1 /*
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  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.
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  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  *
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 18  *
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 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP
 26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP
 27 
 28 #include "logging/log.hpp"
 29 #include "memory/allocation.hpp"
 30 #include "runtime/flags/flagSetting.hpp"
 31 #include "runtime/mutex.hpp"
 32 #include "runtime/perfData.hpp"
 33 #include "runtime/thread.hpp"
 34 
 35 // Mutexes used in the VM.
 36 
 37 extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
 38 extern Mutex*   CompiledMethod_lock;             // a lock used to guard a compiled method and OSR queues
 39 extern Monitor* SystemDictionary_lock;           // a lock on the system dictionary
 40 extern Mutex*   InvokeMethodTypeTable_lock;
 41 extern Monitor* InvokeMethodIntrinsicTable_lock;
 42 extern Mutex*   SharedDictionary_lock;           // a lock on the CDS shared dictionary
 43 extern Monitor* ClassInitError_lock;             // a lock on the class initialization error table
 44 extern Mutex*   Module_lock;                     // a lock on module and package related data structures
 45 extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
 46 extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
 47 extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
 48 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
 49 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
 50 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
 51 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
 52 extern Monitor* EscapeBarrier_lock;              // a lock to sync reallocating and relocking objects because of JVMTI access
 53 extern Monitor* JvmtiVTMSTransition_lock;        // a lock for Virtual Thread Mount State transition (VTMS transition) management
 54 extern Monitor* Heap_lock;                       // a lock on the heap
 55 #ifdef INCLUDE_PARALLELGC
 56 extern Mutex*   PSOldGenExpand_lock;         // a lock on expanding the heap
 57 #endif
 58 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
 59 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
 60 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
 61 extern Mutex*   SymbolArena_lock;                // a lock on the symbol table arena
 62 extern Monitor* StringDedup_lock;                // a lock on the string deduplication facility
 63 extern Mutex*   StringDedupIntern_lock;          // a lock on StringTable notification of StringDedup
 64 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache
 65 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
 66 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
 67 extern Monitor* VMOperation_lock;                // a lock on queue of vm_operations waiting to execute
 68 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
 69                                                  // (also used by Safepoints too to block threads creation/destruction)
 70 extern Mutex*   NonJavaThreadsList_lock;         // a lock on the NonJavaThreads list
 71 extern Mutex*   NonJavaThreadsListSync_lock;     // a lock for NonJavaThreads list synchronization
 72 extern Monitor* CGC_lock;                        // used for coordination between
 73                                                  // fore- & background GC threads.
 74 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
 75 extern Monitor* G1OldGCCount_lock;               // in support of "concurrent" full gc
 76 extern Mutex*   G1RareEvent_lock;                // Synchronizes (rare) parallel GC operations.
 77 extern Mutex*   G1DetachedRefinementStats_lock;  // Lock protecting detached refinement stats
 78 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
 79 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
 80 extern Mutex*   MonitoringSupport_lock;          // Protects updates to the serviceability memory pools and allocated memory high water mark.
 81 extern Monitor* ConcurrentGCBreakpoints_lock;    // Protects concurrent GC breakpoint management
 82 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
 83 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
 84 extern Monitor* MethodCompileQueueC1_lock;       // a lock held when method compilations are enqueued, dequeued
 85 extern Monitor* MethodCompileQueueC2_lock;       // a lock held when method compilations are enqueued, dequeued
 86 extern Monitor* MethodCompileQueueC3_lock;       // a lock held when method compilations are enqueued, dequeued
 87 extern Monitor* MethodCompileQueueSC1_lock;      // a lock held when method compilations are enqueued, dequeued
 88 extern Monitor* MethodCompileQueueSC2_lock;      // a lock held when method compilations are enqueued, dequeued
 89 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
 90 extern Monitor* Compilation_lock;                // a lock used to pause compilation
 91 extern Mutex*   TrainingData_lock;               // a lock used when accessing training records
 92 extern Monitor* TrainingReplayQueue_lock;        // a lock held when class are added/removed to the training replay queue
 93 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
 94 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
 95 extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
 96 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
 97 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 98 extern Monitor* InitCompleted_lock;              // a lock used to signal threads waiting on init completed
 99 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
100 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
101 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
102 
103 #ifndef PRODUCT
104 extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
105 #endif // PRODUCT
106 
107 extern Mutex*   RawMonitor_lock;
108 extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
109 extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
110 extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
111 
112 extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
113 extern Mutex*   OldSets_lock;                    // protects the old region sets
114 extern Mutex*   Uncommit_lock;                   // protects the uncommit list when not at safepoints
115 extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
116 
117 extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
118 extern Monitor* MonitorDeflation_lock;           // a lock used for monitor deflation thread operation
119 extern Monitor* Service_lock;                    // a lock used for service thread operation
120 extern Monitor* Notification_lock;               // a lock used for notification thread operation
121 extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
122 extern Monitor* RedefineClasses_lock;            // locks classes from parallel redefinition
123 extern Mutex*   Verify_lock;                     // synchronize initialization of verify library
124 extern Monitor* ThreadsSMRDelete_lock;           // Used by ThreadsSMRSupport to take pressure off the Threads_lock
125 extern Mutex*   ThreadIdTableCreate_lock;        // Used by ThreadIdTable to lazily create the thread id table
126 extern Mutex*   SharedDecoder_lock;              // serializes access to the decoder during normal (not error reporting) use
127 extern Mutex*   DCmdFactory_lock;                // serialize access to DCmdFactory information
128 extern Mutex*   NMTQuery_lock;                   // serialize NMT Dcmd queries
129 extern Mutex*   NMTCompilationCostHistory_lock;  // guards NMT compilation cost history
130 #if INCLUDE_CDS
131 #if INCLUDE_JVMTI
132 extern Mutex*   CDSClassFileStream_lock;         // FileMapInfo::open_stream_for_jvmti
133 #endif
134 extern Mutex*   DumpTimeTable_lock;              // SystemDictionaryShared::_dumptime_table
135 extern Mutex*   CDSLambda_lock;                  // SystemDictionaryShared::get_shared_lambda_proxy_class
136 extern Mutex*   DumpRegion_lock;                 // Symbol::operator new(size_t sz, int len)
137 extern Mutex*   ClassListFile_lock;              // ClassListWriter()
138 extern Mutex*   UnregisteredClassesTable_lock;   // UnregisteredClassesTableTable
139 extern Mutex*   LambdaFormInvokers_lock;         // Protecting LambdaFormInvokers::_lambdaform_lines
140 extern Mutex*   ScratchObjects_lock;             // Protecting _scratch_xxx_table in heapShared.cpp
141 extern Mutex*   ArchivedObjectTables_lock;       // Protecting the table used by HeapShared::get_archived_object_permanent_index()
142 #endif // INCLUDE_CDS
143 #if INCLUDE_JFR
144 extern Mutex*   JfrStacktrace_lock;              // used to guard access to the JFR stacktrace table
145 extern Monitor* JfrMsg_lock;                     // protects JFR messaging
146 extern Mutex*   JfrBuffer_lock;                  // protects JFR buffer operations
147 extern Monitor* JfrThreadSampler_lock;           // used to suspend/resume JFR thread sampler
148 #endif
149 
150 extern Mutex*   Metaspace_lock;                  // protects Metaspace virtualspace and chunk expansions
151 extern Monitor* MetaspaceCritical_lock;          // synchronizes failed metaspace allocations that risk throwing metaspace OOM
152 extern Mutex*   ClassLoaderDataGraph_lock;       // protects CLDG list, needed for concurrent unloading
153 
154 
155 extern Mutex*   CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.
156                                                  // Only used locally in PrintCodeCacheLayout processing.
157 
158 extern Monitor* ContinuationRelativize_lock;
159 
160 #if INCLUDE_JVMCI
161 extern Monitor* JVMCI_lock;                      // protects global JVMCI critical sections
162 extern Monitor* JVMCIRuntime_lock;               // protects critical sections for a specific JVMCIRuntime object
163 #endif
164 
165 extern Mutex*   Bootclasspath_lock;
166 
167 extern Mutex*   tty_lock;                          // lock to synchronize output.
168 
169 // A MutexLocker provides mutual exclusion with respect to a given mutex
170 // for the scope which contains the locker.  The lock is an OS lock, not
171 // an object lock, and the two do not interoperate.  Do not use Mutex-based
172 // locks to lock on Java objects, because they will not be respected if a
173 // that object is locked using the Java locking mechanism.
174 //
175 //                NOTE WELL!!
176 //
177 // See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
178 // and friends constructors do a fence, a lock and an acquire *in that
179 // order*.  And that their destructors do a release and unlock, in *that*
180 // order.  If their implementations change such that these assumptions
181 // are violated, a whole lot of code will break.
182 
183 // Print all mutexes/monitors that are currently owned by a thread; called
184 // by fatal error handler.
185 void print_owned_locks_on_error(outputStream* st);
186 void print_lock_ranks(outputStream* st);
187 
188 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
189 #ifdef ASSERT
190 void assert_locked_or_safepoint(const Mutex* lock);
191 void assert_lock_strong(const Mutex* lock);
192 #else
193 #define assert_locked_or_safepoint(lock)
194 #define assert_lock_strong(lock)
195 #endif
196 
197 // Internal implementation. Skips on null Mutex.
198 // Subclasses enforce stronger invariants.
199 class MutexLockerImpl: public StackObj {
200  protected:
201   Mutex* _mutex;
202   bool _prof;
203   elapsedTimer _before;
204   elapsedTimer _after;
205 
206 private:
207   static PerfCounter** _perf_lock_count;
208   static PerfCounter** _perf_lock_wait_time;
209   static PerfCounter** _perf_lock_hold_time;
210 
211 public:
212 
213   MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
214     _mutex(mutex), _prof(ProfileVMLocks && Thread::current()->profile_vm_locks()) {
215 
216     bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
217     if (_mutex != nullptr) {
218       if (_prof) { _before.start(); } // before
219 
220       if (no_safepoint_check) {
221         _mutex->lock_without_safepoint_check();
222       } else {
223         _mutex->lock();
224       }
225 
226       if (_prof) { _before.stop(); _after.start(); } // after
227     }
228   }
229 
230   MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
231     _mutex(mutex), _prof(thread->profile_vm_locks()) {
232 
233     if (_prof) { _before.start(); } // before
234 
235     bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
236     if (_mutex != nullptr) {
237       if (no_safepoint_check) {
238         _mutex->lock_without_safepoint_check(thread);
239       } else {
240         _mutex->lock(thread);
241       }
242     }
243 
244     if (_prof) { _before.stop(); _after.start(); } // after
245   }
246 
247   ~MutexLockerImpl() {
248     if (_mutex != nullptr) {
249       assert_lock_strong(_mutex);
250       _mutex->unlock();
251 
252       if (_mutex->id() == -1) {
253         log_trace(init)("Unnamed unclassified lock: %s", _mutex->name());
254       }
255 
256       if (_prof) {
257         assert(UsePerfData, "required");
258         _after.stop();
259         _perf_lock_count    [_mutex->id() + 1]->inc();
260         _perf_lock_wait_time[_mutex->id() + 1]->inc(_before.ticks());
261         _perf_lock_hold_time[_mutex->id() + 1]->inc(_after.ticks());
262       }
263     }
264   }
265 
266  private:
267   static void print_counter_on(outputStream* st, const char* name, bool is_unique, int idx);
268 
269  public:
270   static int name2id(const char* name);
271 
272   static void post_initialize();
273   static void init_counters();
274   static void print_counters_on(outputStream* st);
275 };
276 
277 // Simplest mutex locker.
278 // Does not allow null mutexes.
279 class MutexLocker: public MutexLockerImpl {
280  public:
281    MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
282      MutexLockerImpl(mutex, flag) {
283      assert(mutex != nullptr, "null mutex not allowed");
284    }
285 
286    MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
287      MutexLockerImpl(thread, mutex, flag) {
288      assert(mutex != nullptr, "null mutex not allowed");
289    }
290 };
291 
292 // Conditional mutex locker.
293 // Like MutexLocker above, but only locks when condition is true.
294 class ConditionalMutexLocker: public MutexLockerImpl {
295  public:
296    ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
297      MutexLockerImpl(condition ? mutex : nullptr, flag) {
298      assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
299    }
300 
301    ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
302      MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
303      assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
304    }
305 };
306 
307 // A MonitorLocker is like a MutexLocker above, except it allows
308 // wait/notify as well which are delegated to the underlying Monitor.
309 // It also disallows null.
310 class MonitorLocker: public MutexLockerImpl {
311   Mutex::SafepointCheckFlag _flag;
312 
313  protected:
314   Monitor* as_monitor() const {
315     return static_cast<Monitor*>(_mutex);
316   }
317 
318  public:
319   MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
320     MutexLockerImpl(monitor, flag), _flag(flag) {
321     // Superclass constructor did locking
322     assert(monitor != nullptr, "null monitor not allowed");
323   }
324 
325   MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
326     MutexLockerImpl(thread, monitor, flag), _flag(flag) {
327     // Superclass constructor did locking
328     assert(monitor != nullptr, "null monitor not allowed");
329   }
330 
331   bool wait(int64_t timeout = 0) {
332     return _flag == Mutex::_safepoint_check_flag ?
333       as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
334   }
335 
336   void notify_all() {
337     as_monitor()->notify_all();
338   }
339 
340   void notify() {
341     as_monitor()->notify();
342   }
343 };
344 
345 
346 // A GCMutexLocker is usually initialized with a mutex that is
347 // automatically acquired in order to do GC.  The function that
348 // synchronizes using a GCMutexLocker may be called both during and between
349 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
350 // if GC is in progress (since the mutex is already held on its behalf.)
351 
352 class GCMutexLocker: public StackObj {
353 private:
354   Mutex* _mutex;
355   bool _locked;
356 public:
357   GCMutexLocker(Mutex* mutex);
358   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
359 };
360 
361 // A MutexUnlocker temporarily exits a previously
362 // entered mutex for the scope which contains the unlocker.
363 
364 class MutexUnlocker: StackObj {
365  private:
366   Mutex* _mutex;
367   bool _no_safepoint_check;
368 
369  public:
370   MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
371     _mutex(mutex),
372     _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
373     _mutex->unlock();
374   }
375 
376   ~MutexUnlocker() {
377     if (_no_safepoint_check) {
378       _mutex->lock_without_safepoint_check();
379     } else {
380       _mutex->lock();
381     }
382   }
383 };
384 
385 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP