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 class Thread;
36
37 // Mutexes used in the VM.
38
39 extern Mutex* NMethodState_lock; // a lock used to guard a compiled method state
40 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
41 extern Mutex* InvokeMethodTypeTable_lock;
42 extern Monitor* InvokeMethodIntrinsicTable_lock;
43 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary
44 extern Monitor* ClassInitError_lock; // a lock on the class initialization error table
45 extern Mutex* Module_lock; // a lock on module and package related data structures
46 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
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* ThreadsLockThrottle_lock; // used by Thread start/exit to reduce competition for Threads_lock,
69 // so a VM thread calling a safepoint is prioritized
70 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
71 // (also used by Safepoints too to block threads creation/destruction)
72 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list
73 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization
74 extern Monitor* CGC_lock; // used for coordination between
75 // fore- & background GC threads.
76 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
77 extern Monitor* G1OldGCCount_lock; // in support of "concurrent" full gc
78 extern Mutex* G1RareEvent_lock; // Synchronizes (rare) parallel GC operations.
79 extern Mutex* G1DetachedRefinementStats_lock; // Lock protecting detached refinement stats
80 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
81 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
82 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools and allocated memory high water mark.
83 extern Monitor* ConcurrentGCBreakpoints_lock; // Protects concurrent GC breakpoint management
84 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
85 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
86 extern Monitor* MethodCompileQueueC1_lock; // a lock held when method compilations are enqueued, dequeued
87 extern Monitor* MethodCompileQueueC2_lock; // a lock held when method compilations are enqueued, dequeued
88 extern Monitor* MethodCompileQueueC3_lock; // a lock held when method compilations are enqueued, dequeued
89 extern Monitor* MethodCompileQueueSC1_lock; // a lock held when method compilations are enqueued, dequeued
90 extern Monitor* MethodCompileQueueSC2_lock; // a lock held when method compilations are enqueued, dequeued
91 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
92 extern Monitor* Compilation_lock; // a lock used to pause compilation
93 extern Mutex* TrainingData_lock; // a lock used when accessing training records
94 extern Monitor* TrainingReplayQueue_lock; // a lock held when class are added/removed to the training replay queue
95 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
96 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
97 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
98 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
99 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed
100 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
101 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
102 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
103
104 #ifndef PRODUCT
105 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
106 #endif // PRODUCT
107
108 extern Mutex* RawMonitor_lock;
109 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
110 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
111
112 extern Mutex* FreeList_lock; // protects the free region list during safepoints
113 extern Mutex* OldSets_lock; // protects the old region sets
114 extern Mutex* Uncommit_lock; // protects the uncommit list when not at safepoints
115 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
116
117 extern Mutex* Management_lock; // a lock used to serialize JVM management
118 extern Monitor* MonitorDeflation_lock; // a lock used for monitor deflation thread operation
119 extern Monitor* Service_lock; // a lock used for service thread operation
120 extern Monitor* Notification_lock; // a lock used for notification thread operation
121 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
122 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
123 extern Mutex* Verify_lock; // synchronize initialization of verify library
124 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock
125 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table
126 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use
127 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information
128 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries
129 extern Mutex* NMTCompilationCostHistory_lock; // guards NMT compilation cost history
130 #if INCLUDE_CDS
131 #if INCLUDE_JVMTI
132 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti
133 #endif
134 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::_dumptime_table
135 extern Mutex* CDSLambda_lock; // SystemDictionaryShared::get_shared_lambda_proxy_class
136 extern Mutex* DumpRegion_lock; // Symbol::operator new(size_t sz, int len)
137 extern Mutex* ClassListFile_lock; // ClassListWriter()
138 extern Mutex* UnregisteredClassesTable_lock; // UnregisteredClassesTableTable
139 extern Mutex* LambdaFormInvokers_lock; // Protecting LambdaFormInvokers::_lambdaform_lines
140 extern Mutex* ScratchObjects_lock; // Protecting _scratch_xxx_table in heapShared.cpp
141 extern Mutex* ArchivedObjectTables_lock; // Protecting the table used by HeapShared::get_archived_object_permanent_index()
142 #endif // INCLUDE_CDS
143 #if INCLUDE_JFR
144 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
145 extern Monitor* JfrMsg_lock; // protects JFR messaging
146 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
147 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler
148 #endif
149
150 extern Mutex* Metaspace_lock; // protects Metaspace virtualspace and chunk expansions
151 extern Monitor* MetaspaceCritical_lock; // synchronizes failed metaspace allocations that risk throwing metaspace OOM
152 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
153
154
155 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
156 // Only used locally in PrintCodeCacheLayout processing.
157
158 extern Mutex* ExternalsRecorder_lock; // used to guard access to the external addresses table
159
160 extern Monitor* ContinuationRelativize_lock;
161
162 #if INCLUDE_JVMCI
163 extern Monitor* JVMCI_lock; // protects global JVMCI critical sections
164 extern Monitor* JVMCIRuntime_lock; // protects critical sections for a specific JVMCIRuntime object
165 #endif
166
167 extern Mutex* Bootclasspath_lock;
168
169 extern Mutex* tty_lock; // lock to synchronize output.
170
171 // A MutexLocker provides mutual exclusion with respect to a given mutex
172 // for the scope which contains the locker. The lock is an OS lock, not
173 // an object lock, and the two do not interoperate. Do not use Mutex-based
174 // locks to lock on Java objects, because they will not be respected if a
175 // that object is locked using the Java locking mechanism.
176 //
177 // NOTE WELL!!
178 //
179 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
180 // and friends constructors do a fence, a lock and an acquire *in that
181 // order*. And that their destructors do a release and unlock, in *that*
182 // order. If their implementations change such that these assumptions
183 // are violated, a whole lot of code will break.
184
185 // Print all mutexes/monitors that are currently owned by a thread; called
186 // by fatal error handler.
187 void print_owned_locks_on_error(outputStream* st);
188 void print_lock_ranks(outputStream* st);
189
190 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
191 #ifdef ASSERT
192 void assert_locked_or_safepoint(const Mutex* lock);
193 void assert_lock_strong(const Mutex* lock);
194 #else
195 #define assert_locked_or_safepoint(lock)
196 #define assert_lock_strong(lock)
197 #endif
198
199 // Internal implementation. Skips on null Mutex.
200 // Subclasses enforce stronger invariants.
201 class MutexLockerImpl: public StackObj {
202 protected:
203 Mutex* _mutex;
204 bool _prof;
205 elapsedTimer _before;
206 elapsedTimer _after;
207
208 private:
209 static PerfCounter** _perf_lock_count;
210 static PerfCounter** _perf_lock_wait_time;
211 static PerfCounter** _perf_lock_hold_time;
212
213 public:
214
215 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
216 _mutex(mutex), _prof(ProfileVMLocks && Thread::current_or_null() != nullptr && Thread::current()->profile_vm_locks()) {
217
218 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
219 if (_mutex != nullptr) {
220 if (_prof) { _before.start(); } // before
221
222 if (no_safepoint_check) {
223 _mutex->lock_without_safepoint_check();
224 } else {
225 _mutex->lock();
226 }
227
228 if (_prof) { _before.stop(); _after.start(); } // after
229 }
230 }
231
232 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
233 _mutex(mutex), _prof(thread->profile_vm_locks()) {
234
235 if (_prof) { _before.start(); } // before
236
237 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
238 if (_mutex != nullptr) {
239 if (no_safepoint_check) {
240 _mutex->lock_without_safepoint_check(thread);
241 } else {
242 _mutex->lock(thread);
243 }
244 }
245
246 if (_prof) { _before.stop(); _after.start(); } // after
247 }
248
249 ~MutexLockerImpl() {
250 if (_mutex != nullptr) {
251 assert_lock_strong(_mutex);
252 _mutex->unlock();
253
254 if (_mutex->id() == -1) {
255 log_trace(init)("Unnamed unclassified lock: %s", _mutex->name());
256 }
257
258 if (_prof) {
259 assert(UsePerfData, "required");
260 _after.stop();
261 _perf_lock_count [_mutex->id() + 1]->inc();
262 _perf_lock_wait_time[_mutex->id() + 1]->inc(_before.ticks());
263 _perf_lock_hold_time[_mutex->id() + 1]->inc(_after.ticks());
264 }
265 }
266 }
267
268 private:
269 static void print_counter_on(outputStream* st, const char* name, bool is_unique, int idx);
270
271 public:
272 static int name2id(const char* name);
273
274 static void post_initialize();
275 static void init_counters();
276 static void print_counters_on(outputStream* st);
277 };
278
279 // Simplest mutex locker.
280 // Does not allow null mutexes.
281 class MutexLocker: public MutexLockerImpl {
282 public:
283 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
284 MutexLockerImpl(mutex, flag) {
285 assert(mutex != nullptr, "null mutex not allowed");
286 }
287
288 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
289 MutexLockerImpl(thread, mutex, flag) {
290 assert(mutex != nullptr, "null mutex not allowed");
291 }
292 };
293
294 // Conditional mutex locker.
295 // Like MutexLocker above, but only locks when condition is true.
296 class ConditionalMutexLocker: public MutexLockerImpl {
297 public:
298 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
299 MutexLockerImpl(condition ? mutex : nullptr, flag) {
300 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
301 }
302
303 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
304 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
305 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
306 }
307 };
308
309 // A MonitorLocker is like a MutexLocker above, except it allows
310 // wait/notify as well which are delegated to the underlying Monitor.
311 // It also disallows null.
312 class MonitorLocker: public MutexLockerImpl {
313 Mutex::SafepointCheckFlag _flag;
314
315 protected:
316 Monitor* as_monitor() const {
317 return static_cast<Monitor*>(_mutex);
318 }
319
320 public:
321 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
322 MutexLockerImpl(monitor, flag), _flag(flag) {
323 // Superclass constructor did locking
324 assert(monitor != nullptr, "null monitor not allowed");
325 }
326
327 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
328 MutexLockerImpl(thread, monitor, flag), _flag(flag) {
329 // Superclass constructor did locking
330 assert(monitor != nullptr, "null monitor not allowed");
331 }
332
333 bool wait(int64_t timeout = 0) {
334 return _flag == Mutex::_safepoint_check_flag ?
335 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
336 }
337
338 void notify_all() {
339 as_monitor()->notify_all();
340 }
341
342 void notify() {
343 as_monitor()->notify();
344 }
345 };
346
347
348 // A GCMutexLocker is usually initialized with a mutex that is
349 // automatically acquired in order to do GC. The function that
350 // synchronizes using a GCMutexLocker may be called both during and between
351 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
352 // if GC is in progress (since the mutex is already held on its behalf.)
353
354 class GCMutexLocker: public StackObj {
355 private:
356 Mutex* _mutex;
357 bool _locked;
358 public:
359 GCMutexLocker(Mutex* mutex);
360 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
361 };
362
363 // A MutexUnlocker temporarily exits a previously
364 // entered mutex for the scope which contains the unlocker.
365
366 class MutexUnlocker: StackObj {
367 private:
368 Mutex* _mutex;
369 bool _no_safepoint_check;
370
371 public:
372 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
373 _mutex(mutex),
374 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
375 _mutex->unlock();
376 }
377
378 ~MutexUnlocker() {
379 if (_no_safepoint_check) {
380 _mutex->lock_without_safepoint_check();
381 } else {
382 _mutex->lock();
383 }
384 }
385 };
386
387 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java,
388 // and JNI event notification for resource exhaustion for metaspace or heap.
389 extern RecursiveMutex* MultiArray_lock;
390
391 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information.
392 class RecursiveLocker {
393 RecursiveMutex* _lock;
394 Thread* _thread;
395 public:
396 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) {
397 _lock->lock(_thread);
398 }
399 ~RecursiveLocker() {
400 _lock->unlock(_thread);
401 }
402 };
403
404 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP