1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13 * accompanied this code).
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24
25 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP
26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/flags/flagSetting.hpp"
30 #include "runtime/mutex.hpp"
31
32 class Thread;
33
34 // Mutexes used in the VM.
35
36 extern Mutex* NMethodState_lock; // a lock used to guard a compiled method state
37 extern Mutex* NMethodEntryBarrier_lock; // protects nmethod entry barrier
38 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary
39 extern Mutex* InvokeMethodTypeTable_lock;
40 extern Monitor* InvokeMethodIntrinsicTable_lock;
41 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary
42 extern Monitor* ClassInitError_lock; // a lock on the class initialization error table
43 extern Mutex* Module_lock; // a lock on module and package related data structures
44 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
45 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
46 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
47 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
48 extern Monitor* JNICritical_lock; // a lock used while synchronizing with threads entering/leaving JNI critical regions
49 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
50 extern Monitor* EscapeBarrier_lock; // a lock to sync reallocating and relocking objects because of JVMTI access
51 extern Monitor* JvmtiVTMSTransition_lock; // a lock for Virtual Thread Mount State transition (VTMS transition) management
52 extern Mutex* JvmtiVThreadSuspend_lock; // a lock for virtual threads suspension
53 extern Monitor* Heap_lock; // a lock on the heap
54 #if 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* ThreadsLockThrottle_lock; // used by Thread start/exit to reduce competition for Threads_lock,
68 // so a VM thread calling a safepoint is prioritized
69 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
70 // (also used by Safepoints too to block threads creation/destruction)
71 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list
72 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization
73 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
74 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools and allocated memory high water mark.
75 extern Monitor* ConcurrentGCBreakpoints_lock; // Protects concurrent GC breakpoint management
76 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
77 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
78 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
79 extern Monitor* Compilation_lock; // a lock used to pause compilation
80 extern Mutex* TrainingData_lock; // a lock used when accessing training records
81 extern Monitor* TrainingReplayQueue_lock; // a lock held when class are added/removed to the training replay queue
82 extern Monitor* CompileTaskWait_lock; // a lock held when CompileTasks are waited/notified
83 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
84 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
85 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
86 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed
87 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
88 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
89 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
90
91 #ifndef PRODUCT
92 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
93 #endif // PRODUCT
94
95 #if INCLUDE_G1GC
96 extern Monitor* G1CGC_lock; // used for coordination between fore- & background G1 concurrent GC threads.
97 extern Mutex* G1DetachedRefinementStats_lock; // Lock protecting detached refinement stats for G1.
98 extern Mutex* G1FreeList_lock; // protects the G1 free region list during safepoints
99 extern Mutex* G1MarkStackChunkList_lock; // Protects access to the G1 global mark stack chunk list.
100 extern Mutex* G1MarkStackFreeList_lock; // Protects access to the G1 global mark stack free list.
101 extern Monitor* G1OldGCCount_lock; // in support of "concurrent" full gc
102 extern Mutex* G1OldSets_lock; // protects the G1 old region sets
103 extern Mutex* G1RareEvent_lock; // Synchronizes (rare) parallel GC operations.
104 extern Monitor* G1RootRegionScan_lock; // used to notify that the G1 CM threads have finished scanning the root regions
105 extern Mutex* G1Uncommit_lock; // protects the G1 uncommit list when not at safepoints
106 #endif
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* Management_lock; // a lock used to serialize JVM management
113 extern Monitor* MonitorDeflation_lock; // a lock used for monitor deflation thread operation
114 extern Monitor* Service_lock; // a lock used for service thread operation
115 extern Monitor* Notification_lock; // a lock used for notification thread operation
116 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
117 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
118 extern Mutex* Verify_lock; // synchronize initialization of verify library
119 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock
120 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table
121 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use
122 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information
123 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries
124 extern Mutex* NMTCompilationCostHistory_lock; // guards NMT compilation cost history
125 extern Mutex* NmtVirtualMemory_lock; // guards NMT virtual memory updates
126 #if INCLUDE_CDS
127 #if INCLUDE_JVMTI
128 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti
129 #endif
130 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::_dumptime_table
131 extern Mutex* CDSLambda_lock; // LambdaProxyClassDictionary::find_lambda_proxy_class
132 extern Mutex* DumpRegion_lock; // Symbol::operator new(size_t sz, int len)
133 extern Mutex* ClassListFile_lock; // ClassListWriter()
134 extern Mutex* UnregisteredClassesTable_lock; // UnregisteredClassesTableTable
135 extern Mutex* LambdaFormInvokers_lock; // Protecting LambdaFormInvokers::_lambdaform_lines
136 extern Mutex* ScratchObjects_lock; // Protecting _scratch_xxx_table in heapShared.cpp
137 extern Mutex* FinalImageRecipes_lock; // Protecting the tables used by FinalImageRecipes.
138 #endif // INCLUDE_CDS
139 #if INCLUDE_JFR
140 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
141 extern Monitor* JfrMsg_lock; // protects JFR messaging
142 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
143 #endif
144
145 extern Mutex* Metaspace_lock; // protects Metaspace virtualspace and chunk expansions
146 extern Monitor* MetaspaceCritical_lock; // synchronizes failed metaspace allocations that risk throwing metaspace OOM
147 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
148
149
150 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
151 // Only used locally in PrintCodeCacheLayout processing.
152
153 extern Mutex* ExternalsRecorder_lock; // used to guard access to the external addresses table
154
155 extern Mutex* AOTCodeCStrings_lock; // used to guard access to the AOT code C strings 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 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
183 #ifdef ASSERT
184 void assert_locked_or_safepoint(const Mutex* lock);
185 void assert_lock_strong(const Mutex* lock);
186 #else
187 #define assert_locked_or_safepoint(lock)
188 #define assert_lock_strong(lock)
189 #endif
190
191 // Internal implementation. Skips on null Mutex.
192 // Subclasses enforce stronger invariants.
193 class MutexLockerImpl: public StackObj {
194 protected:
195 Mutex* _mutex;
196
197 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
198 _mutex(mutex) {
199 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
200 if (_mutex != nullptr) {
201 if (no_safepoint_check) {
202 _mutex->lock_without_safepoint_check();
203 } else {
204 _mutex->lock();
205 }
206 }
207 }
208
209 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
210 _mutex(mutex) {
211 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
212 if (_mutex != nullptr) {
213 if (no_safepoint_check) {
214 _mutex->lock_without_safepoint_check(thread);
215 } else {
216 _mutex->lock(thread);
217 }
218 }
219 }
220
221 ~MutexLockerImpl() {
222 if (_mutex != nullptr) {
223 assert_lock_strong(_mutex);
224 _mutex->unlock();
225 }
226 }
227
228 public:
229 static void post_initialize();
230 };
231
232 // Simplest mutex locker.
233 // Does not allow null mutexes.
234 class MutexLocker: public MutexLockerImpl {
235 public:
236 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
237 MutexLockerImpl(mutex, flag) {
238 assert(mutex != nullptr, "null mutex not allowed");
239 }
240
241 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
242 MutexLockerImpl(thread, mutex, flag) {
243 assert(mutex != nullptr, "null mutex not allowed");
244 }
245 };
246
247 // Conditional mutex locker.
248 // Like MutexLocker above, but only locks when condition is true.
249 class ConditionalMutexLocker: public MutexLockerImpl {
250 public:
251 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
252 MutexLockerImpl(condition ? mutex : nullptr, flag) {
253 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
254 }
255
256 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
257 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
258 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
259 }
260 };
261
262 // A MonitorLocker is like a MutexLocker above, except it allows
263 // wait/notify as well which are delegated to the underlying Monitor.
264 // It also disallows null.
265 class MonitorLocker: public MutexLockerImpl {
266 Mutex::SafepointCheckFlag _flag;
267
268 protected:
269 Monitor* as_monitor() const {
270 return static_cast<Monitor*>(_mutex);
271 }
272
273 public:
274 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
275 MutexLockerImpl(monitor, flag), _flag(flag) {
276 // Superclass constructor did locking
277 assert(monitor != nullptr, "null monitor not allowed");
278 }
279
280 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
281 MutexLockerImpl(thread, monitor, flag), _flag(flag) {
282 // Superclass constructor did locking
283 assert(monitor != nullptr, "null monitor not allowed");
284 }
285
286 bool wait(int64_t timeout = 0) {
287 return _flag == Mutex::_safepoint_check_flag ?
288 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
289 }
290
291 void notify_all() {
292 as_monitor()->notify_all();
293 }
294
295 void notify() {
296 as_monitor()->notify();
297 }
298 };
299
300
301 // A GCMutexLocker is usually initialized with a mutex that is
302 // automatically acquired in order to do GC. The function that
303 // synchronizes using a GCMutexLocker may be called both during and between
304 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
305 // if GC is in progress (since the mutex is already held on its behalf.)
306
307 class GCMutexLocker: public StackObj {
308 private:
309 Mutex* _mutex;
310 bool _locked;
311 public:
312 GCMutexLocker(Mutex* mutex);
313 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
314 };
315
316 // A MutexUnlocker temporarily exits a previously
317 // entered mutex for the scope which contains the unlocker.
318
319 class MutexUnlocker: StackObj {
320 private:
321 Mutex* _mutex;
322 bool _no_safepoint_check;
323
324 public:
325 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
326 _mutex(mutex),
327 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
328 _mutex->unlock();
329 }
330
331 ~MutexUnlocker() {
332 if (_no_safepoint_check) {
333 _mutex->lock_without_safepoint_check();
334 } else {
335 _mutex->lock();
336 }
337 }
338 };
339
340 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java,
341 // and JNI event notification for resource exhaustion for metaspace or heap.
342 extern RecursiveMutex* MultiArray_lock;
343
344 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information.
345 class RecursiveLocker {
346 RecursiveMutex* _lock;
347 Thread* _thread;
348 public:
349 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) {
350 _lock->lock(_thread);
351 }
352 ~RecursiveLocker() {
353 _lock->unlock(_thread);
354 }
355 };
356
357 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP