1 /* 2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 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 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 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake) 186 #ifdef ASSERT 187 void assert_locked_or_safepoint(const Mutex* lock); 188 void assert_lock_strong(const Mutex* lock); 189 #else 190 #define assert_locked_or_safepoint(lock) 191 #define assert_lock_strong(lock) 192 #endif 193 194 // Internal implementation. Skips on null Mutex. 195 // Subclasses enforce stronger invariants. 196 class MutexLockerImpl: public StackObj { 197 protected: 198 Mutex* _mutex; 199 bool _prof; 200 elapsedTimer _before; 201 elapsedTimer _after; 202 203 private: 204 static PerfCounter** _perf_lock_count; 205 static PerfCounter** _perf_lock_wait_time; 206 static PerfCounter** _perf_lock_hold_time; 207 208 public: 209 210 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 211 _mutex(mutex), _prof(ProfileVMLocks && Thread::current_or_null() != nullptr && Thread::current()->profile_vm_locks()) { 212 213 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 214 if (_mutex != nullptr) { 215 if (_prof) { _before.start(); } // before 216 217 if (no_safepoint_check) { 218 _mutex->lock_without_safepoint_check(); 219 } else { 220 _mutex->lock(); 221 } 222 223 if (_prof) { _before.stop(); _after.start(); } // after 224 } 225 } 226 227 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 228 _mutex(mutex), _prof(thread->profile_vm_locks()) { 229 230 if (_prof) { _before.start(); } // before 231 232 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 233 if (_mutex != nullptr) { 234 if (no_safepoint_check) { 235 _mutex->lock_without_safepoint_check(thread); 236 } else { 237 _mutex->lock(thread); 238 } 239 } 240 241 if (_prof) { _before.stop(); _after.start(); } // after 242 } 243 244 ~MutexLockerImpl() { 245 if (_mutex != nullptr) { 246 assert_lock_strong(_mutex); 247 _mutex->unlock(); 248 249 if (_mutex->id() == -1) { 250 log_trace(init)("Unnamed unclassified lock: %s", _mutex->name()); 251 } 252 253 if (_prof) { 254 assert(UsePerfData, "required"); 255 _after.stop(); 256 _perf_lock_count [_mutex->id() + 1]->inc(); 257 _perf_lock_wait_time[_mutex->id() + 1]->inc(_before.ticks()); 258 _perf_lock_hold_time[_mutex->id() + 1]->inc(_after.ticks()); 259 } 260 } 261 } 262 263 private: 264 static void print_counter_on(outputStream* st, const char* name, bool is_unique, int idx); 265 266 public: 267 static int name2id(const char* name); 268 269 static void post_initialize(); 270 static void init_counters(); 271 static void print_counters_on(outputStream* st); 272 }; 273 274 // Simplest mutex locker. 275 // Does not allow null mutexes. 276 class MutexLocker: public MutexLockerImpl { 277 public: 278 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 279 MutexLockerImpl(mutex, flag) { 280 assert(mutex != nullptr, "null mutex not allowed"); 281 } 282 283 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 284 MutexLockerImpl(thread, mutex, flag) { 285 assert(mutex != nullptr, "null mutex not allowed"); 286 } 287 }; 288 289 // Conditional mutex locker. 290 // Like MutexLocker above, but only locks when condition is true. 291 class ConditionalMutexLocker: public MutexLockerImpl { 292 public: 293 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 294 MutexLockerImpl(condition ? mutex : nullptr, flag) { 295 assert(!condition || mutex != nullptr, "null mutex not allowed when locking"); 296 } 297 298 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 299 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) { 300 assert(!condition || mutex != nullptr, "null mutex not allowed when locking"); 301 } 302 }; 303 304 // A MonitorLocker is like a MutexLocker above, except it allows 305 // wait/notify as well which are delegated to the underlying Monitor. 306 // It also disallows null. 307 class MonitorLocker: public MutexLockerImpl { 308 Mutex::SafepointCheckFlag _flag; 309 310 protected: 311 Monitor* as_monitor() const { 312 return static_cast<Monitor*>(_mutex); 313 } 314 315 public: 316 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 317 MutexLockerImpl(monitor, flag), _flag(flag) { 318 // Superclass constructor did locking 319 assert(monitor != nullptr, "null monitor not allowed"); 320 } 321 322 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 323 MutexLockerImpl(thread, monitor, flag), _flag(flag) { 324 // Superclass constructor did locking 325 assert(monitor != nullptr, "null monitor not allowed"); 326 } 327 328 bool wait(int64_t timeout = 0) { 329 return _flag == Mutex::_safepoint_check_flag ? 330 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout); 331 } 332 333 void notify_all() { 334 as_monitor()->notify_all(); 335 } 336 337 void notify() { 338 as_monitor()->notify(); 339 } 340 }; 341 342 343 // A GCMutexLocker is usually initialized with a mutex that is 344 // automatically acquired in order to do GC. The function that 345 // synchronizes using a GCMutexLocker may be called both during and between 346 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 347 // if GC is in progress (since the mutex is already held on its behalf.) 348 349 class GCMutexLocker: public StackObj { 350 private: 351 Mutex* _mutex; 352 bool _locked; 353 public: 354 GCMutexLocker(Mutex* mutex); 355 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 356 }; 357 358 // A MutexUnlocker temporarily exits a previously 359 // entered mutex for the scope which contains the unlocker. 360 361 class MutexUnlocker: StackObj { 362 private: 363 Mutex* _mutex; 364 bool _no_safepoint_check; 365 366 public: 367 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 368 _mutex(mutex), 369 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) { 370 _mutex->unlock(); 371 } 372 373 ~MutexUnlocker() { 374 if (_no_safepoint_check) { 375 _mutex->lock_without_safepoint_check(); 376 } else { 377 _mutex->lock(); 378 } 379 } 380 }; 381 382 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java, 383 // and JNI event notification for resource exhaustion for metaspace or heap. 384 extern RecursiveMutex* MultiArray_lock; 385 386 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information. 387 class RecursiveLocker { 388 RecursiveMutex* _lock; 389 Thread* _thread; 390 public: 391 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) { 392 _lock->lock(_thread); 393 } 394 ~RecursiveLocker() { 395 _lock->unlock(_thread); 396 } 397 }; 398 399 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP