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
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  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
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  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*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
  46 extern Mutex*   VMWeakAlloc_lock;                // VM Weak Handles storage allocate list lock
  47 extern Mutex*   VMWeakActive_lock;               // VM Weak Handles storage active list lock
  48 extern Mutex*   ResolvedMethodTable_lock;        // a lock on the ResolvedMethodTable updates
  49 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
  50 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
  51 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
  52 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
  53 extern Monitor* Heap_lock;                       // a lock on the heap
  54 extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
  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*   SymbolTable_lock;                // a lock on the symbol table
  59 extern Mutex*   StringTable_lock;                // a lock on the interned string table
  60 extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
  61 extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
  62 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
  63 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
  64 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
  65 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
  66 extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table
  67 extern Monitor* CGCPhaseManager_lock;            // a lock to protect a concurrent GC's phase management
  68 extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
  69 extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
  70 extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction
  71 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
  72                                                  // (also used by Safepoints too to block threads creation/destruction)
  73 extern Monitor* CGC_lock;                        // used for coordination between
  74                                                  // fore- & background GC threads.
  75 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
  76 extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
  77 extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
  78                                                  // buffer free list.
  79 extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
  80                                                  // completed buffer queue.
  81 extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB
  82                                                  // queue shared by
  83                                                  // non-Java threads.
  84 
  85 extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q
  86                                                  // buffer free list.
  87 extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
  88                                                  // completed buffer queue.
  89 extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
  90                                                  // queue shared by
  91                                                  // non-Java threads.
  92 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
  93 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
  94 extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
  95 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
  96 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
  97 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
  98 extern Monitor* Compilation_lock;                // a lock used to pause compilation
  99 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
 100 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
 101 extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
 102 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
 103 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 104 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
 105 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
 106 extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
 107 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
 108 extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
 109 
 110 #ifndef PRODUCT
 111 extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
 112 #endif // PRODUCT
 113 extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
 114 extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
 115 extern Mutex*   Debug3_lock;
 116 
 117 extern Mutex*   RawMonitor_lock;
 118 extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
 119 extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
 120 extern Mutex*   ParkerFreeList_lock;
 121 extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
 122 
 123 extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
 124 extern Mutex*   OldSets_lock;                    // protects the old region sets
 125 extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
 126 
 127 extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
 128 extern Monitor* Service_lock;                    // a lock used for service thread operation
 129 extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
 130 extern Monitor* RedefineClasses_lock;            // locks classes from parallel redefinition
 131 
 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 Mutex*   JfrStream_lock;                  // protects JFR stream access
 137 #endif
 138 
 139 #ifndef SUPPORTS_NATIVE_CX8
 140 extern Mutex*   UnsafeJlong_lock;                // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
 141 #endif
 142 
 143 extern Mutex*   MetaspaceExpand_lock;            // protects Metaspace virtualspace and chunk expansions
 144 
 145 
 146 extern Monitor* CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.
 147                                                  // Only used locally in PrintCodeCacheLayout processing.
 148 
 149 // A MutexLocker provides mutual exclusion with respect to a given mutex
 150 // for the scope which contains the locker.  The lock is an OS lock, not
 151 // an object lock, and the two do not interoperate.  Do not use Mutex-based
 152 // locks to lock on Java objects, because they will not be respected if a
 153 // that object is locked using the Java locking mechanism.
 154 //
 155 //                NOTE WELL!!
 156 //
 157 // See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
 158 // and friends constructors do a fence, a lock and an acquire *in that
 159 // order*.  And that their destructors do a release and unlock, in *that*
 160 // order.  If their implementations change such that these assumptions
 161 // are violated, a whole lot of code will break.
 162 
 163 // Print all mutexes/monitors that are currently owned by a thread; called
 164 // by fatal error handler.
 165 void print_owned_locks_on_error(outputStream* st);
 166 
 167 char *lock_name(Mutex *mutex);
 168 
 169 class MutexLocker: StackObj {
 170  private:
 171   Monitor * _mutex;
 172  public:
 173   MutexLocker(Monitor * mutex) {
 174     assert(mutex->rank() != Mutex::special,
 175       "Special ranked mutex should only use MutexLockerEx");
 176     _mutex = mutex;
 177     _mutex->lock();
 178   }
 179 
 180   // Overloaded constructor passing current thread
 181   MutexLocker(Monitor * mutex, Thread *thread) {
 182     assert(mutex->rank() != Mutex::special,
 183       "Special ranked mutex should only use MutexLockerEx");
 184     _mutex = mutex;
 185     _mutex->lock(thread);
 186   }
 187 
 188   ~MutexLocker() {
 189     _mutex->unlock();
 190   }
 191 
 192 };
 193 
 194 // for debugging: check that we're already owning this lock (or are at a safepoint)
 195 #ifdef ASSERT
 196 void assert_locked_or_safepoint(const Monitor * lock);
 197 void assert_lock_strong(const Monitor * lock);
 198 #else
 199 #define assert_locked_or_safepoint(lock)
 200 #define assert_lock_strong(lock)
 201 #endif
 202 
 203 // A MutexLockerEx behaves like a MutexLocker when its constructor is
 204 // called with a Mutex.  Unlike a MutexLocker, its constructor can also be
 205 // called with NULL, in which case the MutexLockerEx is a no-op.  There
 206 // is also a corresponding MutexUnlockerEx.  We want to keep the
 207 // basic MutexLocker as fast as possible.  MutexLockerEx can also lock
 208 // without safepoint check.
 209 
 210 class MutexLockerEx: public StackObj {
 211  private:
 212   Monitor * _mutex;
 213  public:
 214   MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 215     _mutex = mutex;
 216     if (_mutex != NULL) {
 217       assert(mutex->rank() > Mutex::special || no_safepoint_check,
 218         "Mutexes with rank special or lower should not do safepoint checks");
 219       if (no_safepoint_check)
 220         _mutex->lock_without_safepoint_check();
 221       else
 222         _mutex->lock();
 223     }
 224   }
 225 
 226   ~MutexLockerEx() {
 227     if (_mutex != NULL) {
 228       _mutex->unlock();
 229     }
 230   }
 231 };
 232 
 233 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
 234 // a possibly null Monitor, and allows wait/notify as well which are
 235 // delegated to the underlying Monitor.
 236 
 237 class MonitorLockerEx: public MutexLockerEx {
 238  private:
 239   Monitor * _monitor;
 240  public:
 241   MonitorLockerEx(Monitor* monitor,
 242                   bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
 243     MutexLockerEx(monitor, no_safepoint_check),
 244     _monitor(monitor) {
 245     // Superclass constructor did locking
 246   }
 247 
 248   ~MonitorLockerEx() {
 249     #ifdef ASSERT
 250       if (_monitor != NULL) {
 251         assert_lock_strong(_monitor);
 252       }
 253     #endif  // ASSERT
 254     // Superclass destructor will do unlocking
 255   }
 256 
 257   bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
 258             long timeout = 0,
 259             bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
 260     if (_monitor != NULL) {
 261       return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
 262     }
 263     return false;
 264   }
 265 
 266   bool notify_all() {
 267     if (_monitor != NULL) {
 268       return _monitor->notify_all();
 269     }
 270     return true;
 271   }
 272 
 273   bool notify() {
 274     if (_monitor != NULL) {
 275       return _monitor->notify();
 276     }
 277     return true;
 278   }
 279 };
 280 
 281 
 282 
 283 // A GCMutexLocker is usually initialized with a mutex that is
 284 // automatically acquired in order to do GC.  The function that
 285 // synchronizes using a GCMutexLocker may be called both during and between
 286 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
 287 // if GC is in progress (since the mutex is already held on its behalf.)
 288 
 289 class GCMutexLocker: public StackObj {
 290 private:
 291   Monitor * _mutex;
 292   bool _locked;
 293 public:
 294   GCMutexLocker(Monitor * mutex);
 295   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
 296 };
 297 
 298 
 299 
 300 // A MutexUnlocker temporarily exits a previously
 301 // entered mutex for the scope which contains the unlocker.
 302 
 303 class MutexUnlocker: StackObj {
 304  private:
 305   Monitor * _mutex;
 306 
 307  public:
 308   MutexUnlocker(Monitor * mutex) {
 309     _mutex = mutex;
 310     _mutex->unlock();
 311   }
 312 
 313   ~MutexUnlocker() {
 314     _mutex->lock();
 315   }
 316 };
 317 
 318 // A MutexUnlockerEx temporarily exits a previously
 319 // entered mutex for the scope which contains the unlocker.
 320 
 321 class MutexUnlockerEx: StackObj {
 322  private:
 323   Monitor * _mutex;
 324   bool _no_safepoint_check;
 325 
 326  public:
 327   MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 328     _mutex = mutex;
 329     _no_safepoint_check = no_safepoint_check;
 330     _mutex->unlock();
 331   }
 332 
 333   ~MutexUnlockerEx() {
 334     if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
 335       _mutex->lock_without_safepoint_check();
 336     } else {
 337       _mutex->lock();
 338     }
 339   }
 340 };
 341 
 342 #ifndef PRODUCT
 343 //
 344 // A special MutexLocker that allows:
 345 //   - reentrant locking
 346 //   - locking out of order
 347 //
 348 // Only to be used for verify code, where we can relax out dead-lock
 349 // detection code a bit (unsafe, but probably ok). This code is NEVER to
 350 // be included in a product version.
 351 //
 352 class VerifyMutexLocker: StackObj {
 353  private:
 354   Monitor * _mutex;
 355   bool   _reentrant;
 356  public:
 357   VerifyMutexLocker(Monitor * mutex) {
 358     _mutex     = mutex;
 359     _reentrant = mutex->owned_by_self();
 360     if (!_reentrant) {
 361       // We temp. disable strict safepoint checking, while we require the lock
 362       FlagSetting fs(StrictSafepointChecks, false);
 363       _mutex->lock();
 364     }
 365   }
 366 
 367   ~VerifyMutexLocker() {
 368     if (!_reentrant) {
 369       _mutex->unlock();
 370     }
 371   }
 372 };
 373 
 374 #endif
 375 
 376 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP