diff -r 000000000000 -r a61af66fc99e src/share/vm/runtime/thread.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/runtime/thread.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1757 @@ +/* + * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +class ThreadSafepointState; +class ThreadProfiler; + +class JvmtiThreadState; +class JvmtiGetLoadedClassesClosure; +class ThreadStatistics; +class ConcurrentLocksDump; +class ParkEvent ; + +class ciEnv; +class CompileThread; +class CompileLog; +class CompileTask; +class CompileQueue; +class CompilerCounters; +class vframeArray; + +class DeoptResourceMark; +class jvmtiDeferredLocalVariableSet; + +class GCTaskQueue; +class ThreadClosure; +class IdealGraphPrinter; + +// Class hierarchy +// - Thread +// - VMThread +// - JavaThread +// - WatcherThread + +class Thread: public ThreadShadow { + friend class VMStructs; + private: + // Exception handling + // (Note: _pending_exception and friends are in ThreadShadow) + //oop _pending_exception; // pending exception for current thread + // const char* _exception_file; // file information for exception (debugging only) + // int _exception_line; // line information for exception (debugging only) + + // Support for forcing alignment of thread objects for biased locking + void* _real_malloc_address; + public: + void* operator new(size_t size); + void operator delete(void* p); + private: + + // *************************************************************** + // Suspend and resume support + // *************************************************************** + // + // VM suspend/resume no longer exists - it was once used for various + // things including safepoints but was deprecated and finally removed + // in Java 7. Because VM suspension was considered "internal" Java-level + // suspension was considered "external", and this legacy naming scheme + // remains. + // + // External suspend/resume requests come from JVM_SuspendThread, + // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI + // ResumeThread. External + // suspend requests cause _external_suspend to be set and external + // resume requests cause _external_suspend to be cleared. + // External suspend requests do not nest on top of other external + // suspend requests. The higher level APIs reject suspend requests + // for already suspended threads. + // + // The external_suspend + // flag is checked by has_special_runtime_exit_condition() and java thread + // will self-suspend when handle_special_runtime_exit_condition() is + // called. Most uses of the _thread_blocked state in JavaThreads are + // considered the same as being externally suspended; if the blocking + // condition lifts, the JavaThread will self-suspend. Other places + // where VM checks for external_suspend include: + // + mutex granting (do not enter monitors when thread is suspended) + // + state transitions from _thread_in_native + // + // In general, java_suspend() does not wait for an external suspend + // request to complete. When it returns, the only guarantee is that + // the _external_suspend field is true. + // + // wait_for_ext_suspend_completion() is used to wait for an external + // suspend request to complete. External suspend requests are usually + // followed by some other interface call that requires the thread to + // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into + // the interface that requires quiescence, we give the JavaThread a + // chance to self-suspend before we need it to be quiescent. This + // improves overall suspend/query performance. + // + // _suspend_flags controls the behavior of java_ suspend/resume. + // It must be set under the protection of SR_lock. Read from the flag is + // OK without SR_lock as long as the value is only used as a hint. + // (e.g., check _external_suspend first without lock and then recheck + // inside SR_lock and finish the suspension) + // + // _suspend_flags is also overloaded for other "special conditions" so + // that a single check indicates whether any special action is needed + // eg. for async exceptions. + // ------------------------------------------------------------------- + // Notes: + // 1. The suspend/resume logic no longer uses ThreadState in OSThread + // but we still update its value to keep other part of the system (mainly + // JVMTI) happy. ThreadState is legacy code (see notes in + // osThread.hpp). + // + // 2. It would be more natural if set_external_suspend() is private and + // part of java_suspend(), but that probably would affect the suspend/query + // performance. Need more investigation on this. + // + + // suspend/resume lock: used for self-suspend + Monitor* _SR_lock; + + protected: + enum SuspendFlags { + // NOTE: avoid using the sign-bit as cc generates different test code + // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 + + _external_suspend = 0x20000000U, // thread is asked to self suspend + _ext_suspended = 0x40000000U, // thread has self-suspended + _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt + + _has_async_exception = 0x00000001U // there is a pending async exception + }; + + // various suspension related flags - atomically updated + // overloaded for async exception checking in check_special_condition_for_native_trans. + volatile uint32_t _suspend_flags; + + private: + int _num_nested_signal; + + public: + void enter_signal_handler() { _num_nested_signal++; } + void leave_signal_handler() { _num_nested_signal--; } + bool is_inside_signal_handler() const { return _num_nested_signal > 0; } + + private: + // Debug tracing + static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN; + + // Active_handles points to a block of handles + JNIHandleBlock* _active_handles; + + // One-element thread local free list + JNIHandleBlock* _free_handle_block; + + // Point to the last handle mark + HandleMark* _last_handle_mark; + + // The parity of the last strong_roots iteration in which this thread was + // claimed as a task. + jint _oops_do_parity; + + public: + void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; } + HandleMark* last_handle_mark() const { return _last_handle_mark; } + private: + + // debug support for checking if code does allow safepoints or not + // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on + // mutex, or blocking on an object synchronizer (Java locking). + // If !allow_safepoint(), then an assertion failure will happen in any of the above cases + // If !allow_allocation(), then an assertion failure will happen during allocation + // (Hence, !allow_safepoint() => !allow_allocation()). + // + // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters. + // + NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen + debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops. + + // Record when GC is locked out via the GC_locker mechanism + CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;) + + friend class No_Alloc_Verifier; + friend class No_Safepoint_Verifier; + friend class Pause_No_Safepoint_Verifier; + friend class ThreadLocalStorage; + friend class GC_locker; + + // In order for all threads to be able to use fast locking, we need to know the highest stack + // address of where a lock is on the stack (stacks normally grow towards lower addresses). This + // variable is initially set to NULL, indicating no locks are used by the thread. During the thread's + // execution, it will be set whenever locking can happen, i.e., when we call out to Java code or use + // an ObjectLocker. The value is never decreased, hence, it will over the lifetime of a thread + // approximate the real stackbase. + address _highest_lock; // Highest stack address where a JavaLock exist + + ThreadLocalAllocBuffer _tlab; // Thread-local eden + + int _vm_operation_started_count; // VM_Operation support + int _vm_operation_completed_count; // VM_Operation support + + ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread + // is waiting to lock + bool _current_pending_monitor_is_from_java; // locking is from Java code + + // ObjectMonitor on which this thread called Object.wait() + ObjectMonitor* _current_waiting_monitor; + + // Private thread-local objectmonitor list - a simple cache organized as a SLL. + public: + ObjectMonitor * omFreeList ; + int omFreeCount ; // length of omFreeList + int omFreeProvision ; // reload chunk size + + public: + enum { + is_definitely_current_thread = true + }; + + // Constructor + Thread(); + virtual ~Thread(); + + // initializtion + void initialize_thread_local_storage(); + + // thread entry point + virtual void run(); + + // Testers + virtual bool is_VM_thread() const { return false; } + virtual bool is_Java_thread() const { return false; } + // Remove this ifdef when C1 is ported to the compiler interface. + virtual bool is_Compiler_thread() const { return false; } + virtual bool is_hidden_from_external_view() const { return false; } + virtual bool is_jvmti_agent_thread() const { return false; } + // True iff the thread can perform GC operations at a safepoint. + // Generally will be true only of VM thread and parallel GC WorkGang + // threads. + virtual bool is_GC_task_thread() const { return false; } + virtual bool is_Watcher_thread() const { return false; } + virtual bool is_ConcurrentGC_thread() const { return false; } + + virtual char* name() const { return (char*)"Unknown thread"; } + + // Returns the current thread + static inline Thread* current(); + + // Common thread operations + static void set_priority(Thread* thread, ThreadPriority priority); + static ThreadPriority get_priority(const Thread* const thread); + static void start(Thread* thread); + static void interrupt(Thread* thr); + static bool is_interrupted(Thread* thr, bool clear_interrupted); + + Monitor* SR_lock() const { return _SR_lock; } + + bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; } + + void set_suspend_flag(SuspendFlags f) { + assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); + uint32_t flags; + do { + flags = _suspend_flags; + } + while (Atomic::cmpxchg((jint)(flags | f), + (volatile jint*)&_suspend_flags, + (jint)flags) != (jint)flags); + } + void clear_suspend_flag(SuspendFlags f) { + assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); + uint32_t flags; + do { + flags = _suspend_flags; + } + while (Atomic::cmpxchg((jint)(flags & ~f), + (volatile jint*)&_suspend_flags, + (jint)flags) != (jint)flags); + } + + void set_has_async_exception() { + set_suspend_flag(_has_async_exception); + } + void clear_has_async_exception() { + clear_suspend_flag(_has_async_exception); + } + + // Support for Unhandled Oop detection +#ifdef CHECK_UNHANDLED_OOPS + private: + UnhandledOops *_unhandled_oops; + public: + UnhandledOops* unhandled_oops() { return _unhandled_oops; } + // Mark oop safe for gc. It may be stack allocated but won't move. + void allow_unhandled_oop(oop *op) { + if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op); + } + // Clear oops at safepoint so crashes point to unhandled oop violator + void clear_unhandled_oops() { + if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops(); + } + bool is_gc_locked_out() { return _gc_locked_out_count > 0; } +#endif // CHECK_UNHANDLED_OOPS + + public: + // Installs a pending exception to be inserted later + static void send_async_exception(oop thread_oop, oop java_throwable); + + // Resource area + ResourceArea* resource_area() const { return _resource_area; } + void set_resource_area(ResourceArea* area) { _resource_area = area; } + + OSThread* osthread() const { return _osthread; } + void set_osthread(OSThread* thread) { _osthread = thread; } + + // JNI handle support + JNIHandleBlock* active_handles() const { return _active_handles; } + void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } + JNIHandleBlock* free_handle_block() const { return _free_handle_block; } + void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } + + // Internal handle support + HandleArea* handle_area() const { return _handle_area; } + void set_handle_area(HandleArea* area) { _handle_area = area; } + + // Thread-Local Allocation Buffer (TLAB) support + ThreadLocalAllocBuffer& tlab() { return _tlab; } + void initialize_tlab() { + if (UseTLAB) { + tlab().initialize(); + } + } + + // VM operation support + int vm_operation_ticket() { return ++_vm_operation_started_count; } + int vm_operation_completed_count() { return _vm_operation_completed_count; } + void increment_vm_operation_completed_count() { _vm_operation_completed_count++; } + + // For tracking the heavyweight monitor the thread is pending on. + ObjectMonitor* current_pending_monitor() { + return _current_pending_monitor; + } + void set_current_pending_monitor(ObjectMonitor* monitor) { + _current_pending_monitor = monitor; + } + void set_current_pending_monitor_is_from_java(bool from_java) { + _current_pending_monitor_is_from_java = from_java; + } + bool current_pending_monitor_is_from_java() { + return _current_pending_monitor_is_from_java; + } + + // For tracking the ObjectMonitor on which this thread called Object.wait() + ObjectMonitor* current_waiting_monitor() { + return _current_waiting_monitor; + } + void set_current_waiting_monitor(ObjectMonitor* monitor) { + _current_waiting_monitor = monitor; + } + + // GC support + // Apply "f->do_oop" to all root oops in "this". + void oops_do(OopClosure* f); + + // Handles the parallel case for the method below. +private: + bool claim_oops_do_par_case(int collection_parity); +public: + // Requires that "collection_parity" is that of the current strong roots + // iteration. If "is_par" is false, sets the parity of "this" to + // "collection_parity", and returns "true". If "is_par" is true, + // uses an atomic instruction to set the current threads parity to + // "collection_parity", if it is not already. Returns "true" iff the + // calling thread does the update, this indicates that the calling thread + // has claimed the thread's stack as a root groop in the current + // collection. + bool claim_oops_do(bool is_par, int collection_parity) { + if (!is_par) { + _oops_do_parity = collection_parity; + return true; + } else { + return claim_oops_do_par_case(collection_parity); + } + } + + // Sweeper support + void nmethods_do(); + + // Fast-locking support + address highest_lock() const { return _highest_lock; } + void update_highest_lock(address base) { if (base > _highest_lock) _highest_lock = base; } + + // Tells if adr belong to this thread. This is used + // for checking if a lock is owned by the running thread. + // Warning: the method can only be used on the running thread + // Fast lock support uses these methods + virtual bool lock_is_in_stack(address adr) const; + virtual bool is_lock_owned(address adr) const; + + // Check if address is in the stack of the thread (not just for locks). + bool is_in_stack(address adr) const; + + // Sets this thread as starting thread. Returns failure if thread + // creation fails due to lack of memory, too many threads etc. + bool set_as_starting_thread(); + + protected: + // OS data associated with the thread + OSThread* _osthread; // Platform-specific thread information + + // Thread local resource area for temporary allocation within the VM + ResourceArea* _resource_area; + + // Thread local handle area for allocation of handles within the VM + HandleArea* _handle_area; + + // Support for stack overflow handling, get_thread, etc. + address _stack_base; + size_t _stack_size; + uintptr_t _self_raw_id; // used by get_thread (mutable) + int _lgrp_id; + + public: + // Stack overflow support + address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; } + + void set_stack_base(address base) { _stack_base = base; } + size_t stack_size() const { return _stack_size; } + void set_stack_size(size_t size) { _stack_size = size; } + void record_stack_base_and_size(); + + int lgrp_id() const { return _lgrp_id; } + void set_lgrp_id(int value) { _lgrp_id = value; } + + // Printing + void print_on(outputStream* st) const; + void print() const { print_on(tty); } + virtual void print_on_error(outputStream* st, char* buf, int buflen) const; + + // Debug-only code + +#ifdef ASSERT + private: + // Deadlock detection support for Mutex locks. List of locks own by thread. + Monitor *_owned_locks; + // Mutex::set_owner_implementation is the only place where _owned_locks is modified, + // thus the friendship + friend class Mutex; + friend class Monitor; + + public: + void print_owned_locks_on(outputStream* st) const; + void print_owned_locks() const { print_owned_locks_on(tty); } + Monitor * owned_locks() const { return _owned_locks; } + bool owns_locks() const { return owned_locks() != NULL; } + bool owns_locks_but_compiled_lock() const; + + // Deadlock detection + bool allow_allocation() { return _allow_allocation_count == 0; } +#endif + + void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN; + + private: + volatile int _jvmti_env_iteration_count; + + public: + void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; } + void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; } + bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; } + + // Code generation + static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); } + static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); } + static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); } + + static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); } + static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); } + static ByteSize omFreeList_offset() { return byte_offset_of(Thread, omFreeList); } + +#define TLAB_FIELD_OFFSET(name) \ + static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); } + + TLAB_FIELD_OFFSET(start) + TLAB_FIELD_OFFSET(end) + TLAB_FIELD_OFFSET(top) + TLAB_FIELD_OFFSET(pf_top) + TLAB_FIELD_OFFSET(size) // desired_size + TLAB_FIELD_OFFSET(refill_waste_limit) + TLAB_FIELD_OFFSET(number_of_refills) + TLAB_FIELD_OFFSET(fast_refill_waste) + TLAB_FIELD_OFFSET(slow_allocations) + +#undef TLAB_FIELD_OFFSET + + public: + volatile intptr_t _Stalled ; + volatile int _TypeTag ; + ParkEvent * _ParkEvent ; // for synchronized() + ParkEvent * _SleepEvent ; // for Thread.sleep + ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor + ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease + int NativeSyncRecursion ; // diagnostic + + volatile int _OnTrap ; // Resume-at IP delta + jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG + jint _hashStateX ; // thread-specific hashCode generator state + jint _hashStateY ; + jint _hashStateZ ; + void * _schedctl ; + + intptr_t _ScratchA, _ScratchB ; // Scratch locations for fast-path sync code + static ByteSize ScratchA_offset() { return byte_offset_of(Thread, _ScratchA ); } + static ByteSize ScratchB_offset() { return byte_offset_of(Thread, _ScratchB ); } + + volatile jint rng [4] ; // RNG for spin loop + + // Low-level leaf-lock primitives used to implement synchronization + // and native monitor-mutex infrastructure. + // Not for general synchronization use. + static void SpinAcquire (volatile int * Lock, const char * Name) ; + static void SpinRelease (volatile int * Lock) ; + static void muxAcquire (volatile intptr_t * Lock, const char * Name) ; + static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ; + static void muxRelease (volatile intptr_t * Lock) ; + +}; + +// Inline implementation of Thread::current() +// Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of +// startup. +// ThreadLocalStorage::thread is warm -- it's called > 16K times in the same +// period. This is inlined in thread_.inline.hpp. + +inline Thread* Thread::current() { +#ifdef ASSERT +// This function is very high traffic. Define PARANOID to enable expensive +// asserts. +#ifdef PARANOID + // Signal handler should call ThreadLocalStorage::get_thread_slow() + Thread* t = ThreadLocalStorage::get_thread_slow(); + assert(t != NULL && !t->is_inside_signal_handler(), + "Don't use Thread::current() inside signal handler"); +#endif +#endif + Thread* thread = ThreadLocalStorage::thread(); + assert(thread != NULL, "just checking"); + return thread; +} + +// Name support for threads. non-JavaThread subclasses with multiple +// uniquely named instances should derive from this. +class NamedThread: public Thread { + friend class VMStructs; + enum { + max_name_len = 64 + }; + private: + char* _name; + public: + NamedThread(); + ~NamedThread(); + // May only be called once per thread. + void set_name(const char* format, ...); + virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; } +}; + +// Worker threads are named and have an id of an assigned work. +class WorkerThread: public NamedThread { +private: + uint _id; +public: + WorkerThread() : _id(0) { } + void set_id(uint work_id) { _id = work_id; } + uint id() const { return _id; } +}; + +// A single WatcherThread is used for simulating timer interrupts. +class WatcherThread: public Thread { + friend class VMStructs; + public: + virtual void run(); + + private: + static WatcherThread* _watcher_thread; + + static bool _should_terminate; + public: + enum SomeConstants { + delay_interval = 10 // interrupt delay in milliseconds + }; + + // Constructor + WatcherThread(); + + // Tester + bool is_Watcher_thread() const { return true; } + + // Printing + char* name() const { return (char*)"VM Periodic Task Thread"; } + void print_on(outputStream* st) const; + void print() const { print_on(tty); } + + // Returns the single instance of WatcherThread + static WatcherThread* watcher_thread() { return _watcher_thread; } + + // Create and start the single instance of WatcherThread, or stop it on shutdown + static void start(); + static void stop(); +}; + + +class CompilerThread; + +typedef void (*ThreadFunction)(JavaThread*, TRAPS); + +class JavaThread: public Thread { + friend class VMStructs; + private: + JavaThread* _next; // The next thread in the Threads list + oop _threadObj; // The Java level thread object + +#ifdef ASSERT + private: + int _java_call_counter; + + public: + int java_call_counter() { return _java_call_counter; } + void inc_java_call_counter() { _java_call_counter++; } + void dec_java_call_counter() { + assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); + _java_call_counter--; + } + private: // restore original namespace restriction +#endif // ifdef ASSERT + +#ifndef PRODUCT + public: + enum { + jump_ring_buffer_size = 16 + }; + private: // restore original namespace restriction +#endif + + JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state + + ThreadFunction _entry_point; + + JNIEnv _jni_environment; + + // Deopt support + DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization + + intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we + // transition out of native + + vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays + vframeArray* _vframe_array_last; // Holds last vFrameArray we popped + // Because deoptimization is lazy we must save jvmti requests to set locals + // in compiled frames until we deoptimize and we have an interpreter frame. + // This holds the pointer to array (yeah like there might be more than one) of + // description of compiled vframes that have locals that need to be updated. + GrowableArray* _deferred_locals_updates; + + // Handshake value for fixing 6243940. We need a place for the i2c + // adapter to store the callee methodOop. This value is NEVER live + // across a gc point so it does NOT have to be gc'd + // The handshake is open ended since we can't be certain that it will + // be NULLed. This is because we rarely ever see the race and end up + // in handle_wrong_method which is the backend of the handshake. See + // code in i2c adapters and handle_wrong_method. + + methodOop _callee_target; + + // Oop results of VM runtime calls + oop _vm_result; // Used to pass back an oop result into Java code, GC-preserved + oop _vm_result_2; // Used to pass back an oop result into Java code, GC-preserved + + MonitorChunk* _monitor_chunks; // Contains the off stack monitors + // allocated during deoptimization + // and by JNI_MonitorEnter/Exit + + // Async. requests support + enum AsyncRequests { + _no_async_condition = 0, + _async_exception, + _async_unsafe_access_error + }; + AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request + oop _pending_async_exception; + + // Safepoint support + public: // Expose _thread_state for SafeFetchInt() + volatile JavaThreadState _thread_state; + private: + ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint + address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened + + // JavaThread termination support + enum TerminatedTypes { + _not_terminated = 0xDEAD - 2, + _thread_exiting, // JavaThread::exit() has been called for this thread + _thread_terminated, // JavaThread is removed from thread list + _vm_exited // JavaThread is still executing native code, but VM is terminated + // only VM_Exit can set _vm_exited + }; + + // In general a JavaThread's _terminated field transitions as follows: + // + // _not_terminated => _thread_exiting => _thread_terminated + // + // _vm_exited is a special value to cover the case of a JavaThread + // executing native code after the VM itself is terminated. + TerminatedTypes _terminated; + // suspend/resume support + volatile bool _suspend_equivalent; // Suspend equivalent condition + jint _in_deopt_handler; // count of deoptimization + // handlers thread is in + volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access + bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was + // never locked) when throwing an exception. Used by interpreter only. + + // Flag to mark a JNI thread in the process of attaching - See CR 6404306 + // This flag is never set true other than at construction, and in that case + // is shortly thereafter set false + volatile bool _is_attaching; + + public: + // State of the stack guard pages for this thread. + enum StackGuardState { + stack_guard_unused, // not needed + stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow + stack_guard_enabled // enabled + }; + + private: + + StackGuardState _stack_guard_state; + + // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is + // used to temp. parsing values into and out of the runtime system during exception handling for compiled + // code) + volatile oop _exception_oop; // Exception thrown in compiled code + volatile address _exception_pc; // PC where exception happened + volatile address _exception_handler_pc; // PC for handler of exception + volatile int _exception_stack_size; // Size of frame where exception happened + + // support for compilation + bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible) + + // support for JNI critical regions + jint _jni_active_critical; // count of entries into JNI critical region + + // For deadlock detection. + int _depth_first_number; + + // JVMTI PopFrame support + // This is set to popframe_pending to signal that top Java frame should be popped immediately + int _popframe_condition; + +#ifndef PRODUCT + int _jmp_ring_index; + struct { + // We use intptr_t instead of address so debugger doesn't try and display strings + intptr_t _target; + intptr_t _instruction; + const char* _file; + int _line; + } _jmp_ring[ jump_ring_buffer_size ]; +#endif /* PRODUCT */ + + friend class VMThread; + friend class ThreadWaitTransition; + friend class VM_Exit; + + void initialize(); // Initialized the instance variables + + public: + // Constructor + JavaThread(bool is_attaching = false); // for main thread and JNI attached threads + JavaThread(ThreadFunction entry_point, size_t stack_size = 0); + ~JavaThread(); + +#ifdef ASSERT + // verify this JavaThread hasn't be published in the Threads::list yet + void verify_not_published(); +#endif + + //JNI functiontable getter/setter for JVMTI jni function table interception API. + void set_jni_functions(struct JNINativeInterface_* functionTable) { + _jni_environment.functions = functionTable; + } + struct JNINativeInterface_* get_jni_functions() { + return (struct JNINativeInterface_ *)_jni_environment.functions; + } + + // Executes Shutdown.shutdown() + void invoke_shutdown_hooks(); + + // Cleanup on thread exit + enum ExitType { + normal_exit, + jni_detach + }; + void exit(bool destroy_vm, ExitType exit_type = normal_exit); + + void cleanup_failed_attach_current_thread(); + + // Testers + virtual bool is_Java_thread() const { return true; } + + // compilation + void set_is_compiling(bool f) { _is_compiling = f; } + bool is_compiling() const { return _is_compiling; } + + // Thread chain operations + JavaThread* next() const { return _next; } + void set_next(JavaThread* p) { _next = p; } + + // Thread oop. threadObj() can be NULL for initial JavaThread + // (or for threads attached via JNI) + oop threadObj() const { return _threadObj; } + void set_threadObj(oop p) { _threadObj = p; } + + ThreadPriority java_priority() const; // Read from threadObj() + + // Prepare thread and add to priority queue. If a priority is + // not specified, use the priority of the thread object. Threads_lock + // must be held while this function is called. + void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); + + void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } + address saved_exception_pc() { return _saved_exception_pc; } + + + ThreadFunction entry_point() const { return _entry_point; } + + // Allocates a new Java level thread object for this thread. thread_name may be NULL. + void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS); + + // Last frame anchor routines + + JavaFrameAnchor* frame_anchor(void) { return &_anchor; } + + // last_Java_sp + bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } + intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } + + // last_Java_pc + + address last_Java_pc(void) { return _anchor.last_Java_pc(); } + + // Safepoint support + JavaThreadState thread_state() const { return _thread_state; } + void set_thread_state(JavaThreadState s) { _thread_state=s; } + ThreadSafepointState *safepoint_state() const { return _safepoint_state; } + void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; } + bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); } + + // thread has called JavaThread::exit() or is terminated + bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); } + // thread is terminated (no longer on the threads list); we compare + // against the two non-terminated values so that a freed JavaThread + // will also be considered terminated. + bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; } + void set_terminated(TerminatedTypes t) { _terminated = t; } + // special for Threads::remove() which is static: + void set_terminated_value() { _terminated = _thread_terminated; } + void block_if_vm_exited(); + + bool doing_unsafe_access() { return _doing_unsafe_access; } + void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; } + + bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; } + void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; } + + + // Suspend/resume support for JavaThread + + private: + void set_ext_suspended() { set_suspend_flag (_ext_suspended); } + void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); } + + public: + void java_suspend(); + void java_resume(); + int java_suspend_self(); + + void check_and_wait_while_suspended() { + assert(JavaThread::current() == this, "sanity check"); + + bool do_self_suspend; + do { + // were we externally suspended while we were waiting? + do_self_suspend = handle_special_suspend_equivalent_condition(); + if (do_self_suspend) { + // don't surprise the thread that suspended us by returning + java_suspend_self(); + set_suspend_equivalent(); + } + } while (do_self_suspend); + } + static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread); + // Check for async exception in addition to safepoint and suspend request. + static void check_special_condition_for_native_trans(JavaThread *thread); + + bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits); + bool is_ext_suspend_completed_with_lock(uint32_t *bits) { + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); + // Warning: is_ext_suspend_completed() may temporarily drop the + // SR_lock to allow the thread to reach a stable thread state if + // it is currently in a transient thread state. + return is_ext_suspend_completed(false /*!called_by_wait */, + SuspendRetryDelay, bits); + } + + // We cannot allow wait_for_ext_suspend_completion() to run forever or + // we could hang. SuspendRetryCount and SuspendRetryDelay are normally + // passed as the count and delay parameters. Experiments with specific + // calls to wait_for_ext_suspend_completion() can be done by passing + // other values in the code. Experiments with all calls can be done + // via the appropriate -XX options. + bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits); + + void set_external_suspend() { set_suspend_flag (_external_suspend); } + void clear_external_suspend() { clear_suspend_flag(_external_suspend); } + + void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); } + void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); } + bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; } + + bool is_external_suspend() const { + return (_suspend_flags & _external_suspend) != 0; + } + // Whenever a thread transitions from native to vm/java it must suspend + // if external|deopt suspend is present. + bool is_suspend_after_native() const { + return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0; + } + + // external suspend request is completed + bool is_ext_suspended() const { + return (_suspend_flags & _ext_suspended) != 0; + } + + // legacy method that checked for either external suspension or vm suspension + bool is_any_suspended() const { + return is_ext_suspended(); + } + + bool is_external_suspend_with_lock() const { + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); + return is_external_suspend(); + } + + // Special method to handle a pending external suspend request + // when a suspend equivalent condition lifts. + bool handle_special_suspend_equivalent_condition() { + assert(is_suspend_equivalent(), + "should only be called in a suspend equivalence condition"); + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); + bool ret = is_external_suspend(); + if (!ret) { + // not about to self-suspend so clear suspend equivalence + clear_suspend_equivalent(); + } + // implied else: + // We have a pending external suspend request so we leave the + // suspend_equivalent flag set until java_suspend_self() sets + // the ext_suspended flag and clears the suspend_equivalent + // flag. This insures that wait_for_ext_suspend_completion() + // will return consistent values. + return ret; + } + + bool is_any_suspended_with_lock() const { + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); + return is_any_suspended(); + } + // utility methods to see if we are doing some kind of suspension + bool is_being_ext_suspended() const { + MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); + return is_ext_suspended() || is_external_suspend(); + } + + bool is_suspend_equivalent() const { return _suspend_equivalent; } + + void set_suspend_equivalent() { _suspend_equivalent = true; }; + void clear_suspend_equivalent() { _suspend_equivalent = false; }; + + // Thread.stop support + void send_thread_stop(oop throwable); + AsyncRequests clear_special_runtime_exit_condition() { + AsyncRequests x = _special_runtime_exit_condition; + _special_runtime_exit_condition = _no_async_condition; + return x; + } + + // Are any async conditions present? + bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); } + + void check_and_handle_async_exceptions(bool check_unsafe_error = true); + + // these next two are also used for self-suspension and async exception support + void handle_special_runtime_exit_condition(bool check_asyncs = true); + + // Return true if JavaThread has an asynchronous condition or + // if external suspension is requested. + bool has_special_runtime_exit_condition() { + // We call is_external_suspend() last since external suspend should + // be less common. Because we don't use is_external_suspend_with_lock + // it is possible that we won't see an asynchronous external suspend + // request that has just gotten started, i.e., SR_lock grabbed but + // _external_suspend field change either not made yet or not visible + // yet. However, this is okay because the request is asynchronous and + // we will see the new flag value the next time through. It's also + // possible that the external suspend request is dropped after + // we have checked is_external_suspend(), we will recheck its value + // under SR_lock in java_suspend_self(). + return (_special_runtime_exit_condition != _no_async_condition) || + is_external_suspend() || is_deopt_suspend(); + } + + void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; } + + void set_pending_async_exception(oop e) { + _pending_async_exception = e; + _special_runtime_exit_condition = _async_exception; + set_has_async_exception(); + } + + // Fast-locking support + bool is_lock_owned(address adr) const; + + // Accessors for vframe array top + // The linked list of vframe arrays are sorted on sp. This means when we + // unpack the head must contain the vframe array to unpack. + void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } + vframeArray* vframe_array_head() const { return _vframe_array_head; } + + // Side structure for defering update of java frame locals until deopt occurs + GrowableArray* deferred_locals() const { return _deferred_locals_updates; } + void set_deferred_locals(GrowableArray* vf) { _deferred_locals_updates = vf; } + + // These only really exist to make debugging deopt problems simpler + + void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } + vframeArray* vframe_array_last() const { return _vframe_array_last; } + + // The special resourceMark used during deoptimization + + void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } + DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } + + intptr_t* must_deopt_id() { return _must_deopt_id; } + void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; } + void clear_must_deopt_id() { _must_deopt_id = NULL; } + + methodOop callee_target() const { return _callee_target; } + void set_callee_target (methodOop x) { _callee_target = x; } + + // Oop results of vm runtime calls + oop vm_result() const { return _vm_result; } + void set_vm_result (oop x) { _vm_result = x; } + + oop vm_result_2() const { return _vm_result_2; } + void set_vm_result_2 (oop x) { _vm_result_2 = x; } + + // Exception handling for compiled methods + oop exception_oop() const { return _exception_oop; } + int exception_stack_size() const { return _exception_stack_size; } + address exception_pc() const { return _exception_pc; } + address exception_handler_pc() const { return _exception_handler_pc; } + + void set_exception_oop(oop o) { _exception_oop = o; } + void set_exception_pc(address a) { _exception_pc = a; } + void set_exception_handler_pc(address a) { _exception_handler_pc = a; } + void set_exception_stack_size(int size) { _exception_stack_size = size; } + + // Stack overflow support + inline size_t stack_available(address cur_sp); + address stack_yellow_zone_base() + { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); } + size_t stack_yellow_zone_size() + { return StackYellowPages * os::vm_page_size(); } + address stack_red_zone_base() + { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); } + size_t stack_red_zone_size() + { return StackRedPages * os::vm_page_size(); } + bool in_stack_yellow_zone(address a) + { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); } + bool in_stack_red_zone(address a) + { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); } + + void create_stack_guard_pages(); + void remove_stack_guard_pages(); + + void enable_stack_yellow_zone(); + void disable_stack_yellow_zone(); + void enable_stack_red_zone(); + void disable_stack_red_zone(); + + inline bool stack_yellow_zone_disabled(); + inline bool stack_yellow_zone_enabled(); + + // Attempt to reguard the stack after a stack overflow may have occurred. + // Returns true if (a) guard pages are not needed on this thread, (b) the + // pages are already guarded, or (c) the pages were successfully reguarded. + // Returns false if there is not enough stack space to reguard the pages, in + // which case the caller should unwind a frame and try again. The argument + // should be the caller's (approximate) sp. + bool reguard_stack(address cur_sp); + // Similar to above but see if current stackpoint is out of the guard area + // and reguard if possible. + bool reguard_stack(void); + + // Misc. accessors/mutators + void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; } + void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; } + bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; } + +#ifndef PRODUCT + void record_jump(address target, address instr, const char* file, int line); +#endif /* PRODUCT */ + + // For assembly stub generation + static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); } +#ifndef PRODUCT + static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); } + static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); } +#endif /* PRODUCT */ + static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); } + static ByteSize last_Java_sp_offset() { + return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); + } + static ByteSize last_Java_pc_offset() { + return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); + } + static ByteSize frame_anchor_offset() { + return byte_offset_of(JavaThread, _anchor); + } + static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); } + static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); } + static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); } + static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); } + static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); } + static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); } + static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); } + static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); } + static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } + static ByteSize exception_stack_size_offset() { return byte_offset_of(JavaThread, _exception_stack_size); } + static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); } + static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); } + + static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } + + // Returns the jni environment for this thread + JNIEnv* jni_environment() { return &_jni_environment; } + + static JavaThread* thread_from_jni_environment(JNIEnv* env) { + JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset())); + // Only return NULL if thread is off the thread list; starting to + // exit should not return NULL. + if (thread_from_jni_env->is_terminated()) { + thread_from_jni_env->block_if_vm_exited(); + return NULL; + } else { + return thread_from_jni_env; + } + } + + // JNI critical regions. These can nest. + bool in_critical() { return _jni_active_critical > 0; } + void enter_critical() { assert(Thread::current() == this, + "this must be current thread"); + _jni_active_critical++; } + void exit_critical() { assert(Thread::current() == this, + "this must be current thread"); + _jni_active_critical--; + assert(_jni_active_critical >= 0, + "JNI critical nesting problem?"); } + + // For deadlock detection + int depth_first_number() { return _depth_first_number; } + void set_depth_first_number(int dfn) { _depth_first_number = dfn; } + + private: + void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; } + + public: + MonitorChunk* monitor_chunks() const { return _monitor_chunks; } + void add_monitor_chunk(MonitorChunk* chunk); + void remove_monitor_chunk(MonitorChunk* chunk); + bool in_deopt_handler() const { return _in_deopt_handler > 0; } + void inc_in_deopt_handler() { _in_deopt_handler++; } + void dec_in_deopt_handler() { + assert(_in_deopt_handler > 0, "mismatched deopt nesting"); + if (_in_deopt_handler > 0) { // robustness + _in_deopt_handler--; + } + } + + private: + void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } + + public: + + // Frame iteration; calls the function f for all frames on the stack + void frames_do(void f(frame*, const RegisterMap*)); + + // Memory operations + void oops_do(OopClosure* f); + + // Sweeper operations + void nmethods_do(); + + // Memory management operations + void gc_epilogue(); + void gc_prologue(); + + // Misc. operations + char* name() const { return (char*)get_thread_name(); } + void print_on(outputStream* st) const; + void print() const { print_on(tty); } + void print_value(); + void print_thread_state_on(outputStream* ) const PRODUCT_RETURN; + void print_thread_state() const PRODUCT_RETURN; + void print_on_error(outputStream* st, char* buf, int buflen) const; + void verify(); + const char* get_thread_name() const; +private: + // factor out low-level mechanics for use in both normal and error cases + const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const; +public: + const char* get_threadgroup_name() const; + const char* get_parent_name() const; + + // Accessing frames + frame last_frame() { + _anchor.make_walkable(this); + return pd_last_frame(); + } + javaVFrame* last_java_vframe(RegisterMap* reg_map); + + // Returns method at 'depth' java or native frames down the stack + // Used for security checks + klassOop security_get_caller_class(int depth); + + // Print stack trace in external format + void print_stack_on(outputStream* st); + void print_stack() { print_stack_on(tty); } + + // Print stack traces in various internal formats + void trace_stack() PRODUCT_RETURN; + void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; + void trace_frames() PRODUCT_RETURN; + + // Returns the number of stack frames on the stack + int depth() const; + + // Function for testing deoptimization + void deoptimize(); + void make_zombies(); + + void deoptimized_wrt_marked_nmethods(); + + // Profiling operation (see fprofile.cpp) + public: + bool profile_last_Java_frame(frame* fr); + + private: + ThreadProfiler* _thread_profiler; + private: + friend class FlatProfiler; // uses both [gs]et_thread_profiler. + friend class FlatProfilerTask; // uses get_thread_profiler. + friend class ThreadProfilerMark; // uses get_thread_profiler. + ThreadProfiler* get_thread_profiler() { return _thread_profiler; } + ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) { + ThreadProfiler* result = _thread_profiler; + _thread_profiler = tp; + return result; + } + + // Static operations + public: + // Returns the running thread as a JavaThread + static inline JavaThread* current(); + + // Returns the active Java thread. Do not use this if you know you are calling + // from a JavaThread, as it's slower than JavaThread::current. If called from + // the VMThread, it also returns the JavaThread that instigated the VMThread's + // operation. You may not want that either. + static JavaThread* active(); + + inline CompilerThread* as_CompilerThread(); + + public: + virtual void run(); + void thread_main_inner(); + + private: + // PRIVILEGED STACK + PrivilegedElement* _privileged_stack_top; + GrowableArray* _array_for_gc; + public: + + // Returns the privileged_stack information. + PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; } + void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; } + void register_array_for_gc(GrowableArray* array) { _array_for_gc = array; } + + public: + // Thread local information maintained by JVMTI. + void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } + JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } + static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } + void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; } + JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; } + + // JVMTI PopFrame support + // Setting and clearing popframe_condition + // All of these enumerated values are bits. popframe_pending + // indicates that a PopFrame() has been requested and not yet been + // completed. popframe_processing indicates that that PopFrame() is in + // the process of being completed. popframe_force_deopt_reexecution_bit + // indicates that special handling is required when returning to a + // deoptimized caller. + enum PopCondition { + popframe_inactive = 0x00, + popframe_pending_bit = 0x01, + popframe_processing_bit = 0x02, + popframe_force_deopt_reexecution_bit = 0x04 + }; + PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } + void set_popframe_condition(PopCondition c) { _popframe_condition = c; } + void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } + void clear_popframe_condition() { _popframe_condition = popframe_inactive; } + static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } + bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } + bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } + void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; } +#ifdef CC_INTERP + bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); } + void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; } + bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } + void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } + void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } +#endif + + private: + // Saved incoming arguments to popped frame. + // Used only when popped interpreted frame returns to deoptimized frame. + void* _popframe_preserved_args; + int _popframe_preserved_args_size; + + public: + void popframe_preserve_args(ByteSize size_in_bytes, void* start); + void* popframe_preserved_args(); + ByteSize popframe_preserved_args_size(); + WordSize popframe_preserved_args_size_in_words(); + void popframe_free_preserved_args(); + + + private: + JvmtiThreadState *_jvmti_thread_state; + JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure; + + // Used by the interpreter in fullspeed mode for frame pop, method + // entry, method exit and single stepping support. This field is + // only set to non-zero by the VM_EnterInterpOnlyMode VM operation. + // It can be set to zero asynchronously (i.e., without a VM operation + // or a lock) so we have to be very careful. + int _interp_only_mode; + + public: + // used by the interpreter for fullspeed debugging support (see above) + static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } + bool is_interp_only_mode() { return (_interp_only_mode != 0); } + int get_interp_only_mode() { return _interp_only_mode; } + void increment_interp_only_mode() { ++_interp_only_mode; } + void decrement_interp_only_mode() { --_interp_only_mode; } + + private: + ThreadStatistics *_thread_stat; + + public: + ThreadStatistics* get_thread_stat() const { return _thread_stat; } + + // Return a blocker object for which this thread is blocked parking. + oop current_park_blocker(); + + private: + static size_t _stack_size_at_create; + + public: + static inline size_t stack_size_at_create(void) { + return _stack_size_at_create; + } + static inline void set_stack_size_at_create(size_t value) { + _stack_size_at_create = value; + } + + // Machine dependent stuff + #include "incls/_thread_pd.hpp.incl" + + public: + void set_blocked_on_compilation(bool value) { + _blocked_on_compilation = value; + } + + bool blocked_on_compilation() { + return _blocked_on_compilation; + } + protected: + bool _blocked_on_compilation; + + + // JSR166 per-thread parker +private: + Parker* _parker; +public: + Parker* parker() { return _parker; } + + // Biased locking support +private: + GrowableArray* _cached_monitor_info; +public: + GrowableArray* cached_monitor_info() { return _cached_monitor_info; } + void set_cached_monitor_info(GrowableArray* info) { _cached_monitor_info = info; } + + // clearing/querying jni attach status + bool is_attaching() const { return _is_attaching; } + void set_attached() { _is_attaching = false; OrderAccess::fence(); } +}; + +// Inline implementation of JavaThread::current +inline JavaThread* JavaThread::current() { + Thread* thread = ThreadLocalStorage::thread(); + assert(thread != NULL && thread->is_Java_thread(), "just checking"); + return (JavaThread*)thread; +} + +inline CompilerThread* JavaThread::as_CompilerThread() { + assert(is_Compiler_thread(), "just checking"); + return (CompilerThread*)this; +} + +inline bool JavaThread::stack_yellow_zone_disabled() { + return _stack_guard_state == stack_guard_yellow_disabled; +} + +inline bool JavaThread::stack_yellow_zone_enabled() { +#ifdef ASSERT + if (os::uses_stack_guard_pages()) { + assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use"); + } +#endif + return _stack_guard_state == stack_guard_enabled; +} + +inline size_t JavaThread::stack_available(address cur_sp) { + // This code assumes java stacks grow down + address low_addr; // Limit on the address for deepest stack depth + if ( _stack_guard_state == stack_guard_unused) { + low_addr = stack_base() - stack_size(); + } else { + low_addr = stack_yellow_zone_base(); + } + return cur_sp > low_addr ? cur_sp - low_addr : 0; +} + +// A JavaThread for low memory detection support +class LowMemoryDetectorThread : public JavaThread { + friend class VMStructs; +public: + LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {}; + + // Hide this thread from external view. + bool is_hidden_from_external_view() const { return true; } +}; + +// A thread used for Compilation. +class CompilerThread : public JavaThread { + friend class VMStructs; + private: + CompilerCounters* _counters; + + ciEnv* _env; + CompileLog* _log; + CompileTask* _task; + CompileQueue* _queue; + + public: + + static CompilerThread* current(); + + CompilerThread(CompileQueue* queue, CompilerCounters* counters); + + bool is_Compiler_thread() const { return true; } + // Hide this compiler thread from external view. + bool is_hidden_from_external_view() const { return true; } + + CompileQueue* queue() { return _queue; } + CompilerCounters* counters() { return _counters; } + + // Get/set the thread's compilation environment. + ciEnv* env() { return _env; } + void set_env(ciEnv* env) { _env = env; } + + // Get/set the thread's logging information + CompileLog* log() { return _log; } + void init_log(CompileLog* log) { + // Set once, for good. + assert(_log == NULL, "set only once"); + _log = log; + } + +#ifndef PRODUCT +private: + IdealGraphPrinter *_ideal_graph_printer; +public: + IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; } + void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; } +#endif + + // Get/set the thread's current task + CompileTask* task() { return _task; } + void set_task(CompileTask* task) { _task = task; } +}; + +inline CompilerThread* CompilerThread::current() { + return JavaThread::current()->as_CompilerThread(); +} + + +// The active thread queue. It also keeps track of the current used +// thread priorities. +class Threads: AllStatic { + friend class VMStructs; + private: + static JavaThread* _thread_list; + static int _number_of_threads; + static int _number_of_non_daemon_threads; + static int _return_code; + + public: + // Thread management + // force_daemon is a concession to JNI, where we may need to add a + // thread to the thread list before allocating its thread object + static void add(JavaThread* p, bool force_daemon = false); + static void remove(JavaThread* p); + static bool includes(JavaThread* p); + static JavaThread* first() { return _thread_list; } + static void threads_do(ThreadClosure* tc); + + // Initializes the vm and creates the vm thread + static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain); + static void convert_vm_init_libraries_to_agents(); + static void create_vm_init_libraries(); + static void create_vm_init_agents(); + static void shutdown_vm_agents(); + static bool destroy_vm(); + // Supported VM versions via JNI + // Includes JNI_VERSION_1_1 + static jboolean is_supported_jni_version_including_1_1(jint version); + // Does not include JNI_VERSION_1_1 + static jboolean is_supported_jni_version(jint version); + + // Garbage collection + static void follow_other_roots(void f(oop*)); + + // Apply "f->do_oop" to all root oops in all threads. + // This version may only be called by sequential code. + static void oops_do(OopClosure* f); + // This version may be called by sequential or parallel code. + static void possibly_parallel_oops_do(OopClosure* f); + // This creates a list of GCTasks, one per thread. + static void create_thread_roots_tasks(GCTaskQueue* q); + // This creates a list of GCTasks, one per thread, for marking objects. + static void create_thread_roots_marking_tasks(GCTaskQueue* q); + + // Apply "f->do_oop" to roots in all threads that + // are part of compiled frames + static void compiled_frame_oops_do(OopClosure* f); + + static void convert_hcode_pointers(); + static void restore_hcode_pointers(); + + // Sweeper + static void nmethods_do(); + + static void gc_epilogue(); + static void gc_prologue(); + + // Verification + static void verify(); + static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks); + static void print(bool print_stacks, bool internal_format) { + // this function is only used by debug.cpp + print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */); + } + static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen); + + // Get Java threads that are waiting to enter a monitor. If doLock + // is true, then Threads_lock is grabbed as needed. Otherwise, the + // VM needs to be at a safepoint. + static GrowableArray* get_pending_threads(int count, + address monitor, bool doLock); + + // Get owning Java thread from the monitor's owner field. If doLock + // is true, then Threads_lock is grabbed as needed. Otherwise, the + // VM needs to be at a safepoint. + static JavaThread *owning_thread_from_monitor_owner(address owner, + bool doLock); + + // Number of threads on the active threads list + static int number_of_threads() { return _number_of_threads; } + // Number of non-daemon threads on the active threads list + static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; } + + // Deoptimizes all frames tied to marked nmethods + static void deoptimized_wrt_marked_nmethods(); + +}; + + +// Thread iterator +class ThreadClosure: public StackObj { + public: + virtual void do_thread(Thread* thread) = 0; +}; + +class SignalHandlerMark: public StackObj { +private: + Thread* _thread; +public: + SignalHandlerMark(Thread* t) { + _thread = t; + if (_thread) _thread->enter_signal_handler(); + } + ~SignalHandlerMark() { + if (_thread) _thread->leave_signal_handler(); + _thread = NULL; + } +}; + +// ParkEvents are type-stable and immortal. +// +// Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains +// associated with the thread for the thread's entire lifetime - the relationship is +// stable. A thread will be associated at most one ParkEvent. When the thread +// expires, the ParkEvent moves to the EventFreeList. New threads attempt to allocate from +// the EventFreeList before creating a new Event. Type-stability frees us from +// worrying about stale Event or Thread references in the objectMonitor subsystem. +// (A reference to ParkEvent is always valid, even though the event may no longer be associated +// with the desired or expected thread. A key aspect of this design is that the callers of +// park, unpark, etc must tolerate stale references and spurious wakeups). +// +// Only the "associated" thread can block (park) on the ParkEvent, although +// any other thread can unpark a reachable parkevent. Park() is allowed to +// return spuriously. In fact park-unpark a really just an optimization to +// avoid unbounded spinning and surrender the CPU to be a polite system citizen. +// A degenerate albeit "impolite" park-unpark implementation could simply return. +// See http://blogs.sun.com/dave for more details. +// +// Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as +// thread proxies, and simply make the THREAD structure type-stable and persistent. +// Currently, we unpark events associated with threads, but ideally we'd just +// unpark threads. +// +// The base-class, PlatformEvent, is platform-specific while the ParkEvent is +// platform-independent. PlatformEvent provides park(), unpark(), etc., and +// is abstract -- that is, a PlatformEvent should never be instantiated except +// as part of a ParkEvent. +// Equivalently we could have defined a platform-independent base-class that +// exported Allocate(), Release(), etc. The platform-specific class would extend +// that base-class, adding park(), unpark(), etc. +// +// A word of caution: The JVM uses 2 very similar constructs: +// 1. ParkEvent are used for Java-level "monitor" synchronization. +// 2. Parkers are used by JSR166-JUC park-unpark. +// +// We'll want to eventually merge these redundant facilities and use ParkEvent. + + +class ParkEvent : public os::PlatformEvent { + private: + ParkEvent * FreeNext ; + + // Current association + Thread * AssociatedWith ; + intptr_t RawThreadIdentity ; // LWPID etc + volatile int Incarnation ; + + // diagnostic : keep track of last thread to wake this thread. + // this is useful for construction of dependency graphs. + void * LastWaker ; + + public: + // MCS-CLH list linkage and Native Mutex/Monitor + ParkEvent * volatile ListNext ; + ParkEvent * volatile ListPrev ; + volatile intptr_t OnList ; + volatile int TState ; + volatile int Notified ; // for native monitor construct + volatile int IsWaiting ; // Enqueued on WaitSet + + + private: + static ParkEvent * volatile FreeList ; + static volatile int ListLock ; + + // It's prudent to mark the dtor as "private" + // ensuring that it's not visible outside the package. + // Unfortunately gcc warns about such usage, so + // we revert to the less desirable "protected" visibility. + // The other compilers accept private dtors. + + protected: // Ensure dtor is never invoked + ~ParkEvent() { guarantee (0, "invariant") ; } + + ParkEvent() : PlatformEvent() { + AssociatedWith = NULL ; + FreeNext = NULL ; + ListNext = NULL ; + ListPrev = NULL ; + OnList = 0 ; + TState = 0 ; + Notified = 0 ; + IsWaiting = 0 ; + } + + // We use placement-new to force ParkEvent instances to be + // aligned on 256-byte address boundaries. This ensures that the least + // significant byte of a ParkEvent address is always 0. + + void * operator new (size_t sz) ; + void operator delete (void * a) ; + + public: + static ParkEvent * Allocate (Thread * t) ; + static void Release (ParkEvent * e) ; +} ;