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