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/mutex.hpp" 30 31 // Mutexes used in the VM. 32 33 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 34 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 35 extern Mutex* Module_lock; // a lock on module and package related data structures 36 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 37 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 38 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 39 extern Mutex* JNIGlobalAlloc_lock; // JNI global storage allocate list lock 40 extern Mutex* JNIGlobalActive_lock; // JNI global storage active list lock 41 extern Mutex* JNIWeakAlloc_lock; // JNI weak storage allocate list lock 42 extern Mutex* JNIWeakActive_lock; // JNI weak storage active list lock 43 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 44 extern Mutex* ResolvedMethodTable_lock; // a lock on the ResolvedMethodTable updates 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* Heap_lock; // a lock on the heap 50 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 51 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 52 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 53 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 54 extern Mutex* SymbolTable_lock; // a lock on the symbol table 55 extern Mutex* StringTable_lock; // a lock on the interned string table 56 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 57 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 58 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 59 extern Mutex* MethodData_lock; // a lock on installation of method data 60 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 61 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 62 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 63 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management 64 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 65 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 66 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 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 Monitor* CGC_lock; // used for coordination between 70 // fore- & background GC threads. 71 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 72 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 73 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 74 // buffer free list. 75 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 76 // completed buffer queue. 77 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 78 // queue shared by 79 // non-Java threads. 80 81 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 82 // buffer free list. 83 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 84 // completed buffer queue. 85 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 86 // queue shared by 87 // non-Java threads. 88 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 89 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 90 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 91 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 92 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 93 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 94 extern Monitor* Compilation_lock; // a lock used to pause compilation 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 Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 99 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 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* ProfilePrint_lock; // a lock used to serialize the printing of profiles 103 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 104 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 105 106 #ifndef PRODUCT 107 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 108 #endif // PRODUCT 109 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 110 extern Mutex* Debug2_lock; // down synchronization related bugs! 111 extern Mutex* Debug3_lock; 112 113 extern Mutex* RawMonitor_lock; 114 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 115 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 116 extern Mutex* ParkerFreeList_lock; 117 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 118 119 extern Mutex* FreeList_lock; // protects the free region list during safepoints 120 extern Mutex* OldSets_lock; // protects the old region sets 121 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 122 123 extern Mutex* Management_lock; // a lock used to serialize JVM management 124 extern Monitor* Service_lock; // a lock used for service thread operation 125 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 126 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 127 extern Mutex* ThreadHeapSampler_lock; // protects the static data for initialization. 128 129 #if INCLUDE_TRACE 130 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 131 extern Monitor* JfrMsg_lock; // protects JFR messaging 132 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 133 extern Mutex* JfrStream_lock; // protects JFR stream access 134 #endif 135 136 #ifndef SUPPORTS_NATIVE_CX8 137 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 138 #endif 139 140 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 141 142 143 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 144 // Only used locally in PrintCodeCacheLayout processing. 145 146 // A MutexLocker provides mutual exclusion with respect to a given mutex 147 // for the scope which contains the locker. The lock is an OS lock, not 148 // an object lock, and the two do not interoperate. Do not use Mutex-based 149 // locks to lock on Java objects, because they will not be respected if a 150 // that object is locked using the Java locking mechanism. 151 // 152 // NOTE WELL!! 153 // 154 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 155 // and friends constructors do a fence, a lock and an acquire *in that 156 // order*. And that their destructors do a release and unlock, in *that* 157 // order. If their implementations change such that these assumptions 158 // are violated, a whole lot of code will break. 159 160 // Print all mutexes/monitors that are currently owned by a thread; called 161 // by fatal error handler. 162 void print_owned_locks_on_error(outputStream* st); 163 164 char *lock_name(Mutex *mutex); 165 166 class MutexLocker: StackObj { 167 private: 168 Monitor * _mutex; 169 public: 170 MutexLocker(Monitor * mutex) { 171 assert(mutex->rank() != Mutex::special, 172 "Special ranked mutex should only use MutexLockerEx"); 173 _mutex = mutex; 174 _mutex->lock(); 175 } 176 177 // Overloaded constructor passing current thread 178 MutexLocker(Monitor * mutex, Thread *thread) { 179 assert(mutex->rank() != Mutex::special, 180 "Special ranked mutex should only use MutexLockerEx"); 181 _mutex = mutex; 182 _mutex->lock(thread); 183 } 184 185 ~MutexLocker() { 186 _mutex->unlock(); 187 } 188 189 }; 190 191 // for debugging: check that we're already owning this lock (or are at a safepoint) 192 #ifdef ASSERT 193 void assert_locked_or_safepoint(const Monitor * lock); 194 void assert_lock_strong(const Monitor * lock); 195 #else 196 #define assert_locked_or_safepoint(lock) 197 #define assert_lock_strong(lock) 198 #endif 199 200 // A MutexLockerEx behaves like a MutexLocker when its constructor is 201 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 202 // called with NULL, in which case the MutexLockerEx is a no-op. There 203 // is also a corresponding MutexUnlockerEx. We want to keep the 204 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 205 // without safepoint check. 206 207 class MutexLockerEx: public StackObj { 208 private: 209 Monitor * _mutex; 210 public: 211 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 212 _mutex = mutex; 213 if (_mutex != NULL) { 214 assert(mutex->rank() > Mutex::special || no_safepoint_check, 215 "Mutexes with rank special or lower should not do safepoint checks"); 216 if (no_safepoint_check) 217 _mutex->lock_without_safepoint_check(); 218 else 219 _mutex->lock(); 220 } 221 } 222 223 ~MutexLockerEx() { 224 if (_mutex != NULL) { 225 _mutex->unlock(); 226 } 227 } 228 }; 229 230 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 231 // a possibly null Monitor, and allows wait/notify as well which are 232 // delegated to the underlying Monitor. 233 234 class MonitorLockerEx: public MutexLockerEx { 235 private: 236 Monitor * _monitor; 237 public: 238 MonitorLockerEx(Monitor* monitor, 239 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 240 MutexLockerEx(monitor, no_safepoint_check), 241 _monitor(monitor) { 242 // Superclass constructor did locking 243 } 244 245 ~MonitorLockerEx() { 246 #ifdef ASSERT 247 if (_monitor != NULL) { 248 assert_lock_strong(_monitor); 249 } 250 #endif // ASSERT 251 // Superclass destructor will do unlocking 252 } 253 254 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 255 long timeout = 0, 256 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 257 if (_monitor != NULL) { 258 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 259 } 260 return false; 261 } 262 263 bool notify_all() { 264 if (_monitor != NULL) { 265 return _monitor->notify_all(); 266 } 267 return true; 268 } 269 270 bool notify() { 271 if (_monitor != NULL) { 272 return _monitor->notify(); 273 } 274 return true; 275 } 276 }; 277 278 279 280 // A GCMutexLocker is usually initialized with a mutex that is 281 // automatically acquired in order to do GC. The function that 282 // synchronizes using a GCMutexLocker may be called both during and between 283 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 284 // if GC is in progress (since the mutex is already held on its behalf.) 285 286 class GCMutexLocker: public StackObj { 287 private: 288 Monitor * _mutex; 289 bool _locked; 290 public: 291 GCMutexLocker(Monitor * mutex); 292 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 293 }; 294 295 296 297 // A MutexUnlocker temporarily exits a previously 298 // entered mutex for the scope which contains the unlocker. 299 300 class MutexUnlocker: StackObj { 301 private: 302 Monitor * _mutex; 303 304 public: 305 MutexUnlocker(Monitor * mutex) { 306 _mutex = mutex; 307 _mutex->unlock(); 308 } 309 310 ~MutexUnlocker() { 311 _mutex->lock(); 312 } 313 }; 314 315 // A MutexUnlockerEx temporarily exits a previously 316 // entered mutex for the scope which contains the unlocker. 317 318 class MutexUnlockerEx: StackObj { 319 private: 320 Monitor * _mutex; 321 bool _no_safepoint_check; 322 323 public: 324 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 325 _mutex = mutex; 326 _no_safepoint_check = no_safepoint_check; 327 _mutex->unlock(); 328 } 329 330 ~MutexUnlockerEx() { 331 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 332 _mutex->lock_without_safepoint_check(); 333 } else { 334 _mutex->lock(); 335 } 336 } 337 }; 338 339 #ifndef PRODUCT 340 // 341 // A special MutexLocker that allows: 342 // - reentrant locking 343 // - locking out of order 344 // 345 // Only to be used for verify code, where we can relax out dead-lock 346 // detection code a bit (unsafe, but probably ok). This code is NEVER to 347 // be included in a product version. 348 // 349 class VerifyMutexLocker: StackObj { 350 private: 351 Monitor * _mutex; 352 bool _reentrant; 353 public: 354 VerifyMutexLocker(Monitor * mutex) { 355 _mutex = mutex; 356 _reentrant = mutex->owned_by_self(); 357 if (!_reentrant) { 358 // We temp. disable strict safepoint checking, while we require the lock 359 FlagSetting fs(StrictSafepointChecks, false); 360 _mutex->lock(); 361 } 362 } 363 364 ~VerifyMutexLocker() { 365 if (!_reentrant) { 366 _mutex->unlock(); 367 } 368 } 369 }; 370 371 #endif 372 373 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP