1 /*
2 * Copyright (c) 1997, 2025, 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 */
24
25 #include "compiler/compiler_globals.hpp"
26 #include "gc/shared/gc_globals.hpp"
27 #include "logging/log.hpp"
28 #include "logging/logStream.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "memory/universe.hpp"
31 #include "runtime/atomic.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/javaThread.hpp"
34 #include "runtime/mutexLocker.hpp"
35 #include "runtime/safepoint.hpp"
36 #include "runtime/vmThread.hpp"
37 #include "services/management.hpp"
38 #include "utilities/vmError.hpp"
39
40 // Mutexes used in the VM (see comment in mutexLocker.hpp):
41
42 Mutex* NMethodState_lock = nullptr;
43 Mutex* NMethodEntryBarrier_lock = nullptr;
44 Monitor* SystemDictionary_lock = nullptr;
45 Mutex* InvokeMethodTypeTable_lock = nullptr;
46 Monitor* InvokeMethodIntrinsicTable_lock = nullptr;
47 Mutex* SharedDictionary_lock = nullptr;
48 Monitor* ClassInitError_lock = nullptr;
49 Mutex* Module_lock = nullptr;
50 Mutex* CompiledIC_lock = nullptr;
51 Mutex* VMStatistic_lock = nullptr;
52 Mutex* JmethodIdCreation_lock = nullptr;
53 Mutex* JfieldIdCreation_lock = nullptr;
54 Monitor* JNICritical_lock = nullptr;
55 Mutex* JvmtiThreadState_lock = nullptr;
56 Monitor* EscapeBarrier_lock = nullptr;
57 Monitor* JvmtiVTMSTransition_lock = nullptr;
58 Mutex* JvmtiVThreadSuspend_lock = nullptr;
59 Monitor* Heap_lock = nullptr;
60 #if INCLUDE_PARALLELGC
61 Mutex* PSOldGenExpand_lock = nullptr;
62 #endif
63 Mutex* AdapterHandlerLibrary_lock = nullptr;
64 Mutex* SignatureHandlerLibrary_lock = nullptr;
65 Mutex* VtableStubs_lock = nullptr;
66 Mutex* SymbolArena_lock = nullptr;
67 Monitor* StringDedup_lock = nullptr;
68 Mutex* StringDedupIntern_lock = nullptr;
69 Monitor* CodeCache_lock = nullptr;
70 Mutex* TouchedMethodLog_lock = nullptr;
71 Mutex* RetData_lock = nullptr;
72 Monitor* VMOperation_lock = nullptr;
73 Monitor* ThreadsLockThrottle_lock = nullptr;
74 Monitor* Threads_lock = nullptr;
75 Mutex* NonJavaThreadsList_lock = nullptr;
76 Mutex* NonJavaThreadsListSync_lock = nullptr;
77 Monitor* STS_lock = nullptr;
78 Mutex* MonitoringSupport_lock = nullptr;
79 Monitor* ConcurrentGCBreakpoints_lock = nullptr;
80 Mutex* Compile_lock = nullptr;
81 Monitor* CompileTaskWait_lock = nullptr;
82 Monitor* MethodCompileQueue_lock = nullptr;
83 Monitor* MethodCompileQueueC1_lock = nullptr;
84 Monitor* MethodCompileQueueC2_lock = nullptr;
85 Monitor* MethodCompileQueueSC1_lock = nullptr;
86 Monitor* MethodCompileQueueSC2_lock = nullptr;
87 Monitor* CompileThread_lock = nullptr;
88 Monitor* Compilation_lock = nullptr;
89 Mutex* CompileStatistics_lock = nullptr;
90 Mutex* DirectivesStack_lock = nullptr;
91 Monitor* Terminator_lock = nullptr;
92 Monitor* InitCompleted_lock = nullptr;
93 Monitor* BeforeExit_lock = nullptr;
94 Monitor* Notify_lock = nullptr;
95 Mutex* ExceptionCache_lock = nullptr;
96 Mutex* TrainingData_lock = nullptr;
97 Monitor* TrainingReplayQueue_lock = nullptr;
98 #ifndef PRODUCT
99 Mutex* FullGCALot_lock = nullptr;
100 #endif
101
102 Mutex* tty_lock = nullptr;
103
104 Mutex* RawMonitor_lock = nullptr;
105 Mutex* PerfDataMemAlloc_lock = nullptr;
106 Mutex* PerfDataManager_lock = nullptr;
107
108 #if INCLUDE_G1GC
109 Monitor* G1CGC_lock = nullptr;
110 Mutex* G1DetachedRefinementStats_lock = nullptr;
111 Mutex* G1FreeList_lock = nullptr;
112 Mutex* G1MarkStackChunkList_lock = nullptr;
113 Mutex* G1MarkStackFreeList_lock = nullptr;
114 Monitor* G1OldGCCount_lock = nullptr;
115 Mutex* G1OldSets_lock = nullptr;
116 Mutex* G1Uncommit_lock = nullptr;
117 Monitor* G1RootRegionScan_lock = nullptr;
118 Mutex* G1RareEvent_lock = nullptr;
119 #endif
120
121 Mutex* Management_lock = nullptr;
122 Monitor* MonitorDeflation_lock = nullptr;
123 Monitor* Service_lock = nullptr;
124 Monitor* Notification_lock = nullptr;
125 Monitor* PeriodicTask_lock = nullptr;
126 Monitor* RedefineClasses_lock = nullptr;
127 Mutex* Verify_lock = nullptr;
128
129 #if INCLUDE_JFR
130 Mutex* JfrStacktrace_lock = nullptr;
131 Monitor* JfrMsg_lock = nullptr;
132 Mutex* JfrBuffer_lock = nullptr;
133 #endif
134
135 Mutex* CodeHeapStateAnalytics_lock = nullptr;
136
137 Mutex* ExternalsRecorder_lock = nullptr;
138
139 Mutex* AOTCodeCStrings_lock = nullptr;
140
141 Monitor* ContinuationRelativize_lock = nullptr;
142
143 Mutex* Metaspace_lock = nullptr;
144 Monitor* MetaspaceCritical_lock = nullptr;
145 Mutex* ClassLoaderDataGraph_lock = nullptr;
146 Monitor* ThreadsSMRDelete_lock = nullptr;
147 Mutex* ThreadIdTableCreate_lock = nullptr;
148 Mutex* SharedDecoder_lock = nullptr;
149 Mutex* DCmdFactory_lock = nullptr;
150 Mutex* NMTQuery_lock = nullptr;
151 Mutex* NMTCompilationCostHistory_lock = nullptr;
152 Mutex* NmtVirtualMemory_lock = nullptr;
153
154 #if INCLUDE_CDS
155 #if INCLUDE_JVMTI
156 Mutex* CDSClassFileStream_lock = nullptr;
157 #endif
158 Mutex* DumpTimeTable_lock = nullptr;
159 Mutex* CDSLambda_lock = nullptr;
160 Mutex* DumpRegion_lock = nullptr;
161 Mutex* ClassListFile_lock = nullptr;
162 Mutex* UnregisteredClassesTable_lock= nullptr;
163 Mutex* LambdaFormInvokers_lock = nullptr;
164 Mutex* ScratchObjects_lock = nullptr;
165 Mutex* ArchivedObjectTables_lock = nullptr;
166 Mutex* FinalImageRecipes_lock = nullptr;
167 #endif // INCLUDE_CDS
168 Mutex* Bootclasspath_lock = nullptr;
169
170 #if INCLUDE_JVMCI
171 Monitor* JVMCI_lock = nullptr;
172 Monitor* JVMCIRuntime_lock = nullptr;
173 #endif
174
175 // Only one RecursiveMutex
176 RecursiveMutex* MultiArray_lock = nullptr;
177
178 #ifdef ASSERT
179 void assert_locked_or_safepoint(const Mutex* lock) {
180 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) return;
181 // check if this thread owns the lock (common case)
182 assert(lock != nullptr, "Need non-null lock");
183 if (lock->owned_by_self()) return;
184 if (SafepointSynchronize::is_at_safepoint()) return;
185 if (!Universe::is_fully_initialized()) return;
186 fatal("must own lock %s", lock->name());
187 }
188
189 // a stronger assertion than the above
190 void assert_lock_strong(const Mutex* lock) {
191 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) return;
192 assert(lock != nullptr, "Need non-null lock");
193 if (lock->owned_by_self()) return;
194 fatal("must own lock %s", lock->name());
195 }
196 #endif
197
198 #define MUTEX_STORAGE_NAME(name) name##_storage
199 #define MUTEX_STORAGE(name, type) alignas(type) static uint8_t MUTEX_STORAGE_NAME(name)[sizeof(type)]
200 #define MUTEX_DEF(name, type, pri, ...) { \
201 assert(name == nullptr, "Mutex/Monitor initialized twice"); \
202 MUTEX_STORAGE(name, type); \
203 name = ::new(static_cast<void*>(MUTEX_STORAGE_NAME(name))) type((pri), #name, ##__VA_ARGS__); \
204 Mutex::add_mutex(name); \
205 }
206 #define MUTEX_DEFN(name, type, pri, ...) MUTEX_DEF(name, type, Mutex::pri, ##__VA_ARGS__)
207
208 // Specify relative ranked lock
209 #ifdef ASSERT
210 #define MUTEX_DEFL(name, type, held_lock, ...) MUTEX_DEF(name, type, (held_lock)->rank() - 1, ##__VA_ARGS__)
211 #else
212 #define MUTEX_DEFL(name, type, held_lock, ...) MUTEX_DEFN(name, type, safepoint, ##__VA_ARGS__)
213 #endif
214
215 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
216 void mutex_init() {
217 MUTEX_DEFN(tty_lock , PaddedMutex , tty); // allow to lock in VM
218
219 MUTEX_DEFN(NMethodEntryBarrier_lock , PaddedMutex , service-1);
220
221 MUTEX_DEFN(STS_lock , PaddedMonitor, nosafepoint);
222
223 #if INCLUDE_G1GC
224 if (UseG1GC) {
225 MUTEX_DEFN(G1CGC_lock , PaddedMonitor, nosafepoint);
226 MUTEX_DEFN(G1DetachedRefinementStats_lock, PaddedMutex , nosafepoint-2);
227 MUTEX_DEFN(G1FreeList_lock , PaddedMutex , service-1);
228 MUTEX_DEFN(G1MarkStackChunkList_lock , PaddedMutex , nosafepoint);
229 MUTEX_DEFN(G1MarkStackFreeList_lock , PaddedMutex , nosafepoint);
230 MUTEX_DEFN(G1OldSets_lock , PaddedMutex , nosafepoint);
231 MUTEX_DEFN(G1RootRegionScan_lock , PaddedMonitor, nosafepoint-1);
232 MUTEX_DEFN(G1Uncommit_lock , PaddedMutex , service-2);
233 }
234 #endif
235
236 MUTEX_DEFN(MonitoringSupport_lock , PaddedMutex , service-1); // used for serviceability monitoring support
237
238 MUTEX_DEFN(StringDedup_lock , PaddedMonitor, nosafepoint);
239 MUTEX_DEFN(StringDedupIntern_lock , PaddedMutex , nosafepoint);
240 MUTEX_DEFN(RawMonitor_lock , PaddedMutex , nosafepoint-1);
241
242 MUTEX_DEFN(Metaspace_lock , PaddedMutex , nosafepoint-3);
243 MUTEX_DEFN(MetaspaceCritical_lock , PaddedMonitor, nosafepoint-1);
244
245 MUTEX_DEFN(MonitorDeflation_lock , PaddedMonitor, nosafepoint); // used for monitor deflation thread operations
246 MUTEX_DEFN(Service_lock , PaddedMonitor, service); // used for service thread operations
247 MUTEX_DEFN(Notification_lock , PaddedMonitor, service); // used for notification thread operations
248
249 MUTEX_DEFN(JmethodIdCreation_lock , PaddedMutex , nosafepoint-1); // used for creating jmethodIDs can also lock HandshakeState_lock
250 MUTEX_DEFN(InvokeMethodTypeTable_lock , PaddedMutex , safepoint);
251 MUTEX_DEFN(InvokeMethodIntrinsicTable_lock , PaddedMonitor, safepoint);
252 MUTEX_DEFN(AdapterHandlerLibrary_lock , PaddedMutex , safepoint);
253 MUTEX_DEFN(SharedDictionary_lock , PaddedMutex , safepoint);
254 MUTEX_DEFN(VMStatistic_lock , PaddedMutex , safepoint);
255 MUTEX_DEFN(SignatureHandlerLibrary_lock , PaddedMutex , safepoint);
256 MUTEX_DEFN(SymbolArena_lock , PaddedMutex , nosafepoint);
257 MUTEX_DEFN(ExceptionCache_lock , PaddedMutex , safepoint);
258 #ifndef PRODUCT
259 MUTEX_DEFN(FullGCALot_lock , PaddedMutex , safepoint); // a lock to make FullGCALot MT safe
260 #endif
261 MUTEX_DEFN(BeforeExit_lock , PaddedMonitor, safepoint);
262
263 MUTEX_DEFN(NonJavaThreadsList_lock , PaddedMutex , nosafepoint-1);
264 MUTEX_DEFN(NonJavaThreadsListSync_lock , PaddedMutex , nosafepoint);
265
266 MUTEX_DEFN(RetData_lock , PaddedMutex , safepoint);
267 MUTEX_DEFN(Terminator_lock , PaddedMonitor, safepoint, true);
268 MUTEX_DEFN(InitCompleted_lock , PaddedMonitor, nosafepoint);
269 MUTEX_DEFN(Notify_lock , PaddedMonitor, safepoint, true);
270
271 MUTEX_DEFN(JfieldIdCreation_lock , PaddedMutex , safepoint);
272
273 MUTEX_DEFN(CompiledIC_lock , PaddedMutex , nosafepoint); // locks VtableStubs_lock
274 MUTEX_DEFN(MethodCompileQueue_lock , PaddedMonitor, safepoint);
275 if (UseGlobalCompileQueueLock) {
276 MethodCompileQueueC1_lock = MethodCompileQueue_lock;
277 MethodCompileQueueC2_lock = MethodCompileQueue_lock;
278 MethodCompileQueueSC1_lock = MethodCompileQueue_lock;
279 MethodCompileQueueSC2_lock = MethodCompileQueue_lock;
280 } else {
281 MUTEX_DEFN(MethodCompileQueueC1_lock , PaddedMonitor, safepoint);
282 MUTEX_DEFN(MethodCompileQueueC2_lock , PaddedMonitor, safepoint);
283 MUTEX_DEFN(MethodCompileQueueSC1_lock , PaddedMonitor, safepoint);
284 MUTEX_DEFN(MethodCompileQueueSC2_lock , PaddedMonitor, safepoint);
285 }
286 MUTEX_DEFN(TrainingData_lock , PaddedMutex , nosafepoint);
287 MUTEX_DEFN(TrainingReplayQueue_lock , PaddedMonitor, safepoint);
288 MUTEX_DEFN(CompileStatistics_lock , PaddedMutex , safepoint);
289 MUTEX_DEFN(DirectivesStack_lock , PaddedMutex , nosafepoint);
290
291 MUTEX_DEFN(JvmtiVTMSTransition_lock , PaddedMonitor, safepoint); // used for Virtual Thread Mount State transition management
292 MUTEX_DEFN(JvmtiVThreadSuspend_lock , PaddedMutex, nosafepoint-1);
293 MUTEX_DEFN(EscapeBarrier_lock , PaddedMonitor, nosafepoint); // Used to synchronize object reallocation/relocking triggered by JVMTI
294 MUTEX_DEFN(Management_lock , PaddedMutex , safepoint); // used for JVM management
295
296 MUTEX_DEFN(ConcurrentGCBreakpoints_lock , PaddedMonitor, safepoint, true);
297 MUTEX_DEFN(TouchedMethodLog_lock , PaddedMutex , safepoint);
298
299 MUTEX_DEFN(CompileThread_lock , PaddedMonitor, safepoint);
300 MUTEX_DEFN(PeriodicTask_lock , PaddedMonitor, safepoint, true);
301 MUTEX_DEFN(RedefineClasses_lock , PaddedMonitor, safepoint);
302 MUTEX_DEFN(Verify_lock , PaddedMutex , safepoint);
303 MUTEX_DEFN(ClassLoaderDataGraph_lock , PaddedMutex , safepoint);
304
305 MUTEX_DEFN(Compilation_lock , PaddedMonitor, nosafepoint);
306
307 #if INCLUDE_JFR
308 MUTEX_DEFN(JfrBuffer_lock , PaddedMutex , event);
309 MUTEX_DEFN(JfrMsg_lock , PaddedMonitor, event);
310 MUTEX_DEFN(JfrStacktrace_lock , PaddedMutex , event);
311 #endif
312
313 MUTEX_DEFN(ContinuationRelativize_lock , PaddedMonitor, nosafepoint-3);
314 MUTEX_DEFN(CodeHeapStateAnalytics_lock , PaddedMutex , safepoint);
315 MUTEX_DEFN(ThreadsSMRDelete_lock , PaddedMonitor, service-2); // Holds ConcurrentHashTableResize_lock
316 MUTEX_DEFN(ThreadIdTableCreate_lock , PaddedMutex , safepoint);
317 MUTEX_DEFN(DCmdFactory_lock , PaddedMutex , nosafepoint);
318 MUTEX_DEFN(NMTQuery_lock , PaddedMutex , safepoint);
319 MUTEX_DEFN(NMTCompilationCostHistory_lock , PaddedMutex , nosafepoint);
320 MUTEX_DEFN(NmtVirtualMemory_lock , PaddedMutex , service-4); // Must be lower than G1Mapper_lock used from G1RegionsSmallerThanCommitSizeMapper::commit_regions
321 #if INCLUDE_CDS
322 #if INCLUDE_JVMTI
323 MUTEX_DEFN(CDSClassFileStream_lock , PaddedMutex , safepoint);
324 #endif
325 MUTEX_DEFN(DumpTimeTable_lock , PaddedMutex , nosafepoint);
326 MUTEX_DEFN(CDSLambda_lock , PaddedMutex , nosafepoint);
327 MUTEX_DEFN(DumpRegion_lock , PaddedMutex , nosafepoint);
328 MUTEX_DEFN(ClassListFile_lock , PaddedMutex , nosafepoint);
329 MUTEX_DEFN(UnregisteredClassesTable_lock , PaddedMutex , nosafepoint-1);
330 MUTEX_DEFN(LambdaFormInvokers_lock , PaddedMutex , safepoint);
331 MUTEX_DEFN(ScratchObjects_lock , PaddedMutex , nosafepoint-1); // Holds DumpTimeTable_lock
332 MUTEX_DEFN(ArchivedObjectTables_lock , PaddedMutex , nosafepoint);
333 MUTEX_DEFN(FinalImageRecipes_lock , PaddedMutex , nosafepoint);
334 #endif // INCLUDE_CDS
335 MUTEX_DEFN(Bootclasspath_lock , PaddedMutex , nosafepoint);
336
337 #if INCLUDE_JVMCI
338 // JVMCIRuntime::_lock must be acquired before JVMCI_lock to avoid deadlock
339 MUTEX_DEFN(JVMCIRuntime_lock , PaddedMonitor, safepoint, true);
340 #endif
341
342 MUTEX_DEFN(ThreadsLockThrottle_lock , PaddedMonitor, safepoint);
343
344 // These locks have relative rankings, and inherit safepoint checking attributes from that rank.
345 MUTEX_DEFL(VtableStubs_lock , PaddedMutex , CompiledIC_lock); // Also holds DumpTimeTable_lock
346 MUTEX_DEFL(CodeCache_lock , PaddedMonitor, VtableStubs_lock);
347 MUTEX_DEFL(NMethodState_lock , PaddedMutex , CodeCache_lock);
348
349 // tty_lock is held when printing nmethod and its relocations which use this lock.
350 MUTEX_DEFL(ExternalsRecorder_lock , PaddedMutex , tty_lock);
351
352 MUTEX_DEFL(AOTCodeCStrings_lock , PaddedMutex , tty_lock);
353
354 MUTEX_DEFL(Threads_lock , PaddedMonitor, CompileThread_lock, true);
355 MUTEX_DEFL(Compile_lock , PaddedMutex , MethodCompileQueue_lock);
356 MUTEX_DEFL(JNICritical_lock , PaddedMonitor, AdapterHandlerLibrary_lock); // used for JNI critical regions
357 MUTEX_DEFL(Heap_lock , PaddedMonitor, JNICritical_lock);
358
359 MUTEX_DEFL(PerfDataMemAlloc_lock , PaddedMutex , Heap_lock);
360 MUTEX_DEFL(PerfDataManager_lock , PaddedMutex , Heap_lock);
361 MUTEX_DEFL(VMOperation_lock , PaddedMonitor, Heap_lock, true);
362 MUTEX_DEFL(ClassInitError_lock , PaddedMonitor, Threads_lock);
363
364 #if INCLUDE_G1GC
365 if (UseG1GC) {
366 MUTEX_DEFL(G1OldGCCount_lock , PaddedMonitor, Threads_lock, true);
367 MUTEX_DEFL(G1RareEvent_lock , PaddedMutex , Threads_lock, true);
368 }
369 #endif
370
371 MUTEX_DEFL(CompileTaskWait_lock , PaddedMonitor, MethodCompileQueue_lock);
372
373 #if INCLUDE_PARALLELGC
374 if (UseParallelGC) {
375 MUTEX_DEFL(PSOldGenExpand_lock , PaddedMutex , Heap_lock, true);
376 }
377 #endif
378 MUTEX_DEFL(Module_lock , PaddedMutex , ClassLoaderDataGraph_lock);
379 MUTEX_DEFL(SystemDictionary_lock , PaddedMonitor, Module_lock);
380 #if INCLUDE_JVMCI
381 // JVMCIRuntime_lock must be acquired before JVMCI_lock to avoid deadlock
382 MUTEX_DEFL(JVMCI_lock , PaddedMonitor, JVMCIRuntime_lock);
383 #endif
384 MUTEX_DEFL(JvmtiThreadState_lock , PaddedMutex , JvmtiVTMSTransition_lock); // Used by JvmtiThreadState/JvmtiEventController
385 MUTEX_DEFL(SharedDecoder_lock , PaddedMutex , NmtVirtualMemory_lock); // Must be lower than NmtVirtualMemory_lock due to MemTracker::print_containing_region
386
387 // Allocate RecursiveMutex
388 MultiArray_lock = new RecursiveMutex();
389 }
390
391 #undef MUTEX_DEFL
392 #undef MUTEX_DEFN
393 #undef MUTEX_DEF
394 #undef MUTEX_STORAGE
395 #undef MUTEX_STORAGE_NAME
396
397 static const int MAX_NAMES = 200;
398 static const char* _names[MAX_NAMES] = { nullptr };
399 static bool _is_unique[MAX_NAMES] = { false };
400 static volatile int _num_names = 0;
401
402 static bool _mutex_init_done = false;
403
404 PerfCounter** MutexLockerImpl::_perf_lock_count = nullptr;
405 PerfCounter** MutexLockerImpl::_perf_lock_wait_time = nullptr;
406 PerfCounter** MutexLockerImpl::_perf_lock_hold_time = nullptr;
407
408 MutexLockerImpl::MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag) :
409 _mutex(mutex),
410 _prof(ProfileVMLocks && Thread::current_or_null() != nullptr && Thread::current()->profile_vm_locks()) {
411
412 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
413 if (_mutex != nullptr) {
414 if (_prof) { _before.start(); } // before
415
416 if (no_safepoint_check) {
417 _mutex->lock_without_safepoint_check();
418 } else {
419 _mutex->lock();
420 }
421
422 if (_prof) { _before.stop(); _after.start(); } // after
423 }
424 }
425
426 MutexLockerImpl::MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag) :
427 _mutex(mutex), _prof(thread->profile_vm_locks()) {
428
429 if (_prof) { _before.start(); } // before
430
431 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
432 if (_mutex != nullptr) {
433 if (no_safepoint_check) {
434 _mutex->lock_without_safepoint_check(thread);
435 } else {
436 _mutex->lock(thread);
437 }
438 }
439
440 if (_prof) { _before.stop(); _after.start(); } // after
441 }
442
443 void MutexLockerImpl::init_counters() {
444 if (ProfileVMLocks && UsePerfData) {
445 ResourceMark rm;
446 EXCEPTION_MARK;
447 _perf_lock_count = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
448 _perf_lock_wait_time = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
449 _perf_lock_hold_time = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
450
451 NEWPERFEVENTCOUNTER(_perf_lock_count[0], SUN_RT, PerfDataManager::counter_name("Other", "Count"));
452 NEWPERFEVENTCOUNTER(_perf_lock_wait_time[0], SUN_RT, PerfDataManager::counter_name("Other", "BeforeTime"));
453 NEWPERFEVENTCOUNTER(_perf_lock_hold_time[0], SUN_RT, PerfDataManager::counter_name("Other", "AfterTime"));
454 for (int i = 0; i < MAX_NAMES; i++) {
455 ResourceMark rm;
456 const char* counter_name = _names[i];
457 if (counter_name == nullptr) {
458 stringStream ss;
459 ss.print("UnnamedMutex#%d", i);
460 counter_name = ss.as_string();
461 _names[i] = os::strdup(counter_name, mtInternal); // replace default nullptr
462 }
463 NEWPERFEVENTCOUNTER(_perf_lock_count[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "Count"));
464 NEWPERFEVENTCOUNTER(_perf_lock_wait_time[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "BeforeTime"));
465 NEWPERFEVENTCOUNTER(_perf_lock_hold_time[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "AfterTime"));
466 }
467 if (HAS_PENDING_EXCEPTION) {
468 vm_exit_during_initialization("MutexLockerImpl::init_counters() failed unexpectedly");
469 }
470 }
471 _mutex_init_done = true;
472 }
473
474 int MutexLockerImpl::name2id(const char* name) {
475 if (ProfileVMLocks && UsePerfData) {
476 // There is not concurency or duplication in mutex_init().
477 if (!_mutex_init_done) {
478 int new_id = Atomic::load(&_num_names);
479 precond(new_id < MAX_NAMES);
480 Atomic::inc(&_num_names);
481 _names[new_id] = os::strdup(name, mtInternal);
482 _is_unique[new_id] = true;
483 return new_id;
484 }
485 int limit = Atomic::load(&_num_names); // Cache static value which can be updated concurently
486 for (int i = Mutex::num_mutex(); i < limit; i++) {
487 if (strcmp(_names[i], name) == 0) {
488 _is_unique[i] = false;
489 return i;
490 }
491 }
492 if (limit < MAX_NAMES) {
493 int old_limit = limit;
494 const char* name_dup = os::strdup(name, mtInternal);
495 int new_id; // Get new id for this name
496 do {
497 new_id = limit++;
498 if (new_id == MAX_NAMES) break;
499 } while (Atomic::cmpxchg(&_num_names, new_id, limit) != new_id);
500 for (int i = old_limit; i < new_id; i++) {
501 if (strcmp(_names[i], name) == 0) { // Other thread put it there
502 _is_unique[i] = false;
503 return i; // Wasted new_id slot to simplify code: _num_names is only incremented
504 }
505 }
506 if (new_id < MAX_NAMES) {
507 _names[new_id] = name_dup;
508 _is_unique[new_id] = true;
509 return new_id;
510 }
511 }
512 log_debug(init)("Unnamed: %s", name); // no slots left
513 }
514 return -1;
515 }
516
517 void MutexLockerImpl::print_counter_on(outputStream* st, const char* name, bool is_unique, int idx) {
518 jlong count = _perf_lock_count[idx]->get_value();
519 if (count > 0) {
520 st->print_cr(" %3d: %s%40s = " JLONG_FORMAT_W(5) "us (" JLONG_FORMAT_W(5) "us) / " JLONG_FORMAT_W(9) " events",
521 idx, (is_unique ? " " : "M"), name,
522 Management::ticks_to_us(_perf_lock_hold_time[idx]->get_value()),
523 Management::ticks_to_us(_perf_lock_wait_time[idx]->get_value()),
524 count);
525 }
526 }
527
528 static jlong accumulate_lock_counters(PerfCounter** lock_counters) {
529 jlong acc = 0;
530 for (int i = 0; i < _num_names + 1; i++) { // 0 slot is reserved for unnamed locks
531 if (lock_counters[i] == nullptr) {
532 break;
533 }
534 acc += lock_counters[i]->get_value();
535 }
536 return acc;
537 }
538
539 void MutexLockerImpl::print_counters_on(outputStream* st) {
540 if (ProfileVMLocks && UsePerfData) {
541 jlong total_count = accumulate_lock_counters(_perf_lock_count);
542 jlong total_wait_time = accumulate_lock_counters(_perf_lock_wait_time);
543 jlong total_hold_time = accumulate_lock_counters(_perf_lock_hold_time);
544
545 st->print_cr("MutexLocker: Total: %d named locks (%d unique names); hold = " JLONG_FORMAT "us (wait = " JLONG_FORMAT "us) / " JLONG_FORMAT " events for thread \"main\"",
546 Mutex::num_mutex(), _num_names,
547 Management::ticks_to_us(total_hold_time),
548 Management::ticks_to_us(total_wait_time),
549 total_count);
550 for (int i = 0; i < _num_names; i++) {
551 print_counter_on(st, _names[i], _is_unique[i], i+1);
552 }
553 print_counter_on(st, "Unnamed / Other", false /*is_unique*/, 0);
554 } else {
555 st->print_cr("MutexLocker: no info (%s is disabled)", (UsePerfData ? "ProfileVMLocks" : "UsePerfData"));
556 }
557 }
558
559 void MutexLockerImpl::post_initialize() {
560 // Print mutex ranks if requested.
561 LogTarget(Info, vmmutex) lt;
562 if (lt.is_enabled()) {
563 ResourceMark rm;
564 LogStream ls(lt);
565 Mutex::print_lock_ranks(&ls);
566 }
567 }
568
569 GCMutexLocker::GCMutexLocker(Mutex* mutex) {
570 if (SafepointSynchronize::is_at_safepoint()) {
571 _locked = false;
572 } else {
573 _mutex = mutex;
574 _locked = true;
575 _mutex->lock();
576 }
577 }