1 /* 2 * Copyright (c) 1997, 2017, 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* JNIGlobalHandle_lock; // a lock on creating JNI global handles 40 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 41 extern Mutex* MemberNameTable_lock; // a lock on the MemberNameTable updates 42 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 43 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 44 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 45 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 46 extern Monitor* Heap_lock; // a lock on the heap 47 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 48 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 49 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 50 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 51 extern Mutex* SymbolTable_lock; // a lock on the symbol table 52 extern Mutex* StringTable_lock; // a lock on the interned string table 53 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 54 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 55 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 56 extern Mutex* MethodData_lock; // a lock on installation of method data 57 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 58 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 59 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 60 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management 61 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 62 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 63 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 64 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 65 // (also used by Safepoints too to block threads creation/destruction) 66 extern Monitor* CGC_lock; // used for coordination between 67 // fore- & background GC threads. 68 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 69 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 70 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 71 // buffer free list. 72 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 73 // completed buffer queue. 74 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 75 // queue shared by 76 // non-Java threads. 77 78 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 79 // buffer free list. 80 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 81 // completed buffer queue. 82 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 83 // queue shared by 84 // non-Java threads. 85 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 86 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 87 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 88 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 89 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 90 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 91 extern Monitor* Compilation_lock; // a lock used to pause compilation 92 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 93 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 94 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 95 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 96 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 97 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 98 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 99 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 100 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 101 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 102 103 #ifndef PRODUCT 104 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 105 #endif // PRODUCT 106 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 107 extern Mutex* Debug2_lock; // down synchronization related bugs! 108 extern Mutex* Debug3_lock; 109 110 extern Mutex* RawMonitor_lock; 111 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 112 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 113 extern Mutex* ParkerFreeList_lock; 114 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 115 116 extern Mutex* FreeList_lock; // protects the free region list during safepoints 117 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list 118 extern Mutex* OldSets_lock; // protects the old region sets 119 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 120 extern Mutex* MMUTracker_lock; // protects the MMU 121 // tracker data structures 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 127 128 #ifdef INCLUDE_TRACE 129 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 130 extern Monitor* JfrMsg_lock; // protects JFR messaging 131 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 132 extern Mutex* JfrStream_lock; // protects JFR stream access 133 extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups 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 // A MutexLocker provides mutual exclusion with respect to a given mutex 141 // for the scope which contains the locker. The lock is an OS lock, not 142 // an object lock, and the two do not interoperate. Do not use Mutex-based 143 // locks to lock on Java objects, because they will not be respected if a 144 // that object is locked using the Java locking mechanism. 145 // 146 // NOTE WELL!! 147 // 148 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 149 // and friends constructors do a fence, a lock and an acquire *in that 150 // order*. And that their destructors do a release and unlock, in *that* 151 // order. If their implementations change such that these assumptions 152 // are violated, a whole lot of code will break. 153 154 // Print all mutexes/monitors that are currently owned by a thread; called 155 // by fatal error handler. 156 void print_owned_locks_on_error(outputStream* st); 157 158 char *lock_name(Mutex *mutex); 159 160 class MutexLocker: StackObj { 161 private: 162 Monitor * _mutex; 163 public: 164 MutexLocker(Monitor * mutex) { 165 assert(mutex->rank() != Mutex::special, 166 "Special ranked mutex should only use MutexLockerEx"); 167 _mutex = mutex; 168 _mutex->lock(); 169 } 170 171 // Overloaded constructor passing current thread 172 MutexLocker(Monitor * mutex, Thread *thread) { 173 assert(mutex->rank() != Mutex::special, 174 "Special ranked mutex should only use MutexLockerEx"); 175 _mutex = mutex; 176 _mutex->lock(thread); 177 } 178 179 ~MutexLocker() { 180 _mutex->unlock(); 181 } 182 183 }; 184 185 // for debugging: check that we're already owning this lock (or are at a safepoint) 186 #ifdef ASSERT 187 void assert_locked_or_safepoint(const Monitor * lock); 188 void assert_lock_strong(const Monitor * lock); 189 #else 190 #define assert_locked_or_safepoint(lock) 191 #define assert_lock_strong(lock) 192 #endif 193 194 // A MutexLockerEx behaves like a MutexLocker when its constructor is 195 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 196 // called with NULL, in which case the MutexLockerEx is a no-op. There 197 // is also a corresponding MutexUnlockerEx. We want to keep the 198 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 199 // without safepoint check. 200 201 class MutexLockerEx: public StackObj { 202 private: 203 Monitor * _mutex; 204 public: 205 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 206 _mutex = mutex; 207 if (_mutex != NULL) { 208 assert(mutex->rank() > Mutex::special || no_safepoint_check, 209 "Mutexes with rank special or lower should not do safepoint checks"); 210 if (no_safepoint_check) 211 _mutex->lock_without_safepoint_check(); 212 else 213 _mutex->lock(); 214 } 215 } 216 217 ~MutexLockerEx() { 218 if (_mutex != NULL) { 219 _mutex->unlock(); 220 } 221 } 222 }; 223 224 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 225 // a possibly null Monitor, and allows wait/notify as well which are 226 // delegated to the underlying Monitor. 227 228 class MonitorLockerEx: public MutexLockerEx { 229 private: 230 Monitor * _monitor; 231 public: 232 MonitorLockerEx(Monitor* monitor, 233 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 234 MutexLockerEx(monitor, no_safepoint_check), 235 _monitor(monitor) { 236 // Superclass constructor did locking 237 } 238 239 ~MonitorLockerEx() { 240 #ifdef ASSERT 241 if (_monitor != NULL) { 242 assert_lock_strong(_monitor); 243 } 244 #endif // ASSERT 245 // Superclass destructor will do unlocking 246 } 247 248 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 249 long timeout = 0, 250 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 251 if (_monitor != NULL) { 252 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 253 } 254 return false; 255 } 256 257 bool notify_all() { 258 if (_monitor != NULL) { 259 return _monitor->notify_all(); 260 } 261 return true; 262 } 263 264 bool notify() { 265 if (_monitor != NULL) { 266 return _monitor->notify(); 267 } 268 return true; 269 } 270 }; 271 272 273 274 // A GCMutexLocker is usually initialized with a mutex that is 275 // automatically acquired in order to do GC. The function that 276 // synchronizes using a GCMutexLocker may be called both during and between 277 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 278 // if GC is in progress (since the mutex is already held on its behalf.) 279 280 class GCMutexLocker: public StackObj { 281 private: 282 Monitor * _mutex; 283 bool _locked; 284 public: 285 GCMutexLocker(Monitor * mutex); 286 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 287 }; 288 289 290 291 // A MutexUnlocker temporarily exits a previously 292 // entered mutex for the scope which contains the unlocker. 293 294 class MutexUnlocker: StackObj { 295 private: 296 Monitor * _mutex; 297 298 public: 299 MutexUnlocker(Monitor * mutex) { 300 _mutex = mutex; 301 _mutex->unlock(); 302 } 303 304 ~MutexUnlocker() { 305 _mutex->lock(); 306 } 307 }; 308 309 // A MutexUnlockerEx temporarily exits a previously 310 // entered mutex for the scope which contains the unlocker. 311 312 class MutexUnlockerEx: StackObj { 313 private: 314 Monitor * _mutex; 315 bool _no_safepoint_check; 316 317 public: 318 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 319 _mutex = mutex; 320 _no_safepoint_check = no_safepoint_check; 321 _mutex->unlock(); 322 } 323 324 ~MutexUnlockerEx() { 325 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 326 _mutex->lock_without_safepoint_check(); 327 } else { 328 _mutex->lock(); 329 } 330 } 331 }; 332 333 #ifndef PRODUCT 334 // 335 // A special MutexLocker that allows: 336 // - reentrant locking 337 // - locking out of order 338 // 339 // Only to be used for verify code, where we can relax out dead-lock 340 // detection code a bit (unsafe, but probably ok). This code is NEVER to 341 // be included in a product version. 342 // 343 class VerifyMutexLocker: StackObj { 344 private: 345 Monitor * _mutex; 346 bool _reentrant; 347 public: 348 VerifyMutexLocker(Monitor * mutex) { 349 _mutex = mutex; 350 _reentrant = mutex->owned_by_self(); 351 if (!_reentrant) { 352 // We temp. disable strict safepoint checking, while we require the lock 353 FlagSetting fs(StrictSafepointChecks, false); 354 _mutex->lock(); 355 } 356 } 357 358 ~VerifyMutexLocker() { 359 if (!_reentrant) { 360 _mutex->unlock(); 361 } 362 } 363 }; 364 365 #endif 366 367 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP