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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7 * published by the Free Software Foundation.
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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 "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 Monitor* SystemDictionary_lock; // a lock on the system dictionary
38 extern Mutex* InvokeMethodTypeTable_lock;
39 extern Monitor* InvokeMethodIntrinsicTable_lock;
40 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary
41 extern Monitor* ClassInitError_lock; // a lock on the class initialization error table
42 extern Mutex* Module_lock; // a lock on module and package related data structures
43 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
44 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
45 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
46 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
47 extern Monitor* JNICritical_lock; // a lock used while synchronizing with threads entering/leaving JNI critical regions
48 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
49 extern Monitor* EscapeBarrier_lock; // a lock to sync reallocating and relocking objects because of JVMTI access
50 extern Monitor* JvmtiVTMSTransition_lock; // a lock for Virtual Thread Mount State transition (VTMS transition) management
51 extern Mutex* JvmtiVThreadSuspend_lock; // a lock for virtual threads suspension
52 extern Monitor* Heap_lock; // a lock on the heap
53 #if INCLUDE_PARALLELGC
54 extern Mutex* PSOldGenExpand_lock; // a lock on expanding the heap
55 #endif
56 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
57 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
58 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
59 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena
60 extern Monitor* StringDedup_lock; // a lock on the string deduplication facility
61 extern Mutex* StringDedupIntern_lock; // a lock on StringTable notification of StringDedup
62 extern Monitor* CodeCache_lock; // a lock on the CodeCache
63 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
64 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
65 extern Monitor* VMOperation_lock; // a lock on queue of vm_operations waiting to execute
66 extern Monitor* ThreadsLockThrottle_lock; // used by Thread start/exit to reduce competition for Threads_lock,
67 // so a VM thread calling a safepoint is prioritized
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* CompileThread_lock; // a lock held by compile threads during compilation system initialization
85 extern Monitor* Compilation_lock; // a lock used to pause compilation
86 extern Mutex* TrainingData_lock; // a lock used when accessing training records
87 extern Monitor* TrainingReplayQueue_lock; // a lock held when class are added/removed to the training replay queue
88 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
89 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
90 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
91 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
92 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed
93 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
94 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
95 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
96
97 #ifndef PRODUCT
98 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
99 #endif // PRODUCT
100
101 extern Mutex* RawMonitor_lock;
102 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
103 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
104
105 extern Mutex* FreeList_lock; // protects the free region list during safepoints
106 extern Mutex* OldSets_lock; // protects the old region sets
107 extern Mutex* Uncommit_lock; // protects the uncommit list when not at safepoints
108 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
109
110 extern Mutex* Management_lock; // a lock used to serialize JVM management
111 extern Monitor* MonitorDeflation_lock; // a lock used for monitor deflation thread operation
112 extern Monitor* Service_lock; // a lock used for service thread operation
113 extern Monitor* Notification_lock; // a lock used for notification thread operation
114 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
115 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
116 extern Mutex* Verify_lock; // synchronize initialization of verify library
117 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock
118 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table
119 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use
120 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information
121 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries
122 extern Mutex* NMTCompilationCostHistory_lock; // guards NMT compilation cost history
123 extern Mutex* NmtVirtualMemory_lock; // guards NMT virtual memory updates
124 #if INCLUDE_CDS
125 #if INCLUDE_JVMTI
126 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti
127 #endif
128 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::_dumptime_table
129 extern Mutex* CDSLambda_lock; // LambdaProxyClassDictionary::find_lambda_proxy_class
130 extern Mutex* DumpRegion_lock; // Symbol::operator new(size_t sz, int len)
131 extern Mutex* ClassListFile_lock; // ClassListWriter()
132 extern Mutex* UnregisteredClassesTable_lock; // UnregisteredClassesTableTable
133 extern Mutex* LambdaFormInvokers_lock; // Protecting LambdaFormInvokers::_lambdaform_lines
134 extern Mutex* ScratchObjects_lock; // Protecting _scratch_xxx_table in heapShared.cpp
135 extern Mutex* FinalImageRecipes_lock; // Protecting the tables used by FinalImageRecipes.
136 #endif // INCLUDE_CDS
137 #if INCLUDE_JFR
138 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
139 extern Monitor* JfrMsg_lock; // protects JFR messaging
140 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
141 #endif
142
143 extern Mutex* Metaspace_lock; // protects Metaspace virtualspace and chunk expansions
144 extern Monitor* MetaspaceCritical_lock; // synchronizes failed metaspace allocations that risk throwing metaspace OOM
145 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
146
147
148 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
149 // Only used locally in PrintCodeCacheLayout processing.
150
151 extern Mutex* ExternalsRecorder_lock; // used to guard access to the external addresses table
152
153 extern Mutex* AOTCodeCStrings_lock; // used to guard access to the AOT code C strings table
154
155 extern Monitor* ContinuationRelativize_lock;
156
157 #if INCLUDE_JVMCI
158 extern Monitor* JVMCI_lock; // protects global JVMCI critical sections
159 extern Monitor* JVMCIRuntime_lock; // protects critical sections for a specific JVMCIRuntime object
160 #endif
161
162 extern Mutex* Bootclasspath_lock;
163
164 extern Mutex* tty_lock; // lock to synchronize output.
165
166 // A MutexLocker provides mutual exclusion with respect to a given mutex
167 // for the scope which contains the locker. The lock is an OS lock, not
168 // an object lock, and the two do not interoperate. Do not use Mutex-based
169 // locks to lock on Java objects, because they will not be respected if a
170 // that object is locked using the Java locking mechanism.
171 //
172 // NOTE WELL!!
173 //
174 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
175 // and friends constructors do a fence, a lock and an acquire *in that
176 // order*. And that their destructors do a release and unlock, in *that*
177 // order. If their implementations change such that these assumptions
178 // are violated, a whole lot of code will break.
179
180 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
181 #ifdef ASSERT
182 void assert_locked_or_safepoint(const Mutex* lock);
183 void assert_lock_strong(const Mutex* lock);
184 #else
185 #define assert_locked_or_safepoint(lock)
186 #define assert_lock_strong(lock)
187 #endif
188
189 // Internal implementation. Skips on null Mutex.
190 // Subclasses enforce stronger invariants.
191 class MutexLockerImpl: public StackObj {
192 protected:
193 Mutex* _mutex;
194
195 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
196 _mutex(mutex) {
197 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
198 if (_mutex != nullptr) {
199 if (no_safepoint_check) {
200 _mutex->lock_without_safepoint_check();
201 } else {
202 _mutex->lock();
203 }
204 }
205 }
206
207 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
208 _mutex(mutex) {
209 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
210 if (_mutex != nullptr) {
211 if (no_safepoint_check) {
212 _mutex->lock_without_safepoint_check(thread);
213 } else {
214 _mutex->lock(thread);
215 }
216 }
217 }
218
219 ~MutexLockerImpl() {
220 if (_mutex != nullptr) {
221 assert_lock_strong(_mutex);
222 _mutex->unlock();
223 }
224 }
225
226 public:
227 static void post_initialize();
228 };
229
230 // Simplest mutex locker.
231 // Does not allow null mutexes.
232 class MutexLocker: public MutexLockerImpl {
233 public:
234 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
235 MutexLockerImpl(mutex, flag) {
236 assert(mutex != nullptr, "null mutex not allowed");
237 }
238
239 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
240 MutexLockerImpl(thread, mutex, flag) {
241 assert(mutex != nullptr, "null mutex not allowed");
242 }
243 };
244
245 // Conditional mutex locker.
246 // Like MutexLocker above, but only locks when condition is true.
247 class ConditionalMutexLocker: public MutexLockerImpl {
248 public:
249 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
250 MutexLockerImpl(condition ? mutex : nullptr, flag) {
251 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
252 }
253
254 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
255 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
256 assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
257 }
258 };
259
260 // A MonitorLocker is like a MutexLocker above, except it allows
261 // wait/notify as well which are delegated to the underlying Monitor.
262 // It also disallows null.
263 class MonitorLocker: public MutexLockerImpl {
264 Mutex::SafepointCheckFlag _flag;
265
266 protected:
267 Monitor* as_monitor() const {
268 return static_cast<Monitor*>(_mutex);
269 }
270
271 public:
272 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
273 MutexLockerImpl(monitor, flag), _flag(flag) {
274 // Superclass constructor did locking
275 assert(monitor != nullptr, "null monitor not allowed");
276 }
277
278 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
279 MutexLockerImpl(thread, monitor, flag), _flag(flag) {
280 // Superclass constructor did locking
281 assert(monitor != nullptr, "null monitor not allowed");
282 }
283
284 bool wait(int64_t timeout = 0) {
285 return _flag == Mutex::_safepoint_check_flag ?
286 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
287 }
288
289 void notify_all() {
290 as_monitor()->notify_all();
291 }
292
293 void notify() {
294 as_monitor()->notify();
295 }
296 };
297
298
299 // A GCMutexLocker is usually initialized with a mutex that is
300 // automatically acquired in order to do GC. The function that
301 // synchronizes using a GCMutexLocker may be called both during and between
302 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
303 // if GC is in progress (since the mutex is already held on its behalf.)
304
305 class GCMutexLocker: public StackObj {
306 private:
307 Mutex* _mutex;
308 bool _locked;
309 public:
310 GCMutexLocker(Mutex* mutex);
311 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
312 };
313
314 // A MutexUnlocker temporarily exits a previously
315 // entered mutex for the scope which contains the unlocker.
316
317 class MutexUnlocker: StackObj {
318 private:
319 Mutex* _mutex;
320 bool _no_safepoint_check;
321
322 public:
323 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
324 _mutex(mutex),
325 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
326 _mutex->unlock();
327 }
328
329 ~MutexUnlocker() {
330 if (_no_safepoint_check) {
331 _mutex->lock_without_safepoint_check();
332 } else {
333 _mutex->lock();
334 }
335 }
336 };
337
338 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java,
339 // and JNI event notification for resource exhaustion for metaspace or heap.
340 extern RecursiveMutex* MultiArray_lock;
341
342 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information.
343 class RecursiveLocker {
344 RecursiveMutex* _lock;
345 Thread* _thread;
346 public:
347 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) {
348 _lock->lock(_thread);
349 }
350 ~RecursiveLocker() {
351 _lock->unlock(_thread);
352 }
353 };
354
355 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP