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* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 98 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 99 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 100 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 101 extern Monitor* Compilation_lock; // a lock used to pause compilation 102 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 103 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 104 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 105 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 106 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 107 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 108 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 109 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 110 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 111 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 112 113 #ifndef PRODUCT 114 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 115 #endif // PRODUCT 116 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 117 extern Mutex* Debug2_lock; // down synchronization related bugs! 118 extern Mutex* Debug3_lock; 119 120 extern Mutex* RawMonitor_lock; 121 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 122 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 123 extern Mutex* ParkerFreeList_lock; 124 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 125 126 extern Mutex* FreeList_lock; // protects the free region list during safepoints 127 extern Mutex* OldSets_lock; // protects the old region sets 128 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 129 130 extern Mutex* Management_lock; // a lock used to serialize JVM management 131 extern Monitor* Service_lock; // a lock used for service thread operation 132 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 133 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 134 extern Mutex* ThreadHeapSampler_lock; // protects the static data for initialization. 135 136 #if INCLUDE_JFR 137 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 138 extern Monitor* JfrMsg_lock; // protects JFR messaging 139 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 140 extern Mutex* JfrStream_lock; // protects JFR stream access 141 #endif 142 143 #ifndef SUPPORTS_NATIVE_CX8 144 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 145 #endif 146 147 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 148 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading 149 150 151 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 152 // Only used locally in PrintCodeCacheLayout processing. 153 154 // A MutexLocker provides mutual exclusion with respect to a given mutex 155 // for the scope which contains the locker. The lock is an OS lock, not 156 // an object lock, and the two do not interoperate. Do not use Mutex-based 157 // locks to lock on Java objects, because they will not be respected if a 158 // that object is locked using the Java locking mechanism. 159 // 160 // NOTE WELL!! 161 // 162 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 163 // and friends constructors do a fence, a lock and an acquire *in that 164 // order*. And that their destructors do a release and unlock, in *that* 165 // order. If their implementations change such that these assumptions 166 // are violated, a whole lot of code will break. 167 168 // Print all mutexes/monitors that are currently owned by a thread; called 169 // by fatal error handler. 170 void print_owned_locks_on_error(outputStream* st); 171 172 char *lock_name(Mutex *mutex); 173 174 class MutexLocker: StackObj { 175 private: 176 Monitor * _mutex; 177 public: 178 MutexLocker(Monitor * mutex) { 179 assert(mutex->rank() != Mutex::special, 180 "Special ranked mutex should only use MutexLockerEx"); 181 _mutex = mutex; 182 _mutex->lock(); 183 } 184 185 // Overloaded constructor passing current thread 186 MutexLocker(Monitor * mutex, Thread *thread) { 187 assert(mutex->rank() != Mutex::special, 188 "Special ranked mutex should only use MutexLockerEx"); 189 _mutex = mutex; 190 _mutex->lock(thread); 191 } 192 193 ~MutexLocker() { 194 _mutex->unlock(); 195 } 196 197 }; 198 199 // for debugging: check that we're already owning this lock (or are at a safepoint) 200 #ifdef ASSERT 201 void assert_locked_or_safepoint(const Monitor * lock); 202 void assert_locked_or_safepoint_weak(const Monitor * lock); 203 void assert_lock_strong(const Monitor * lock); 204 #else 205 #define assert_locked_or_safepoint(lock) 206 #define assert_locked_or_safepoint_weak(lock) 207 #define assert_lock_strong(lock) 208 #endif 209 210 // A MutexLockerEx behaves like a MutexLocker when its constructor is 211 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 212 // called with NULL, in which case the MutexLockerEx is a no-op. There 213 // is also a corresponding MutexUnlockerEx. We want to keep the 214 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 215 // without safepoint check. 216 217 class MutexLockerEx: public StackObj { 218 private: 219 Monitor * _mutex; 220 public: 221 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 222 _mutex = mutex; 223 if (_mutex != NULL) { 224 assert(mutex->rank() > Mutex::special || no_safepoint_check, 225 "Mutexes with rank special or lower should not do safepoint checks"); 226 if (no_safepoint_check) 227 _mutex->lock_without_safepoint_check(); 228 else 229 _mutex->lock(); 230 } 231 } 232 233 ~MutexLockerEx() { 234 if (_mutex != NULL) { 235 _mutex->unlock(); 236 } 237 } 238 }; 239 240 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 241 // a possibly null Monitor, and allows wait/notify as well which are 242 // delegated to the underlying Monitor. 243 244 class MonitorLockerEx: public MutexLockerEx { 245 private: 246 Monitor * _monitor; 247 public: 248 MonitorLockerEx(Monitor* monitor, 249 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 250 MutexLockerEx(monitor, no_safepoint_check), 251 _monitor(monitor) { 252 // Superclass constructor did locking 253 } 254 255 ~MonitorLockerEx() { 256 #ifdef ASSERT 257 if (_monitor != NULL) { 258 assert_lock_strong(_monitor); 259 } 260 #endif // ASSERT 261 // Superclass destructor will do unlocking 262 } 263 264 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 265 long timeout = 0, 266 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 267 if (_monitor != NULL) { 268 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 269 } 270 return false; 271 } 272 273 bool notify_all() { 274 if (_monitor != NULL) { 275 return _monitor->notify_all(); 276 } 277 return true; 278 } 279 280 bool notify() { 281 if (_monitor != NULL) { 282 return _monitor->notify(); 283 } 284 return true; 285 } 286 }; 287 288 289 290 // A GCMutexLocker is usually initialized with a mutex that is 291 // automatically acquired in order to do GC. The function that 292 // synchronizes using a GCMutexLocker may be called both during and between 293 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 294 // if GC is in progress (since the mutex is already held on its behalf.) 295 296 class GCMutexLocker: public StackObj { 297 private: 298 Monitor * _mutex; 299 bool _locked; 300 public: 301 GCMutexLocker(Monitor * mutex); 302 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 303 }; 304 305 306 307 // A MutexUnlocker temporarily exits a previously 308 // entered mutex for the scope which contains the unlocker. 309 310 class MutexUnlocker: StackObj { 311 private: 312 Monitor * _mutex; 313 314 public: 315 MutexUnlocker(Monitor * mutex) { 316 _mutex = mutex; 317 _mutex->unlock(); 318 } 319 320 ~MutexUnlocker() { 321 _mutex->lock(); 322 } 323 }; 324 325 // A MutexUnlockerEx temporarily exits a previously 326 // entered mutex for the scope which contains the unlocker. 327 328 class MutexUnlockerEx: StackObj { 329 private: 330 Monitor * _mutex; 331 bool _no_safepoint_check; 332 333 public: 334 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 335 _mutex = mutex; 336 _no_safepoint_check = no_safepoint_check; 337 _mutex->unlock(); 338 } 339 340 ~MutexUnlockerEx() { 341 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 342 _mutex->lock_without_safepoint_check(); 343 } else { 344 _mutex->lock(); 345 } 346 } 347 }; 348 349 #ifndef PRODUCT 350 // 351 // A special MutexLocker that allows: 352 // - reentrant locking 353 // - locking out of order 354 // 355 // Only to be used for verify code, where we can relax out dead-lock 356 // detection code a bit (unsafe, but probably ok). This code is NEVER to 357 // be included in a product version. 358 // 359 class VerifyMutexLocker: StackObj { 360 private: 361 Monitor * _mutex; 362 bool _reentrant; 363 public: 364 VerifyMutexLocker(Monitor * mutex) { 365 _mutex = mutex; 366 _reentrant = mutex->owned_by_self(); 367 if (!_reentrant) { 368 // We temp. disable strict safepoint checking, while we require the lock 369 FlagSetting fs(StrictSafepointChecks, false); 370 _mutex->lock(); 371 } 372 } 373 374 ~VerifyMutexLocker() { 375 if (!_reentrant) { 376 _mutex->unlock(); 377 } 378 } 379 }; 380 381 #endif 382 383 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP