1 /* 2 * Copyright (c) 1997, 2019, 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_RUNTIME_MUTEXLOCKER_HPP 26 #define SHARE_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 Mutex* CompiledMethod_lock; // a lock used to guard a compiled method and OSR queues 36 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 37 extern Mutex* ProtectionDomainSet_lock; // a lock on the pd_set list in the system dictionary 38 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary 39 extern Mutex* Module_lock; // a lock on module and package related data structures 40 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 41 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 42 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 43 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 44 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 45 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 46 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 47 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 48 extern Monitor* Heap_lock; // a lock on the heap 49 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 50 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 51 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 52 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 53 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena 54 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 55 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 56 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special 57 extern Mutex* MethodData_lock; // a lock on installation of method data 58 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 59 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 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* Threads_lock; // a lock on the Threads table of active Java threads 64 // (also used by Safepoints too to block threads creation/destruction) 65 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list 66 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization 67 extern Monitor* CGC_lock; // used for coordination between 68 // fore- & background GC threads. 69 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 70 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 71 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 72 // completed buffer queue. 73 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 74 // queue shared by 75 // non-Java threads. 76 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 77 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 78 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools. 79 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 80 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 81 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 82 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 83 extern Monitor* Compilation_lock; // a lock used to pause compilation 84 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 85 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 86 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 87 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 88 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 89 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed 90 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 91 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 92 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 93 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 94 extern Mutex* NMethodSweeperStats_lock; // a lock used to serialize access to sweeper statistics 95 96 #ifndef PRODUCT 97 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 98 #endif // PRODUCT 99 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 100 extern Mutex* Debug2_lock; // down synchronization related bugs! 101 extern Mutex* Debug3_lock; 102 103 extern Mutex* RawMonitor_lock; 104 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 105 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 106 extern Mutex* ParkerFreeList_lock; 107 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 108 109 extern Mutex* FreeList_lock; // protects the free region list during safepoints 110 extern Mutex* OldSets_lock; // protects the old region sets 111 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 112 113 extern Mutex* Management_lock; // a lock used to serialize JVM management 114 extern Monitor* Service_lock; // a lock used for service thread operation 115 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 116 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 117 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock 118 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use 119 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information 120 #if INCLUDE_NMT 121 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries 122 #endif 123 #if INCLUDE_CDS 124 #if INCLUDE_JVMTI 125 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti 126 #endif 127 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::find_or_allocate_info_for 128 #endif // INCLUDE_CDS 129 #if INCLUDE_JFR 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 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler 135 #endif 136 137 #ifndef SUPPORTS_NATIVE_CX8 138 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 139 #endif 140 141 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 142 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading 143 144 145 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 146 // Only used locally in PrintCodeCacheLayout processing. 147 148 #if INCLUDE_JVMCI 149 extern Monitor* JVMCI_lock; // Monitor to control initialization of JVMCI 150 #endif 151 152 // A MutexLocker provides mutual exclusion with respect to a given mutex 153 // for the scope which contains the locker. The lock is an OS lock, not 154 // an object lock, and the two do not interoperate. Do not use Mutex-based 155 // locks to lock on Java objects, because they will not be respected if a 156 // that object is locked using the Java locking mechanism. 157 // 158 // NOTE WELL!! 159 // 160 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 161 // and friends constructors do a fence, a lock and an acquire *in that 162 // order*. And that their destructors do a release and unlock, in *that* 163 // order. If their implementations change such that these assumptions 164 // are violated, a whole lot of code will break. 165 166 // Print all mutexes/monitors that are currently owned by a thread; called 167 // by fatal error handler. 168 void print_owned_locks_on_error(outputStream* st); 169 170 char *lock_name(Mutex *mutex); 171 172 // for debugging: check that we're already owning this lock (or are at a safepoint) 173 #ifdef ASSERT 174 void assert_locked_or_safepoint(const Mutex* lock); 175 void assert_locked_or_safepoint_weak(const Mutex* lock); 176 void assert_lock_strong(const Mutex* lock); 177 #else 178 #define assert_locked_or_safepoint(lock) 179 #define assert_locked_or_safepoint_weak(lock) 180 #define assert_lock_strong(lock) 181 #endif 182 183 class MutexLocker: public StackObj { 184 protected: 185 Mutex* _mutex; 186 private: 187 public: 188 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 189 _mutex(mutex) { 190 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 191 if (_mutex != NULL) { 192 assert(_mutex->rank() > Mutex::special || no_safepoint_check, 193 "Mutexes with rank special or lower should not do safepoint checks"); 194 if (no_safepoint_check) { 195 _mutex->lock_without_safepoint_check(); 196 } else { 197 _mutex->lock(); 198 } 199 } 200 } 201 202 MutexLocker(Mutex* mutex, Thread* thread, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 203 _mutex(mutex) { 204 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 205 if (_mutex != NULL) { 206 assert(_mutex->rank() > Mutex::special || no_safepoint_check, 207 "Mutexes with rank special or lower should not do safepoint checks"); 208 if (no_safepoint_check) { 209 _mutex->lock_without_safepoint_check(thread); 210 } else { 211 _mutex->lock(thread); 212 } 213 } 214 } 215 216 ~MutexLocker() { 217 if (_mutex != NULL) { 218 assert_lock_strong(_mutex); 219 _mutex->unlock(); 220 } 221 } 222 }; 223 224 // A MonitorLocker is like a MutexLocker above, except it allows 225 // wait/notify as well which are delegated to the underlying Monitor. 226 // It also disallows NULL. 227 228 class MonitorLocker: public MutexLocker { 229 Mutex::SafepointCheckFlag _flag; 230 Monitor* _monitor; 231 public: 232 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 233 MutexLocker(monitor, flag), _flag(flag), _monitor(monitor) { 234 // Superclass constructor did locking 235 assert(_monitor != NULL, "NULL monitor not allowed"); 236 } 237 238 MonitorLocker(Monitor* monitor, Thread* thread, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 239 MutexLocker(monitor, thread, flag), _flag(flag), _monitor(monitor) { 240 // Superclass constructor did locking 241 assert(_monitor != NULL, "NULL monitor not allowed"); 242 } 243 244 bool wait(long timeout = 0, 245 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 246 if (_flag == Mutex::_safepoint_check_flag) { 247 return _monitor->wait(timeout, as_suspend_equivalent); 248 } else { 249 return _monitor->wait_without_safepoint_check(timeout); 250 } 251 return false; 252 } 253 254 void notify_all() { 255 _monitor->notify_all(); 256 } 257 258 void notify() { 259 _monitor->notify(); 260 } 261 }; 262 263 264 // A GCMutexLocker is usually initialized with a mutex that is 265 // automatically acquired in order to do GC. The function that 266 // synchronizes using a GCMutexLocker may be called both during and between 267 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 268 // if GC is in progress (since the mutex is already held on its behalf.) 269 270 class GCMutexLocker: public StackObj { 271 private: 272 Mutex* _mutex; 273 bool _locked; 274 public: 275 GCMutexLocker(Mutex* mutex); 276 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 277 }; 278 279 // A MutexUnlocker temporarily exits a previously 280 // entered mutex for the scope which contains the unlocker. 281 282 class MutexUnlocker: StackObj { 283 private: 284 Mutex* _mutex; 285 bool _no_safepoint_check; 286 287 public: 288 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 289 _mutex(mutex), 290 _no_safepoint_check(flag) { 291 _mutex->unlock(); 292 } 293 294 ~MutexUnlocker() { 295 if (_no_safepoint_check) { 296 _mutex->lock_without_safepoint_check(); 297 } else { 298 _mutex->lock(); 299 } 300 } 301 }; 302 303 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP