1 /*
  2  * Copyright (c) 1997, 2023, 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*   InvokeMethodTypeTable_lock;
 38 extern Monitor* InvokeMethodIntrinsicTable_lock;
 39 extern Mutex*   SharedDictionary_lock;           // a lock on the CDS shared dictionary
 40 extern Monitor* ClassInitError_lock;             // a lock on the class initialization error table
 41 extern Mutex*   Module_lock;                     // a lock on module and package related data structures
 42 extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
 43 extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
 44 extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
 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* EscapeBarrier_lock;              // a lock to sync reallocating and relocking objects because of JVMTI access
 50 extern Monitor* JvmtiVTMSTransition_lock;        // a lock for Virtual Thread Mount State transition (VTMS transition) management
 51 extern Monitor* Heap_lock;                       // a lock on the heap
 52 #ifdef INCLUDE_PARALLELGC
 53 extern Mutex*   PSOldGenExpand_lock;         // a lock on expanding the heap
 54 #endif
 55 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
 56 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
 57 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
 58 extern Mutex*   SymbolArena_lock;                // a lock on the symbol table arena
 59 extern Monitor* StringDedup_lock;                // a lock on the string deduplication facility
 60 extern Mutex*   StringDedupIntern_lock;          // a lock on StringTable notification of StringDedup
 61 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache
 62 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
 63 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
 64 extern Monitor* VMOperation_lock;                // a lock on queue of vm_operations waiting to execute
 65 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
 66                                                  // (also used by Safepoints too to block threads creation/destruction)
 67 extern Mutex*   NonJavaThreadsList_lock;         // a lock on the NonJavaThreads list
 68 extern Mutex*   NonJavaThreadsListSync_lock;     // a lock for NonJavaThreads list synchronization
 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* G1OldGCCount_lock;               // in support of "concurrent" full gc
 73 extern Mutex*   G1RareEvent_lock;                // Synchronizes (rare) parallel GC operations.
 74 extern Mutex*   G1DetachedRefinementStats_lock;  // Lock protecting detached refinement stats
 75 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
 76 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
 77 extern Mutex*   MonitoringSupport_lock;          // Protects updates to the serviceability memory pools and allocated memory high water mark.
 78 extern Monitor* ConcurrentGCBreakpoints_lock;    // Protects concurrent GC breakpoint management
 79 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
 80 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
 81 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
 82 extern Monitor* Compilation_lock;                // a lock used to pause compilation
 83 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
 84 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
 85 extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
 86 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
 87 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 88 extern Monitor* InitCompleted_lock;              // a lock used to signal threads waiting on init completed
 89 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
 90 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
 91 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
 92 
 93 #ifndef PRODUCT
 94 extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
 95 #endif // PRODUCT
 96 
 97 extern Mutex*   RawMonitor_lock;
 98 extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
 99 extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
100 extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
101 
102 extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
103 extern Mutex*   OldSets_lock;                    // protects the old region sets
104 extern Mutex*   Uncommit_lock;                   // protects the uncommit list when not at safepoints
105 extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
106 
107 extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
108 extern Monitor* MonitorDeflation_lock;           // a lock used for monitor deflation thread operation
109 extern Monitor* Service_lock;                    // a lock used for service thread operation
110 extern Monitor* Notification_lock;               // a lock used for notification thread operation
111 extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
112 extern Monitor* RedefineClasses_lock;            // locks classes from parallel redefinition
113 extern Mutex*   Verify_lock;                     // synchronize initialization of verify library
114 extern Monitor* ThreadsSMRDelete_lock;           // Used by ThreadsSMRSupport to take pressure off the Threads_lock
115 extern Mutex*   ThreadIdTableCreate_lock;        // Used by ThreadIdTable to lazily create the thread id table
116 extern Mutex*   SharedDecoder_lock;              // serializes access to the decoder during normal (not error reporting) use
117 extern Mutex*   DCmdFactory_lock;                // serialize access to DCmdFactory information
118 extern Mutex*   NMTQuery_lock;                   // serialize NMT Dcmd queries
119 extern Mutex*   NMTCompilationCostHistory_lock;  // guards NMT compilation cost history
120 #if INCLUDE_CDS
121 #if INCLUDE_JVMTI
122 extern Mutex*   CDSClassFileStream_lock;         // FileMapInfo::open_stream_for_jvmti
123 #endif
124 extern Mutex*   DumpTimeTable_lock;              // SystemDictionaryShared::_dumptime_table
125 extern Mutex*   CDSLambda_lock;                  // SystemDictionaryShared::get_shared_lambda_proxy_class
126 extern Mutex*   DumpRegion_lock;                 // Symbol::operator new(size_t sz, int len)
127 extern Mutex*   ClassListFile_lock;              // ClassListWriter()
128 extern Mutex*   UnregisteredClassesTable_lock;   // UnregisteredClassesTableTable
129 extern Mutex*   LambdaFormInvokers_lock;         // Protecting LambdaFormInvokers::_lambdaform_lines
130 extern Mutex*   ScratchObjects_lock;             // Protecting _scratch_xxx_table in heapShared.cpp
131 #endif // INCLUDE_CDS
132 #if INCLUDE_JFR
133 extern Mutex*   JfrStacktrace_lock;              // used to guard access to the JFR stacktrace table
134 extern Monitor* JfrMsg_lock;                     // protects JFR messaging
135 extern Mutex*   JfrBuffer_lock;                  // protects JFR buffer operations
136 extern Monitor* JfrThreadSampler_lock;           // used to suspend/resume JFR thread sampler
137 #endif
138 
139 extern Mutex*   Metaspace_lock;                  // protects Metaspace virtualspace and chunk expansions
140 extern Monitor* MetaspaceCritical_lock;          // synchronizes failed metaspace allocations that risk throwing metaspace OOM
141 extern Mutex*   ClassLoaderDataGraph_lock;       // protects CLDG list, needed for concurrent unloading
142 
143 
144 extern Mutex*   CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.
145                                                  // Only used locally in PrintCodeCacheLayout processing.
146 
147 extern Monitor* ContinuationRelativize_lock;
148 
149 #if INCLUDE_JVMCI
150 extern Monitor* JVMCI_lock;                      // protects global JVMCI critical sections
151 extern Monitor* JVMCIRuntime_lock;               // protects critical sections for a specific JVMCIRuntime object
152 #endif
153 
154 extern Mutex*   Bootclasspath_lock;
155 
156 extern Mutex*   tty_lock;                          // lock to synchronize output.
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 void print_lock_ranks(outputStream* st);
176 
177 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake)
178 #ifdef ASSERT
179 void assert_locked_or_safepoint(const Mutex* lock);
180 void assert_lock_strong(const Mutex* lock);
181 #else
182 #define assert_locked_or_safepoint(lock)
183 #define assert_lock_strong(lock)
184 #endif
185 
186 // Internal implementation. Skips on null Mutex.
187 // Subclasses enforce stronger invariants.
188 class MutexLockerImpl: public StackObj {
189  protected:
190   Mutex* _mutex;
191 
192   MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
193     _mutex(mutex) {
194     bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
195     if (_mutex != nullptr) {
196       if (no_safepoint_check) {
197         _mutex->lock_without_safepoint_check();
198       } else {
199         _mutex->lock();
200       }
201     }
202   }
203 
204   MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
205     _mutex(mutex) {
206     bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
207     if (_mutex != nullptr) {
208       if (no_safepoint_check) {
209         _mutex->lock_without_safepoint_check(thread);
210       } else {
211         _mutex->lock(thread);
212       }
213     }
214   }
215 
216   ~MutexLockerImpl() {
217     if (_mutex != nullptr) {
218       assert_lock_strong(_mutex);
219       _mutex->unlock();
220     }
221   }
222 
223  public:
224   static void post_initialize();
225 };
226 
227 // Simplest mutex locker.
228 // Does not allow null mutexes.
229 class MutexLocker: public MutexLockerImpl {
230  public:
231    MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
232      MutexLockerImpl(mutex, flag) {
233      assert(mutex != nullptr, "null mutex not allowed");
234    }
235 
236    MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
237      MutexLockerImpl(thread, mutex, flag) {
238      assert(mutex != nullptr, "null mutex not allowed");
239    }
240 };
241 
242 // Conditional mutex locker.
243 // Like MutexLocker above, but only locks when condition is true.
244 class ConditionalMutexLocker: public MutexLockerImpl {
245  public:
246    ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
247      MutexLockerImpl(condition ? mutex : nullptr, flag) {
248      assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
249    }
250 
251    ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
252      MutexLockerImpl(thread, condition ? mutex : nullptr, flag) {
253      assert(!condition || mutex != nullptr, "null mutex not allowed when locking");
254    }
255 };
256 
257 // A MonitorLocker is like a MutexLocker above, except it allows
258 // wait/notify as well which are delegated to the underlying Monitor.
259 // It also disallows null.
260 class MonitorLocker: public MutexLockerImpl {
261   Mutex::SafepointCheckFlag _flag;
262 
263  protected:
264   Monitor* as_monitor() const {
265     return static_cast<Monitor*>(_mutex);
266   }
267 
268  public:
269   MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
270     MutexLockerImpl(monitor, flag), _flag(flag) {
271     // Superclass constructor did locking
272     assert(monitor != nullptr, "null monitor not allowed");
273   }
274 
275   MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
276     MutexLockerImpl(thread, monitor, flag), _flag(flag) {
277     // Superclass constructor did locking
278     assert(monitor != nullptr, "null monitor not allowed");
279   }
280 
281   bool wait(int64_t timeout = 0) {
282     return _flag == Mutex::_safepoint_check_flag ?
283       as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout);
284   }
285 
286   void notify_all() {
287     as_monitor()->notify_all();
288   }
289 
290   void notify() {
291     as_monitor()->notify();
292   }
293 };
294 
295 
296 // A GCMutexLocker is usually initialized with a mutex that is
297 // automatically acquired in order to do GC.  The function that
298 // synchronizes using a GCMutexLocker may be called both during and between
299 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
300 // if GC is in progress (since the mutex is already held on its behalf.)
301 
302 class GCMutexLocker: public StackObj {
303 private:
304   Mutex* _mutex;
305   bool _locked;
306 public:
307   GCMutexLocker(Mutex* mutex);
308   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
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   Mutex* _mutex;
317   bool _no_safepoint_check;
318 
319  public:
320   MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
321     _mutex(mutex),
322     _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) {
323     _mutex->unlock();
324   }
325 
326   ~MutexUnlocker() {
327     if (_no_safepoint_check) {
328       _mutex->lock_without_safepoint_check();
329     } else {
330       _mutex->lock();
331     }
332   }
333 };
334 
335 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP