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 extern Mutex* NMethodSweeper_stat_lock; // a lock used to serialize access to sweeper statistics 114 115 #ifndef PRODUCT 116 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 117 #endif // PRODUCT 118 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 119 extern Mutex* Debug2_lock; // down synchronization related bugs! 120 extern Mutex* Debug3_lock; 121 122 extern Mutex* RawMonitor_lock; 123 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 124 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 125 extern Mutex* ParkerFreeList_lock; 126 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 127 128 extern Mutex* FreeList_lock; // protects the free region list during safepoints 129 extern Mutex* OldSets_lock; // protects the old region sets 130 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 131 132 extern Mutex* Management_lock; // a lock used to serialize JVM management 133 extern Monitor* Service_lock; // a lock used for service thread operation 134 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 135 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 136 extern Monitor* ThreadsSMRSupport_delete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock 137 extern Mutex* Decoder_shared_decoder_lock; // serializes access to the decoder during normal (not error reporting) use 138 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information 139 #if INCLUDE_JFR 140 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 141 extern Monitor* JfrMsg_lock; // protects JFR messaging 142 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 143 extern Mutex* JfrStream_lock; // protects JFR stream access 144 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler 145 #endif 146 147 #ifndef SUPPORTS_NATIVE_CX8 148 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 149 #endif 150 151 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 152 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading 153 154 155 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 156 // Only used locally in PrintCodeCacheLayout processing. 157 158 // A MutexLocker provides mutual exclusion with respect to a given mutex 159 // for the scope which contains the locker. The lock is an OS lock, not 160 // an object lock, and the two do not interoperate. Do not use Mutex-based 161 // locks to lock on Java objects, because they will not be respected if a 162 // that object is locked using the Java locking mechanism. 163 // 164 // NOTE WELL!! 165 // 166 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 167 // and friends constructors do a fence, a lock and an acquire *in that 168 // order*. And that their destructors do a release and unlock, in *that* 169 // order. If their implementations change such that these assumptions 170 // are violated, a whole lot of code will break. 171 172 // Print all mutexes/monitors that are currently owned by a thread; called 173 // by fatal error handler. 174 void print_owned_locks_on_error(outputStream* st); 175 176 char *lock_name(Mutex *mutex); 177 178 class MutexLocker: StackObj { 179 private: 180 Monitor * _mutex; 181 public: 182 MutexLocker(Monitor * mutex) { 183 assert(mutex->rank() != Mutex::special, 184 "Special ranked mutex should only use MutexLockerEx"); 185 _mutex = mutex; 186 _mutex->lock(); 187 } 188 189 // Overloaded constructor passing current thread 190 MutexLocker(Monitor * mutex, Thread *thread) { 191 assert(mutex->rank() != Mutex::special, 192 "Special ranked mutex should only use MutexLockerEx"); 193 _mutex = mutex; 194 _mutex->lock(thread); 195 } 196 197 ~MutexLocker() { 198 _mutex->unlock(); 199 } 200 201 }; 202 203 // for debugging: check that we're already owning this lock (or are at a safepoint) 204 #ifdef ASSERT 205 void assert_locked_or_safepoint(const Monitor * lock); 206 void assert_locked_or_safepoint_weak(const Monitor * lock); 207 void assert_lock_strong(const Monitor * lock); 208 #else 209 #define assert_locked_or_safepoint(lock) 210 #define assert_locked_or_safepoint_weak(lock) 211 #define assert_lock_strong(lock) 212 #endif 213 214 // A MutexLockerEx behaves like a MutexLocker when its constructor is 215 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 216 // called with NULL, in which case the MutexLockerEx is a no-op. There 217 // is also a corresponding MutexUnlockerEx. We want to keep the 218 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 219 // without safepoint check. 220 221 class MutexLockerEx: public StackObj { 222 private: 223 Monitor * _mutex; 224 public: 225 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 226 _mutex = mutex; 227 if (_mutex != NULL) { 228 assert(mutex->rank() > Mutex::special || no_safepoint_check, 229 "Mutexes with rank special or lower should not do safepoint checks"); 230 if (no_safepoint_check) 231 _mutex->lock_without_safepoint_check(); 232 else 233 _mutex->lock(); 234 } 235 } 236 237 ~MutexLockerEx() { 238 if (_mutex != NULL) { 239 _mutex->unlock(); 240 } 241 } 242 }; 243 244 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 245 // a possibly null Monitor, and allows wait/notify as well which are 246 // delegated to the underlying Monitor. 247 248 class MonitorLockerEx: public MutexLockerEx { 249 private: 250 Monitor * _monitor; 251 public: 252 MonitorLockerEx(Monitor* monitor, 253 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 254 MutexLockerEx(monitor, no_safepoint_check), 255 _monitor(monitor) { 256 // Superclass constructor did locking 257 } 258 259 ~MonitorLockerEx() { 260 #ifdef ASSERT 261 if (_monitor != NULL) { 262 assert_lock_strong(_monitor); 263 } 264 #endif // ASSERT 265 // Superclass destructor will do unlocking 266 } 267 268 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 269 long timeout = 0, 270 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 271 if (_monitor != NULL) { 272 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 273 } 274 return false; 275 } 276 277 bool notify_all() { 278 if (_monitor != NULL) { 279 return _monitor->notify_all(); 280 } 281 return true; 282 } 283 284 bool notify() { 285 if (_monitor != NULL) { 286 return _monitor->notify(); 287 } 288 return true; 289 } 290 }; 291 292 293 294 // A GCMutexLocker is usually initialized with a mutex that is 295 // automatically acquired in order to do GC. The function that 296 // synchronizes using a GCMutexLocker may be called both during and between 297 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 298 // if GC is in progress (since the mutex is already held on its behalf.) 299 300 class GCMutexLocker: public StackObj { 301 private: 302 Monitor * _mutex; 303 bool _locked; 304 public: 305 GCMutexLocker(Monitor * mutex); 306 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 307 }; 308 309 310 311 // A MutexUnlocker temporarily exits a previously 312 // entered mutex for the scope which contains the unlocker. 313 314 class MutexUnlocker: StackObj { 315 private: 316 Monitor * _mutex; 317 318 public: 319 MutexUnlocker(Monitor * mutex) { 320 _mutex = mutex; 321 _mutex->unlock(); 322 } 323 324 ~MutexUnlocker() { 325 _mutex->lock(); 326 } 327 }; 328 329 // A MutexUnlockerEx temporarily exits a previously 330 // entered mutex for the scope which contains the unlocker. 331 332 class MutexUnlockerEx: StackObj { 333 private: 334 Monitor * _mutex; 335 bool _no_safepoint_check; 336 337 public: 338 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 339 _mutex = mutex; 340 _no_safepoint_check = no_safepoint_check; 341 _mutex->unlock(); 342 } 343 344 ~MutexUnlockerEx() { 345 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 346 _mutex->lock_without_safepoint_check(); 347 } else { 348 _mutex->lock(); 349 } 350 } 351 }; 352 353 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP