1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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23 */
24
25 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP
26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP
27
28 #include "logging/log.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/flags/flagSetting.hpp"
31 #include "runtime/mutex.hpp"
32 #include "runtime/perfData.hpp"
33 #include "runtime/thread.hpp"
34
35 // Mutexes used in the VM.
36
37 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
38 extern Mutex* NMethodState_lock; // a lock used to guard a compiled method state
39 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
40 extern Mutex* InvokeMethodTypeTable_lock;
41 extern Monitor* InvokeMethodIntrinsicTable_lock;
42 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary
43 extern Monitor* ClassInitError_lock; // a lock on the class initialization error table
44 extern Mutex* Module_lock; // a lock on module and package related data structures
45 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
46 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
47 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
48 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
49 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
50 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
51 extern Monitor* EscapeBarrier_lock; // a lock to sync reallocating and relocking objects because of JVMTI access
52 extern Monitor* JvmtiVTMSTransition_lock; // a lock for Virtual Thread Mount State transition (VTMS transition) management
53 extern Monitor* Heap_lock; // a lock on the heap
54 #ifdef INCLUDE_PARALLELGC
55 extern Mutex* PSOldGenExpand_lock; // a lock on expanding the heap
56 #endif
57 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
58 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
59 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
60 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena
61 extern Monitor* StringDedup_lock; // a lock on the string deduplication facility
62 extern Mutex* StringDedupIntern_lock; // a lock on StringTable notification of StringDedup
63 extern Monitor* CodeCache_lock; // a lock on the CodeCache
64 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
65 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
66 extern Monitor* VMOperation_lock; // a lock on queue of vm_operations waiting to execute
67 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
68 // (also used by Safepoints too to block threads creation/destruction)
69 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list
70 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization
71 extern Monitor* CGC_lock; // used for coordination between
72 // fore- & background GC threads.
73 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
74 extern Monitor* G1OldGCCount_lock; // in support of "concurrent" full gc
75 extern Mutex* G1RareEvent_lock; // Synchronizes (rare) parallel GC operations.
76 extern Mutex* G1DetachedRefinementStats_lock; // Lock protecting detached refinement stats
77 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
78 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
79 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools and allocated memory high water mark.
80 extern Monitor* ConcurrentGCBreakpoints_lock; // Protects concurrent GC breakpoint management
81 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
82 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
83 extern Monitor* MethodCompileQueueC1_lock; // a lock held when method compilations are enqueued, dequeued
84 extern Monitor* MethodCompileQueueC2_lock; // a lock held when method compilations are enqueued, dequeued
85 extern Monitor* MethodCompileQueueC3_lock; // a lock held when method compilations are enqueued, dequeued
86 extern Monitor* MethodCompileQueueSC1_lock; // a lock held when method compilations are enqueued, dequeued
87 extern Monitor* MethodCompileQueueSC2_lock; // a lock held when method compilations are enqueued, dequeued
88 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
89 extern Monitor* Compilation_lock; // a lock used to pause compilation
90 extern Mutex* TrainingData_lock; // a lock used when accessing training records
91 extern Monitor* TrainingReplayQueue_lock; // a lock held when class are added/removed to the training replay queue
92 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
93 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
94 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
95 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
96 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed
97 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
98 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
99 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
100
101 #ifndef PRODUCT
102 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
103 #endif // PRODUCT
104
105 extern Mutex* RawMonitor_lock;
106 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
107 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
108
109 extern Mutex* FreeList_lock; // protects the free region list during safepoints
110 extern Mutex* OldSets_lock; // protects the old region sets
111 extern Mutex* Uncommit_lock; // protects the uncommit list when not at safepoints
112 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
113
114 extern Mutex* Management_lock; // a lock used to serialize JVM management
115 extern Monitor* MonitorDeflation_lock; // a lock used for monitor deflation thread operation
116 extern Monitor* Service_lock; // a lock used for service thread operation
117 extern Monitor* Notification_lock; // a lock used for notification thread operation
118 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
119 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
120 extern Mutex* Verify_lock; // synchronize initialization of verify library
121 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock
122 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table
123 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use
124 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information
125 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries
126 extern Mutex* NMTCompilationCostHistory_lock; // guards NMT compilation cost history
127 #if INCLUDE_CDS
128 #if INCLUDE_JVMTI
129 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti
130 #endif
131 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::_dumptime_table
132 extern Mutex* CDSLambda_lock; // SystemDictionaryShared::get_shared_lambda_proxy_class
133 extern Mutex* DumpRegion_lock; // Symbol::operator new(size_t sz, int len)
134 extern Mutex* ClassListFile_lock; // ClassListWriter()
135 extern Mutex* UnregisteredClassesTable_lock; // UnregisteredClassesTableTable
136 extern Mutex* LambdaFormInvokers_lock; // Protecting LambdaFormInvokers::_lambdaform_lines
137 extern Mutex* ScratchObjects_lock; // Protecting _scratch_xxx_table in heapShared.cpp
138 extern Mutex* ArchivedObjectTables_lock; // Protecting the table used by HeapShared::get_archived_object_permanent_index()
139 #endif // INCLUDE_CDS
140 #if INCLUDE_JFR
141 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
142 extern Monitor* JfrMsg_lock; // protects JFR messaging
143 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
144 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler
145 #endif
146
147 extern Mutex* Metaspace_lock; // protects Metaspace virtualspace and chunk expansions
148 extern Monitor* MetaspaceCritical_lock; // synchronizes failed metaspace allocations that risk throwing metaspace OOM
149 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
150
151
152 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
153 // Only used locally in PrintCodeCacheLayout processing.
154
155 extern Mutex* ExternalsRecorder_lock; // used to guard access to the external addresses table
156
157 extern Monitor* ContinuationRelativize_lock;
158
159 #if INCLUDE_JVMCI
160 extern Monitor* JVMCI_lock; // protects global JVMCI critical sections
161 extern Monitor* JVMCIRuntime_lock; // protects critical sections for a specific JVMCIRuntime object
162 #endif
163
164 extern Mutex* Bootclasspath_lock;
165
166 extern Mutex* tty_lock; // lock to synchronize output.
167
168 // A MutexLocker provides mutual exclusion with respect to a given mutex
169 // for the scope which contains the locker. The lock is an OS lock, not
170 // an object lock, and the two do not interoperate. Do not use Mutex-based
171 // locks to lock on Java objects, because they will not be respected if a
172 // that object is locked using the Java locking mechanism.
173 //
174 // NOTE WELL!!
175 //
176 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
177 // and friends constructors do a fence, a lock and an acquire *in that
178 // order*. And that their destructors do a release and unlock, in *that*
179 // order. If their implementations change such that these assumptions
180 // are violated, a whole lot of code will break.
181
182 // Print all mutexes/monitors that are currently owned by a thread; called
183 // by fatal error handler.
184 void print_owned_locks_on_error(outputStream* st);
185 void print_lock_ranks(outputStream* st);
186
187 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
188 #ifdef ASSERT
189 void assert_locked_or_safepoint(const Mutex* lock);
190 void assert_lock_strong(const Mutex* lock);
191 #else
192 #define assert_locked_or_safepoint(lock)
193 #define assert_lock_strong(lock)
194 #endif
195
196 // Internal implementation. Skips on null Mutex.
197 // Subclasses enforce stronger invariants.
198 class MutexLockerImpl: public StackObj {
199 protected:
200 Mutex* _mutex;
201 bool _prof;
202 elapsedTimer _before;
203 elapsedTimer _after;
204
205 private:
206 static PerfCounter** _perf_lock_count;
207 static PerfCounter** _perf_lock_wait_time;
208 static PerfCounter** _perf_lock_hold_time;
209
210 public:
211
212 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
213 _mutex(mutex), _prof(ProfileVMLocks && Thread::current_or_null() != nullptr && Thread::current()->profile_vm_locks()) {
214
215 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
216 if (_mutex != nullptr) {
217 if (_prof) { _before.start(); } // before
218
219 if (no_safepoint_check) {
220 _mutex->lock_without_safepoint_check();
221 } else {
222 _mutex->lock();
223 }
224
225 if (_prof) { _before.stop(); _after.start(); } // after
226 }
227 }
228
229 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
230 _mutex(mutex), _prof(thread->profile_vm_locks()) {
231
232 if (_prof) { _before.start(); } // before
233
234 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
235 if (_mutex != nullptr) {
236 if (no_safepoint_check) {
237 _mutex->lock_without_safepoint_check(thread);
238 } else {
239 _mutex->lock(thread);
240 }
241 }
242
243 if (_prof) { _before.stop(); _after.start(); } // after
244 }
245
246 ~MutexLockerImpl() {
247 if (_mutex != nullptr) {
248 assert_lock_strong(_mutex);
249 _mutex->unlock();
250
251 if (_mutex->id() == -1) {
252 log_trace(init)("Unnamed unclassified lock: %s", _mutex->name());
253 }
254
255 if (_prof) {
256 assert(UsePerfData, "required");
257 _after.stop();
258 _perf_lock_count [_mutex->id() + 1]->inc();
259 _perf_lock_wait_time[_mutex->id() + 1]->inc(_before.ticks());
260 _perf_lock_hold_time[_mutex->id() + 1]->inc(_after.ticks());
261 }
262 }
263 }
264
265 private:
266 static void print_counter_on(outputStream* st, const char* name, bool is_unique, int idx);
267
268 public:
269 static int name2id(const char* name);
270
271 static void post_initialize();
272 static void init_counters();
273 static void print_counters_on(outputStream* st);
274 };
275
276 // Simplest mutex locker.
277 // Does not allow null mutexes.
278 class MutexLocker: public MutexLockerImpl {
279 public:
280 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
281 MutexLockerImpl(mutex, flag) {
282 assert(mutex != nullptr, "null mutex not allowed");
283 }
284
285 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
286 MutexLockerImpl(thread, mutex, flag) {
287 assert(mutex != nullptr, "null mutex not allowed");
288 }
289 };
290
291 // Conditional mutex locker.
292 // Like MutexLocker above, but only locks when condition is true.
293 class ConditionalMutexLocker: public MutexLockerImpl {
294 public:
295 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
296 MutexLockerImpl(condition ? mutex : nullptr, flag) {
297 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
298 }
299
300 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
301 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
302 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
303 }
304 };
305
306 // A MonitorLocker is like a MutexLocker above, except it allows
307 // wait/notify as well which are delegated to the underlying Monitor.
308 // It also disallows null.
309 class MonitorLocker: public MutexLockerImpl {
310 Mutex::SafepointCheckFlag _flag;
311
312 protected:
313 Monitor* as_monitor() const {
314 return static_cast<Monitor*>(_mutex);
315 }
316
317 public:
318 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
319 MutexLockerImpl(monitor, flag), _flag(flag) {
320 // Superclass constructor did locking
321 assert(monitor != nullptr, "null monitor not allowed");
322 }
323
324 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
325 MutexLockerImpl(thread, monitor, flag), _flag(flag) {
326 // Superclass constructor did locking
327 assert(monitor != nullptr, "null monitor not allowed");
328 }
329
330 bool wait(int64_t timeout = 0) {
331 return _flag == Mutex::_safepoint_check_flag ?
332 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
333 }
334
335 void notify_all() {
336 as_monitor()->notify_all();
337 }
338
339 void notify() {
340 as_monitor()->notify();
341 }
342 };
343
344
345 // A GCMutexLocker is usually initialized with a mutex that is
346 // automatically acquired in order to do GC. The function that
347 // synchronizes using a GCMutexLocker may be called both during and between
348 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
349 // if GC is in progress (since the mutex is already held on its behalf.)
350
351 class GCMutexLocker: public StackObj {
352 private:
353 Mutex* _mutex;
354 bool _locked;
355 public:
356 GCMutexLocker(Mutex* mutex);
357 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
358 };
359
360 // A MutexUnlocker temporarily exits a previously
361 // entered mutex for the scope which contains the unlocker.
362
363 class MutexUnlocker: StackObj {
364 private:
365 Mutex* _mutex;
366 bool _no_safepoint_check;
367
368 public:
369 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
370 _mutex(mutex),
371 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
372 _mutex->unlock();
373 }
374
375 ~MutexUnlocker() {
376 if (_no_safepoint_check) {
377 _mutex->lock_without_safepoint_check();
378 } else {
379 _mutex->lock();
380 }
381 }
382 };
383
384 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java,
385 // and JNI event notification for resource exhaustion for metaspace or heap.
386 extern RecursiveMutex* MultiArray_lock;
387
388 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information.
389 class RecursiveLocker {
390 RecursiveMutex* _lock;
391 Thread* _thread;
392 public:
393 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) {
394 _lock->lock(_thread);
395 }
396 ~RecursiveLocker() {
397 _lock->unlock(_thread);
398 }
399 };
400
401 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP