1 /* 2 * Copyright (c) 1997, 2018, 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_VM_RUNTIME_MUTEXLOCKER_HPP 26 #define SHARE_VM_RUNTIME_MUTEXLOCKER_HPP 27 28 #include "memory/allocation.hpp" 29 #include "runtime/flags/flagSetting.hpp" 30 #include "runtime/mutex.hpp" 31 32 // Mutexes used in the VM. 33 34 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 35 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 36 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary 37 extern Mutex* Module_lock; // a lock on module and package related data structures 38 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 39 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 40 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 41 extern Mutex* JNIGlobalAlloc_lock; // JNI global storage allocate list lock 42 extern Mutex* JNIGlobalActive_lock; // JNI global storage active list lock 43 extern Mutex* JNIWeakAlloc_lock; // JNI weak storage allocate list lock 44 extern Mutex* JNIWeakActive_lock; // JNI weak storage active list lock 45 extern Mutex* StringTableWeakAlloc_lock; // StringTable weak storage allocate list lock 46 extern Mutex* StringTableWeakActive_lock; // STringTable weak storage active list lock 47 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 48 extern Mutex* VMWeakAlloc_lock; // VM Weak Handles storage allocate list lock 49 extern Mutex* VMWeakActive_lock; // VM Weak Handles storage active list lock 50 extern Mutex* ResolvedMethodTable_lock; // a lock on the ResolvedMethodTable updates 51 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 52 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 53 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 54 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 55 extern Monitor* Heap_lock; // a lock on the heap 56 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 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 Mutex* StringTable_lock; // a lock on the interned string table 62 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 63 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 64 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 65 extern Mutex* MethodData_lock; // a lock on installation of method data 66 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 67 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 68 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 69 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management 70 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 71 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 72 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 73 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 74 // (also used by Safepoints too to block threads creation/destruction) 75 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list 76 extern Monitor* CGC_lock; // used for coordination between 77 // fore- & background GC threads. 78 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 79 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 80 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 81 // buffer free list. 82 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 83 // completed buffer queue. 84 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 85 // queue shared by 86 // non-Java threads. 87 88 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 89 // buffer free list. 90 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 91 // completed buffer queue. 92 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 93 // queue shared by 94 // non-Java threads. 95 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 96 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 97 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools. 98 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 99 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 100 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 101 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 102 extern Monitor* Compilation_lock; // a lock used to pause compilation 103 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 104 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 105 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 106 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 107 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 108 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 109 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 110 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 111 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 112 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 113 114 #ifndef PRODUCT 115 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 116 #endif // PRODUCT 117 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 118 extern Mutex* Debug2_lock; // down synchronization related bugs! 119 extern Mutex* Debug3_lock; 120 121 extern Mutex* RawMonitor_lock; 122 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 123 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 124 extern Mutex* ParkerFreeList_lock; 125 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 126 127 extern Mutex* FreeList_lock; // protects the free region list during safepoints 128 extern Mutex* OldSets_lock; // protects the old region sets 129 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 130 131 extern Mutex* Management_lock; // a lock used to serialize JVM management 132 extern Monitor* Service_lock; // a lock used for service thread operation 133 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 134 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 135 extern Mutex* ThreadHeapSampler_lock; // protects the static data for initialization. 136 137 #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 extern Mutex* JfrStream_lock; // protects JFR stream access 142 #endif 143 144 #ifndef SUPPORTS_NATIVE_CX8 145 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 146 #endif 147 148 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 149 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading 150 151 152 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 153 // Only used locally in PrintCodeCacheLayout processing. 154 155 // A MutexLocker provides mutual exclusion with respect to a given mutex 156 // for the scope which contains the locker. The lock is an OS lock, not 157 // an object lock, and the two do not interoperate. Do not use Mutex-based 158 // locks to lock on Java objects, because they will not be respected if a 159 // that object is locked using the Java locking mechanism. 160 // 161 // NOTE WELL!! 162 // 163 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 164 // and friends constructors do a fence, a lock and an acquire *in that 165 // order*. And that their destructors do a release and unlock, in *that* 166 // order. If their implementations change such that these assumptions 167 // are violated, a whole lot of code will break. 168 169 // Print all mutexes/monitors that are currently owned by a thread; called 170 // by fatal error handler. 171 void print_owned_locks_on_error(outputStream* st); 172 173 char *lock_name(Mutex *mutex); 174 175 class MutexLocker: StackObj { 176 private: 177 Monitor * _mutex; 178 public: 179 MutexLocker(Monitor * mutex) { 180 assert(mutex->rank() != Mutex::special, 181 "Special ranked mutex should only use MutexLockerEx"); 182 _mutex = mutex; 183 _mutex->lock(); 184 } 185 186 // Overloaded constructor passing current thread 187 MutexLocker(Monitor * mutex, Thread *thread) { 188 assert(mutex->rank() != Mutex::special, 189 "Special ranked mutex should only use MutexLockerEx"); 190 _mutex = mutex; 191 _mutex->lock(thread); 192 } 193 194 ~MutexLocker() { 195 _mutex->unlock(); 196 } 197 198 }; 199 200 // for debugging: check that we're already owning this lock (or are at a safepoint) 201 #ifdef ASSERT 202 void assert_locked_or_safepoint(const Monitor * lock); 203 void assert_lock_strong(const Monitor * lock); 204 #else 205 #define assert_locked_or_safepoint(lock) 206 #define assert_lock_strong(lock) 207 #endif 208 209 // A MutexLockerEx behaves like a MutexLocker when its constructor is 210 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 211 // called with NULL, in which case the MutexLockerEx is a no-op. There 212 // is also a corresponding MutexUnlockerEx. We want to keep the 213 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 214 // without safepoint check. 215 216 class MutexLockerEx: public StackObj { 217 private: 218 Monitor * _mutex; 219 public: 220 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 221 _mutex = mutex; 222 if (_mutex != NULL) { 223 assert(mutex->rank() > Mutex::special || no_safepoint_check, 224 "Mutexes with rank special or lower should not do safepoint checks"); 225 if (no_safepoint_check) 226 _mutex->lock_without_safepoint_check(); 227 else 228 _mutex->lock(); 229 } 230 } 231 232 ~MutexLockerEx() { 233 if (_mutex != NULL) { 234 _mutex->unlock(); 235 } 236 } 237 }; 238 239 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 240 // a possibly null Monitor, and allows wait/notify as well which are 241 // delegated to the underlying Monitor. 242 243 class MonitorLockerEx: public MutexLockerEx { 244 private: 245 Monitor * _monitor; 246 public: 247 MonitorLockerEx(Monitor* monitor, 248 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 249 MutexLockerEx(monitor, no_safepoint_check), 250 _monitor(monitor) { 251 // Superclass constructor did locking 252 } 253 254 ~MonitorLockerEx() { 255 #ifdef ASSERT 256 if (_monitor != NULL) { 257 assert_lock_strong(_monitor); 258 } 259 #endif // ASSERT 260 // Superclass destructor will do unlocking 261 } 262 263 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 264 long timeout = 0, 265 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 266 if (_monitor != NULL) { 267 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 268 } 269 return false; 270 } 271 272 bool notify_all() { 273 if (_monitor != NULL) { 274 return _monitor->notify_all(); 275 } 276 return true; 277 } 278 279 bool notify() { 280 if (_monitor != NULL) { 281 return _monitor->notify(); 282 } 283 return true; 284 } 285 }; 286 287 288 289 // A GCMutexLocker is usually initialized with a mutex that is 290 // automatically acquired in order to do GC. The function that 291 // synchronizes using a GCMutexLocker may be called both during and between 292 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 293 // if GC is in progress (since the mutex is already held on its behalf.) 294 295 class GCMutexLocker: public StackObj { 296 private: 297 Monitor * _mutex; 298 bool _locked; 299 public: 300 GCMutexLocker(Monitor * mutex); 301 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 302 }; 303 304 305 306 // A MutexUnlocker temporarily exits a previously 307 // entered mutex for the scope which contains the unlocker. 308 309 class MutexUnlocker: StackObj { 310 private: 311 Monitor * _mutex; 312 313 public: 314 MutexUnlocker(Monitor * mutex) { 315 _mutex = mutex; 316 _mutex->unlock(); 317 } 318 319 ~MutexUnlocker() { 320 _mutex->lock(); 321 } 322 }; 323 324 // A MutexUnlockerEx temporarily exits a previously 325 // entered mutex for the scope which contains the unlocker. 326 327 class MutexUnlockerEx: StackObj { 328 private: 329 Monitor * _mutex; 330 bool _no_safepoint_check; 331 332 public: 333 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 334 _mutex = mutex; 335 _no_safepoint_check = no_safepoint_check; 336 _mutex->unlock(); 337 } 338 339 ~MutexUnlockerEx() { 340 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 341 _mutex->lock_without_safepoint_check(); 342 } else { 343 _mutex->lock(); 344 } 345 } 346 }; 347 348 #ifndef PRODUCT 349 // 350 // A special MutexLocker that allows: 351 // - reentrant locking 352 // - locking out of order 353 // 354 // Only to be used for verify code, where we can relax out dead-lock 355 // detection code a bit (unsafe, but probably ok). This code is NEVER to 356 // be included in a product version. 357 // 358 class VerifyMutexLocker: StackObj { 359 private: 360 Monitor * _mutex; 361 bool _reentrant; 362 public: 363 VerifyMutexLocker(Monitor * mutex) { 364 _mutex = mutex; 365 _reentrant = mutex->owned_by_self(); 366 if (!_reentrant) { 367 // We temp. disable strict safepoint checking, while we require the lock 368 FlagSetting fs(StrictSafepointChecks, false); 369 _mutex->lock(); 370 } 371 } 372 373 ~VerifyMutexLocker() { 374 if (!_reentrant) { 375 _mutex->unlock(); 376 } 377 } 378 }; 379 380 #endif 381 382 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP