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/atomicAccess.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 Monitor* SystemDictionary_lock = nullptr;
44 Mutex* InvokeMethodTypeTable_lock = nullptr;
45 Monitor* InvokeMethodIntrinsicTable_lock = nullptr;
46 Mutex* SharedDictionary_lock = nullptr;
47 Monitor* ClassInitError_lock = nullptr;
48 Mutex* Module_lock = nullptr;
49 Mutex* CompiledIC_lock = nullptr;
50 Mutex* VMStatistic_lock = nullptr;
51 Mutex* JmethodIdCreation_lock = nullptr;
52 Mutex* JfieldIdCreation_lock = nullptr;
53 Monitor* JNICritical_lock = nullptr;
54 Mutex* JvmtiThreadState_lock = nullptr;
55 Monitor* EscapeBarrier_lock = nullptr;
56 Monitor* JvmtiVTMSTransition_lock = nullptr;
57 Mutex* JvmtiVThreadSuspend_lock = nullptr;
58 Monitor* Heap_lock = nullptr;
59 #if INCLUDE_PARALLELGC
60 Mutex* PSOldGenExpand_lock = nullptr;
61 #endif
62 Mutex* AdapterHandlerLibrary_lock = nullptr;
63 Mutex* SignatureHandlerLibrary_lock = nullptr;
64 Mutex* VtableStubs_lock = nullptr;
65 Mutex* SymbolArena_lock = nullptr;
66 Monitor* StringDedup_lock = nullptr;
67 Mutex* StringDedupIntern_lock = nullptr;
68 Monitor* CodeCache_lock = nullptr;
69 Mutex* TouchedMethodLog_lock = nullptr;
70 Mutex* RetData_lock = nullptr;
71 Monitor* VMOperation_lock = nullptr;
72 Monitor* ThreadsLockThrottle_lock = nullptr;
73 Monitor* Threads_lock = nullptr;
74 Mutex* NonJavaThreadsList_lock = nullptr;
75 Mutex* NonJavaThreadsListSync_lock = nullptr;
76 Monitor* STS_lock = nullptr;
77 Mutex* MonitoringSupport_lock = nullptr;
78 Monitor* ConcurrentGCBreakpoints_lock = nullptr;
79 Mutex* Compile_lock = nullptr;
80 Monitor* CompileTaskWait_lock = nullptr;
81 Monitor* MethodCompileQueue_lock = nullptr;
82 Monitor* MethodCompileQueueC1_lock = nullptr;
83 Monitor* MethodCompileQueueC2_lock = nullptr;
84 Monitor* MethodCompileQueueSC1_lock = nullptr;
85 Monitor* MethodCompileQueueSC2_lock = nullptr;
86 Monitor* CompileThread_lock = nullptr;
87 Monitor* Compilation_lock = nullptr;
88 Mutex* CompileStatistics_lock = nullptr;
89 Mutex* DirectivesStack_lock = nullptr;
90 Monitor* Terminator_lock = nullptr;
91 Monitor* InitCompleted_lock = nullptr;
92 Monitor* BeforeExit_lock = nullptr;
93 Monitor* Notify_lock = nullptr;
94 Mutex* ExceptionCache_lock = nullptr;
95 Mutex* TrainingData_lock = nullptr;
96 Monitor* TrainingReplayQueue_lock = nullptr;
97 #ifndef PRODUCT
98 Mutex* FullGCALot_lock = nullptr;
99 #endif
100
101 Mutex* tty_lock = nullptr;
102
103 Mutex* RawMonitor_lock = nullptr;
104 Mutex* PerfDataMemAlloc_lock = nullptr;
105 Mutex* PerfDataManager_lock = nullptr;
106
107 #if INCLUDE_G1GC
108 Monitor* G1CGC_lock = nullptr;
109 Mutex* G1FreeList_lock = nullptr;
110 Mutex* G1MarkStackChunkList_lock = nullptr;
111 Mutex* G1MarkStackFreeList_lock = nullptr;
112 Monitor* G1OldGCCount_lock = nullptr;
113 Mutex* G1OldSets_lock = nullptr;
114 Mutex* G1ReviseYoungLength_lock = nullptr;
115 Monitor* G1RootRegionScan_lock = nullptr;
116 Mutex* G1RareEvent_lock = nullptr;
117 Mutex* G1Uncommit_lock = nullptr;
118 #endif
119
120 Mutex* Management_lock = nullptr;
121 Monitor* MonitorDeflation_lock = nullptr;
122 Monitor* Service_lock = nullptr;
123 Monitor* Notification_lock = nullptr;
124 Monitor* PeriodicTask_lock = nullptr;
125 Monitor* RedefineClasses_lock = nullptr;
126 Mutex* Verify_lock = nullptr;
127
128 #if INCLUDE_JFR
129 Mutex* JfrStacktrace_lock = nullptr;
130 Monitor* JfrMsg_lock = nullptr;
131 Mutex* JfrBuffer_lock = nullptr;
132 #endif
133
134 Mutex* CodeHeapStateAnalytics_lock = nullptr;
135
136 Mutex* ExternalsRecorder_lock = nullptr;
137
138 Mutex* AOTCodeCStrings_lock = nullptr;
139
140 Monitor* ContinuationRelativize_lock = nullptr;
141
142 Mutex* Metaspace_lock = nullptr;
143 Monitor* MetaspaceCritical_lock = nullptr;
144 Mutex* ClassLoaderDataGraph_lock = nullptr;
145 Monitor* ThreadsSMRDelete_lock = nullptr;
146 Mutex* ThreadIdTableCreate_lock = nullptr;
147 Mutex* SharedDecoder_lock = nullptr;
148 Mutex* DCmdFactory_lock = nullptr;
149 Mutex* NMTQuery_lock = nullptr;
150 Mutex* NMTCompilationCostHistory_lock = nullptr;
151 Mutex* NmtVirtualMemory_lock = nullptr;
152
153 #if INCLUDE_CDS
154 #if INCLUDE_JVMTI
155 Mutex* CDSClassFileStream_lock = nullptr;
156 #endif
157 Mutex* DumpTimeTable_lock = nullptr;
158 Mutex* CDSLambda_lock = nullptr;
159 Mutex* DumpRegion_lock = nullptr;
160 Mutex* ClassListFile_lock = nullptr;
161 Mutex* UnregisteredClassesTable_lock= nullptr;
162 Mutex* LambdaFormInvokers_lock = nullptr;
163 Mutex* ScratchObjects_lock = nullptr;
164 Mutex* ArchivedObjectTables_lock = nullptr;
165 Mutex* FinalImageRecipes_lock = nullptr;
166 #endif // INCLUDE_CDS
167 Mutex* Bootclasspath_lock = nullptr;
168
169 #if INCLUDE_JVMCI
170 Monitor* JVMCI_lock = nullptr;
171 Monitor* JVMCIRuntime_lock = nullptr;
172 #endif
173
174 // Only one RecursiveMutex
175 RecursiveMutex* MultiArray_lock = nullptr;
176
177 #ifdef ASSERT
178 void assert_locked_or_safepoint(const Mutex* lock) {
179 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) return;
180 // check if this thread owns the lock (common case)
181 assert(lock != nullptr, "Need non-null lock");
182 if (lock->owned_by_self()) return;
183 if (SafepointSynchronize::is_at_safepoint()) return;
184 if (!Universe::is_fully_initialized()) return;
185 fatal("must own lock %s", lock->name());
186 }
187
188 // a stronger assertion than the above
189 void assert_lock_strong(const Mutex* lock) {
190 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) return;
191 assert(lock != nullptr, "Need non-null lock");
192 if (lock->owned_by_self()) return;
193 fatal("must own lock %s", lock->name());
194 }
195 #endif
196
197 #define MUTEX_STORAGE_NAME(name) name##_storage
198 #define MUTEX_STORAGE(name, type) alignas(type) static uint8_t MUTEX_STORAGE_NAME(name)[sizeof(type)]
199 #define MUTEX_DEF(name, type, pri, ...) { \
200 assert(name == nullptr, "Mutex/Monitor initialized twice"); \
201 MUTEX_STORAGE(name, type); \
202 name = ::new(static_cast<void*>(MUTEX_STORAGE_NAME(name))) type((pri), #name, ##__VA_ARGS__); \
203 Mutex::add_mutex(name); \
204 }
205 #define MUTEX_DEFN(name, type, pri, ...) MUTEX_DEF(name, type, Mutex::pri, ##__VA_ARGS__)
206
207 // Specify relative ranked lock
208 #ifdef ASSERT
209 #define MUTEX_DEFL(name, type, held_lock, ...) MUTEX_DEF(name, type, (held_lock)->rank() - 1, ##__VA_ARGS__)
210 #else
211 #define MUTEX_DEFL(name, type, held_lock, ...) MUTEX_DEFN(name, type, safepoint, ##__VA_ARGS__)
212 #endif
213
214 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes.
215 void mutex_init() {
216 MUTEX_DEFN(tty_lock , PaddedMutex , tty); // allow to lock in VM
217
218 MUTEX_DEFN(STS_lock , PaddedMonitor, nosafepoint);
219
220 #if INCLUDE_G1GC
221 if (UseG1GC) {
222 MUTEX_DEFN(G1CGC_lock , PaddedMonitor, nosafepoint);
223 MUTEX_DEFN(G1FreeList_lock , PaddedMutex , service-1);
224 MUTEX_DEFN(G1MarkStackChunkList_lock , PaddedMutex , nosafepoint);
225 MUTEX_DEFN(G1MarkStackFreeList_lock , PaddedMutex , nosafepoint);
226 MUTEX_DEFN(G1OldSets_lock , PaddedMutex , nosafepoint);
227 MUTEX_DEFN(G1RootRegionScan_lock , PaddedMonitor, nosafepoint-1);
228 MUTEX_DEFN(G1Uncommit_lock , PaddedMutex , service-2);
229 }
230 #endif
231
232 MUTEX_DEFN(MonitoringSupport_lock , PaddedMutex , service-1); // used for serviceability monitoring support
233
234 MUTEX_DEFN(StringDedup_lock , PaddedMonitor, nosafepoint);
235 MUTEX_DEFN(StringDedupIntern_lock , PaddedMutex , nosafepoint);
236 MUTEX_DEFN(RawMonitor_lock , PaddedMutex , nosafepoint-1);
237
238 MUTEX_DEFN(Metaspace_lock , PaddedMutex , nosafepoint-3);
239 MUTEX_DEFN(MetaspaceCritical_lock , PaddedMonitor, nosafepoint-1);
240
241 MUTEX_DEFN(MonitorDeflation_lock , PaddedMonitor, nosafepoint); // used for monitor deflation thread operations
242 MUTEX_DEFN(Service_lock , PaddedMonitor, service); // used for service thread operations
243 MUTEX_DEFN(Notification_lock , PaddedMonitor, service); // used for notification thread operations
244
245 MUTEX_DEFN(JmethodIdCreation_lock , PaddedMutex , nosafepoint-1); // used for creating jmethodIDs can also lock HandshakeState_lock
246 MUTEX_DEFN(InvokeMethodTypeTable_lock , PaddedMutex , safepoint);
247 MUTEX_DEFN(InvokeMethodIntrinsicTable_lock , PaddedMonitor, safepoint);
248 MUTEX_DEFN(AdapterHandlerLibrary_lock , PaddedMutex , safepoint);
249 MUTEX_DEFN(SharedDictionary_lock , PaddedMutex , safepoint);
250 MUTEX_DEFN(VMStatistic_lock , PaddedMutex , safepoint);
251 MUTEX_DEFN(SignatureHandlerLibrary_lock , PaddedMutex , safepoint);
252 MUTEX_DEFN(SymbolArena_lock , PaddedMutex , nosafepoint);
253 MUTEX_DEFN(ExceptionCache_lock , PaddedMutex , safepoint);
254 #ifndef PRODUCT
255 MUTEX_DEFN(FullGCALot_lock , PaddedMutex , safepoint); // a lock to make FullGCALot MT safe
256 #endif
257 MUTEX_DEFN(BeforeExit_lock , PaddedMonitor, safepoint);
258
259 MUTEX_DEFN(NonJavaThreadsList_lock , PaddedMutex , nosafepoint-1);
260 MUTEX_DEFN(NonJavaThreadsListSync_lock , PaddedMutex , nosafepoint);
261
262 MUTEX_DEFN(RetData_lock , PaddedMutex , safepoint);
263 MUTEX_DEFN(Terminator_lock , PaddedMonitor, safepoint, true);
264 MUTEX_DEFN(InitCompleted_lock , PaddedMonitor, nosafepoint);
265 MUTEX_DEFN(Notify_lock , PaddedMonitor, safepoint, true);
266
267 MUTEX_DEFN(JfieldIdCreation_lock , PaddedMutex , safepoint);
268
269 MUTEX_DEFN(CompiledIC_lock , PaddedMutex , nosafepoint); // locks VtableStubs_lock
270 MUTEX_DEFN(MethodCompileQueue_lock , PaddedMonitor, safepoint);
271 if (UseGlobalCompileQueueLock) {
272 MethodCompileQueueC1_lock = MethodCompileQueue_lock;
273 MethodCompileQueueC2_lock = MethodCompileQueue_lock;
274 MethodCompileQueueSC1_lock = MethodCompileQueue_lock;
275 MethodCompileQueueSC2_lock = MethodCompileQueue_lock;
276 } else {
277 MUTEX_DEFN(MethodCompileQueueC1_lock , PaddedMonitor, safepoint);
278 MUTEX_DEFN(MethodCompileQueueC2_lock , PaddedMonitor, safepoint);
279 MUTEX_DEFN(MethodCompileQueueSC1_lock , PaddedMonitor, safepoint);
280 MUTEX_DEFN(MethodCompileQueueSC2_lock , PaddedMonitor, safepoint);
281 }
282 MUTEX_DEFN(TrainingData_lock , PaddedMutex , nosafepoint);
283 MUTEX_DEFN(TrainingReplayQueue_lock , PaddedMonitor, safepoint);
284 MUTEX_DEFN(CompileStatistics_lock , PaddedMutex , safepoint);
285 MUTEX_DEFN(DirectivesStack_lock , PaddedMutex , nosafepoint);
286
287 MUTEX_DEFN(JvmtiVTMSTransition_lock , PaddedMonitor, safepoint); // used for Virtual Thread Mount State transition management
288 MUTEX_DEFN(JvmtiVThreadSuspend_lock , PaddedMutex, nosafepoint-1);
289 MUTEX_DEFN(EscapeBarrier_lock , PaddedMonitor, nosafepoint); // Used to synchronize object reallocation/relocking triggered by JVMTI
290 MUTEX_DEFN(Management_lock , PaddedMutex , safepoint); // used for JVM management
291
292 MUTEX_DEFN(ConcurrentGCBreakpoints_lock , PaddedMonitor, safepoint, true);
293 MUTEX_DEFN(TouchedMethodLog_lock , PaddedMutex , safepoint);
294
295 MUTEX_DEFN(CompileThread_lock , PaddedMonitor, safepoint);
296 MUTEX_DEFN(PeriodicTask_lock , PaddedMonitor, safepoint, true);
297 MUTEX_DEFN(RedefineClasses_lock , PaddedMonitor, safepoint);
298 MUTEX_DEFN(Verify_lock , PaddedMutex , safepoint);
299 MUTEX_DEFN(ClassLoaderDataGraph_lock , PaddedMutex , safepoint);
300
301 MUTEX_DEFN(Compilation_lock , PaddedMonitor, nosafepoint);
302
303 #if INCLUDE_JFR
304 MUTEX_DEFN(JfrBuffer_lock , PaddedMutex , event);
305 MUTEX_DEFN(JfrMsg_lock , PaddedMonitor, event);
306 MUTEX_DEFN(JfrStacktrace_lock , PaddedMutex , event);
307 #endif
308
309 MUTEX_DEFN(ContinuationRelativize_lock , PaddedMonitor, nosafepoint-3);
310 MUTEX_DEFN(CodeHeapStateAnalytics_lock , PaddedMutex , safepoint);
311 MUTEX_DEFN(ThreadsSMRDelete_lock , PaddedMonitor, service-2); // Holds ConcurrentHashTableResize_lock
312 MUTEX_DEFN(ThreadIdTableCreate_lock , PaddedMutex , safepoint);
313 MUTEX_DEFN(DCmdFactory_lock , PaddedMutex , nosafepoint);
314 MUTEX_DEFN(NMTQuery_lock , PaddedMutex , safepoint);
315 MUTEX_DEFN(NMTCompilationCostHistory_lock , PaddedMutex , nosafepoint);
316 MUTEX_DEFN(NmtVirtualMemory_lock , PaddedMutex , service-4); // Must be lower than G1Mapper_lock used from G1RegionsSmallerThanCommitSizeMapper::commit_regions
317 #if INCLUDE_CDS
318 #if INCLUDE_JVMTI
319 MUTEX_DEFN(CDSClassFileStream_lock , PaddedMutex , safepoint);
320 #endif
321 MUTEX_DEFN(DumpTimeTable_lock , PaddedMutex , nosafepoint);
322 MUTEX_DEFN(CDSLambda_lock , PaddedMutex , nosafepoint);
323 MUTEX_DEFL(DumpRegion_lock , PaddedMutex , DumpTimeTable_lock);
324 MUTEX_DEFN(ClassListFile_lock , PaddedMutex , nosafepoint);
325 MUTEX_DEFN(UnregisteredClassesTable_lock , PaddedMutex , nosafepoint-1);
326 MUTEX_DEFN(LambdaFormInvokers_lock , PaddedMutex , safepoint);
327 MUTEX_DEFL(ScratchObjects_lock , PaddedMutex , DumpTimeTable_lock);
328 MUTEX_DEFN(ArchivedObjectTables_lock , PaddedMutex , nosafepoint);
329 MUTEX_DEFN(FinalImageRecipes_lock , PaddedMutex , nosafepoint);
330 #endif // INCLUDE_CDS
331 MUTEX_DEFN(Bootclasspath_lock , PaddedMutex , nosafepoint);
332
333 #if INCLUDE_JVMCI
334 // JVMCIRuntime::_lock must be acquired before JVMCI_lock to avoid deadlock
335 MUTEX_DEFN(JVMCIRuntime_lock , PaddedMonitor, safepoint, true);
336 #endif
337
338 MUTEX_DEFN(ThreadsLockThrottle_lock , PaddedMonitor, safepoint);
339
340 // These locks have relative rankings, and inherit safepoint checking attributes from that rank.
341 MUTEX_DEFL(VtableStubs_lock , PaddedMutex , CompiledIC_lock); // Also holds DumpTimeTable_lock
342 MUTEX_DEFL(CodeCache_lock , PaddedMonitor, VtableStubs_lock);
343 MUTEX_DEFL(NMethodState_lock , PaddedMutex , CodeCache_lock);
344
345 // tty_lock is held when printing nmethod and its relocations which use this lock.
346 MUTEX_DEFL(ExternalsRecorder_lock , PaddedMutex , tty_lock);
347
348 MUTEX_DEFL(AOTCodeCStrings_lock , PaddedMutex , tty_lock);
349
350 MUTEX_DEFL(Threads_lock , PaddedMonitor, CompileThread_lock, true);
351 MUTEX_DEFL(Compile_lock , PaddedMutex , MethodCompileQueue_lock);
352 MUTEX_DEFL(JNICritical_lock , PaddedMonitor, AdapterHandlerLibrary_lock); // used for JNI critical regions
353 MUTEX_DEFL(Heap_lock , PaddedMonitor, JNICritical_lock);
354
355 MUTEX_DEFL(PerfDataMemAlloc_lock , PaddedMutex , Heap_lock);
356 MUTEX_DEFL(PerfDataManager_lock , PaddedMutex , Heap_lock);
357 MUTEX_DEFL(VMOperation_lock , PaddedMonitor, Heap_lock, true);
358 MUTEX_DEFL(ClassInitError_lock , PaddedMonitor, Threads_lock);
359
360 #if INCLUDE_G1GC
361 if (UseG1GC) {
362 MUTEX_DEFL(G1OldGCCount_lock , PaddedMonitor, Threads_lock, true);
363 MUTEX_DEFL(G1RareEvent_lock , PaddedMutex , Threads_lock, true);
364 MUTEX_DEFL(G1ReviseYoungLength_lock , PaddedMutex , Threads_lock, true);
365 }
366 #endif
367
368 MUTEX_DEFL(CompileTaskWait_lock , PaddedMonitor, MethodCompileQueue_lock);
369
370 #if INCLUDE_PARALLELGC
371 if (UseParallelGC) {
372 MUTEX_DEFL(PSOldGenExpand_lock , PaddedMutex , Heap_lock, true);
373 }
374 #endif
375 MUTEX_DEFL(Module_lock , PaddedMutex , ClassLoaderDataGraph_lock);
376 MUTEX_DEFL(SystemDictionary_lock , PaddedMonitor, Module_lock);
377 #if INCLUDE_JVMCI
378 // JVMCIRuntime_lock must be acquired before JVMCI_lock to avoid deadlock
379 MUTEX_DEFL(JVMCI_lock , PaddedMonitor, JVMCIRuntime_lock);
380 #endif
381 MUTEX_DEFL(JvmtiThreadState_lock , PaddedMutex , JvmtiVTMSTransition_lock); // Used by JvmtiThreadState/JvmtiEventController
382 MUTEX_DEFL(SharedDecoder_lock , PaddedMutex , NmtVirtualMemory_lock); // Must be lower than NmtVirtualMemory_lock due to MemTracker::print_containing_region
383
384 // Allocate RecursiveMutex
385 MultiArray_lock = new RecursiveMutex();
386 }
387
388 #undef MUTEX_DEFL
389 #undef MUTEX_DEFN
390 #undef MUTEX_DEF
391 #undef MUTEX_STORAGE
392 #undef MUTEX_STORAGE_NAME
393
394 static const int MAX_NAMES = 200;
395 static const char* _names[MAX_NAMES] = { nullptr };
396 static bool _is_unique[MAX_NAMES] = { false };
397 static volatile int _num_names = 0;
398
399 static bool _mutex_init_done = false;
400
401 PerfCounter** MutexLockerImpl::_perf_lock_count = nullptr;
402 PerfCounter** MutexLockerImpl::_perf_lock_wait_time = nullptr;
403 PerfCounter** MutexLockerImpl::_perf_lock_hold_time = nullptr;
404
405 MutexLockerImpl::MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag) :
406 _mutex(mutex),
407 _prof(ProfileVMLocks && Thread::current_or_null() != nullptr && Thread::current()->profile_vm_locks()) {
408
409 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
410 if (_mutex != nullptr) {
411 if (_prof) { _before.start(); } // before
412
413 if (no_safepoint_check) {
414 _mutex->lock_without_safepoint_check();
415 } else {
416 _mutex->lock();
417 }
418
419 if (_prof) { _before.stop(); _after.start(); } // after
420 }
421 }
422
423 MutexLockerImpl::MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag) :
424 _mutex(mutex), _prof(thread->profile_vm_locks()) {
425
426 if (_prof) { _before.start(); } // before
427
428 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
429 if (_mutex != nullptr) {
430 if (no_safepoint_check) {
431 _mutex->lock_without_safepoint_check(thread);
432 } else {
433 _mutex->lock(thread);
434 }
435 }
436
437 if (_prof) { _before.stop(); _after.start(); } // after
438 }
439
440 void MutexLockerImpl::init_counters() {
441 if (ProfileVMLocks && UsePerfData) {
442 ResourceMark rm;
443 EXCEPTION_MARK;
444 _perf_lock_count = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
445 _perf_lock_wait_time = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
446 _perf_lock_hold_time = NEW_C_HEAP_ARRAY(PerfCounter*, MAX_NAMES + 1, mtInternal);
447
448 NEWPERFEVENTCOUNTER(_perf_lock_count[0], SUN_RT, PerfDataManager::counter_name("Other", "Count"));
449 NEWPERFEVENTCOUNTER(_perf_lock_wait_time[0], SUN_RT, PerfDataManager::counter_name("Other", "BeforeTime"));
450 NEWPERFEVENTCOUNTER(_perf_lock_hold_time[0], SUN_RT, PerfDataManager::counter_name("Other", "AfterTime"));
451 for (int i = 0; i < MAX_NAMES; i++) {
452 ResourceMark rm;
453 const char* counter_name = _names[i];
454 if (counter_name == nullptr) {
455 stringStream ss;
456 ss.print("UnnamedMutex#%d", i);
457 counter_name = ss.as_string();
458 _names[i] = os::strdup(counter_name, mtInternal); // replace default nullptr
459 }
460 NEWPERFEVENTCOUNTER(_perf_lock_count[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "Count"));
461 NEWPERFEVENTCOUNTER(_perf_lock_wait_time[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "BeforeTime"));
462 NEWPERFEVENTCOUNTER(_perf_lock_hold_time[i + 1], SUN_RT, PerfDataManager::counter_name(counter_name, "AfterTime"));
463 }
464 if (HAS_PENDING_EXCEPTION) {
465 vm_exit_during_initialization("MutexLockerImpl::init_counters() failed unexpectedly");
466 }
467 }
468 _mutex_init_done = true;
469 }
470
471 int MutexLockerImpl::name2id(const char* name) {
472 if (ProfileVMLocks && UsePerfData) {
473 // There is not concurency or duplication in mutex_init().
474 if (!_mutex_init_done) {
475 int new_id = AtomicAccess::load(&_num_names);
476 precond(new_id < MAX_NAMES);
477 AtomicAccess::inc(&_num_names);
478 _names[new_id] = os::strdup(name, mtInternal);
479 _is_unique[new_id] = true;
480 return new_id;
481 }
482 int limit = AtomicAccess::load(&_num_names); // Cache static value which can be updated concurently
483 for (int i = Mutex::num_mutex(); i < limit; i++) {
484 if (strcmp(_names[i], name) == 0) {
485 _is_unique[i] = false;
486 return i;
487 }
488 }
489 if (limit < MAX_NAMES) {
490 int old_limit = limit;
491 const char* name_dup = os::strdup(name, mtInternal);
492 int new_id; // Get new id for this name
493 do {
494 new_id = limit++;
495 if (new_id == MAX_NAMES) break;
496 } while (AtomicAccess::cmpxchg(&_num_names, new_id, limit) != new_id);
497 for (int i = old_limit; i < new_id; i++) {
498 if (strcmp(_names[i], name) == 0) { // Other thread put it there
499 _is_unique[i] = false;
500 return i; // Wasted new_id slot to simplify code: _num_names is only incremented
501 }
502 }
503 if (new_id < MAX_NAMES) {
504 _names[new_id] = name_dup;
505 _is_unique[new_id] = true;
506 return new_id;
507 }
508 }
509 log_debug(init)("Unnamed: %s", name); // no slots left
510 }
511 return -1;
512 }
513
514 void MutexLockerImpl::print_counter_on(outputStream* st, const char* name, bool is_unique, int idx) {
515 jlong count = _perf_lock_count[idx]->get_value();
516 if (count > 0) {
517 st->print_cr(" %3d: %s%40s = " JLONG_FORMAT_W(5) "us (" JLONG_FORMAT_W(5) "us) / " JLONG_FORMAT_W(9) " events",
518 idx, (is_unique ? " " : "M"), name,
519 Management::ticks_to_us(_perf_lock_hold_time[idx]->get_value()),
520 Management::ticks_to_us(_perf_lock_wait_time[idx]->get_value()),
521 count);
522 }
523 }
524
525 static jlong accumulate_lock_counters(PerfCounter** lock_counters) {
526 jlong acc = 0;
527 for (int i = 0; i < _num_names + 1; i++) { // 0 slot is reserved for unnamed locks
528 if (lock_counters[i] == nullptr) {
529 break;
530 }
531 acc += lock_counters[i]->get_value();
532 }
533 return acc;
534 }
535
536 void MutexLockerImpl::print_counters_on(outputStream* st) {
537 if (ProfileVMLocks && UsePerfData) {
538 jlong total_count = accumulate_lock_counters(_perf_lock_count);
539 jlong total_wait_time = accumulate_lock_counters(_perf_lock_wait_time);
540 jlong total_hold_time = accumulate_lock_counters(_perf_lock_hold_time);
541
542 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\"",
543 Mutex::num_mutex(), _num_names,
544 Management::ticks_to_us(total_hold_time),
545 Management::ticks_to_us(total_wait_time),
546 total_count);
547 for (int i = 0; i < _num_names; i++) {
548 print_counter_on(st, _names[i], _is_unique[i], i+1);
549 }
550 print_counter_on(st, "Unnamed / Other", false /*is_unique*/, 0);
551 } else {
552 st->print_cr("MutexLocker: no info (%s is disabled)", (UsePerfData ? "ProfileVMLocks" : "UsePerfData"));
553 }
554 }
555
556 void MutexLockerImpl::post_initialize() {
557 // Print mutex ranks if requested.
558 LogTarget(Info, vmmutex) lt;
559 if (lt.is_enabled()) {
560 ResourceMark rm;
561 LogStream ls(lt);
562 Mutex::print_lock_ranks(&ls);
563 }
564 }
565
566 GCMutexLocker::GCMutexLocker(Mutex* mutex) {
567 if (SafepointSynchronize::is_at_safepoint()) {
568 _locked = false;
569 } else {
570 _mutex = mutex;
571 _locked = true;
572 _mutex->lock();
573 }
574 }