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