
1.2059 + if (has_last_Java_frame() && has_async_condition()) {
1.2060 + // If we are at a polling page safepoint (not a poll return)
1.2061 + // then we must defer async exception because live registers
1.2062 + // will be clobbered by the exception path. Poll return is
1.2063 + // ok because the call we a returning from already collides
1.2064 + // with exception handling registers and so there is no issue.
1.2065 + // (The exception handling path kills call result registers but
1.2066 + // this is ok since the exception kills the result anyway).
1.2067 +
1.2068 + if (is_at_poll_safepoint()) {
1.2069 + // if the code we are returning to has deoptimized we must defer
1.2070 + // the exception otherwise live registers get clobbered on the
1.2071 + // exception path before deoptimization is able to retrieve them.
1.2072 + //
1.2073 + RegisterMap map(this, false);
1.2074 + frame caller_fr = last_frame().sender(&map);
1.2075 + assert(caller_fr.is_compiled_frame(), "what?");
1.2076 + if (caller_fr.is_deoptimized_frame()) {
1.2077 + if (TraceExceptions) {
1.2078 + ResourceMark rm;
1.2079 + tty->print_cr("deferred async exception at compiled safepoint");
1.2080 + }
1.2081 + return;
1.2082 + }
1.2083 + }
1.2084 + }
1.2085 +
1.2086 + JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
1.2087 + if (condition == _no_async_condition) {
1.2088 + // Conditions have changed since has_special_runtime_exit_condition()
1.2089 + // was called:
1.2090 + // - if we were here only because of an external suspend request,
1.2091 + // then that was taken care of above (or cancelled) so we are done
1.2092 + // - if we were here because of another async request, then it has
1.2093 + // been cleared between the has_special_runtime_exit_condition()
1.2094 + // and now so again we are done
1.2095 + return;
1.2096 + }
1.2097 +
1.2098 + // Check for pending async. exception
1.2099 + if (_pending_async_exception != NULL) {
1.2100 + // Only overwrite an already pending exception, if it is not a threadDeath.
1.2101 + if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
1.2102 +
1.2103 + // We cannot call Exceptions::_throw(...) here because we cannot block
1.2104 + set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
1.2105 +
1.2106 + if (TraceExceptions) {
1.2107 + ResourceMark rm;
1.2108 + tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
1.2109 + if (has_last_Java_frame() ) {
1.2110 + frame f = last_frame();
1.2111 + tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
1.2112 + }
1.2113 + tty->print_cr(" of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
1.2114 + }
1.2115 + _pending_async_exception = NULL;
1.2116 + clear_has_async_exception();
1.2117 + }
1.2118 + }
1.2119 +
1.2120 + if (check_unsafe_error &&
1.2121 + condition == _async_unsafe_access_error && !has_pending_exception()) {
1.2122 + condition = _no_async_condition; // done
1.2123 + switch (thread_state()) {
1.2124 + case _thread_in_vm:
1.2125 + {
1.2126 + JavaThread* THREAD = this;
1.2127 + THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1.2128 + }
1.2129 + case _thread_in_native:
1.2130 + {
1.2131 + ThreadInVMfromNative tiv(this);
1.2132 + JavaThread* THREAD = this;
1.2133 + THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
1.2134 + }
1.2135 + case _thread_in_Java:
1.2136 + {
1.2137 + ThreadInVMfromJava tiv(this);
1.2138 + JavaThread* THREAD = this;
1.2139 + THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
1.2140 + }
1.2141 + default:
1.2142 + ShouldNotReachHere();
1.2143 + }
1.2144 + }
1.2145 +
1.2146 + assert(condition == _no_async_condition || has_pending_exception() ||
1.2147 + (!check_unsafe_error && condition == _async_unsafe_access_error),
1.2148 + "must have handled the async condition, if no exception");
1.2149 +}
1.2150 +
1.2151 +void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
1.2152 + //
1.2153 + // Check for pending external suspend. Internal suspend requests do
1.2154 + // not use handle_special_runtime_exit_condition().
1.2155 + // If JNIEnv proxies are allowed, don't self-suspend if the target
1.2156 + // thread is not the current thread. In older versions of jdbx, jdbx
1.2157 + // threads could call into the VM with another thread's JNIEnv so we
1.2158 + // can be here operating on behalf of a suspended thread (4432884).
1.2159 + bool do_self_suspend = is_external_suspend_with_lock();
1.2160 + if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
1.2161 + //
1.2162 + // Because thread is external suspended the safepoint code will count
1.2163 + // thread as at a safepoint. This can be odd because we can be here
1.2164 + // as _thread_in_Java which would normally transition to _thread_blocked
1.2165 + // at a safepoint. We would like to mark the thread as _thread_blocked
1.2166 + // before calling java_suspend_self like all other callers of it but
1.2167 + // we must then observe proper safepoint protocol. (We can't leave
1.2168 + // _thread_blocked with a safepoint in progress). However we can be
1.2169 + // here as _thread_in_native_trans so we can't use a normal transition
1.2170 + // constructor/destructor pair because they assert on that type of
1.2171 + // transition. We could do something like:
1.2172 + //
1.2173 + // JavaThreadState state = thread_state();
1.2174 + // set_thread_state(_thread_in_vm);
1.2175 + // {
1.2176 + // ThreadBlockInVM tbivm(this);
1.2177 + // java_suspend_self()
1.2178 + // }
1.2179 + // set_thread_state(_thread_in_vm_trans);
1.2180 + // if (safepoint) block;
1.2181 + // set_thread_state(state);
1.2182 + //
1.2183 + // but that is pretty messy. Instead we just go with the way the
1.2184 + // code has worked before and note that this is the only path to
1.2185 + // java_suspend_self that doesn't put the thread in _thread_blocked
1.2186 + // mode.
1.2187 +
1.2188 + frame_anchor()->make_walkable(this);
1.2189 + java_suspend_self();
1.2190 +
1.2191 + // We might be here for reasons in addition to the self-suspend request
1.2192 + // so check for other async requests.
1.2193 + }
1.2194 +
1.2195 + if (check_asyncs) {
1.2196 + check_and_handle_async_exceptions();
1.2197 + }
1.2198 +}
1.2199 +
1.2200 +void JavaThread::send_thread_stop(oop java_throwable) {
1.2201 + assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
1.2202 + assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
1.2203 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.2204 +
1.2205 + // Do not throw asynchronous exceptions against the compiler thread
1.2206 + // (the compiler thread should not be a Java thread -- fix in 1.4.2)
1.2207 + if (is_Compiler_thread()) return;
1.2208 +
1.2209 + {
1.2210 + // Actually throw the Throwable against the target Thread - however
1.2211 + // only if there is no thread death exception installed already.
1.2212 + if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
1.2213 + // If the topmost frame is a runtime stub, then we are calling into
1.2214 + // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
1.2215 + // must deoptimize the caller before continuing, as the compiled exception handler table
1.2216 + // may not be valid
1.2217 + if (has_last_Java_frame()) {
1.2218 + frame f = last_frame();
1.2219 + if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
1.2220 + // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1.2221 + RegisterMap reg_map(this, UseBiasedLocking);
1.2222 + frame compiled_frame = f.sender(®_map);
1.2223 + if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
1.2224 + Deoptimization::deoptimize(this, compiled_frame, ®_map);
1.2225 + }
1.2226 + }
1.2227 + }
1.2228 +
1.2229 + // Set async. pending exception in thread.
1.2230 + set_pending_async_exception(java_throwable);
1.2231 +
1.2232 + if (TraceExceptions) {
1.2233 + ResourceMark rm;
1.2234 + tty->print_cr("Pending Async. exception installed of type: %s", InstanceKlass::cast(_pending_async_exception->klass())->external_name());
1.2235 + }
1.2236 + // for AbortVMOnException flag
1.2237 + NOT_PRODUCT(Exceptions::debug_check_abort(InstanceKlass::cast(_pending_async_exception->klass())->external_name()));
1.2238 + }
1.2239 + }
1.2240 +
1.2241 +
1.2242 + // Interrupt thread so it will wake up from a potential wait()
1.2243 + Thread::interrupt(this);
1.2244 +}
1.2245 +
1.2246 +// External suspension mechanism.
1.2247 +//
1.2248 +// Tell the VM to suspend a thread when ever it knows that it does not hold on
1.2249 +// to any VM_locks and it is at a transition
1.2250 +// Self-suspension will happen on the transition out of the vm.
1.2251 +// Catch "this" coming in from JNIEnv pointers when the thread has been freed
1.2252 +//
1.2253 +// Guarantees on return:
1.2254 +// + Target thread will not execute any new bytecode (that's why we need to
1.2255 +// force a safepoint)
1.2256 +// + Target thread will not enter any new monitors
1.2257 +//
1.2258 +void JavaThread::java_suspend() {
1.2259 + { MutexLocker mu(Threads_lock);
1.2260 + if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
1.2261 + return;
1.2262 + }
1.2263 + }
1.2264 +
1.2265 + { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1.2266 + if (!is_external_suspend()) {
1.2267 + // a racing resume has cancelled us; bail out now
1.2268 + return;
1.2269 + }
1.2270 +
1.2271 + // suspend is done
1.2272 + uint32_t debug_bits = 0;
1.2273 + // Warning: is_ext_suspend_completed() may temporarily drop the
1.2274 + // SR_lock to allow the thread to reach a stable thread state if
1.2275 + // it is currently in a transient thread state.
1.2276 + if (is_ext_suspend_completed(false /* !called_by_wait */,
1.2277 + SuspendRetryDelay, &debug_bits) ) {
1.2278 + return;
1.2279 + }
1.2280 + }
1.2281 +
1.2282 + VM_ForceSafepoint vm_suspend;
1.2283 + VMThread::execute(&vm_suspend);
1.2284 +}
1.2285 +
1.2286 +// Part II of external suspension.
1.2287 +// A JavaThread self suspends when it detects a pending external suspend
1.2288 +// request. This is usually on transitions. It is also done in places
1.2289 +// where continuing to the next transition would surprise the caller,
1.2290 +// e.g., monitor entry.
1.2291 +//
1.2292 +// Returns the number of times that the thread self-suspended.
1.2293 +//
1.2294 +// Note: DO NOT call java_suspend_self() when you just want to block current
1.2295 +// thread. java_suspend_self() is the second stage of cooperative
1.2296 +// suspension for external suspend requests and should only be used
1.2297 +// to complete an external suspend request.
1.2298 +//
1.2299 +int JavaThread::java_suspend_self() {
1.2300 + int ret = 0;
1.2301 +
1.2302 + // we are in the process of exiting so don't suspend
1.2303 + if (is_exiting()) {
1.2304 + clear_external_suspend();
1.2305 + return ret;
1.2306 + }
1.2307 +
1.2308 + assert(_anchor.walkable() ||
1.2309 + (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
1.2310 + "must have walkable stack");
1.2311 +
1.2312 + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1.2313 +
1.2314 + assert(!this->is_ext_suspended(),
1.2315 + "a thread trying to self-suspend should not already be suspended");
1.2316 +
1.2317 + if (this->is_suspend_equivalent()) {
1.2318 + // If we are self-suspending as a result of the lifting of a
1.2319 + // suspend equivalent condition, then the suspend_equivalent
1.2320 + // flag is not cleared until we set the ext_suspended flag so
1.2321 + // that wait_for_ext_suspend_completion() returns consistent
1.2322 + // results.
1.2323 + this->clear_suspend_equivalent();
1.2324 + }
1.2325 +
1.2326 + // A racing resume may have cancelled us before we grabbed SR_lock
1.2327 + // above. Or another external suspend request could be waiting for us
1.2328 + // by the time we return from SR_lock()->wait(). The thread
1.2329 + // that requested the suspension may already be trying to walk our
1.2330 + // stack and if we return now, we can change the stack out from under
1.2331 + // it. This would be a "bad thing (TM)" and cause the stack walker
1.2332 + // to crash. We stay self-suspended until there are no more pending
1.2333 + // external suspend requests.
1.2334 + while (is_external_suspend()) {
1.2335 + ret++;
1.2336 + this->set_ext_suspended();
1.2337 +
1.2338 + // _ext_suspended flag is cleared by java_resume()
1.2339 + while (is_ext_suspended()) {
1.2340 + this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
1.2341 + }
1.2342 + }
1.2343 +
1.2344 + return ret;
1.2345 +}
1.2346 +
1.2347 +#ifdef ASSERT
1.2348 +// verify the JavaThread has not yet been published in the Threads::list, and
1.2349 +// hence doesn't need protection from concurrent access at this stage
1.2350 +void JavaThread::verify_not_published() {
1.2351 + if (!Threads_lock->owned_by_self()) {
1.2352 + MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
1.2353 + assert( !Threads::includes(this),
1.2354 + "java thread shouldn't have been published yet!");
1.2355 + }
1.2356 + else {
1.2357 + assert( !Threads::includes(this),
1.2358 + "java thread shouldn't have been published yet!");
1.2359 + }
1.2360 +}
1.2361 +#endif
1.2362 +
1.2363 +// Slow path when the native==>VM/Java barriers detect a safepoint is in
1.2364 +// progress or when _suspend_flags is non-zero.
1.2365 +// Current thread needs to self-suspend if there is a suspend request and/or
1.2366 +// block if a safepoint is in progress.
1.2367 +// Async exception ISN'T checked.
1.2368 +// Note only the ThreadInVMfromNative transition can call this function
1.2369 +// directly and when thread state is _thread_in_native_trans
1.2370 +void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
1.2371 + assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
1.2372 +
1.2373 + JavaThread *curJT = JavaThread::current();
1.2374 + bool do_self_suspend = thread->is_external_suspend();
1.2375 +
1.2376 + assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
1.2377 +
1.2378 + // If JNIEnv proxies are allowed, don't self-suspend if the target
1.2379 + // thread is not the current thread. In older versions of jdbx, jdbx
1.2380 + // threads could call into the VM with another thread's JNIEnv so we
1.2381 + // can be here operating on behalf of a suspended thread (4432884).
1.2382 + if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
1.2383 + JavaThreadState state = thread->thread_state();
1.2384 +
1.2385 + // We mark this thread_blocked state as a suspend-equivalent so
1.2386 + // that a caller to is_ext_suspend_completed() won't be confused.
1.2387 + // The suspend-equivalent state is cleared by java_suspend_self().
1.2388 + thread->set_suspend_equivalent();
1.2389 +
1.2390 + // If the safepoint code sees the _thread_in_native_trans state, it will
1.2391 + // wait until the thread changes to other thread state. There is no
1.2392 + // guarantee on how soon we can obtain the SR_lock and complete the
1.2393 + // self-suspend request. It would be a bad idea to let safepoint wait for
1.2394 + // too long. Temporarily change the state to _thread_blocked to
1.2395 + // let the VM thread know that this thread is ready for GC. The problem
1.2396 + // of changing thread state is that safepoint could happen just after
1.2397 + // java_suspend_self() returns after being resumed, and VM thread will
1.2398 + // see the _thread_blocked state. We must check for safepoint
1.2399 + // after restoring the state and make sure we won't leave while a safepoint
1.2400 + // is in progress.
1.2401 + thread->set_thread_state(_thread_blocked);
1.2402 + thread->java_suspend_self();
1.2403 + thread->set_thread_state(state);
1.2404 + // Make sure new state is seen by VM thread
1.2405 + if (os::is_MP()) {
1.2406 + if (UseMembar) {
1.2407 + // Force a fence between the write above and read below
1.2408 + OrderAccess::fence();
1.2409 + } else {
1.2410 + // Must use this rather than serialization page in particular on Windows
1.2411 + InterfaceSupport::serialize_memory(thread);
1.2412 + }
1.2413 + }
1.2414 + }
1.2415 +
1.2416 + if (SafepointSynchronize::do_call_back()) {
1.2417 + // If we are safepointing, then block the caller which may not be
1.2418 + // the same as the target thread (see above).
1.2419 + SafepointSynchronize::block(curJT);
1.2420 + }
1.2421 +
1.2422 + if (thread->is_deopt_suspend()) {
1.2423 + thread->clear_deopt_suspend();
1.2424 + RegisterMap map(thread, false);
1.2425 + frame f = thread->last_frame();
1.2426 + while ( f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
1.2427 + f = f.sender(&map);
1.2428 + }
1.2429 + if (f.id() == thread->must_deopt_id()) {
1.2430 + thread->clear_must_deopt_id();
1.2431 + f.deoptimize(thread);
1.2432 + } else {
1.2433 + fatal("missed deoptimization!");
1.2434 + }
1.2435 + }
1.2436 +}
1.2437 +
1.2438 +// Slow path when the native==>VM/Java barriers detect a safepoint is in
1.2439 +// progress or when _suspend_flags is non-zero.
1.2440 +// Current thread needs to self-suspend if there is a suspend request and/or
1.2441 +// block if a safepoint is in progress.
1.2442 +// Also check for pending async exception (not including unsafe access error).
1.2443 +// Note only the native==>VM/Java barriers can call this function and when
1.2444 +// thread state is _thread_in_native_trans.
1.2445 +void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
1.2446 + check_safepoint_and_suspend_for_native_trans(thread);
1.2447 +
1.2448 + if (thread->has_async_exception()) {
1.2449 + // We are in _thread_in_native_trans state, don't handle unsafe
1.2450 + // access error since that may block.
1.2451 + thread->check_and_handle_async_exceptions(false);
1.2452 + }
1.2453 +}
1.2454 +
1.2455 +// This is a variant of the normal
1.2456 +// check_special_condition_for_native_trans with slightly different
1.2457 +// semantics for use by critical native wrappers. It does all the
1.2458 +// normal checks but also performs the transition back into
1.2459 +// thread_in_Java state. This is required so that critical natives
1.2460 +// can potentially block and perform a GC if they are the last thread
1.2461 +// exiting the GC_locker.
1.2462 +void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
1.2463 + check_special_condition_for_native_trans(thread);
1.2464 +
1.2465 + // Finish the transition
1.2466 + thread->set_thread_state(_thread_in_Java);
1.2467 +
1.2468 + if (thread->do_critical_native_unlock()) {
1.2469 + ThreadInVMfromJavaNoAsyncException tiv(thread);
1.2470 + GC_locker::unlock_critical(thread);
1.2471 + thread->clear_critical_native_unlock();
1.2472 + }
1.2473 +}
1.2474 +
1.2475 +// We need to guarantee the Threads_lock here, since resumes are not
1.2476 +// allowed during safepoint synchronization
1.2477 +// Can only resume from an external suspension
1.2478 +void JavaThread::java_resume() {
1.2479 + assert_locked_or_safepoint(Threads_lock);
1.2480 +
1.2481 + // Sanity check: thread is gone, has started exiting or the thread
1.2482 + // was not externally suspended.
1.2483 + if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
1.2484 + return;
1.2485 + }
1.2486 +
1.2487 + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1.2488 +
1.2489 + clear_external_suspend();
1.2490 +
1.2491 + if (is_ext_suspended()) {
1.2492 + clear_ext_suspended();
1.2493 + SR_lock()->notify_all();
1.2494 + }
1.2495 +}
1.2496 +
1.2497 +void JavaThread::create_stack_guard_pages() {
1.2498 + if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
1.2499 + address low_addr = stack_base() - stack_size();
1.2500 + size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
1.2501 +
1.2502 + int allocate = os::allocate_stack_guard_pages();
1.2503 + // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
1.2504 +
1.2505 + if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
1.2506 + warning("Attempt to allocate stack guard pages failed.");
1.2507 + return;
1.2508 + }
1.2509 +
1.2510 + if (os::guard_memory((char *) low_addr, len)) {
1.2511 + _stack_guard_state = stack_guard_enabled;
1.2512 + } else {
1.2513 + warning("Attempt to protect stack guard pages failed.");
1.2514 + if (os::uncommit_memory((char *) low_addr, len)) {
1.2515 + warning("Attempt to deallocate stack guard pages failed.");
1.2516 + }
1.2517 + }
1.2518 +}
1.2519 +
1.2520 +void JavaThread::remove_stack_guard_pages() {
1.2521 + assert(Thread::current() == this, "from different thread");
1.2522 + if (_stack_guard_state == stack_guard_unused) return;
1.2523 + address low_addr = stack_base() - stack_size();
1.2524 + size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
1.2525 +
1.2526 + if (os::allocate_stack_guard_pages()) {
1.2527 + if (os::remove_stack_guard_pages((char *) low_addr, len)) {
1.2528 + _stack_guard_state = stack_guard_unused;
1.2529 + } else {
1.2530 + warning("Attempt to deallocate stack guard pages failed.");
1.2531 + }
1.2532 + } else {
1.2533 + if (_stack_guard_state == stack_guard_unused) return;
1.2534 + if (os::unguard_memory((char *) low_addr, len)) {
1.2535 + _stack_guard_state = stack_guard_unused;
1.2536 + } else {
1.2537 + warning("Attempt to unprotect stack guard pages failed.");
1.2538 + }
1.2539 + }
1.2540 +}
1.2541 +
1.2542 +void JavaThread::enable_stack_yellow_zone() {
1.2543 + assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
1.2544 + assert(_stack_guard_state != stack_guard_enabled, "already enabled");
1.2545 +
1.2546 + // The base notation is from the stacks point of view, growing downward.
1.2547 + // We need to adjust it to work correctly with guard_memory()
1.2548 + address base = stack_yellow_zone_base() - stack_yellow_zone_size();
1.2549 +
1.2550 + guarantee(base < stack_base(),"Error calculating stack yellow zone");
1.2551 + guarantee(base < os::current_stack_pointer(),"Error calculating stack yellow zone");
1.2552 +
1.2553 + if (os::guard_memory((char *) base, stack_yellow_zone_size())) {
1.2554 + _stack_guard_state = stack_guard_enabled;
1.2555 + } else {
1.2556 + warning("Attempt to guard stack yellow zone failed.");
1.2557 + }
1.2558 + enable_register_stack_guard();
1.2559 +}
1.2560 +
1.2561 +void JavaThread::disable_stack_yellow_zone() {
1.2562 + assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
1.2563 + assert(_stack_guard_state != stack_guard_yellow_disabled, "already disabled");
1.2564 +
1.2565 + // Simply return if called for a thread that does not use guard pages.
1.2566 + if (_stack_guard_state == stack_guard_unused) return;
1.2567 +
1.2568 + // The base notation is from the stacks point of view, growing downward.
1.2569 + // We need to adjust it to work correctly with guard_memory()
1.2570 + address base = stack_yellow_zone_base() - stack_yellow_zone_size();
1.2571 +
1.2572 + if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
1.2573 + _stack_guard_state = stack_guard_yellow_disabled;
1.2574 + } else {
1.2575 + warning("Attempt to unguard stack yellow zone failed.");
1.2576 + }
1.2577 + disable_register_stack_guard();
1.2578 +}
1.2579 +
1.2580 +void JavaThread::enable_stack_red_zone() {
1.2581 + // The base notation is from the stacks point of view, growing downward.
1.2582 + // We need to adjust it to work correctly with guard_memory()
1.2583 + assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
1.2584 + address base = stack_red_zone_base() - stack_red_zone_size();
1.2585 +
1.2586 + guarantee(base < stack_base(),"Error calculating stack red zone");
1.2587 + guarantee(base < os::current_stack_pointer(),"Error calculating stack red zone");
1.2588 +
1.2589 + if(!os::guard_memory((char *) base, stack_red_zone_size())) {
1.2590 + warning("Attempt to guard stack red zone failed.");
1.2591 + }
1.2592 +}
1.2593 +
1.2594 +void JavaThread::disable_stack_red_zone() {
1.2595 + // The base notation is from the stacks point of view, growing downward.
1.2596 + // We need to adjust it to work correctly with guard_memory()
1.2597 + assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
1.2598 + address base = stack_red_zone_base() - stack_red_zone_size();
1.2599 + if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
1.2600 + warning("Attempt to unguard stack red zone failed.");
1.2601 + }
1.2602 +}
1.2603 +
1.2604 +void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
1.2605 + // ignore is there is no stack
1.2606 + if (!has_last_Java_frame()) return;
1.2607 + // traverse the stack frames. Starts from top frame.
1.2608 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.2609 + frame* fr = fst.current();
1.2610 + f(fr, fst.register_map());
1.2611 + }
1.2612 +}
1.2613 +
1.2614 +
1.2615 +#ifndef PRODUCT
1.2616 +// Deoptimization
1.2617 +// Function for testing deoptimization
1.2618 +void JavaThread::deoptimize() {
1.2619 + // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1.2620 + StackFrameStream fst(this, UseBiasedLocking);
1.2621 + bool deopt = false; // Dump stack only if a deopt actually happens.
1.2622 + bool only_at = strlen(DeoptimizeOnlyAt) > 0;
1.2623 + // Iterate over all frames in the thread and deoptimize
1.2624 + for(; !fst.is_done(); fst.next()) {
1.2625 + if(fst.current()->can_be_deoptimized()) {
1.2626 +
1.2627 + if (only_at) {
1.2628 + // Deoptimize only at particular bcis. DeoptimizeOnlyAt
1.2629 + // consists of comma or carriage return separated numbers so
1.2630 + // search for the current bci in that string.
1.2631 + address pc = fst.current()->pc();
1.2632 + nmethod* nm = (nmethod*) fst.current()->cb();
1.2633 + ScopeDesc* sd = nm->scope_desc_at( pc);
1.2634 + char buffer[8];
1.2635 + jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
1.2636 + size_t len = strlen(buffer);
1.2637 + const char * found = strstr(DeoptimizeOnlyAt, buffer);
1.2638 + while (found != NULL) {
1.2639 + if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
1.2640 + (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
1.2641 + // Check that the bci found is bracketed by terminators.
1.2642 + break;
1.2643 + }
1.2644 + found = strstr(found + 1, buffer);
1.2645 + }
1.2646 + if (!found) {
1.2647 + continue;
1.2648 + }
1.2649 + }
1.2650 +
1.2651 + if (DebugDeoptimization && !deopt) {
1.2652 + deopt = true; // One-time only print before deopt
1.2653 + tty->print_cr("[BEFORE Deoptimization]");
1.2654 + trace_frames();
1.2655 + trace_stack();
1.2656 + }
1.2657 + Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
1.2658 + }
1.2659 + }
1.2660 +
1.2661 + if (DebugDeoptimization && deopt) {
1.2662 + tty->print_cr("[AFTER Deoptimization]");
1.2663 + trace_frames();
1.2664 + }
1.2665 +}
1.2666 +
1.2667 +
1.2668 +// Make zombies
1.2669 +void JavaThread::make_zombies() {
1.2670 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.2671 + if (fst.current()->can_be_deoptimized()) {
1.2672 + // it is a Java nmethod
1.2673 + nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
1.2674 + nm->make_not_entrant();
1.2675 + }
1.2676 + }
1.2677 +}
1.2678 +#endif // PRODUCT
1.2679 +
1.2680 +
1.2681 +void JavaThread::deoptimized_wrt_marked_nmethods() {
1.2682 + if (!has_last_Java_frame()) return;
1.2683 + // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
1.2684 + StackFrameStream fst(this, UseBiasedLocking);
1.2685 + for(; !fst.is_done(); fst.next()) {
1.2686 + if (fst.current()->should_be_deoptimized()) {
1.2687 + if (LogCompilation && xtty != NULL) {
1.2688 + nmethod* nm = fst.current()->cb()->as_nmethod_or_null();
1.2689 + xtty->elem("deoptimized thread='" UINTX_FORMAT "' compile_id='%d'",
1.2690 + this->name(), nm != NULL ? nm->compile_id() : -1);
1.2691 + }
1.2692 +
1.2693 + Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
1.2694 + }
1.2695 + }
1.2696 +}
1.2697 +
1.2698 +
1.2699 +// GC support
1.2700 +static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
1.2701 +
1.2702 +void JavaThread::gc_epilogue() {
1.2703 + frames_do(frame_gc_epilogue);
1.2704 +}
1.2705 +
1.2706 +
1.2707 +static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
1.2708 +
1.2709 +void JavaThread::gc_prologue() {
1.2710 + frames_do(frame_gc_prologue);
1.2711 +}
1.2712 +
1.2713 +// If the caller is a NamedThread, then remember, in the current scope,
1.2714 +// the given JavaThread in its _processed_thread field.
1.2715 +class RememberProcessedThread: public StackObj {
1.2716 + NamedThread* _cur_thr;
1.2717 +public:
1.2718 + RememberProcessedThread(JavaThread* jthr) {
1.2719 + Thread* thread = Thread::current();
1.2720 + if (thread->is_Named_thread()) {
1.2721 + _cur_thr = (NamedThread *)thread;
1.2722 + _cur_thr->set_processed_thread(jthr);
1.2723 + } else {
1.2724 + _cur_thr = NULL;
1.2725 + }
1.2726 + }
1.2727 +
1.2728 + ~RememberProcessedThread() {
1.2729 + if (_cur_thr) {
1.2730 + _cur_thr->set_processed_thread(NULL);
1.2731 + }
1.2732 + }
1.2733 +};
1.2734 +
1.2735 +void JavaThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
1.2736 + // Verify that the deferred card marks have been flushed.
1.2737 + assert(deferred_card_mark().is_empty(), "Should be empty during GC");
1.2738 +
1.2739 + // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
1.2740 + // since there may be more than one thread using each ThreadProfiler.
1.2741 +
1.2742 + // Traverse the GCHandles
1.2743 + Thread::oops_do(f, cld_f, cf);
1.2744 +
1.2745 + assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
1.2746 + (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
1.2747 +
1.2748 + if (has_last_Java_frame()) {
1.2749 + // Record JavaThread to GC thread
1.2750 + RememberProcessedThread rpt(this);
1.2751 +
1.2752 + // Traverse the privileged stack
1.2753 + if (_privileged_stack_top != NULL) {
1.2754 + _privileged_stack_top->oops_do(f);
1.2755 + }
1.2756 +
1.2757 + // traverse the registered growable array
1.2758 + if (_array_for_gc != NULL) {
1.2759 + for (int index = 0; index < _array_for_gc->length(); index++) {
1.2760 + f->do_oop(_array_for_gc->adr_at(index));
1.2761 + }
1.2762 + }
1.2763 +
1.2764 + // Traverse the monitor chunks
1.2765 + for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
1.2766 + chunk->oops_do(f);
1.2767 + }
1.2768 +
1.2769 + // Traverse the execution stack
1.2770 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.2771 + fst.current()->oops_do(f, cld_f, cf, fst.register_map());
1.2772 + }
1.2773 + }
1.2774 +
1.2775 + // callee_target is never live across a gc point so NULL it here should
1.2776 + // it still contain a methdOop.
1.2777 +
1.2778 + set_callee_target(NULL);
1.2779 +
1.2780 + assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
1.2781 + // If we have deferred set_locals there might be oops waiting to be
1.2782 + // written
1.2783 + GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
1.2784 + if (list != NULL) {
1.2785 + for (int i = 0; i < list->length(); i++) {
1.2786 + list->at(i)->oops_do(f);
1.2787 + }
1.2788 + }
1.2789 +
1.2790 + // Traverse instance variables at the end since the GC may be moving things
1.2791 + // around using this function
1.2792 + f->do_oop((oop*) &_threadObj);
1.2793 + f->do_oop((oop*) &_vm_result);
1.2794 + f->do_oop((oop*) &_exception_oop);
1.2795 + f->do_oop((oop*) &_pending_async_exception);
1.2796 +
1.2797 + if (jvmti_thread_state() != NULL) {
1.2798 + jvmti_thread_state()->oops_do(f);
1.2799 + }
1.2800 +}
1.2801 +
1.2802 +void JavaThread::nmethods_do(CodeBlobClosure* cf) {
1.2803 + Thread::nmethods_do(cf); // (super method is a no-op)
1.2804 +
1.2805 + assert( (!has_last_Java_frame() && java_call_counter() == 0) ||
1.2806 + (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
1.2807 +
1.2808 + if (has_last_Java_frame()) {
1.2809 + // Traverse the execution stack
1.2810 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.2811 + fst.current()->nmethods_do(cf);
1.2812 + }
1.2813 + }
1.2814 +}
1.2815 +
1.2816 +void JavaThread::metadata_do(void f(Metadata*)) {
1.2817 + Thread::metadata_do(f);
1.2818 + if (has_last_Java_frame()) {
1.2819 + // Traverse the execution stack to call f() on the methods in the stack
1.2820 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.2821 + fst.current()->metadata_do(f);
1.2822 + }
1.2823 + } else if (is_Compiler_thread()) {
1.2824 + // need to walk ciMetadata in current compile tasks to keep alive.
1.2825 + CompilerThread* ct = (CompilerThread*)this;
1.2826 + if (ct->env() != NULL) {
1.2827 + ct->env()->metadata_do(f);
1.2828 + }
1.2829 + }
1.2830 +}
1.2831 +
1.2832 +// Printing
1.2833 +const char* _get_thread_state_name(JavaThreadState _thread_state) {
1.2834 + switch (_thread_state) {
1.2835 + case _thread_uninitialized: return "_thread_uninitialized";
1.2836 + case _thread_new: return "_thread_new";
1.2837 + case _thread_new_trans: return "_thread_new_trans";
1.2838 + case _thread_in_native: return "_thread_in_native";
1.2839 + case _thread_in_native_trans: return "_thread_in_native_trans";
1.2840 + case _thread_in_vm: return "_thread_in_vm";
1.2841 + case _thread_in_vm_trans: return "_thread_in_vm_trans";
1.2842 + case _thread_in_Java: return "_thread_in_Java";
1.2843 + case _thread_in_Java_trans: return "_thread_in_Java_trans";
1.2844 + case _thread_blocked: return "_thread_blocked";
1.2845 + case _thread_blocked_trans: return "_thread_blocked_trans";
1.2846 + default: return "unknown thread state";
1.2847 + }
1.2848 +}
1.2849 +
1.2850 +#ifndef PRODUCT
1.2851 +void JavaThread::print_thread_state_on(outputStream *st) const {
1.2852 + st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
1.2853 +};
1.2854 +void JavaThread::print_thread_state() const {
1.2855 + print_thread_state_on(tty);
1.2856 +};
1.2857 +#endif // PRODUCT
1.2858 +
1.2859 +// Called by Threads::print() for VM_PrintThreads operation
1.2860 +void JavaThread::print_on(outputStream *st) const {
1.2861 + st->print("\"%s\" ", get_thread_name());
1.2862 + oop thread_oop = threadObj();
1.2863 + if (thread_oop != NULL) {
1.2864 + st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
1.2865 + if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
1.2866 + st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
1.2867 + }
1.2868 + Thread::print_on(st);
1.2869 + // print guess for valid stack memory region (assume 4K pages); helps lock debugging
1.2870 + st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
1.2871 + if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
1.2872 + st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
1.2873 + }
1.2874 +#ifndef PRODUCT
1.2875 + print_thread_state_on(st);
1.2876 + _safepoint_state->print_on(st);
1.2877 +#endif // PRODUCT
1.2878 +}
1.2879 +
1.2880 +// Called by fatal error handler. The difference between this and
1.2881 +// JavaThread::print() is that we can't grab lock or allocate memory.
1.2882 +void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
1.2883 + st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
1.2884 + oop thread_obj = threadObj();
1.2885 + if (thread_obj != NULL) {
1.2886 + if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
1.2887 + }
1.2888 + st->print(" [");
1.2889 + st->print("%s", _get_thread_state_name(_thread_state));
1.2890 + if (osthread()) {
1.2891 + st->print(", id=%d", osthread()->thread_id());
1.2892 + }
1.2893 + st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
1.2894 + _stack_base - _stack_size, _stack_base);
1.2895 + st->print("]");
1.2896 + return;
1.2897 +}
1.2898 +
1.2899 +// Verification
1.2900 +
1.2901 +static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
1.2902 +
1.2903 +void JavaThread::verify() {
1.2904 + // Verify oops in the thread.
1.2905 + oops_do(&VerifyOopClosure::verify_oop, NULL, NULL);
1.2906 +
1.2907 + // Verify the stack frames.
1.2908 + frames_do(frame_verify);
1.2909 +}
1.2910 +
1.2911 +// CR 6300358 (sub-CR 2137150)
1.2912 +// Most callers of this method assume that it can't return NULL but a
1.2913 +// thread may not have a name whilst it is in the process of attaching to
1.2914 +// the VM - see CR 6412693, and there are places where a JavaThread can be
1.2915 +// seen prior to having it's threadObj set (eg JNI attaching threads and
1.2916 +// if vm exit occurs during initialization). These cases can all be accounted
1.2917 +// for such that this method never returns NULL.
1.2918 +const char* JavaThread::get_thread_name() const {
1.2919 +#ifdef ASSERT
1.2920 + // early safepoints can hit while current thread does not yet have TLS
1.2921 + if (!SafepointSynchronize::is_at_safepoint()) {
1.2922 + Thread *cur = Thread::current();
1.2923 + if (!(cur->is_Java_thread() && cur == this)) {
1.2924 + // Current JavaThreads are allowed to get their own name without
1.2925 + // the Threads_lock.
1.2926 + assert_locked_or_safepoint(Threads_lock);
1.2927 + }
1.2928 + }
1.2929 +#endif // ASSERT
1.2930 + return get_thread_name_string();
1.2931 +}
1.2932 +
1.2933 +// Returns a non-NULL representation of this thread's name, or a suitable
1.2934 +// descriptive string if there is no set name
1.2935 +const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
1.2936 + const char* name_str;
1.2937 + oop thread_obj = threadObj();
1.2938 + if (thread_obj != NULL) {
1.2939 + typeArrayOop name = java_lang_Thread::name(thread_obj);
1.2940 + if (name != NULL) {
1.2941 + if (buf == NULL) {
1.2942 + name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
1.2943 + }
1.2944 + else {
1.2945 + name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
1.2946 + }
1.2947 + }
1.2948 + else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
1.2949 + name_str = "<no-name - thread is attaching>";
1.2950 + }
1.2951 + else {
1.2952 + name_str = Thread::name();
1.2953 + }
1.2954 + }
1.2955 + else {
1.2956 + name_str = Thread::name();
1.2957 + }
1.2958 + assert(name_str != NULL, "unexpected NULL thread name");
1.2959 + return name_str;
1.2960 +}
1.2961 +
1.2962 +
1.2963 +const char* JavaThread::get_threadgroup_name() const {
1.2964 + debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
1.2965 + oop thread_obj = threadObj();
1.2966 + if (thread_obj != NULL) {
1.2967 + oop thread_group = java_lang_Thread::threadGroup(thread_obj);
1.2968 + if (thread_group != NULL) {
1.2969 + typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
1.2970 + // ThreadGroup.name can be null
1.2971 + if (name != NULL) {
1.2972 + const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
1.2973 + return str;
1.2974 + }
1.2975 + }
1.2976 + }
1.2977 + return NULL;
1.2978 +}
1.2979 +
1.2980 +const char* JavaThread::get_parent_name() const {
1.2981 + debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
1.2982 + oop thread_obj = threadObj();
1.2983 + if (thread_obj != NULL) {
1.2984 + oop thread_group = java_lang_Thread::threadGroup(thread_obj);
1.2985 + if (thread_group != NULL) {
1.2986 + oop parent = java_lang_ThreadGroup::parent(thread_group);
1.2987 + if (parent != NULL) {
1.2988 + typeArrayOop name = java_lang_ThreadGroup::name(parent);
1.2989 + // ThreadGroup.name can be null
1.2990 + if (name != NULL) {
1.2991 + const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
1.2992 + return str;
1.2993 + }
1.2994 + }
1.2995 + }
1.2996 + }
1.2997 + return NULL;
1.2998 +}
1.2999 +
1.3000 +ThreadPriority JavaThread::java_priority() const {
1.3001 + oop thr_oop = threadObj();
1.3002 + if (thr_oop == NULL) return NormPriority; // Bootstrapping
1.3003 + ThreadPriority priority = java_lang_Thread::priority(thr_oop);
1.3004 + assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
1.3005 + return priority;
1.3006 +}
1.3007 +
1.3008 +void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
1.3009 +
1.3010 + assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
1.3011 + // Link Java Thread object <-> C++ Thread
1.3012 +
1.3013 + // Get the C++ thread object (an oop) from the JNI handle (a jthread)
1.3014 + // and put it into a new Handle. The Handle "thread_oop" can then
1.3015 + // be used to pass the C++ thread object to other methods.
1.3016 +
1.3017 + // Set the Java level thread object (jthread) field of the
1.3018 + // new thread (a JavaThread *) to C++ thread object using the
1.3019 + // "thread_oop" handle.
1.3020 +
1.3021 + // Set the thread field (a JavaThread *) of the
1.3022 + // oop representing the java_lang_Thread to the new thread (a JavaThread *).
1.3023 +
1.3024 + Handle thread_oop(Thread::current(),
1.3025 + JNIHandles::resolve_non_null(jni_thread));
1.3026 + assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
1.3027 + "must be initialized");
1.3028 + set_threadObj(thread_oop());
1.3029 + java_lang_Thread::set_thread(thread_oop(), this);
1.3030 +
1.3031 + if (prio == NoPriority) {
1.3032 + prio = java_lang_Thread::priority(thread_oop());
1.3033 + assert(prio != NoPriority, "A valid priority should be present");
1.3034 + }
1.3035 +
1.3036 + // Push the Java priority down to the native thread; needs Threads_lock
1.3037 + Thread::set_priority(this, prio);
1.3038 +
1.3039 + // Add the new thread to the Threads list and set it in motion.
1.3040 + // We must have threads lock in order to call Threads::add.
1.3041 + // It is crucial that we do not block before the thread is
1.3042 + // added to the Threads list for if a GC happens, then the java_thread oop
1.3043 + // will not be visited by GC.
1.3044 + Threads::add(this);
1.3045 +}
1.3046 +
1.3047 +oop JavaThread::current_park_blocker() {
1.3048 + // Support for JSR-166 locks
1.3049 + oop thread_oop = threadObj();
1.3050 + if (thread_oop != NULL &&
1.3051 + JDK_Version::current().supports_thread_park_blocker()) {
1.3052 + return java_lang_Thread::park_blocker(thread_oop);
1.3053 + }
1.3054 + return NULL;
1.3055 +}
1.3056 +
1.3057 +
1.3058 +void JavaThread::print_stack_on(outputStream* st) {
1.3059 + if (!has_last_Java_frame()) return;
1.3060 + ResourceMark rm;
1.3061 + HandleMark hm;
1.3062 +
1.3063 + RegisterMap reg_map(this);
1.3064 + vframe* start_vf = last_java_vframe(®_map);
1.3065 + int count = 0;
1.3066 + for (vframe* f = start_vf; f; f = f->sender() ) {
1.3067 + if (f->is_java_frame()) {
1.3068 + javaVFrame* jvf = javaVFrame::cast(f);
1.3069 + java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
1.3070 +
1.3071 + // Print out lock information
1.3072 + if (JavaMonitorsInStackTrace) {
1.3073 + jvf->print_lock_info_on(st, count);
1.3074 + }
1.3075 + } else {
1.3076 + // Ignore non-Java frames
1.3077 + }
1.3078 +
1.3079 + // Bail-out case for too deep stacks
1.3080 + count++;
1.3081 + if (MaxJavaStackTraceDepth == count) return;
1.3082 + }
1.3083 +}
1.3084 +
1.3085 +
1.3086 +// JVMTI PopFrame support
1.3087 +void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
1.3088 + assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
1.3089 + if (in_bytes(size_in_bytes) != 0) {
1.3090 + _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
1.3091 + _popframe_preserved_args_size = in_bytes(size_in_bytes);
1.3092 + Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
1.3093 + }
1.3094 +}
1.3095 +
1.3096 +void* JavaThread::popframe_preserved_args() {
1.3097 + return _popframe_preserved_args;
1.3098 +}
1.3099 +
1.3100 +ByteSize JavaThread::popframe_preserved_args_size() {
1.3101 + return in_ByteSize(_popframe_preserved_args_size);
1.3102 +}
1.3103 +
1.3104 +WordSize JavaThread::popframe_preserved_args_size_in_words() {
1.3105 + int sz = in_bytes(popframe_preserved_args_size());
1.3106 + assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
1.3107 + return in_WordSize(sz / wordSize);
1.3108 +}
1.3109 +
1.3110 +void JavaThread::popframe_free_preserved_args() {
1.3111 + assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
1.3112 + FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args, mtThread);
1.3113 + _popframe_preserved_args = NULL;
1.3114 + _popframe_preserved_args_size = 0;
1.3115 +}
1.3116 +
1.3117 +#ifndef PRODUCT
1.3118 +
1.3119 +void JavaThread::trace_frames() {
1.3120 + tty->print_cr("[Describe stack]");
1.3121 + int frame_no = 1;
1.3122 + for(StackFrameStream fst(this); !fst.is_done(); fst.next()) {
1.3123 + tty->print(" %d. ", frame_no++);
1.3124 + fst.current()->print_value_on(tty,this);
1.3125 + tty->cr();
1.3126 + }
1.3127 +}
1.3128 +
1.3129 +class PrintAndVerifyOopClosure: public OopClosure {
1.3130 + protected:
1.3131 + template <class T> inline void do_oop_work(T* p) {
1.3132 + oop obj = oopDesc::load_decode_heap_oop(p);
1.3133 + if (obj == NULL) return;
1.3134 + tty->print(INTPTR_FORMAT ": ", p);
1.3135 + if (obj->is_oop_or_null()) {
1.3136 + if (obj->is_objArray()) {
1.3137 + tty->print_cr("valid objArray: " INTPTR_FORMAT, (oopDesc*) obj);
1.3138 + } else {
1.3139 + obj->print();
1.3140 + }
1.3141 + } else {
1.3142 + tty->print_cr("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj);
1.3143 + }
1.3144 + tty->cr();
1.3145 + }
1.3146 + public:
1.3147 + virtual void do_oop(oop* p) { do_oop_work(p); }
1.3148 + virtual void do_oop(narrowOop* p) { do_oop_work(p); }
1.3149 +};
1.3150 +
1.3151 +
1.3152 +static void oops_print(frame* f, const RegisterMap *map) {
1.3153 + PrintAndVerifyOopClosure print;
1.3154 + f->print_value();
1.3155 + f->oops_do(&print, NULL, NULL, (RegisterMap*)map);
1.3156 +}
1.3157 +
1.3158 +// Print our all the locations that contain oops and whether they are
1.3159 +// valid or not. This useful when trying to find the oldest frame
1.3160 +// where an oop has gone bad since the frame walk is from youngest to
1.3161 +// oldest.
1.3162 +void JavaThread::trace_oops() {
1.3163 + tty->print_cr("[Trace oops]");
1.3164 + frames_do(oops_print);
1.3165 +}
1.3166 +
1.3167 +
1.3168 +#ifdef ASSERT
1.3169 +// Print or validate the layout of stack frames
1.3170 +void JavaThread::print_frame_layout(int depth, bool validate_only) {
1.3171 + ResourceMark rm;
1.3172 + PRESERVE_EXCEPTION_MARK;
1.3173 + FrameValues values;
1.3174 + int frame_no = 0;
1.3175 + for(StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
1.3176 + fst.current()->describe(values, ++frame_no);
1.3177 + if (depth == frame_no) break;
1.3178 + }
1.3179 + if (validate_only) {
1.3180 + values.validate();
1.3181 + } else {
1.3182 + tty->print_cr("[Describe stack layout]");
1.3183 + values.print(this);
1.3184 + }
1.3185 +}
1.3186 +#endif
1.3187 +
1.3188 +void JavaThread::trace_stack_from(vframe* start_vf) {
1.3189 + ResourceMark rm;
1.3190 + int vframe_no = 1;
1.3191 + for (vframe* f = start_vf; f; f = f->sender() ) {
1.3192 + if (f->is_java_frame()) {
1.3193 + javaVFrame::cast(f)->print_activation(vframe_no++);
1.3194 + } else {
1.3195 + f->print();
1.3196 + }
1.3197 + if (vframe_no > StackPrintLimit) {
1.3198 + tty->print_cr("...<more frames>...");
1.3199 + return;
1.3200 + }
1.3201 + }
1.3202 +}
1.3203 +
1.3204 +
1.3205 +void JavaThread::trace_stack() {
1.3206 + if (!has_last_Java_frame()) return;
1.3207 + ResourceMark rm;
1.3208 + HandleMark hm;
1.3209 + RegisterMap reg_map(this);
1.3210 + trace_stack_from(last_java_vframe(®_map));
1.3211 +}
1.3212 +
1.3213 +
1.3214 +#endif // PRODUCT
1.3215 +
1.3216 +
1.3217 +javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
1.3218 + assert(reg_map != NULL, "a map must be given");
1.3219 + frame f = last_frame();
1.3220 + for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender() ) {
1.3221 + if (vf->is_java_frame()) return javaVFrame::cast(vf);
1.3222 + }
1.3223 + return NULL;
1.3224 +}
1.3225 +
1.3226 +
1.3227 +Klass* JavaThread::security_get_caller_class(int depth) {
1.3228 + vframeStream vfst(this);
1.3229 + vfst.security_get_caller_frame(depth);
1.3230 + if (!vfst.at_end()) {
1.3231 + return vfst.method()->method_holder();
1.3232 + }
1.3233 + return NULL;
1.3234 +}
1.3235 +
1.3236 +static void compiler_thread_entry(JavaThread* thread, TRAPS) {
1.3237 + assert(thread->is_Compiler_thread(), "must be compiler thread");
1.3238 + CompileBroker::compiler_thread_loop();
1.3239 +}
1.3240 +
1.3241 +// Create a CompilerThread
1.3242 +CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
1.3243 +: JavaThread(&compiler_thread_entry) {
1.3244 + _env = NULL;
1.3245 + _log = NULL;
1.3246 + _task = NULL;
1.3247 + _queue = queue;
1.3248 + _counters = counters;
1.3249 + _buffer_blob = NULL;
1.3250 + _scanned_nmethod = NULL;
1.3251 + _compiler = NULL;
1.3252 +
1.3253 +#ifndef PRODUCT
1.3254 + _ideal_graph_printer = NULL;
1.3255 +#endif
1.3256 +}
1.3257 +
1.3258 +void CompilerThread::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
1.3259 + JavaThread::oops_do(f, cld_f, cf);
1.3260 + if (_scanned_nmethod != NULL && cf != NULL) {
1.3261 + // Safepoints can occur when the sweeper is scanning an nmethod so
1.3262 + // process it here to make sure it isn't unloaded in the middle of
1.3263 + // a scan.
1.3264 + cf->do_code_blob(_scanned_nmethod);
1.3265 + }
1.3266 +}
1.3267 +
1.3268 +
1.3269 +// ======= Threads ========
1.3270 +
1.3271 +// The Threads class links together all active threads, and provides
1.3272 +// operations over all threads. It is protected by its own Mutex
1.3273 +// lock, which is also used in other contexts to protect thread
1.3274 +// operations from having the thread being operated on from exiting
1.3275 +// and going away unexpectedly (e.g., safepoint synchronization)
1.3276 +
1.3277 +JavaThread* Threads::_thread_list = NULL;
1.3278 +int Threads::_number_of_threads = 0;
1.3279 +int Threads::_number_of_non_daemon_threads = 0;
1.3280 +int Threads::_return_code = 0;
1.3281 +size_t JavaThread::_stack_size_at_create = 0;
1.3282 +#ifdef ASSERT
1.3283 +bool Threads::_vm_complete = false;
1.3284 +#endif
1.3285 +
1.3286 +// All JavaThreads
1.3287 +#define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
1.3288 +
1.3289 +// All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
1.3290 +void Threads::threads_do(ThreadClosure* tc) {
1.3291 + assert_locked_or_safepoint(Threads_lock);
1.3292 + // ALL_JAVA_THREADS iterates through all JavaThreads
1.3293 + ALL_JAVA_THREADS(p) {
1.3294 + tc->do_thread(p);
1.3295 + }
1.3296 + // Someday we could have a table or list of all non-JavaThreads.
1.3297 + // For now, just manually iterate through them.
1.3298 + tc->do_thread(VMThread::vm_thread());
1.3299 + Universe::heap()->gc_threads_do(tc);
1.3300 + WatcherThread *wt = WatcherThread::watcher_thread();
1.3301 + // Strictly speaking, the following NULL check isn't sufficient to make sure
1.3302 + // the data for WatcherThread is still valid upon being examined. However,
1.3303 + // considering that WatchThread terminates when the VM is on the way to
1.3304 + // exit at safepoint, the chance of the above is extremely small. The right
1.3305 + // way to prevent termination of WatcherThread would be to acquire
1.3306 + // Terminator_lock, but we can't do that without violating the lock rank
1.3307 + // checking in some cases.
1.3308 + if (wt != NULL)
1.3309 + tc->do_thread(wt);
1.3310 +
1.3311 + // If CompilerThreads ever become non-JavaThreads, add them here
1.3312 +}
1.3313 +
1.3314 +jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
1.3315 +
1.3316 + extern void JDK_Version_init();
1.3317 +
1.3318 + // Check version
1.3319 + if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
1.3320 +
1.3321 + // Initialize the output stream module
1.3322 + ostream_init();
1.3323 +
1.3324 + // Process java launcher properties.
1.3325 + Arguments::process_sun_java_launcher_properties(args);
1.3326 +
1.3327 + // Initialize the os module before using TLS
1.3328 + os::init();
1.3329 +
1.3330 + // Initialize system properties.
1.3331 + Arguments::init_system_properties();
1.3332 +
1.3333 + // So that JDK version can be used as a discrimintor when parsing arguments
1.3334 + JDK_Version_init();
1.3335 +
1.3336 + // Update/Initialize System properties after JDK version number is known
1.3337 + Arguments::init_version_specific_system_properties();
1.3338 +
1.3339 + // Parse arguments
1.3340 + jint parse_result = Arguments::parse(args);
1.3341 + if (parse_result != JNI_OK) return parse_result;
1.3342 +
1.3343 + os::init_before_ergo();
1.3344 +
1.3345 + jint ergo_result = Arguments::apply_ergo();
1.3346 + if (ergo_result != JNI_OK) return ergo_result;
1.3347 +
1.3348 + if (PauseAtStartup) {
1.3349 + os::pause();
1.3350 + }
1.3351 +
1.3352 +#ifndef USDT2
1.3353 + HS_DTRACE_PROBE(hotspot, vm__init__begin);
1.3354 +#else /* USDT2 */
1.3355 + HOTSPOT_VM_INIT_BEGIN();
1.3356 +#endif /* USDT2 */
1.3357 +
1.3358 + // Record VM creation timing statistics
1.3359 + TraceVmCreationTime create_vm_timer;
1.3360 + create_vm_timer.start();
1.3361 +
1.3362 + // Timing (must come after argument parsing)
1.3363 + TraceTime timer("Create VM", TraceStartupTime);
1.3364 +
1.3365 + // Initialize the os module after parsing the args
1.3366 + jint os_init_2_result = os::init_2();
1.3367 + if (os_init_2_result != JNI_OK) return os_init_2_result;
1.3368 +
1.3369 + jint adjust_after_os_result = Arguments::adjust_after_os();
1.3370 + if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
1.3371 +
1.3372 + // intialize TLS
1.3373 + ThreadLocalStorage::init();
1.3374 +
1.3375 + // Bootstrap native memory tracking, so it can start recording memory
1.3376 + // activities before worker thread is started. This is the first phase
1.3377 + // of bootstrapping, VM is currently running in single-thread mode.
1.3378 + MemTracker::bootstrap_single_thread();
1.3379 +
1.3380 + // Initialize output stream logging
1.3381 + ostream_init_log();
1.3382 +
1.3383 + // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
1.3384 + // Must be before create_vm_init_agents()
1.3385 + if (Arguments::init_libraries_at_startup()) {
1.3386 + convert_vm_init_libraries_to_agents();
1.3387 + }
1.3388 +
1.3389 + // Launch -agentlib/-agentpath and converted -Xrun agents
1.3390 + if (Arguments::init_agents_at_startup()) {
1.3391 + create_vm_init_agents();
1.3392 + }
1.3393 +
1.3394 + // Initialize Threads state
1.3395 + _thread_list = NULL;
1.3396 + _number_of_threads = 0;
1.3397 + _number_of_non_daemon_threads = 0;
1.3398 +
1.3399 + // Initialize global data structures and create system classes in heap
1.3400 + vm_init_globals();
1.3401 +
1.3402 + // Attach the main thread to this os thread
1.3403 + JavaThread* main_thread = new JavaThread();
1.3404 + main_thread->set_thread_state(_thread_in_vm);
1.3405 + // must do this before set_active_handles and initialize_thread_local_storage
1.3406 + // Note: on solaris initialize_thread_local_storage() will (indirectly)
1.3407 + // change the stack size recorded here to one based on the java thread
1.3408 + // stacksize. This adjusted size is what is used to figure the placement
1.3409 + // of the guard pages.
1.3410 + main_thread->record_stack_base_and_size();
1.3411 + main_thread->initialize_thread_local_storage();
1.3412 +
1.3413 + main_thread->set_active_handles(JNIHandleBlock::allocate_block());
1.3414 +
1.3415 + if (!main_thread->set_as_starting_thread()) {
1.3416 + vm_shutdown_during_initialization(
1.3417 + "Failed necessary internal allocation. Out of swap space");
1.3418 + delete main_thread;
1.3419 + *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
1.3420 + return JNI_ENOMEM;
1.3421 + }
1.3422 +
1.3423 + // Enable guard page *after* os::create_main_thread(), otherwise it would
1.3424 + // crash Linux VM, see notes in os_linux.cpp.
1.3425 + main_thread->create_stack_guard_pages();
1.3426 +
1.3427 + // Initialize Java-Level synchronization subsystem
1.3428 + ObjectMonitor::Initialize() ;
1.3429 +
1.3430 + // Second phase of bootstrapping, VM is about entering multi-thread mode
1.3431 + MemTracker::bootstrap_multi_thread();
1.3432 +
1.3433 + // Initialize global modules
1.3434 + jint status = init_globals();
1.3435 + if (status != JNI_OK) {
1.3436 + delete main_thread;
1.3437 + *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
1.3438 + return status;
1.3439 + }
1.3440 +
1.3441 + // Should be done after the heap is fully created
1.3442 + main_thread->cache_global_variables();
1.3443 +
1.3444 + HandleMark hm;
1.3445 +
1.3446 + { MutexLocker mu(Threads_lock);
1.3447 + Threads::add(main_thread);
1.3448 + }
1.3449 +
1.3450 + // Any JVMTI raw monitors entered in onload will transition into
1.3451 + // real raw monitor. VM is setup enough here for raw monitor enter.
1.3452 + JvmtiExport::transition_pending_onload_raw_monitors();
1.3453 +
1.3454 + // Fully start NMT
1.3455 + MemTracker::start();
1.3456 +
1.3457 + // Create the VMThread
1.3458 + { TraceTime timer("Start VMThread", TraceStartupTime);
1.3459 + VMThread::create();
1.3460 + Thread* vmthread = VMThread::vm_thread();
1.3461 +
1.3462 + if (!os::create_thread(vmthread, os::vm_thread))
1.3463 + vm_exit_during_initialization("Cannot create VM thread. Out of system resources.");
1.3464 +
1.3465 + // Wait for the VM thread to become ready, and VMThread::run to initialize
1.3466 + // Monitors can have spurious returns, must always check another state flag
1.3467 + {
1.3468 + MutexLocker ml(Notify_lock);
1.3469 + os::start_thread(vmthread);
1.3470 + while (vmthread->active_handles() == NULL) {
1.3471 + Notify_lock->wait();
1.3472 + }
1.3473 + }
1.3474 + }
1.3475 +
1.3476 + assert (Universe::is_fully_initialized(), "not initialized");
1.3477 + if (VerifyDuringStartup) {
1.3478 + // Make sure we're starting with a clean slate.
1.3479 + VM_Verify verify_op;
1.3480 + VMThread::execute(&verify_op);
1.3481 + }
1.3482 +
1.3483 + EXCEPTION_MARK;
1.3484 +
1.3485 + // At this point, the Universe is initialized, but we have not executed
1.3486 + // any byte code. Now is a good time (the only time) to dump out the
1.3487 + // internal state of the JVM for sharing.
1.3488 + if (DumpSharedSpaces) {
1.3489 + MetaspaceShared::preload_and_dump(CHECK_0);
1.3490 + ShouldNotReachHere();
1.3491 + }
1.3492 +
1.3493 + // Always call even when there are not JVMTI environments yet, since environments
1.3494 + // may be attached late and JVMTI must track phases of VM execution
1.3495 + JvmtiExport::enter_start_phase();
1.3496 +
1.3497 + // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
1.3498 + JvmtiExport::post_vm_start();
1.3499 +
1.3500 + {
1.3501 + TraceTime timer("Initialize java.lang classes", TraceStartupTime);
1.3502 +
1.3503 + if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
1.3504 + create_vm_init_libraries();
1.3505 + }
1.3506 +
1.3507 + initialize_class(vmSymbols::java_lang_String(), CHECK_0);
1.3508 +
1.3509 + // Initialize java_lang.System (needed before creating the thread)
1.3510 + initialize_class(vmSymbols::java_lang_System(), CHECK_0);
1.3511 + initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK_0);
1.3512 + Handle thread_group = create_initial_thread_group(CHECK_0);
1.3513 + Universe::set_main_thread_group(thread_group());
1.3514 + initialize_class(vmSymbols::java_lang_Thread(), CHECK_0);
1.3515 + oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
1.3516 + main_thread->set_threadObj(thread_object);
1.3517 + // Set thread status to running since main thread has
1.3518 + // been started and running.
1.3519 + java_lang_Thread::set_thread_status(thread_object,
1.3520 + java_lang_Thread::RUNNABLE);
1.3521 +
1.3522 + // The VM creates & returns objects of this class. Make sure it's initialized.
1.3523 + initialize_class(vmSymbols::java_lang_Class(), CHECK_0);
1.3524 +
1.3525 + // The VM preresolves methods to these classes. Make sure that they get initialized
1.3526 + initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK_0);
1.3527 + initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK_0);
1.3528 + call_initializeSystemClass(CHECK_0);
1.3529 +
1.3530 + // get the Java runtime name after java.lang.System is initialized
1.3531 + JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
1.3532 + JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
1.3533 +
1.3534 + // an instance of OutOfMemory exception has been allocated earlier
1.3535 + initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK_0);
1.3536 + initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK_0);
1.3537 + initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK_0);
1.3538 + initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK_0);
1.3539 + initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK_0);
1.3540 + initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK_0);
1.3541 + initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK_0);
1.3542 + initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK_0);
1.3543 + }
1.3544 +
1.3545 + // See : bugid 4211085.
1.3546 + // Background : the static initializer of java.lang.Compiler tries to read
1.3547 + // property"java.compiler" and read & write property "java.vm.info".
1.3548 + // When a security manager is installed through the command line
1.3549 + // option "-Djava.security.manager", the above properties are not
1.3550 + // readable and the static initializer for java.lang.Compiler fails
1.3551 + // resulting in a NoClassDefFoundError. This can happen in any
1.3552 + // user code which calls methods in java.lang.Compiler.
1.3553 + // Hack : the hack is to pre-load and initialize this class, so that only
1.3554 + // system domains are on the stack when the properties are read.
1.3555 + // Currently even the AWT code has calls to methods in java.lang.Compiler.
1.3556 + // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
1.3557 + // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
1.3558 + // read and write"java.vm.info" in the default policy file. See bugid 4211383
1.3559 + // Once that is done, we should remove this hack.
1.3560 + initialize_class(vmSymbols::java_lang_Compiler(), CHECK_0);
1.3561 +
1.3562 + // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
1.3563 + // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
1.3564 + // compiler does not get loaded through java.lang.Compiler). "java -version" with the
1.3565 + // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
1.3566 + // This should also be taken out as soon as 4211383 gets fixed.
1.3567 + reset_vm_info_property(CHECK_0);
1.3568 +
1.3569 + quicken_jni_functions();
1.3570 +
1.3571 + // Must be run after init_ft which initializes ft_enabled
1.3572 + if (TRACE_INITIALIZE() != JNI_OK) {
1.3573 + vm_exit_during_initialization("Failed to initialize tracing backend");
1.3574 + }
1.3575 +
1.3576 + // Set flag that basic initialization has completed. Used by exceptions and various
1.3577 + // debug stuff, that does not work until all basic classes have been initialized.
1.3578 + set_init_completed();
1.3579 +
1.3580 + Metaspace::post_initialize();
1.3581 +
1.3582 +#ifndef USDT2
1.3583 + HS_DTRACE_PROBE(hotspot, vm__init__end);
1.3584 +#else /* USDT2 */
1.3585 + HOTSPOT_VM_INIT_END();
1.3586 +#endif /* USDT2 */
1.3587 +
1.3588 + // record VM initialization completion time
1.3589 +#if INCLUDE_MANAGEMENT
1.3590 + Management::record_vm_init_completed();
1.3591 +#endif // INCLUDE_MANAGEMENT
1.3592 +
1.3593 + // Compute system loader. Note that this has to occur after set_init_completed, since
1.3594 + // valid exceptions may be thrown in the process.
1.3595 + // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
1.3596 + // set_init_completed has just been called, causing exceptions not to be shortcut
1.3597 + // anymore. We call vm_exit_during_initialization directly instead.
1.3598 + SystemDictionary::compute_java_system_loader(THREAD);
1.3599 + if (HAS_PENDING_EXCEPTION) {
1.3600 + vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
1.3601 + }
1.3602 +
1.3603 +#if INCLUDE_ALL_GCS
1.3604 + // Support for ConcurrentMarkSweep. This should be cleaned up
1.3605 + // and better encapsulated. The ugly nested if test would go away
1.3606 + // once things are properly refactored. XXX YSR
1.3607 + if (UseConcMarkSweepGC || UseG1GC) {
1.3608 + if (UseConcMarkSweepGC) {
1.3609 + ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
1.3610 + } else {
1.3611 + ConcurrentMarkThread::makeSurrogateLockerThread(THREAD);
1.3612 + }
1.3613 + if (HAS_PENDING_EXCEPTION) {
1.3614 + vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
1.3615 + }
1.3616 + }
1.3617 +#endif // INCLUDE_ALL_GCS
1.3618 +
1.3619 + // Always call even when there are not JVMTI environments yet, since environments
1.3620 + // may be attached late and JVMTI must track phases of VM execution
1.3621 + JvmtiExport::enter_live_phase();
1.3622 +
1.3623 + // Signal Dispatcher needs to be started before VMInit event is posted
1.3624 + os::signal_init();
1.3625 +
1.3626 + // Start Attach Listener if +StartAttachListener or it can't be started lazily
1.3627 + if (!DisableAttachMechanism) {
1.3628 + AttachListener::vm_start();
1.3629 + if (StartAttachListener || AttachListener::init_at_startup()) {
1.3630 + AttachListener::init();
1.3631 + }
1.3632 + }
1.3633 +
1.3634 + // Launch -Xrun agents
1.3635 + // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
1.3636 + // back-end can launch with -Xdebug -Xrunjdwp.
1.3637 + if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
1.3638 + create_vm_init_libraries();
1.3639 + }
1.3640 +
1.3641 + // Notify JVMTI agents that VM initialization is complete - nop if no agents.
1.3642 + JvmtiExport::post_vm_initialized();
1.3643 +
1.3644 + if (TRACE_START() != JNI_OK) {
1.3645 + vm_exit_during_initialization("Failed to start tracing backend.");
1.3646 + }
1.3647 +
1.3648 + if (CleanChunkPoolAsync) {
1.3649 + Chunk::start_chunk_pool_cleaner_task();
1.3650 + }
1.3651 +
1.3652 + // initialize compiler(s)
1.3653 +#if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK)
1.3654 + CompileBroker::compilation_init();
1.3655 +#endif
1.3656 +
1.3657 + if (EnableInvokeDynamic) {
1.3658 + // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
1.3659 + // It is done after compilers are initialized, because otherwise compilations of
1.3660 + // signature polymorphic MH intrinsics can be missed
1.3661 + // (see SystemDictionary::find_method_handle_intrinsic).
1.3662 + initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK_0);
1.3663 + initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK_0);
1.3664 + initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK_0);
1.3665 + }
1.3666 +
1.3667 +#if INCLUDE_MANAGEMENT
1.3668 + Management::initialize(THREAD);
1.3669 +#endif // INCLUDE_MANAGEMENT
1.3670 +
1.3671 + if (HAS_PENDING_EXCEPTION) {
1.3672 + // management agent fails to start possibly due to
1.3673 + // configuration problem and is responsible for printing
1.3674 + // stack trace if appropriate. Simply exit VM.
1.3675 + vm_exit(1);
1.3676 + }
1.3677 +
1.3678 + if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
1.3679 + if (MemProfiling) MemProfiler::engage();
1.3680 + StatSampler::engage();
1.3681 + if (CheckJNICalls) JniPeriodicChecker::engage();
1.3682 +
1.3683 + BiasedLocking::init();
1.3684 +
1.3685 +#if INCLUDE_RTM_OPT
1.3686 + RTMLockingCounters::init();
1.3687 +#endif
1.3688 +
1.3689 + if (JDK_Version::current().post_vm_init_hook_enabled()) {
1.3690 + call_postVMInitHook(THREAD);
1.3691 + // The Java side of PostVMInitHook.run must deal with all
1.3692 + // exceptions and provide means of diagnosis.
1.3693 + if (HAS_PENDING_EXCEPTION) {
1.3694 + CLEAR_PENDING_EXCEPTION;
1.3695 + }
1.3696 + }
1.3697 +
1.3698 + {
1.3699 + MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
1.3700 + // Make sure the watcher thread can be started by WatcherThread::start()
1.3701 + // or by dynamic enrollment.
1.3702 + WatcherThread::make_startable();
1.3703 + // Start up the WatcherThread if there are any periodic tasks
1.3704 + // NOTE: All PeriodicTasks should be registered by now. If they
1.3705 + // aren't, late joiners might appear to start slowly (we might
1.3706 + // take a while to process their first tick).
1.3707 + if (PeriodicTask::num_tasks() > 0) {
1.3708 + WatcherThread::start();
1.3709 + }
1.3710 + }
1.3711 +
1.3712 + // Give os specific code one last chance to start
1.3713 + os::init_3();
1.3714 +
1.3715 + create_vm_timer.end();
1.3716 +#ifdef ASSERT
1.3717 + _vm_complete = true;
1.3718 +#endif
1.3719 + return JNI_OK;
1.3720 +}
1.3721 +
1.3722 +// type for the Agent_OnLoad and JVM_OnLoad entry points
1.3723 +extern "C" {
1.3724 + typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
1.3725 +}
1.3726 +// Find a command line agent library and return its entry point for
1.3727 +// -agentlib: -agentpath: -Xrun
1.3728 +// num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
1.3729 +static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, const char *on_load_symbols[], size_t num_symbol_entries) {
1.3730 + OnLoadEntry_t on_load_entry = NULL;
1.3731 + void *library = NULL;
1.3732 +
1.3733 + if (!agent->valid()) {
1.3734 + char buffer[JVM_MAXPATHLEN];
1.3735 + char ebuf[1024];
1.3736 + const char *name = agent->name();
1.3737 + const char *msg = "Could not find agent library ";
1.3738 +
1.3739 + // First check to see if agent is statically linked into executable
1.3740 + if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
1.3741 + library = agent->os_lib();
1.3742 + } else if (agent->is_absolute_path()) {
1.3743 + library = os::dll_load(name, ebuf, sizeof ebuf);
1.3744 + if (library == NULL) {
1.3745 + const char *sub_msg = " in absolute path, with error: ";
1.3746 + size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
1.3747 + char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
1.3748 + jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
1.3749 + // If we can't find the agent, exit.
1.3750 + vm_exit_during_initialization(buf, NULL);
1.3751 + FREE_C_HEAP_ARRAY(char, buf, mtThread);
1.3752 + }
1.3753 + } else {
1.3754 + // Try to load the agent from the standard dll directory
1.3755 + if (os::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
1.3756 + name)) {
1.3757 + library = os::dll_load(buffer, ebuf, sizeof ebuf);
1.3758 + }
1.3759 + if (library == NULL) { // Try the local directory
1.3760 + char ns[1] = {0};
1.3761 + if (os::dll_build_name(buffer, sizeof(buffer), ns, name)) {
1.3762 + library = os::dll_load(buffer, ebuf, sizeof ebuf);
1.3763 + }
1.3764 + if (library == NULL) {
1.3765 + const char *sub_msg = " on the library path, with error: ";
1.3766 + size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
1.3767 + char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
1.3768 + jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
1.3769 + // If we can't find the agent, exit.
1.3770 + vm_exit_during_initialization(buf, NULL);
1.3771 + FREE_C_HEAP_ARRAY(char, buf, mtThread);
1.3772 + }
1.3773 + }
1.3774 + }
1.3775 + agent->set_os_lib(library);
1.3776 + agent->set_valid();
1.3777 + }
1.3778 +
1.3779 + // Find the OnLoad function.
1.3780 + on_load_entry =
1.3781 + CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
1.3782 + false,
1.3783 + on_load_symbols,
1.3784 + num_symbol_entries));
1.3785 + return on_load_entry;
1.3786 +}
1.3787 +
1.3788 +// Find the JVM_OnLoad entry point
1.3789 +static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
1.3790 + const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
1.3791 + return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
1.3792 +}
1.3793 +
1.3794 +// Find the Agent_OnLoad entry point
1.3795 +static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
1.3796 + const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
1.3797 + return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
1.3798 +}
1.3799 +
1.3800 +// For backwards compatibility with -Xrun
1.3801 +// Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
1.3802 +// treated like -agentpath:
1.3803 +// Must be called before agent libraries are created
1.3804 +void Threads::convert_vm_init_libraries_to_agents() {
1.3805 + AgentLibrary* agent;
1.3806 + AgentLibrary* next;
1.3807 +
1.3808 + for (agent = Arguments::libraries(); agent != NULL; agent = next) {
1.3809 + next = agent->next(); // cache the next agent now as this agent may get moved off this list
1.3810 + OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
1.3811 +
1.3812 + // If there is an JVM_OnLoad function it will get called later,
1.3813 + // otherwise see if there is an Agent_OnLoad
1.3814 + if (on_load_entry == NULL) {
1.3815 + on_load_entry = lookup_agent_on_load(agent);
1.3816 + if (on_load_entry != NULL) {
1.3817 + // switch it to the agent list -- so that Agent_OnLoad will be called,
1.3818 + // JVM_OnLoad won't be attempted and Agent_OnUnload will
1.3819 + Arguments::convert_library_to_agent(agent);
1.3820 + } else {
1.3821 + vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
1.3822 + }
1.3823 + }
1.3824 + }
1.3825 +}
1.3826 +
1.3827 +// Create agents for -agentlib: -agentpath: and converted -Xrun
1.3828 +// Invokes Agent_OnLoad
1.3829 +// Called very early -- before JavaThreads exist
1.3830 +void Threads::create_vm_init_agents() {
1.3831 + extern struct JavaVM_ main_vm;
1.3832 + AgentLibrary* agent;
1.3833 +
1.3834 + JvmtiExport::enter_onload_phase();
1.3835 +
1.3836 + for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
1.3837 + OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
1.3838 +
1.3839 + if (on_load_entry != NULL) {
1.3840 + // Invoke the Agent_OnLoad function
1.3841 + jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
1.3842 + if (err != JNI_OK) {
1.3843 + vm_exit_during_initialization("agent library failed to init", agent->name());
1.3844 + }
1.3845 + } else {
1.3846 + vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
1.3847 + }
1.3848 + }
1.3849 + JvmtiExport::enter_primordial_phase();
1.3850 +}
1.3851 +
1.3852 +extern "C" {
1.3853 + typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
1.3854 +}
1.3855 +
1.3856 +void Threads::shutdown_vm_agents() {
1.3857 + // Send any Agent_OnUnload notifications
1.3858 + const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
1.3859 + size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
1.3860 + extern struct JavaVM_ main_vm;
1.3861 + for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
1.3862 +
1.3863 + // Find the Agent_OnUnload function.
1.3864 + Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
1.3865 + os::find_agent_function(agent,
1.3866 + false,
1.3867 + on_unload_symbols,
1.3868 + num_symbol_entries));
1.3869 +
1.3870 + // Invoke the Agent_OnUnload function
1.3871 + if (unload_entry != NULL) {
1.3872 + JavaThread* thread = JavaThread::current();
1.3873 + ThreadToNativeFromVM ttn(thread);
1.3874 + HandleMark hm(thread);
1.3875 + (*unload_entry)(&main_vm);
1.3876 + }
1.3877 + }
1.3878 +}
1.3879 +
1.3880 +// Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
1.3881 +// Invokes JVM_OnLoad
1.3882 +void Threads::create_vm_init_libraries() {
1.3883 + extern struct JavaVM_ main_vm;
1.3884 + AgentLibrary* agent;
1.3885 +
1.3886 + for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
1.3887 + OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
1.3888 +
1.3889 + if (on_load_entry != NULL) {
1.3890 + // Invoke the JVM_OnLoad function
1.3891 + JavaThread* thread = JavaThread::current();
1.3892 + ThreadToNativeFromVM ttn(thread);
1.3893 + HandleMark hm(thread);
1.3894 + jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
1.3895 + if (err != JNI_OK) {
1.3896 + vm_exit_during_initialization("-Xrun library failed to init", agent->name());
1.3897 + }
1.3898 + } else {
1.3899 + vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
1.3900 + }
1.3901 + }
1.3902 +}
1.3903 +
1.3904 +// Last thread running calls java.lang.Shutdown.shutdown()
1.3905 +void JavaThread::invoke_shutdown_hooks() {
1.3906 + HandleMark hm(this);
1.3907 +
1.3908 + // We could get here with a pending exception, if so clear it now.
1.3909 + if (this->has_pending_exception()) {
1.3910 + this->clear_pending_exception();
1.3911 + }
1.3912 +
1.3913 + EXCEPTION_MARK;
1.3914 + Klass* k =
1.3915 + SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
1.3916 + THREAD);
1.3917 + if (k != NULL) {
1.3918 + // SystemDictionary::resolve_or_null will return null if there was
1.3919 + // an exception. If we cannot load the Shutdown class, just don't
1.3920 + // call Shutdown.shutdown() at all. This will mean the shutdown hooks
1.3921 + // and finalizers (if runFinalizersOnExit is set) won't be run.
1.3922 + // Note that if a shutdown hook was registered or runFinalizersOnExit
1.3923 + // was called, the Shutdown class would have already been loaded
1.3924 + // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
1.3925 + instanceKlassHandle shutdown_klass (THREAD, k);
1.3926 + JavaValue result(T_VOID);
1.3927 + JavaCalls::call_static(&result,
1.3928 + shutdown_klass,
1.3929 + vmSymbols::shutdown_method_name(),
1.3930 + vmSymbols::void_method_signature(),
1.3931 + THREAD);
1.3932 + }
1.3933 + CLEAR_PENDING_EXCEPTION;
1.3934 +}
1.3935 +
1.3936 +// Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
1.3937 +// the program falls off the end of main(). Another VM exit path is through
1.3938 +// vm_exit() when the program calls System.exit() to return a value or when
1.3939 +// there is a serious error in VM. The two shutdown paths are not exactly
1.3940 +// the same, but they share Shutdown.shutdown() at Java level and before_exit()
1.3941 +// and VM_Exit op at VM level.
1.3942 +//
1.3943 +// Shutdown sequence:
1.3944 +// + Shutdown native memory tracking if it is on
1.3945 +// + Wait until we are the last non-daemon thread to execute
1.3946 +// <-- every thing is still working at this moment -->
1.3947 +// + Call java.lang.Shutdown.shutdown(), which will invoke Java level
1.3948 +// shutdown hooks, run finalizers if finalization-on-exit
1.3949 +// + Call before_exit(), prepare for VM exit
1.3950 +// > run VM level shutdown hooks (they are registered through JVM_OnExit(),
1.3951 +// currently the only user of this mechanism is File.deleteOnExit())
1.3952 +// > stop flat profiler, StatSampler, watcher thread, CMS threads,
1.3953 +// post thread end and vm death events to JVMTI,
1.3954 +// stop signal thread
1.3955 +// + Call JavaThread::exit(), it will:
1.3956 +// > release JNI handle blocks, remove stack guard pages
1.3957 +// > remove this thread from Threads list
1.3958 +// <-- no more Java code from this thread after this point -->
1.3959 +// + Stop VM thread, it will bring the remaining VM to a safepoint and stop
1.3960 +// the compiler threads at safepoint
1.3961 +// <-- do not use anything that could get blocked by Safepoint -->
1.3962 +// + Disable tracing at JNI/JVM barriers
1.3963 +// + Set _vm_exited flag for threads that are still running native code
1.3964 +// + Delete this thread
1.3965 +// + Call exit_globals()
1.3966 +// > deletes tty
1.3967 +// > deletes PerfMemory resources
1.3968 +// + Return to caller
1.3969 +
1.3970 +bool Threads::destroy_vm() {
1.3971 + JavaThread* thread = JavaThread::current();
1.3972 +
1.3973 +#ifdef ASSERT
1.3974 + _vm_complete = false;
1.3975 +#endif
1.3976 + // Wait until we are the last non-daemon thread to execute
1.3977 + { MutexLocker nu(Threads_lock);
1.3978 + while (Threads::number_of_non_daemon_threads() > 1 )
1.3979 + // This wait should make safepoint checks, wait without a timeout,
1.3980 + // and wait as a suspend-equivalent condition.
1.3981 + //
1.3982 + // Note: If the FlatProfiler is running and this thread is waiting
1.3983 + // for another non-daemon thread to finish, then the FlatProfiler
1.3984 + // is waiting for the external suspend request on this thread to
1.3985 + // complete. wait_for_ext_suspend_completion() will eventually
1.3986 + // timeout, but that takes time. Making this wait a suspend-
1.3987 + // equivalent condition solves that timeout problem.
1.3988 + //
1.3989 + Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
1.3990 + Mutex::_as_suspend_equivalent_flag);
1.3991 + }
1.3992 +
1.3993 + // Hang forever on exit if we are reporting an error.
1.3994 + if (ShowMessageBoxOnError && is_error_reported()) {
1.3995 + os::infinite_sleep();
1.3996 + }
1.3997 + os::wait_for_keypress_at_exit();
1.3998 +
1.3999 + if (JDK_Version::is_jdk12x_version()) {
1.4000 + // We are the last thread running, so check if finalizers should be run.
1.4001 + // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
1.4002 + HandleMark rm(thread);
1.4003 + Universe::run_finalizers_on_exit();
1.4004 + } else {
1.4005 + // run Java level shutdown hooks
1.4006 + thread->invoke_shutdown_hooks();
1.4007 + }
1.4008 +
1.4009 + before_exit(thread);
1.4010 +
1.4011 + thread->exit(true);
1.4012 +
1.4013 + // Stop VM thread.
1.4014 + {
1.4015 + // 4945125 The vm thread comes to a safepoint during exit.
1.4016 + // GC vm_operations can get caught at the safepoint, and the
1.4017 + // heap is unparseable if they are caught. Grab the Heap_lock
1.4018 + // to prevent this. The GC vm_operations will not be able to
1.4019 + // queue until after the vm thread is dead. After this point,
1.4020 + // we'll never emerge out of the safepoint before the VM exits.
1.4021 +
1.4022 + MutexLocker ml(Heap_lock);
1.4023 +
1.4024 + VMThread::wait_for_vm_thread_exit();
1.4025 + assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1.4026 + VMThread::destroy();
1.4027 + }
1.4028 +
1.4029 + // clean up ideal graph printers
1.4030 +#if defined(COMPILER2) && !defined(PRODUCT)
1.4031 + IdealGraphPrinter::clean_up();
1.4032 +#endif
1.4033 +
1.4034 + // Now, all Java threads are gone except daemon threads. Daemon threads
1.4035 + // running Java code or in VM are stopped by the Safepoint. However,
1.4036 + // daemon threads executing native code are still running. But they
1.4037 + // will be stopped at native=>Java/VM barriers. Note that we can't
1.4038 + // simply kill or suspend them, as it is inherently deadlock-prone.
1.4039 +
1.4040 +#ifndef PRODUCT
1.4041 + // disable function tracing at JNI/JVM barriers
1.4042 + TraceJNICalls = false;
1.4043 + TraceJVMCalls = false;
1.4044 + TraceRuntimeCalls = false;
1.4045 +#endif
1.4046 +
1.4047 + VM_Exit::set_vm_exited();
1.4048 +
1.4049 + notify_vm_shutdown();
1.4050 +
1.4051 + delete thread;
1.4052 +
1.4053 + // exit_globals() will delete tty
1.4054 + exit_globals();
1.4055 +
1.4056 + return true;
1.4057 +}
1.4058 +
1.4059 +
1.4060 +jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1.4061 + if (version == JNI_VERSION_1_1) return JNI_TRUE;
1.4062 + return is_supported_jni_version(version);
1.4063 +}
1.4064 +
1.4065 +
1.4066 +jboolean Threads::is_supported_jni_version(jint version) {
1.4067 + if (version == JNI_VERSION_1_2) return JNI_TRUE;
1.4068 + if (version == JNI_VERSION_1_4) return JNI_TRUE;
1.4069 + if (version == JNI_VERSION_1_6) return JNI_TRUE;
1.4070 + if (version == JNI_VERSION_1_8) return JNI_TRUE;
1.4071 + return JNI_FALSE;
1.4072 +}
1.4073 +
1.4074 +
1.4075 +void Threads::add(JavaThread* p, bool force_daemon) {
1.4076 + // The threads lock must be owned at this point
1.4077 + assert_locked_or_safepoint(Threads_lock);
1.4078 +
1.4079 + // See the comment for this method in thread.hpp for its purpose and
1.4080 + // why it is called here.
1.4081 + p->initialize_queues();
1.4082 + p->set_next(_thread_list);
1.4083 + _thread_list = p;
1.4084 + _number_of_threads++;
1.4085 + oop threadObj = p->threadObj();
1.4086 + bool daemon = true;
1.4087 + // Bootstrapping problem: threadObj can be null for initial
1.4088 + // JavaThread (or for threads attached via JNI)
1.4089 + if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
1.4090 + _number_of_non_daemon_threads++;
1.4091 + daemon = false;
1.4092 + }
1.4093 +
1.4094 + p->set_safepoint_visible(true);
1.4095 +
1.4096 + ThreadService::add_thread(p, daemon);
1.4097 +
1.4098 + // Possible GC point.
1.4099 + Events::log(p, "Thread added: " INTPTR_FORMAT, p);
1.4100 +}
1.4101 +
1.4102 +void Threads::remove(JavaThread* p) {
1.4103 + // Extra scope needed for Thread_lock, so we can check
1.4104 + // that we do not remove thread without safepoint code notice
1.4105 + { MutexLocker ml(Threads_lock);
1.4106 +
1.4107 + assert(includes(p), "p must be present");
1.4108 +
1.4109 + JavaThread* current = _thread_list;
1.4110 + JavaThread* prev = NULL;
1.4111 +
1.4112 + while (current != p) {
1.4113 + prev = current;
1.4114 + current = current->next();
1.4115 + }
1.4116 +
1.4117 + if (prev) {
1.4118 + prev->set_next(current->next());
1.4119 + } else {
1.4120 + _thread_list = p->next();
1.4121 + }
1.4122 + _number_of_threads--;
1.4123 + oop threadObj = p->threadObj();
1.4124 + bool daemon = true;
1.4125 + if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
1.4126 + _number_of_non_daemon_threads--;
1.4127 + daemon = false;
1.4128 +
1.4129 + // Only one thread left, do a notify on the Threads_lock so a thread waiting
1.4130 + // on destroy_vm will wake up.
1.4131 + if (number_of_non_daemon_threads() == 1)
1.4132 + Threads_lock->notify_all();
1.4133 + }
1.4134 + ThreadService::remove_thread(p, daemon);
1.4135 +
1.4136 + // Make sure that safepoint code disregard this thread. This is needed since
1.4137 + // the thread might mess around with locks after this point. This can cause it
1.4138 + // to do callbacks into the safepoint code. However, the safepoint code is not aware
1.4139 + // of this thread since it is removed from the queue.
1.4140 + p->set_terminated_value();
1.4141 +
1.4142 + // Now, this thread is not visible to safepoint
1.4143 + p->set_safepoint_visible(false);
1.4144 + // once the thread becomes safepoint invisible, we can not use its per-thread
1.4145 + // recorder. And Threads::do_threads() no longer walks this thread, so we have
1.4146 + // to release its per-thread recorder here.
1.4147 + MemTracker::thread_exiting(p);
1.4148 + } // unlock Threads_lock
1.4149 +
1.4150 + // Since Events::log uses a lock, we grab it outside the Threads_lock
1.4151 + Events::log(p, "Thread exited: " INTPTR_FORMAT, p);
1.4152 +}
1.4153 +
1.4154 +// Threads_lock must be held when this is called (or must be called during a safepoint)
1.4155 +bool Threads::includes(JavaThread* p) {
1.4156 + assert(Threads_lock->is_locked(), "sanity check");
1.4157 + ALL_JAVA_THREADS(q) {
1.4158 + if (q == p ) {
1.4159 + return true;
1.4160 + }
1.4161 + }
1.4162 + return false;
1.4163 +}
1.4164 +
1.4165 +// Operations on the Threads list for GC. These are not explicitly locked,
1.4166 +// but the garbage collector must provide a safe context for them to run.
1.4167 +// In particular, these things should never be called when the Threads_lock
1.4168 +// is held by some other thread. (Note: the Safepoint abstraction also
1.4169 +// uses the Threads_lock to gurantee this property. It also makes sure that
1.4170 +// all threads gets blocked when exiting or starting).
1.4171 +
1.4172 +void Threads::oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
1.4173 + ALL_JAVA_THREADS(p) {
1.4174 + p->oops_do(f, cld_f, cf);
1.4175 + }
1.4176 + VMThread::vm_thread()->oops_do(f, cld_f, cf);
1.4177 +}
1.4178 +
1.4179 +void Threads::possibly_parallel_oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf) {
1.4180 + // Introduce a mechanism allowing parallel threads to claim threads as
1.4181 + // root groups. Overhead should be small enough to use all the time,
1.4182 + // even in sequential code.
1.4183 + SharedHeap* sh = SharedHeap::heap();
1.4184 + // Cannot yet substitute active_workers for n_par_threads
1.4185 + // because of G1CollectedHeap::verify() use of
1.4186 + // SharedHeap::process_strong_roots(). n_par_threads == 0 will
1.4187 + // turn off parallelism in process_strong_roots while active_workers
1.4188 + // is being used for parallelism elsewhere.
1.4189 + bool is_par = sh->n_par_threads() > 0;
1.4190 + assert(!is_par ||
1.4191 + (SharedHeap::heap()->n_par_threads() ==
1.4192 + SharedHeap::heap()->workers()->active_workers()), "Mismatch");
1.4193 + int cp = SharedHeap::heap()->strong_roots_parity();
1.4194 + ALL_JAVA_THREADS(p) {
1.4195 + if (p->claim_oops_do(is_par, cp)) {
1.4196 + p->oops_do(f, cld_f, cf);
1.4197 + }
1.4198 + }
1.4199 + VMThread* vmt = VMThread::vm_thread();
1.4200 + if (vmt->claim_oops_do(is_par, cp)) {
1.4201 + vmt->oops_do(f, cld_f, cf);
1.4202 + }
1.4203 +}
1.4204 +
1.4205 +#if INCLUDE_ALL_GCS
1.4206 +// Used by ParallelScavenge
1.4207 +void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
1.4208 + ALL_JAVA_THREADS(p) {
1.4209 + q->enqueue(new ThreadRootsTask(p));
1.4210 + }
1.4211 + q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
1.4212 +}
1.4213 +
1.4214 +// Used by Parallel Old
1.4215 +void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
1.4216 + ALL_JAVA_THREADS(p) {
1.4217 + q->enqueue(new ThreadRootsMarkingTask(p));
1.4218 + }
1.4219 + q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
1.4220 +}
1.4221 +#endif // INCLUDE_ALL_GCS
1.4222 +
1.4223 +void Threads::nmethods_do(CodeBlobClosure* cf) {
1.4224 + ALL_JAVA_THREADS(p) {
1.4225 + p->nmethods_do(cf);
1.4226 + }
1.4227 + VMThread::vm_thread()->nmethods_do(cf);
1.4228 +}
1.4229 +
1.4230 +void Threads::metadata_do(void f(Metadata*)) {
1.4231 + ALL_JAVA_THREADS(p) {
1.4232 + p->metadata_do(f);
1.4233 + }
1.4234 +}
1.4235 +
1.4236 +void Threads::gc_epilogue() {
1.4237 + ALL_JAVA_THREADS(p) {
1.4238 + p->gc_epilogue();
1.4239 + }
1.4240 +}
1.4241 +
1.4242 +void Threads::gc_prologue() {
1.4243 + ALL_JAVA_THREADS(p) {
1.4244 + p->gc_prologue();
1.4245 + }
1.4246 +}
1.4247 +
1.4248 +void Threads::deoptimized_wrt_marked_nmethods() {
1.4249 + ALL_JAVA_THREADS(p) {
1.4250 + p->deoptimized_wrt_marked_nmethods();
1.4251 + }
1.4252 +}
1.4253 +
1.4254 +
1.4255 +// Get count Java threads that are waiting to enter the specified monitor.
1.4256 +GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
1.4257 + address monitor, bool doLock) {
1.4258 + assert(doLock || SafepointSynchronize::is_at_safepoint(),
1.4259 + "must grab Threads_lock or be at safepoint");
1.4260 + GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1.4261 +
1.4262 + int i = 0;
1.4263 + {
1.4264 + MutexLockerEx ml(doLock ? Threads_lock : NULL);
1.4265 + ALL_JAVA_THREADS(p) {
1.4266 + if (p->is_Compiler_thread()) continue;
1.4267 +
1.4268 + address pending = (address)p->current_pending_monitor();
1.4269 + if (pending == monitor) { // found a match
1.4270 + if (i < count) result->append(p); // save the first count matches
1.4271 + i++;
1.4272 + }
1.4273 + }
1.4274 + }
1.4275 + return result;
1.4276 +}
1.4277 +
1.4278 +
1.4279 +JavaThread *Threads::owning_thread_from_monitor_owner(address owner, bool doLock) {
1.4280 + assert(doLock ||
1.4281 + Threads_lock->owned_by_self() ||
1.4282 + SafepointSynchronize::is_at_safepoint(),
1.4283 + "must grab Threads_lock or be at safepoint");
1.4284 +
1.4285 + // NULL owner means not locked so we can skip the search
1.4286 + if (owner == NULL) return NULL;
1.4287 +
1.4288 + {
1.4289 + MutexLockerEx ml(doLock ? Threads_lock : NULL);
1.4290 + ALL_JAVA_THREADS(p) {
1.4291 + // first, see if owner is the address of a Java thread
1.4292 + if (owner == (address)p) return p;
1.4293 + }
1.4294 + }
1.4295 + // Cannot assert on lack of success here since this function may be
1.4296 + // used by code that is trying to report useful problem information
1.4297 + // like deadlock detection.
1.4298 + if (UseHeavyMonitors) return NULL;
1.4299 +
1.4300 + //
1.4301 + // If we didn't find a matching Java thread and we didn't force use of
1.4302 + // heavyweight monitors, then the owner is the stack address of the
1.4303 + // Lock Word in the owning Java thread's stack.
1.4304 + //
1.4305 + JavaThread* the_owner = NULL;
1.4306 + {
1.4307 + MutexLockerEx ml(doLock ? Threads_lock : NULL);
1.4308 + ALL_JAVA_THREADS(q) {
1.4309 + if (q->is_lock_owned(owner)) {
1.4310 + the_owner = q;
1.4311 + break;
1.4312 + }
1.4313 + }
1.4314 + }
1.4315 + // cannot assert on lack of success here; see above comment
1.4316 + return the_owner;
1.4317 +}
1.4318 +
1.4319 +// Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1.4320 +void Threads::print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks) {
1.4321 + char buf[32];
1.4322 + st->print_cr("%s", os::local_time_string(buf, sizeof(buf)));
1.4323 +
1.4324 + st->print_cr("Full thread dump %s (%s %s):",
1.4325 + Abstract_VM_Version::vm_name(),
1.4326 + Abstract_VM_Version::vm_release(),
1.4327 + Abstract_VM_Version::vm_info_string()
1.4328 + );
1.4329 + st->cr();
1.4330 +
1.4331 +#if INCLUDE_ALL_GCS
1.4332 + // Dump concurrent locks
1.4333 + ConcurrentLocksDump concurrent_locks;
1.4334 + if (print_concurrent_locks) {
1.4335 + concurrent_locks.dump_at_safepoint();
1.4336 + }
1.4337 +#endif // INCLUDE_ALL_GCS
1.4338 +
1.4339 + ALL_JAVA_THREADS(p) {
1.4340 + ResourceMark rm;
1.4341 + p->print_on(st);
1.4342 + if (print_stacks) {
1.4343 + if (internal_format) {
1.4344 + p->trace_stack();
1.4345 + } else {
1.4346 + p->print_stack_on(st);
1.4347 + }
1.4348 + }
1.4349 + st->cr();
1.4350 +#if INCLUDE_ALL_GCS
1.4351 + if (print_concurrent_locks) {
1.4352 + concurrent_locks.print_locks_on(p, st);
1.4353 + }
1.4354 +#endif // INCLUDE_ALL_GCS
1.4355 + }
1.4356 +
1.4357 + VMThread::vm_thread()->print_on(st);
1.4358 + st->cr();
1.4359 + Universe::heap()->print_gc_threads_on(st);
1.4360 + WatcherThread* wt = WatcherThread::watcher_thread();
1.4361 + if (wt != NULL) {
1.4362 + wt->print_on(st);
1.4363 + st->cr();
1.4364 + }
1.4365 + CompileBroker::print_compiler_threads_on(st);
1.4366 + st->flush();
1.4367 +}
1.4368 +
1.4369 +// Threads::print_on_error() is called by fatal error handler. It's possible
1.4370 +// that VM is not at safepoint and/or current thread is inside signal handler.
1.4371 +// Don't print stack trace, as the stack may not be walkable. Don't allocate
1.4372 +// memory (even in resource area), it might deadlock the error handler.
1.4373 +void Threads::print_on_error(outputStream* st, Thread* current, char* buf, int buflen) {
1.4374 + bool found_current = false;
1.4375 + st->print_cr("Java Threads: ( => current thread )");
1.4376 + ALL_JAVA_THREADS(thread) {
1.4377 + bool is_current = (current == thread);
1.4378 + found_current = found_current || is_current;
1.4379 +
1.4380 + st->print("%s", is_current ? "=>" : " ");
1.4381 +
1.4382 + st->print(PTR_FORMAT, thread);
1.4383 + st->print(" ");
1.4384 + thread->print_on_error(st, buf, buflen);
1.4385 + st->cr();
1.4386 + }
1.4387 + st->cr();
1.4388 +
1.4389 + st->print_cr("Other Threads:");
1.4390 + if (VMThread::vm_thread()) {
1.4391 + bool is_current = (current == VMThread::vm_thread());
1.4392 + found_current = found_current || is_current;
1.4393 + st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
1.4394 +
1.4395 + st->print(PTR_FORMAT, VMThread::vm_thread());
1.4396 + st->print(" ");
1.4397 + VMThread::vm_thread()->print_on_error(st, buf, buflen);
1.4398 + st->cr();
1.4399 + }
1.4400 + WatcherThread* wt = WatcherThread::watcher_thread();
1.4401 + if (wt != NULL) {
1.4402 + bool is_current = (current == wt);
1.4403 + found_current = found_current || is_current;
1.4404 + st->print("%s", is_current ? "=>" : " ");
1.4405 +
1.4406 + st->print(PTR_FORMAT, wt);
1.4407 + st->print(" ");
1.4408 + wt->print_on_error(st, buf, buflen);
1.4409 + st->cr();
1.4410 + }
1.4411 + if (!found_current) {
1.4412 + st->cr();
1.4413 + st->print("=>" PTR_FORMAT " (exited) ", current);
1.4414 + current->print_on_error(st, buf, buflen);
1.4415 + st->cr();
1.4416 + }
1.4417 +}
1.4418 +
1.4419 +// Internal SpinLock and Mutex
1.4420 +// Based on ParkEvent
1.4421 +
1.4422 +// Ad-hoc mutual exclusion primitives: SpinLock and Mux
1.4423 +//
1.4424 +// We employ SpinLocks _only for low-contention, fixed-length
1.4425 +// short-duration critical sections where we're concerned
1.4426 +// about native mutex_t or HotSpot Mutex:: latency.
1.4427 +// The mux construct provides a spin-then-block mutual exclusion
1.4428 +// mechanism.
1.4429 +//
1.4430 +// Testing has shown that contention on the ListLock guarding gFreeList
1.4431 +// is common. If we implement ListLock as a simple SpinLock it's common
1.4432 +// for the JVM to devolve to yielding with little progress. This is true
1.4433 +// despite the fact that the critical sections protected by ListLock are
1.4434 +// extremely short.
1.4435 +//
1.4436 +// TODO-FIXME: ListLock should be of type SpinLock.
1.4437 +// We should make this a 1st-class type, integrated into the lock
1.4438 +// hierarchy as leaf-locks. Critically, the SpinLock structure
1.4439 +// should have sufficient padding to avoid false-sharing and excessive
1.4440 +// cache-coherency traffic.
1.4441 +
1.4442 +
1.4443 +typedef volatile int SpinLockT ;
1.4444 +
1.4445 +void Thread::SpinAcquire (volatile int * adr, const char * LockName) {
1.4446 + if (Atomic::cmpxchg (1, adr, 0) == 0) {
1.4447 + return ; // normal fast-path return
1.4448 + }
1.4449 +
1.4450 + // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
1.4451 + TEVENT (SpinAcquire - ctx) ;
1.4452 + int ctr = 0 ;
1.4453 + int Yields = 0 ;
1.4454 + for (;;) {
1.4455 + while (*adr != 0) {
1.4456 + ++ctr ;
1.4457 + if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
1.4458 + if (Yields > 5) {
1.4459 + os::naked_short_sleep(1);
1.4460 + } else {
1.4461 + os::NakedYield() ;
1.4462 + ++Yields ;
1.4463 + }
1.4464 + } else {
1.4465 + SpinPause() ;
1.4466 + }
1.4467 + }
1.4468 + if (Atomic::cmpxchg (1, adr, 0) == 0) return ;
1.4469 + }
1.4470 +}
1.4471 +
1.4472 +void Thread::SpinRelease (volatile int * adr) {
1.4473 + assert (*adr != 0, "invariant") ;
1.4474 + OrderAccess::fence() ; // guarantee at least release consistency.
1.4475 + // Roach-motel semantics.
1.4476 + // It's safe if subsequent LDs and STs float "up" into the critical section,
1.4477 + // but prior LDs and STs within the critical section can't be allowed
1.4478 + // to reorder or float past the ST that releases the lock.
1.4479 + *adr = 0 ;
1.4480 +}
1.4481 +
1.4482 +// muxAcquire and muxRelease:
1.4483 +//
1.4484 +// * muxAcquire and muxRelease support a single-word lock-word construct.
1.4485 +// The LSB of the word is set IFF the lock is held.
1.4486 +// The remainder of the word points to the head of a singly-linked list
1.4487 +// of threads blocked on the lock.
1.4488 +//
1.4489 +// * The current implementation of muxAcquire-muxRelease uses its own
1.4490 +// dedicated Thread._MuxEvent instance. If we're interested in
1.4491 +// minimizing the peak number of extant ParkEvent instances then
1.4492 +// we could eliminate _MuxEvent and "borrow" _ParkEvent as long
1.4493 +// as certain invariants were satisfied. Specifically, care would need
1.4494 +// to be taken with regards to consuming unpark() "permits".
1.4495 +// A safe rule of thumb is that a thread would never call muxAcquire()
1.4496 +// if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
1.4497 +// park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
1.4498 +// consume an unpark() permit intended for monitorenter, for instance.
1.4499 +// One way around this would be to widen the restricted-range semaphore
1.4500 +// implemented in park(). Another alternative would be to provide
1.4501 +// multiple instances of the PlatformEvent() for each thread. One
1.4502 +// instance would be dedicated to muxAcquire-muxRelease, for instance.
1.4503 +//
1.4504 +// * Usage:
1.4505 +// -- Only as leaf locks
1.4506 +// -- for short-term locking only as muxAcquire does not perform
1.4507 +// thread state transitions.
1.4508 +//
1.4509 +// Alternatives:
1.4510 +// * We could implement muxAcquire and muxRelease with MCS or CLH locks
1.4511 +// but with parking or spin-then-park instead of pure spinning.
1.4512 +// * Use Taura-Oyama-Yonenzawa locks.
1.4513 +// * It's possible to construct a 1-0 lock if we encode the lockword as
1.4514 +// (List,LockByte). Acquire will CAS the full lockword while Release
1.4515 +// will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
1.4516 +// acquiring threads use timers (ParkTimed) to detect and recover from
1.4517 +// the stranding window. Thread/Node structures must be aligned on 256-byte
1.4518 +// boundaries by using placement-new.
1.4519 +// * Augment MCS with advisory back-link fields maintained with CAS().
1.4520 +// Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
1.4521 +// The validity of the backlinks must be ratified before we trust the value.
1.4522 +// If the backlinks are invalid the exiting thread must back-track through the
1.4523 +// the forward links, which are always trustworthy.
1.4524 +// * Add a successor indication. The LockWord is currently encoded as
1.4525 +// (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
1.4526 +// to provide the usual futile-wakeup optimization.
1.4527 +// See RTStt for details.
1.4528 +// * Consider schedctl.sc_nopreempt to cover the critical section.
1.4529 +//
1.4530 +
1.4531 +
1.4532 +typedef volatile intptr_t MutexT ; // Mux Lock-word
1.4533 +enum MuxBits { LOCKBIT = 1 } ;
1.4534 +
1.4535 +void Thread::muxAcquire (volatile intptr_t * Lock, const char * LockName) {
1.4536 + intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
1.4537 + if (w == 0) return ;
1.4538 + if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4539 + return ;
1.4540 + }
1.4541 +
1.4542 + TEVENT (muxAcquire - Contention) ;
1.4543 + ParkEvent * const Self = Thread::current()->_MuxEvent ;
1.4544 + assert ((intptr_t(Self) & LOCKBIT) == 0, "invariant") ;
1.4545 + for (;;) {
1.4546 + int its = (os::is_MP() ? 100 : 0) + 1 ;
1.4547 +
1.4548 + // Optional spin phase: spin-then-park strategy
1.4549 + while (--its >= 0) {
1.4550 + w = *Lock ;
1.4551 + if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4552 + return ;
1.4553 + }
1.4554 + }
1.4555 +
1.4556 + Self->reset() ;
1.4557 + Self->OnList = intptr_t(Lock) ;
1.4558 + // The following fence() isn't _strictly necessary as the subsequent
1.4559 + // CAS() both serializes execution and ratifies the fetched *Lock value.
1.4560 + OrderAccess::fence();
1.4561 + for (;;) {
1.4562 + w = *Lock ;
1.4563 + if ((w & LOCKBIT) == 0) {
1.4564 + if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4565 + Self->OnList = 0 ; // hygiene - allows stronger asserts
1.4566 + return ;
1.4567 + }
1.4568 + continue ; // Interference -- *Lock changed -- Just retry
1.4569 + }
1.4570 + assert (w & LOCKBIT, "invariant") ;
1.4571 + Self->ListNext = (ParkEvent *) (w & ~LOCKBIT );
1.4572 + if (Atomic::cmpxchg_ptr (intptr_t(Self)|LOCKBIT, Lock, w) == w) break ;
1.4573 + }
1.4574 +
1.4575 + while (Self->OnList != 0) {
1.4576 + Self->park() ;
1.4577 + }
1.4578 + }
1.4579 +}
1.4580 +
1.4581 +void Thread::muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) {
1.4582 + intptr_t w = Atomic::cmpxchg_ptr (LOCKBIT, Lock, 0) ;
1.4583 + if (w == 0) return ;
1.4584 + if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4585 + return ;
1.4586 + }
1.4587 +
1.4588 + TEVENT (muxAcquire - Contention) ;
1.4589 + ParkEvent * ReleaseAfter = NULL ;
1.4590 + if (ev == NULL) {
1.4591 + ev = ReleaseAfter = ParkEvent::Allocate (NULL) ;
1.4592 + }
1.4593 + assert ((intptr_t(ev) & LOCKBIT) == 0, "invariant") ;
1.4594 + for (;;) {
1.4595 + guarantee (ev->OnList == 0, "invariant") ;
1.4596 + int its = (os::is_MP() ? 100 : 0) + 1 ;
1.4597 +
1.4598 + // Optional spin phase: spin-then-park strategy
1.4599 + while (--its >= 0) {
1.4600 + w = *Lock ;
1.4601 + if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4602 + if (ReleaseAfter != NULL) {
1.4603 + ParkEvent::Release (ReleaseAfter) ;
1.4604 + }
1.4605 + return ;
1.4606 + }
1.4607 + }
1.4608 +
1.4609 + ev->reset() ;
1.4610 + ev->OnList = intptr_t(Lock) ;
1.4611 + // The following fence() isn't _strictly necessary as the subsequent
1.4612 + // CAS() both serializes execution and ratifies the fetched *Lock value.
1.4613 + OrderAccess::fence();
1.4614 + for (;;) {
1.4615 + w = *Lock ;
1.4616 + if ((w & LOCKBIT) == 0) {
1.4617 + if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
1.4618 + ev->OnList = 0 ;
1.4619 + // We call ::Release while holding the outer lock, thus
1.4620 + // artificially lengthening the critical section.
1.4621 + // Consider deferring the ::Release() until the subsequent unlock(),
1.4622 + // after we've dropped the outer lock.
1.4623 + if (ReleaseAfter != NULL) {
1.4624 + ParkEvent::Release (ReleaseAfter) ;
1.4625 + }
1.4626 + return ;
1.4627 + }
1.4628 + continue ; // Interference -- *Lock changed -- Just retry
1.4629 + }
1.4630 + assert (w & LOCKBIT, "invariant") ;
1.4631 + ev->ListNext = (ParkEvent *) (w & ~LOCKBIT );
1.4632 + if (Atomic::cmpxchg_ptr (intptr_t(ev)|LOCKBIT, Lock, w) == w) break ;
1.4633 + }
1.4634 +
1.4635 + while (ev->OnList != 0) {
1.4636 + ev->park() ;
1.4637 + }
1.4638 + }
1.4639 +}
1.4640 +
1.4641 +// Release() must extract a successor from the list and then wake that thread.
1.4642 +// It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
1.4643 +// similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
1.4644 +// Release() would :
1.4645 +// (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
1.4646 +// (B) Extract a successor from the private list "in-hand"
1.4647 +// (C) attempt to CAS() the residual back into *Lock over null.
1.4648 +// If there were any newly arrived threads and the CAS() would fail.
1.4649 +// In that case Release() would detach the RATs, re-merge the list in-hand
1.4650 +// with the RATs and repeat as needed. Alternately, Release() might
1.4651 +// detach and extract a successor, but then pass the residual list to the wakee.
1.4652 +// The wakee would be responsible for reattaching and remerging before it
1.4653 +// competed for the lock.
1.4654 +//
1.4655 +// Both "pop" and DMR are immune from ABA corruption -- there can be
1.4656 +// multiple concurrent pushers, but only one popper or detacher.
1.4657 +// This implementation pops from the head of the list. This is unfair,
1.4658 +// but tends to provide excellent throughput as hot threads remain hot.
1.4659 +// (We wake recently run threads first).
1.4660 +
1.4661 +void Thread::muxRelease (volatile intptr_t * Lock) {
1.4662 + for (;;) {
1.4663 + const intptr_t w = Atomic::cmpxchg_ptr (0, Lock, LOCKBIT) ;
1.4664 + assert (w & LOCKBIT, "invariant") ;
1.4665 + if (w == LOCKBIT) return ;
1.4666 + ParkEvent * List = (ParkEvent *) (w & ~LOCKBIT) ;
1.4667 + assert (List != NULL, "invariant") ;
1.4668 + assert (List->OnList == intptr_t(Lock), "invariant") ;
1.4669 + ParkEvent * nxt = List->ListNext ;
1.4670 +
1.4671 + // The following CAS() releases the lock and pops the head element.
1.4672 + if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
1.4673 + continue ;
1.4674 + }
1.4675 + List->OnList = 0 ;
1.4676 + OrderAccess::fence() ;
1.4677 + List->unpark () ;
1.4678 + return ;
1.4679 + }
1.4680 +}
1.4681 +
1.4682 +
1.4683 +void Threads::verify() {
1.4684 + ALL_JAVA_THREADS(p) {
1.4685 + p->verify();
1.4686 + }
1.4687 + VMThread* thread = VMThread::vm_thread();
1.4688 + if (thread != NULL) thread->verify();
1.4689 +}
