Fri, 05 Sep 2014 12:36:37 -0700
8057623: add an extension class for argument handling
Reviewed-by: brutisso, mgerdin, tschatzl
1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "gc_implementation/shared/vmGCOperations.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "memory/allocation.inline.hpp"
35 #ifdef ASSERT
36 #include "memory/guardedMemory.hpp"
37 #endif
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvm.h"
40 #include "prims/jvm_misc.hpp"
41 #include "prims/privilegedStack.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/os.hpp"
49 #include "runtime/stubRoutines.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "services/attachListener.hpp"
52 #include "services/nmtCommon.hpp"
53 #include "services/memTracker.hpp"
54 #include "services/threadService.hpp"
55 #include "utilities/defaultStream.hpp"
56 #include "utilities/events.hpp"
57 #ifdef TARGET_OS_FAMILY_linux
58 # include "os_linux.inline.hpp"
59 #endif
60 #ifdef TARGET_OS_FAMILY_solaris
61 # include "os_solaris.inline.hpp"
62 #endif
63 #ifdef TARGET_OS_FAMILY_windows
64 # include "os_windows.inline.hpp"
65 #endif
66 #ifdef TARGET_OS_FAMILY_bsd
67 # include "os_bsd.inline.hpp"
68 #endif
70 # include <signal.h>
72 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
74 OSThread* os::_starting_thread = NULL;
75 address os::_polling_page = NULL;
76 volatile int32_t* os::_mem_serialize_page = NULL;
77 uintptr_t os::_serialize_page_mask = 0;
78 long os::_rand_seed = 1;
79 int os::_processor_count = 0;
80 size_t os::_page_sizes[os::page_sizes_max];
82 #ifndef PRODUCT
83 julong os::num_mallocs = 0; // # of calls to malloc/realloc
84 julong os::alloc_bytes = 0; // # of bytes allocated
85 julong os::num_frees = 0; // # of calls to free
86 julong os::free_bytes = 0; // # of bytes freed
87 #endif
89 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
91 void os_init_globals() {
92 // Called from init_globals().
93 // See Threads::create_vm() in thread.cpp, and init.cpp.
94 os::init_globals();
95 }
97 // Fill in buffer with current local time as an ISO-8601 string.
98 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
99 // Returns buffer, or NULL if it failed.
100 // This would mostly be a call to
101 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
102 // except that on Windows the %z behaves badly, so we do it ourselves.
103 // Also, people wanted milliseconds on there,
104 // and strftime doesn't do milliseconds.
105 char* os::iso8601_time(char* buffer, size_t buffer_length) {
106 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
107 // 1 2
108 // 12345678901234567890123456789
109 static const char* iso8601_format =
110 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
111 static const size_t needed_buffer = 29;
113 // Sanity check the arguments
114 if (buffer == NULL) {
115 assert(false, "NULL buffer");
116 return NULL;
117 }
118 if (buffer_length < needed_buffer) {
119 assert(false, "buffer_length too small");
120 return NULL;
121 }
122 // Get the current time
123 jlong milliseconds_since_19700101 = javaTimeMillis();
124 const int milliseconds_per_microsecond = 1000;
125 const time_t seconds_since_19700101 =
126 milliseconds_since_19700101 / milliseconds_per_microsecond;
127 const int milliseconds_after_second =
128 milliseconds_since_19700101 % milliseconds_per_microsecond;
129 // Convert the time value to a tm and timezone variable
130 struct tm time_struct;
131 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
132 assert(false, "Failed localtime_pd");
133 return NULL;
134 }
135 #if defined(_ALLBSD_SOURCE)
136 const time_t zone = (time_t) time_struct.tm_gmtoff;
137 #else
138 const time_t zone = timezone;
139 #endif
141 // If daylight savings time is in effect,
142 // we are 1 hour East of our time zone
143 const time_t seconds_per_minute = 60;
144 const time_t minutes_per_hour = 60;
145 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
146 time_t UTC_to_local = zone;
147 if (time_struct.tm_isdst > 0) {
148 UTC_to_local = UTC_to_local - seconds_per_hour;
149 }
150 // Compute the time zone offset.
151 // localtime_pd() sets timezone to the difference (in seconds)
152 // between UTC and and local time.
153 // ISO 8601 says we need the difference between local time and UTC,
154 // we change the sign of the localtime_pd() result.
155 const time_t local_to_UTC = -(UTC_to_local);
156 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
157 char sign_local_to_UTC = '+';
158 time_t abs_local_to_UTC = local_to_UTC;
159 if (local_to_UTC < 0) {
160 sign_local_to_UTC = '-';
161 abs_local_to_UTC = -(abs_local_to_UTC);
162 }
163 // Convert time zone offset seconds to hours and minutes.
164 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
165 const time_t zone_min =
166 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
168 // Print an ISO 8601 date and time stamp into the buffer
169 const int year = 1900 + time_struct.tm_year;
170 const int month = 1 + time_struct.tm_mon;
171 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
172 year,
173 month,
174 time_struct.tm_mday,
175 time_struct.tm_hour,
176 time_struct.tm_min,
177 time_struct.tm_sec,
178 milliseconds_after_second,
179 sign_local_to_UTC,
180 zone_hours,
181 zone_min);
182 if (printed == 0) {
183 assert(false, "Failed jio_printf");
184 return NULL;
185 }
186 return buffer;
187 }
189 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
190 #ifdef ASSERT
191 if (!(!thread->is_Java_thread() ||
192 Thread::current() == thread ||
193 Threads_lock->owned_by_self()
194 || thread->is_Compiler_thread()
195 )) {
196 assert(false, "possibility of dangling Thread pointer");
197 }
198 #endif
200 if (p >= MinPriority && p <= MaxPriority) {
201 int priority = java_to_os_priority[p];
202 return set_native_priority(thread, priority);
203 } else {
204 assert(false, "Should not happen");
205 return OS_ERR;
206 }
207 }
209 // The mapping from OS priority back to Java priority may be inexact because
210 // Java priorities can map M:1 with native priorities. If you want the definite
211 // Java priority then use JavaThread::java_priority()
212 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
213 int p;
214 int os_prio;
215 OSReturn ret = get_native_priority(thread, &os_prio);
216 if (ret != OS_OK) return ret;
218 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
219 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
220 } else {
221 // niceness values are in reverse order
222 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
223 }
224 priority = (ThreadPriority)p;
225 return OS_OK;
226 }
229 // --------------------- sun.misc.Signal (optional) ---------------------
232 // SIGBREAK is sent by the keyboard to query the VM state
233 #ifndef SIGBREAK
234 #define SIGBREAK SIGQUIT
235 #endif
237 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
240 static void signal_thread_entry(JavaThread* thread, TRAPS) {
241 os::set_priority(thread, NearMaxPriority);
242 while (true) {
243 int sig;
244 {
245 // FIXME : Currently we have not decieded what should be the status
246 // for this java thread blocked here. Once we decide about
247 // that we should fix this.
248 sig = os::signal_wait();
249 }
250 if (sig == os::sigexitnum_pd()) {
251 // Terminate the signal thread
252 return;
253 }
255 switch (sig) {
256 case SIGBREAK: {
257 // Check if the signal is a trigger to start the Attach Listener - in that
258 // case don't print stack traces.
259 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
260 continue;
261 }
262 // Print stack traces
263 // Any SIGBREAK operations added here should make sure to flush
264 // the output stream (e.g. tty->flush()) after output. See 4803766.
265 // Each module also prints an extra carriage return after its output.
266 VM_PrintThreads op;
267 VMThread::execute(&op);
268 VM_PrintJNI jni_op;
269 VMThread::execute(&jni_op);
270 VM_FindDeadlocks op1(tty);
271 VMThread::execute(&op1);
272 Universe::print_heap_at_SIGBREAK();
273 if (PrintClassHistogram) {
274 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
275 VMThread::execute(&op1);
276 }
277 if (JvmtiExport::should_post_data_dump()) {
278 JvmtiExport::post_data_dump();
279 }
280 break;
281 }
282 default: {
283 // Dispatch the signal to java
284 HandleMark hm(THREAD);
285 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
286 KlassHandle klass (THREAD, k);
287 if (klass.not_null()) {
288 JavaValue result(T_VOID);
289 JavaCallArguments args;
290 args.push_int(sig);
291 JavaCalls::call_static(
292 &result,
293 klass,
294 vmSymbols::dispatch_name(),
295 vmSymbols::int_void_signature(),
296 &args,
297 THREAD
298 );
299 }
300 if (HAS_PENDING_EXCEPTION) {
301 // tty is initialized early so we don't expect it to be null, but
302 // if it is we can't risk doing an initialization that might
303 // trigger additional out-of-memory conditions
304 if (tty != NULL) {
305 char klass_name[256];
306 char tmp_sig_name[16];
307 const char* sig_name = "UNKNOWN";
308 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
309 name()->as_klass_external_name(klass_name, 256);
310 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
311 sig_name = tmp_sig_name;
312 warning("Exception %s occurred dispatching signal %s to handler"
313 "- the VM may need to be forcibly terminated",
314 klass_name, sig_name );
315 }
316 CLEAR_PENDING_EXCEPTION;
317 }
318 }
319 }
320 }
321 }
323 void os::init_before_ergo() {
324 // We need to initialize large page support here because ergonomics takes some
325 // decisions depending on large page support and the calculated large page size.
326 large_page_init();
327 }
329 void os::signal_init() {
330 if (!ReduceSignalUsage) {
331 // Setup JavaThread for processing signals
332 EXCEPTION_MARK;
333 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
334 instanceKlassHandle klass (THREAD, k);
335 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
337 const char thread_name[] = "Signal Dispatcher";
338 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
340 // Initialize thread_oop to put it into the system threadGroup
341 Handle thread_group (THREAD, Universe::system_thread_group());
342 JavaValue result(T_VOID);
343 JavaCalls::call_special(&result, thread_oop,
344 klass,
345 vmSymbols::object_initializer_name(),
346 vmSymbols::threadgroup_string_void_signature(),
347 thread_group,
348 string,
349 CHECK);
351 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
352 JavaCalls::call_special(&result,
353 thread_group,
354 group,
355 vmSymbols::add_method_name(),
356 vmSymbols::thread_void_signature(),
357 thread_oop, // ARG 1
358 CHECK);
360 os::signal_init_pd();
362 { MutexLocker mu(Threads_lock);
363 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
365 // At this point it may be possible that no osthread was created for the
366 // JavaThread due to lack of memory. We would have to throw an exception
367 // in that case. However, since this must work and we do not allow
368 // exceptions anyway, check and abort if this fails.
369 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
370 vm_exit_during_initialization("java.lang.OutOfMemoryError",
371 "unable to create new native thread");
372 }
374 java_lang_Thread::set_thread(thread_oop(), signal_thread);
375 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
376 java_lang_Thread::set_daemon(thread_oop());
378 signal_thread->set_threadObj(thread_oop());
379 Threads::add(signal_thread);
380 Thread::start(signal_thread);
381 }
382 // Handle ^BREAK
383 os::signal(SIGBREAK, os::user_handler());
384 }
385 }
388 void os::terminate_signal_thread() {
389 if (!ReduceSignalUsage)
390 signal_notify(sigexitnum_pd());
391 }
394 // --------------------- loading libraries ---------------------
396 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
397 extern struct JavaVM_ main_vm;
399 static void* _native_java_library = NULL;
401 void* os::native_java_library() {
402 if (_native_java_library == NULL) {
403 char buffer[JVM_MAXPATHLEN];
404 char ebuf[1024];
406 // Try to load verify dll first. In 1.3 java dll depends on it and is not
407 // always able to find it when the loading executable is outside the JDK.
408 // In order to keep working with 1.2 we ignore any loading errors.
409 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
410 "verify")) {
411 dll_load(buffer, ebuf, sizeof(ebuf));
412 }
414 // Load java dll
415 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
416 "java")) {
417 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
418 }
419 if (_native_java_library == NULL) {
420 vm_exit_during_initialization("Unable to load native library", ebuf);
421 }
423 #if defined(__OpenBSD__)
424 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
425 // ignore errors
426 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
427 "net")) {
428 dll_load(buffer, ebuf, sizeof(ebuf));
429 }
430 #endif
431 }
432 static jboolean onLoaded = JNI_FALSE;
433 if (onLoaded) {
434 // We may have to wait to fire OnLoad until TLS is initialized.
435 if (ThreadLocalStorage::is_initialized()) {
436 // The JNI_OnLoad handling is normally done by method load in
437 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
438 // explicitly so we have to check for JNI_OnLoad as well
439 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
440 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
441 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
442 if (JNI_OnLoad != NULL) {
443 JavaThread* thread = JavaThread::current();
444 ThreadToNativeFromVM ttn(thread);
445 HandleMark hm(thread);
446 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
447 onLoaded = JNI_TRUE;
448 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
449 vm_exit_during_initialization("Unsupported JNI version");
450 }
451 }
452 }
453 }
454 return _native_java_library;
455 }
457 /*
458 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
459 * If check_lib == true then we are looking for an
460 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
461 * this library is statically linked into the image.
462 * If check_lib == false then we will look for the appropriate symbol in the
463 * executable if agent_lib->is_static_lib() == true or in the shared library
464 * referenced by 'handle'.
465 */
466 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
467 const char *syms[], size_t syms_len) {
468 assert(agent_lib != NULL, "sanity check");
469 const char *lib_name;
470 void *handle = agent_lib->os_lib();
471 void *entryName = NULL;
472 char *agent_function_name;
473 size_t i;
475 // If checking then use the agent name otherwise test is_static_lib() to
476 // see how to process this lookup
477 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
478 for (i = 0; i < syms_len; i++) {
479 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
480 if (agent_function_name == NULL) {
481 break;
482 }
483 entryName = dll_lookup(handle, agent_function_name);
484 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
485 if (entryName != NULL) {
486 break;
487 }
488 }
489 return entryName;
490 }
492 // See if the passed in agent is statically linked into the VM image.
493 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
494 size_t syms_len) {
495 void *ret;
496 void *proc_handle;
497 void *save_handle;
499 assert(agent_lib != NULL, "sanity check");
500 if (agent_lib->name() == NULL) {
501 return false;
502 }
503 proc_handle = get_default_process_handle();
504 // Check for Agent_OnLoad/Attach_lib_name function
505 save_handle = agent_lib->os_lib();
506 // We want to look in this process' symbol table.
507 agent_lib->set_os_lib(proc_handle);
508 ret = find_agent_function(agent_lib, true, syms, syms_len);
509 if (ret != NULL) {
510 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
511 agent_lib->set_valid();
512 agent_lib->set_static_lib(true);
513 return true;
514 }
515 agent_lib->set_os_lib(save_handle);
516 return false;
517 }
519 // --------------------- heap allocation utilities ---------------------
521 char *os::strdup(const char *str, MEMFLAGS flags) {
522 size_t size = strlen(str);
523 char *dup_str = (char *)malloc(size + 1, flags);
524 if (dup_str == NULL) return NULL;
525 strcpy(dup_str, str);
526 return dup_str;
527 }
531 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
533 #ifdef ASSERT
534 static void verify_memory(void* ptr) {
535 GuardedMemory guarded(ptr);
536 if (!guarded.verify_guards()) {
537 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
538 tty->print_cr("## memory stomp:");
539 guarded.print_on(tty);
540 fatal("memory stomping error");
541 }
542 }
543 #endif
545 //
546 // This function supports testing of the malloc out of memory
547 // condition without really running the system out of memory.
548 //
549 static u_char* testMalloc(size_t alloc_size) {
550 assert(MallocMaxTestWords > 0, "sanity check");
552 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
553 return NULL;
554 }
556 u_char* ptr = (u_char*)::malloc(alloc_size);
558 if (ptr != NULL) {
559 Atomic::add(((jint) (alloc_size / BytesPerWord)),
560 (volatile jint *) &cur_malloc_words);
561 }
562 return ptr;
563 }
565 void* os::malloc(size_t size, MEMFLAGS flags) {
566 return os::malloc(size, flags, CALLER_PC);
567 }
569 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
570 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
571 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
573 #ifdef ASSERT
574 // checking for the WatcherThread and crash_protection first
575 // since os::malloc can be called when the libjvm.{dll,so} is
576 // first loaded and we don't have a thread yet.
577 // try to find the thread after we see that the watcher thread
578 // exists and has crash protection.
579 WatcherThread *wt = WatcherThread::watcher_thread();
580 if (wt != NULL && wt->has_crash_protection()) {
581 Thread* thread = ThreadLocalStorage::get_thread_slow();
582 if (thread == wt) {
583 assert(!wt->has_crash_protection(),
584 "Can't malloc with crash protection from WatcherThread");
585 }
586 }
587 #endif
589 if (size == 0) {
590 // return a valid pointer if size is zero
591 // if NULL is returned the calling functions assume out of memory.
592 size = 1;
593 }
595 // NMT support
596 NMT_TrackingLevel level = MemTracker::tracking_level();
597 size_t nmt_header_size = MemTracker::malloc_header_size(level);
599 #ifndef ASSERT
600 const size_t alloc_size = size + nmt_header_size;
601 #else
602 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
603 if (size + nmt_header_size > alloc_size) { // Check for rollover.
604 return NULL;
605 }
606 #endif
608 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
610 u_char* ptr;
611 if (MallocMaxTestWords > 0) {
612 ptr = testMalloc(alloc_size);
613 } else {
614 ptr = (u_char*)::malloc(alloc_size);
615 }
617 #ifdef ASSERT
618 if (ptr == NULL) {
619 return NULL;
620 }
621 // Wrap memory with guard
622 GuardedMemory guarded(ptr, size + nmt_header_size);
623 ptr = guarded.get_user_ptr();
624 #endif
625 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
626 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
627 breakpoint();
628 }
629 debug_only(if (paranoid) verify_memory(ptr));
630 if (PrintMalloc && tty != NULL) {
631 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
632 }
634 // we do not track guard memory
635 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
636 }
638 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
639 return os::realloc(memblock, size, flags, CALLER_PC);
640 }
642 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
643 #ifndef ASSERT
644 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
645 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
646 // NMT support
647 void* membase = MemTracker::record_free(memblock);
648 NMT_TrackingLevel level = MemTracker::tracking_level();
649 size_t nmt_header_size = MemTracker::malloc_header_size(level);
650 void* ptr = ::realloc(membase, size + nmt_header_size);
651 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
652 #else
653 if (memblock == NULL) {
654 return os::malloc(size, memflags, stack);
655 }
656 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
657 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
658 breakpoint();
659 }
660 // NMT support
661 void* membase = MemTracker::malloc_base(memblock);
662 verify_memory(membase);
663 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
664 if (size == 0) {
665 return NULL;
666 }
667 // always move the block
668 void* ptr = os::malloc(size, memflags, stack);
669 if (PrintMalloc) {
670 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
671 }
672 // Copy to new memory if malloc didn't fail
673 if ( ptr != NULL ) {
674 GuardedMemory guarded(MemTracker::malloc_base(memblock));
675 // Guard's user data contains NMT header
676 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
677 memcpy(ptr, memblock, MIN2(size, memblock_size));
678 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
679 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
680 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
681 breakpoint();
682 }
683 os::free(memblock);
684 }
685 return ptr;
686 #endif
687 }
690 void os::free(void *memblock, MEMFLAGS memflags) {
691 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
692 #ifdef ASSERT
693 if (memblock == NULL) return;
694 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
695 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
696 breakpoint();
697 }
698 void* membase = MemTracker::record_free(memblock);
699 verify_memory(membase);
700 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
702 GuardedMemory guarded(membase);
703 size_t size = guarded.get_user_size();
704 inc_stat_counter(&free_bytes, size);
705 membase = guarded.release_for_freeing();
706 if (PrintMalloc && tty != NULL) {
707 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
708 }
709 ::free(membase);
710 #else
711 void* membase = MemTracker::record_free(memblock);
712 ::free(membase);
713 #endif
714 }
716 void os::init_random(long initval) {
717 _rand_seed = initval;
718 }
721 long os::random() {
722 /* standard, well-known linear congruential random generator with
723 * next_rand = (16807*seed) mod (2**31-1)
724 * see
725 * (1) "Random Number Generators: Good Ones Are Hard to Find",
726 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
727 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
728 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
729 */
730 const long a = 16807;
731 const unsigned long m = 2147483647;
732 const long q = m / a; assert(q == 127773, "weird math");
733 const long r = m % a; assert(r == 2836, "weird math");
735 // compute az=2^31p+q
736 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
737 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
738 lo += (hi & 0x7FFF) << 16;
740 // if q overflowed, ignore the overflow and increment q
741 if (lo > m) {
742 lo &= m;
743 ++lo;
744 }
745 lo += hi >> 15;
747 // if (p+q) overflowed, ignore the overflow and increment (p+q)
748 if (lo > m) {
749 lo &= m;
750 ++lo;
751 }
752 return (_rand_seed = lo);
753 }
755 // The INITIALIZED state is distinguished from the SUSPENDED state because the
756 // conditions in which a thread is first started are different from those in which
757 // a suspension is resumed. These differences make it hard for us to apply the
758 // tougher checks when starting threads that we want to do when resuming them.
759 // However, when start_thread is called as a result of Thread.start, on a Java
760 // thread, the operation is synchronized on the Java Thread object. So there
761 // cannot be a race to start the thread and hence for the thread to exit while
762 // we are working on it. Non-Java threads that start Java threads either have
763 // to do so in a context in which races are impossible, or should do appropriate
764 // locking.
766 void os::start_thread(Thread* thread) {
767 // guard suspend/resume
768 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
769 OSThread* osthread = thread->osthread();
770 osthread->set_state(RUNNABLE);
771 pd_start_thread(thread);
772 }
774 //---------------------------------------------------------------------------
775 // Helper functions for fatal error handler
777 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
778 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
780 int cols = 0;
781 int cols_per_line = 0;
782 switch (unitsize) {
783 case 1: cols_per_line = 16; break;
784 case 2: cols_per_line = 8; break;
785 case 4: cols_per_line = 4; break;
786 case 8: cols_per_line = 2; break;
787 default: return;
788 }
790 address p = start;
791 st->print(PTR_FORMAT ": ", start);
792 while (p < end) {
793 switch (unitsize) {
794 case 1: st->print("%02x", *(u1*)p); break;
795 case 2: st->print("%04x", *(u2*)p); break;
796 case 4: st->print("%08x", *(u4*)p); break;
797 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
798 }
799 p += unitsize;
800 cols++;
801 if (cols >= cols_per_line && p < end) {
802 cols = 0;
803 st->cr();
804 st->print(PTR_FORMAT ": ", p);
805 } else {
806 st->print(" ");
807 }
808 }
809 st->cr();
810 }
812 void os::print_environment_variables(outputStream* st, const char** env_list,
813 char* buffer, int len) {
814 if (env_list) {
815 st->print_cr("Environment Variables:");
817 for (int i = 0; env_list[i] != NULL; i++) {
818 if (getenv(env_list[i], buffer, len)) {
819 st->print("%s", env_list[i]);
820 st->print("=");
821 st->print_cr("%s", buffer);
822 }
823 }
824 }
825 }
827 void os::print_cpu_info(outputStream* st) {
828 // cpu
829 st->print("CPU:");
830 st->print("total %d", os::processor_count());
831 // It's not safe to query number of active processors after crash
832 // st->print("(active %d)", os::active_processor_count());
833 st->print(" %s", VM_Version::cpu_features());
834 st->cr();
835 pd_print_cpu_info(st);
836 }
838 void os::print_date_and_time(outputStream *st) {
839 const int secs_per_day = 86400;
840 const int secs_per_hour = 3600;
841 const int secs_per_min = 60;
843 time_t tloc;
844 (void)time(&tloc);
845 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
847 double t = os::elapsedTime();
848 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
849 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
850 // before printf. We lost some precision, but who cares?
851 int eltime = (int)t; // elapsed time in seconds
853 // print elapsed time in a human-readable format:
854 int eldays = eltime / secs_per_day;
855 int day_secs = eldays * secs_per_day;
856 int elhours = (eltime - day_secs) / secs_per_hour;
857 int hour_secs = elhours * secs_per_hour;
858 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
859 int minute_secs = elmins * secs_per_min;
860 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
861 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
862 }
864 // moved from debug.cpp (used to be find()) but still called from there
865 // The verbose parameter is only set by the debug code in one case
866 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
867 address addr = (address)x;
868 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
869 if (b != NULL) {
870 if (b->is_buffer_blob()) {
871 // the interpreter is generated into a buffer blob
872 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
873 if (i != NULL) {
874 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
875 i->print_on(st);
876 return;
877 }
878 if (Interpreter::contains(addr)) {
879 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
880 " (not bytecode specific)", addr);
881 return;
882 }
883 //
884 if (AdapterHandlerLibrary::contains(b)) {
885 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
886 AdapterHandlerLibrary::print_handler_on(st, b);
887 }
888 // the stubroutines are generated into a buffer blob
889 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
890 if (d != NULL) {
891 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
892 d->print_on(st);
893 st->cr();
894 return;
895 }
896 if (StubRoutines::contains(addr)) {
897 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
898 "stub routine", addr);
899 return;
900 }
901 // the InlineCacheBuffer is using stubs generated into a buffer blob
902 if (InlineCacheBuffer::contains(addr)) {
903 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
904 return;
905 }
906 VtableStub* v = VtableStubs::stub_containing(addr);
907 if (v != NULL) {
908 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
909 v->print_on(st);
910 st->cr();
911 return;
912 }
913 }
914 nmethod* nm = b->as_nmethod_or_null();
915 if (nm != NULL) {
916 ResourceMark rm;
917 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
918 addr, (int)(addr - nm->entry_point()), nm);
919 if (verbose) {
920 st->print(" for ");
921 nm->method()->print_value_on(st);
922 }
923 st->cr();
924 nm->print_nmethod(verbose);
925 return;
926 }
927 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
928 b->print_on(st);
929 return;
930 }
932 if (Universe::heap()->is_in(addr)) {
933 HeapWord* p = Universe::heap()->block_start(addr);
934 bool print = false;
935 // If we couldn't find it it just may mean that heap wasn't parseable
936 // See if we were just given an oop directly
937 if (p != NULL && Universe::heap()->block_is_obj(p)) {
938 print = true;
939 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
940 p = (HeapWord*) addr;
941 print = true;
942 }
943 if (print) {
944 if (p == (HeapWord*) addr) {
945 st->print_cr(INTPTR_FORMAT " is an oop", addr);
946 } else {
947 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
948 }
949 oop(p)->print_on(st);
950 return;
951 }
952 } else {
953 if (Universe::heap()->is_in_reserved(addr)) {
954 st->print_cr(INTPTR_FORMAT " is an unallocated location "
955 "in the heap", addr);
956 return;
957 }
958 }
959 if (JNIHandles::is_global_handle((jobject) addr)) {
960 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
961 return;
962 }
963 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
964 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
965 return;
966 }
967 #ifndef PRODUCT
968 // we don't keep the block list in product mode
969 if (JNIHandleBlock::any_contains((jobject) addr)) {
970 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
971 return;
972 }
973 #endif
975 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
976 // Check for privilege stack
977 if (thread->privileged_stack_top() != NULL &&
978 thread->privileged_stack_top()->contains(addr)) {
979 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
980 "for thread: " INTPTR_FORMAT, addr, thread);
981 if (verbose) thread->print_on(st);
982 return;
983 }
984 // If the addr is a java thread print information about that.
985 if (addr == (address)thread) {
986 if (verbose) {
987 thread->print_on(st);
988 } else {
989 st->print_cr(INTPTR_FORMAT " is a thread", addr);
990 }
991 return;
992 }
993 // If the addr is in the stack region for this thread then report that
994 // and print thread info
995 if (thread->stack_base() >= addr &&
996 addr > (thread->stack_base() - thread->stack_size())) {
997 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
998 INTPTR_FORMAT, addr, thread);
999 if (verbose) thread->print_on(st);
1000 return;
1001 }
1003 }
1005 // Check if in metaspace and print types that have vptrs (only method now)
1006 if (Metaspace::contains(addr)) {
1007 if (Method::has_method_vptr((const void*)addr)) {
1008 ((Method*)addr)->print_value_on(st);
1009 st->cr();
1010 } else {
1011 // Use addr->print() from the debugger instead (not here)
1012 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1013 }
1014 return;
1015 }
1017 // Try an OS specific find
1018 if (os::find(addr, st)) {
1019 return;
1020 }
1022 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1023 }
1025 // Looks like all platforms except IA64 can use the same function to check
1026 // if C stack is walkable beyond current frame. The check for fp() is not
1027 // necessary on Sparc, but it's harmless.
1028 bool os::is_first_C_frame(frame* fr) {
1029 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1030 // On IA64 we have to check if the callers bsp is still valid
1031 // (i.e. within the register stack bounds).
1032 // Notice: this only works for threads created by the VM and only if
1033 // we walk the current stack!!! If we want to be able to walk
1034 // arbitrary other threads, we'll have to somehow store the thread
1035 // object in the frame.
1036 Thread *thread = Thread::current();
1037 if ((address)fr->fp() <=
1038 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1039 // This check is a little hacky, because on Linux the first C
1040 // frame's ('start_thread') register stack frame starts at
1041 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1042 // ('__pthread_bound_body') register stack frame seems to really
1043 // start at "register_stack_base".
1044 return true;
1045 } else {
1046 return false;
1047 }
1048 #elif defined(IA64) && defined(_WIN32)
1049 return true;
1050 #else
1051 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1052 // Check usp first, because if that's bad the other accessors may fault
1053 // on some architectures. Ditto ufp second, etc.
1054 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1055 // sp on amd can be 32 bit aligned.
1056 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1058 uintptr_t usp = (uintptr_t)fr->sp();
1059 if ((usp & sp_align_mask) != 0) return true;
1061 uintptr_t ufp = (uintptr_t)fr->fp();
1062 if ((ufp & fp_align_mask) != 0) return true;
1064 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1065 if ((old_sp & sp_align_mask) != 0) return true;
1066 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1068 uintptr_t old_fp = (uintptr_t)fr->link();
1069 if ((old_fp & fp_align_mask) != 0) return true;
1070 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1072 // stack grows downwards; if old_fp is below current fp or if the stack
1073 // frame is too large, either the stack is corrupted or fp is not saved
1074 // on stack (i.e. on x86, ebp may be used as general register). The stack
1075 // is not walkable beyond current frame.
1076 if (old_fp < ufp) return true;
1077 if (old_fp - ufp > 64 * K) return true;
1079 return false;
1080 #endif
1081 }
1083 #ifdef ASSERT
1084 extern "C" void test_random() {
1085 const double m = 2147483647;
1086 double mean = 0.0, variance = 0.0, t;
1087 long reps = 10000;
1088 unsigned long seed = 1;
1090 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1091 os::init_random(seed);
1092 long num;
1093 for (int k = 0; k < reps; k++) {
1094 num = os::random();
1095 double u = (double)num / m;
1096 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1098 // calculate mean and variance of the random sequence
1099 mean += u;
1100 variance += (u*u);
1101 }
1102 mean /= reps;
1103 variance /= (reps - 1);
1105 assert(num == 1043618065, "bad seed");
1106 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1107 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1108 const double eps = 0.0001;
1109 t = fabsd(mean - 0.5018);
1110 assert(t < eps, "bad mean");
1111 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1112 assert(t < eps, "bad variance");
1113 }
1114 #endif
1117 // Set up the boot classpath.
1119 char* os::format_boot_path(const char* format_string,
1120 const char* home,
1121 int home_len,
1122 char fileSep,
1123 char pathSep) {
1124 assert((fileSep == '/' && pathSep == ':') ||
1125 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1127 // Scan the format string to determine the length of the actual
1128 // boot classpath, and handle platform dependencies as well.
1129 int formatted_path_len = 0;
1130 const char* p;
1131 for (p = format_string; *p != 0; ++p) {
1132 if (*p == '%') formatted_path_len += home_len - 1;
1133 ++formatted_path_len;
1134 }
1136 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1137 if (formatted_path == NULL) {
1138 return NULL;
1139 }
1141 // Create boot classpath from format, substituting separator chars and
1142 // java home directory.
1143 char* q = formatted_path;
1144 for (p = format_string; *p != 0; ++p) {
1145 switch (*p) {
1146 case '%':
1147 strcpy(q, home);
1148 q += home_len;
1149 break;
1150 case '/':
1151 *q++ = fileSep;
1152 break;
1153 case ':':
1154 *q++ = pathSep;
1155 break;
1156 default:
1157 *q++ = *p;
1158 }
1159 }
1160 *q = '\0';
1162 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1163 return formatted_path;
1164 }
1167 bool os::set_boot_path(char fileSep, char pathSep) {
1168 const char* home = Arguments::get_java_home();
1169 int home_len = (int)strlen(home);
1171 static const char* meta_index_dir_format = "%/lib/";
1172 static const char* meta_index_format = "%/lib/meta-index";
1173 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1174 if (meta_index == NULL) return false;
1175 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1176 if (meta_index_dir == NULL) return false;
1177 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1179 // Any modification to the JAR-file list, for the boot classpath must be
1180 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1181 // path class JARs, are stripped for StackMapTable to reduce download size.
1182 static const char classpath_format[] =
1183 "%/lib/resources.jar:"
1184 "%/lib/rt.jar:"
1185 "%/lib/sunrsasign.jar:"
1186 "%/lib/jsse.jar:"
1187 "%/lib/jce.jar:"
1188 "%/lib/charsets.jar:"
1189 "%/lib/jfr.jar:"
1190 "%/classes";
1191 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1192 if (sysclasspath == NULL) return false;
1193 Arguments::set_sysclasspath(sysclasspath);
1195 return true;
1196 }
1198 /*
1199 * Splits a path, based on its separator, the number of
1200 * elements is returned back in n.
1201 * It is the callers responsibility to:
1202 * a> check the value of n, and n may be 0.
1203 * b> ignore any empty path elements
1204 * c> free up the data.
1205 */
1206 char** os::split_path(const char* path, int* n) {
1207 *n = 0;
1208 if (path == NULL || strlen(path) == 0) {
1209 return NULL;
1210 }
1211 const char psepchar = *os::path_separator();
1212 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1213 if (inpath == NULL) {
1214 return NULL;
1215 }
1216 strcpy(inpath, path);
1217 int count = 1;
1218 char* p = strchr(inpath, psepchar);
1219 // Get a count of elements to allocate memory
1220 while (p != NULL) {
1221 count++;
1222 p++;
1223 p = strchr(p, psepchar);
1224 }
1225 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1226 if (opath == NULL) {
1227 return NULL;
1228 }
1230 // do the actual splitting
1231 p = inpath;
1232 for (int i = 0 ; i < count ; i++) {
1233 size_t len = strcspn(p, os::path_separator());
1234 if (len > JVM_MAXPATHLEN) {
1235 return NULL;
1236 }
1237 // allocate the string and add terminator storage
1238 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1239 if (s == NULL) {
1240 return NULL;
1241 }
1242 strncpy(s, p, len);
1243 s[len] = '\0';
1244 opath[i] = s;
1245 p += len + 1;
1246 }
1247 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1248 *n = count;
1249 return opath;
1250 }
1252 void os::set_memory_serialize_page(address page) {
1253 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1254 _mem_serialize_page = (volatile int32_t *)page;
1255 // We initialize the serialization page shift count here
1256 // We assume a cache line size of 64 bytes
1257 assert(SerializePageShiftCount == count,
1258 "thread size changed, fix SerializePageShiftCount constant");
1259 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1260 }
1262 static volatile intptr_t SerializePageLock = 0;
1264 // This method is called from signal handler when SIGSEGV occurs while the current
1265 // thread tries to store to the "read-only" memory serialize page during state
1266 // transition.
1267 void os::block_on_serialize_page_trap() {
1268 if (TraceSafepoint) {
1269 tty->print_cr("Block until the serialize page permission restored");
1270 }
1271 // When VMThread is holding the SerializePageLock during modifying the
1272 // access permission of the memory serialize page, the following call
1273 // will block until the permission of that page is restored to rw.
1274 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1275 // this case, it's OK as the signal is synchronous and we know precisely when
1276 // it can occur.
1277 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1278 Thread::muxRelease(&SerializePageLock);
1279 }
1281 // Serialize all thread state variables
1282 void os::serialize_thread_states() {
1283 // On some platforms such as Solaris & Linux, the time duration of the page
1284 // permission restoration is observed to be much longer than expected due to
1285 // scheduler starvation problem etc. To avoid the long synchronization
1286 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1287 // the mutator thread if such case is encountered. See bug 6546278 for details.
1288 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1289 os::protect_memory((char *)os::get_memory_serialize_page(),
1290 os::vm_page_size(), MEM_PROT_READ);
1291 os::protect_memory((char *)os::get_memory_serialize_page(),
1292 os::vm_page_size(), MEM_PROT_RW);
1293 Thread::muxRelease(&SerializePageLock);
1294 }
1296 // Returns true if the current stack pointer is above the stack shadow
1297 // pages, false otherwise.
1299 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1300 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1301 address sp = current_stack_pointer();
1302 // Check if we have StackShadowPages above the yellow zone. This parameter
1303 // is dependent on the depth of the maximum VM call stack possible from
1304 // the handler for stack overflow. 'instanceof' in the stack overflow
1305 // handler or a println uses at least 8k stack of VM and native code
1306 // respectively.
1307 const int framesize_in_bytes =
1308 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1309 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1310 * vm_page_size()) + framesize_in_bytes;
1311 // The very lower end of the stack
1312 address stack_limit = thread->stack_base() - thread->stack_size();
1313 return (sp > (stack_limit + reserved_area));
1314 }
1316 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1317 uint min_pages)
1318 {
1319 assert(min_pages > 0, "sanity");
1320 if (UseLargePages) {
1321 const size_t max_page_size = region_max_size / min_pages;
1323 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1324 const size_t sz = _page_sizes[i];
1325 const size_t mask = sz - 1;
1326 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1327 // The largest page size with no fragmentation.
1328 return sz;
1329 }
1331 if (sz <= max_page_size) {
1332 // The largest page size that satisfies the min_pages requirement.
1333 return sz;
1334 }
1335 }
1336 }
1338 return vm_page_size();
1339 }
1341 #ifndef PRODUCT
1342 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1343 {
1344 if (TracePageSizes) {
1345 tty->print("%s: ", str);
1346 for (int i = 0; i < count; ++i) {
1347 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1348 }
1349 tty->cr();
1350 }
1351 }
1353 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1354 const size_t region_max_size, const size_t page_size,
1355 const char* base, const size_t size)
1356 {
1357 if (TracePageSizes) {
1358 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1359 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1360 " size=" SIZE_FORMAT,
1361 str, region_min_size, region_max_size,
1362 page_size, base, size);
1363 }
1364 }
1365 #endif // #ifndef PRODUCT
1367 // This is the working definition of a server class machine:
1368 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1369 // because the graphics memory (?) sometimes masks physical memory.
1370 // If you want to change the definition of a server class machine
1371 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1372 // then you'll have to parameterize this method based on that state,
1373 // as was done for logical processors here, or replicate and
1374 // specialize this method for each platform. (Or fix os to have
1375 // some inheritance structure and use subclassing. Sigh.)
1376 // If you want some platform to always or never behave as a server
1377 // class machine, change the setting of AlwaysActAsServerClassMachine
1378 // and NeverActAsServerClassMachine in globals*.hpp.
1379 bool os::is_server_class_machine() {
1380 // First check for the early returns
1381 if (NeverActAsServerClassMachine) {
1382 return false;
1383 }
1384 if (AlwaysActAsServerClassMachine) {
1385 return true;
1386 }
1387 // Then actually look at the machine
1388 bool result = false;
1389 const unsigned int server_processors = 2;
1390 const julong server_memory = 2UL * G;
1391 // We seem not to get our full complement of memory.
1392 // We allow some part (1/8?) of the memory to be "missing",
1393 // based on the sizes of DIMMs, and maybe graphics cards.
1394 const julong missing_memory = 256UL * M;
1396 /* Is this a server class machine? */
1397 if ((os::active_processor_count() >= (int)server_processors) &&
1398 (os::physical_memory() >= (server_memory - missing_memory))) {
1399 const unsigned int logical_processors =
1400 VM_Version::logical_processors_per_package();
1401 if (logical_processors > 1) {
1402 const unsigned int physical_packages =
1403 os::active_processor_count() / logical_processors;
1404 if (physical_packages > server_processors) {
1405 result = true;
1406 }
1407 } else {
1408 result = true;
1409 }
1410 }
1411 return result;
1412 }
1414 void os::SuspendedThreadTask::run() {
1415 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1416 internal_do_task();
1417 _done = true;
1418 }
1420 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1421 return os::pd_create_stack_guard_pages(addr, bytes);
1422 }
1424 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1425 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1426 if (result != NULL) {
1427 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1428 }
1430 return result;
1431 }
1433 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1434 MEMFLAGS flags) {
1435 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1436 if (result != NULL) {
1437 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1438 MemTracker::record_virtual_memory_type((address)result, flags);
1439 }
1441 return result;
1442 }
1444 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1445 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1446 if (result != NULL) {
1447 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1448 }
1449 return result;
1450 }
1452 void os::split_reserved_memory(char *base, size_t size,
1453 size_t split, bool realloc) {
1454 pd_split_reserved_memory(base, size, split, realloc);
1455 }
1457 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1458 bool res = pd_commit_memory(addr, bytes, executable);
1459 if (res) {
1460 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1461 }
1462 return res;
1463 }
1465 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1466 bool executable) {
1467 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1468 if (res) {
1469 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1470 }
1471 return res;
1472 }
1474 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1475 const char* mesg) {
1476 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1477 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1478 }
1480 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1481 bool executable, const char* mesg) {
1482 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1483 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1484 }
1486 bool os::uncommit_memory(char* addr, size_t bytes) {
1487 bool res;
1488 if (MemTracker::tracking_level() > NMT_minimal) {
1489 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1490 res = pd_uncommit_memory(addr, bytes);
1491 if (res) {
1492 tkr.record((address)addr, bytes);
1493 }
1494 } else {
1495 res = pd_uncommit_memory(addr, bytes);
1496 }
1497 return res;
1498 }
1500 bool os::release_memory(char* addr, size_t bytes) {
1501 bool res;
1502 if (MemTracker::tracking_level() > NMT_minimal) {
1503 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1504 res = pd_release_memory(addr, bytes);
1505 if (res) {
1506 tkr.record((address)addr, bytes);
1507 }
1508 } else {
1509 res = pd_release_memory(addr, bytes);
1510 }
1511 return res;
1512 }
1515 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1516 char *addr, size_t bytes, bool read_only,
1517 bool allow_exec) {
1518 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1519 if (result != NULL) {
1520 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1521 }
1522 return result;
1523 }
1525 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1526 char *addr, size_t bytes, bool read_only,
1527 bool allow_exec) {
1528 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1529 read_only, allow_exec);
1530 }
1532 bool os::unmap_memory(char *addr, size_t bytes) {
1533 bool result;
1534 if (MemTracker::tracking_level() > NMT_minimal) {
1535 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1536 result = pd_unmap_memory(addr, bytes);
1537 if (result) {
1538 tkr.record((address)addr, bytes);
1539 }
1540 } else {
1541 result = pd_unmap_memory(addr, bytes);
1542 }
1543 return result;
1544 }
1546 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1547 pd_free_memory(addr, bytes, alignment_hint);
1548 }
1550 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1551 pd_realign_memory(addr, bytes, alignment_hint);
1552 }
1554 #ifndef TARGET_OS_FAMILY_windows
1555 /* try to switch state from state "from" to state "to"
1556 * returns the state set after the method is complete
1557 */
1558 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1559 os::SuspendResume::State to)
1560 {
1561 os::SuspendResume::State result =
1562 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1563 if (result == from) {
1564 // success
1565 return to;
1566 }
1567 return result;
1568 }
1569 #endif