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 Monitor* SystemDictionary_lock;           // a lock on the system dictionary
  36 extern Mutex*   ProtectionDomainSet_lock;        // a lock on the pd_set list in the system dictionary
  37 extern Mutex*   SharedDictionary_lock;           // a lock on the CDS shared dictionary
  38 extern Mutex*   Module_lock;                     // a lock on module and package related data structures
  39 extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
  40 extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
  41 extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
  42 extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
  43 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
  44 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
  45 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
  46 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
  47 extern Monitor* Heap_lock;                       // a lock on the heap
  48 extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
  49 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
  50 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
  51 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
  52 extern Mutex*   SymbolArena_lock;                // a lock on the symbol table arena
  53 extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
  54 extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
  55 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache, rank is special
  56 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
  57 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
  58 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
  59 extern Monitor* CGCPhaseManager_lock;            // a lock to protect a concurrent GC's phase management
  60 extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
  61 extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
  62 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
  63                                                  // (also used by Safepoints too to block threads creation/destruction)
  64 extern Mutex*   NonJavaThreadsList_lock;         // a lock on the NonJavaThreads list
  65 extern Mutex*   NonJavaThreadsListSync_lock;     // a lock for NonJavaThreads list synchronization
  66 extern Monitor* CGC_lock;                        // used for coordination between
  67                                                  // fore- & background GC threads.
  68 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
  69 extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
  70 extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
  71                                                  // completed buffer queue.
  72 extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
  73                                                  // queue shared by
  74                                                  // non-Java threads.
  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.
  78 extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
  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*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
  92 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
  93 extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
  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 Monitor* 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 Monitor * lock);
 175 void assert_locked_or_safepoint_weak(const Monitor * lock);
 176 void assert_lock_strong(const Monitor * 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   Monitor* _mutex;
 186  private:
 187  public:
 188   MutexLocker(Monitor* 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(Monitor* 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  public:
 231   MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 232     MutexLocker(monitor, flag), _flag(flag) {
 233     // Superclass constructor did locking
 234     assert(_mutex != NULL, "NULL monitor not allowed");
 235   }
 236 
 237   MonitorLocker(Monitor* monitor, Thread* thread, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 238     MutexLocker(monitor, thread, flag), _flag(flag)  {
 239     // Superclass constructor did locking
 240     assert(_mutex != NULL, "NULL monitor not allowed");
 241   }
 242 
 243   bool wait(long timeout = 0,
 244             bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
 245     if (_flag == Mutex::_safepoint_check_flag) {
 246       return _mutex->wait(timeout, as_suspend_equivalent);
 247     } else {
 248       return _mutex->wait_without_safepoint_check(timeout);
 249     }
 250     return false;
 251   }
 252 
 253   void notify_all() {
 254     _mutex->notify_all();
 255   }
 256 
 257   void notify() {
 258     _mutex->notify();
 259   }
 260 };
 261 
 262 
 263 // A GCMutexLocker is usually initialized with a mutex that is
 264 // automatically acquired in order to do GC.  The function that
 265 // synchronizes using a GCMutexLocker may be called both during and between
 266 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
 267 // if GC is in progress (since the mutex is already held on its behalf.)
 268 
 269 class GCMutexLocker: public StackObj {
 270 private:
 271   Monitor* _mutex;
 272   bool _locked;
 273 public:
 274   GCMutexLocker(Monitor* mutex);
 275   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
 276 };
 277 
 278 // A MutexUnlocker temporarily exits a previously
 279 // entered mutex for the scope which contains the unlocker.
 280 
 281 class MutexUnlocker: StackObj {
 282  private:
 283   Monitor* _mutex;
 284   bool _no_safepoint_check;
 285 
 286  public:
 287   MutexUnlocker(Monitor* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 288     _mutex(mutex),
 289     _no_safepoint_check(flag) {
 290     _mutex->unlock();
 291   }
 292 
 293   ~MutexUnlocker() {
 294     if (_no_safepoint_check) {
 295       _mutex->lock_without_safepoint_check();
 296     } else {
 297       _mutex->lock();
 298     }
 299   }
 300 };
 301 
 302 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP
--- EOF ---