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*   JNIGlobalAlloc_lock;             // JNI global storage allocate list lock
  43 extern Mutex*   JNIGlobalActive_lock;            // JNI global storage active list lock
  44 extern Mutex*   JNIWeakAlloc_lock;               // JNI weak storage allocate list lock
  45 extern Mutex*   JNIWeakActive_lock;              // JNI weak storage active list lock
  46 extern Mutex*   StringTableWeakAlloc_lock;       // StringTable weak storage allocate list lock
  47 extern Mutex*   StringTableWeakActive_lock;      // STringTable weak storage active list lock
  48 extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
  49 extern Mutex*   VMGlobalAlloc_lock;              // VM Global Handles storage allocate list lock
  50 extern Mutex*   VMGlobalActive_lock;             // VM Global Handles storage active list lock
  51 extern Mutex*   VMWeakAlloc_lock;                // VM Weak Handles storage allocate list lock
  52 extern Mutex*   VMWeakActive_lock;               // VM Weak Handles storage active list lock
  53 extern Mutex*   ResolvedMethodTableWeakAlloc_lock;  // ResolvedMethodTable weak storage allocate list
  54 extern Mutex*   ResolvedMethodTableWeakActive_lock; // ResolvedMethodTable weak storage active list
  55 extern Mutex*   NMethodKeepaliveAlloc_lock;      // Continuation weak storage allocate list
  56 extern Mutex*   NMethodKeepaliveActive_lock;     // Continuation weak storage active list
  57 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
  58 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
  59 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
  60 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
  61 extern Monitor* Heap_lock;                       // a lock on the heap
  62 extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
  63 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
  64 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
  65 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
  66 extern Mutex*   SymbolArena_lock;                // a lock on the symbol table arena
  67 extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
  68 extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
  69 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache, rank is special
  70 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
  71 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
  72 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
  73 extern Monitor* CGCPhaseManager_lock;            // a lock to protect a concurrent GC's phase management
  74 extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
  75 extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
  76 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
  77                                                  // (also used by Safepoints too to block threads creation/destruction)
  78 extern Mutex*   NonJavaThreadsList_lock;         // a lock on the NonJavaThreads list
  79 extern Mutex*   NonJavaThreadsListSync_lock;     // a lock for NonJavaThreads list synchronization
  80 extern Monitor* CGC_lock;                        // used for coordination between
  81                                                  // fore- & background GC threads.
  82 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
  83 extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
  84 extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
  85                                                  // completed buffer queue.
  86 extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
  87                                                  // queue shared by
  88                                                  // non-Java threads.
  89 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
  90 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
  91 extern Mutex*   MonitoringSupport_lock;          // Protects updates to the serviceability memory pools.
  92 extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
  93 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
  94 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
  95 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
  96 extern Monitor* Compilation_lock;                // a lock used to pause compilation
  97 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
  98 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
  99 extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
 100 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
 101 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 102 extern Monitor* InitCompleted_lock;              // a lock used to signal threads waiting on init completed
 103 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
 104 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
 105 extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
 106 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
 107 extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
 108 extern Mutex*   NMethodSweeperStats_lock;        // a lock used to serialize access to sweeper statistics
 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 extern Monitor* ThreadsSMRDelete_lock;           // Used by ThreadsSMRSupport to take pressure off the Threads_lock
 132 extern Mutex*   SharedDecoder_lock;              // serializes access to the decoder during normal (not error reporting) use
 133 extern Mutex*   DCmdFactory_lock;                // serialize access to DCmdFactory information
 134 #if INCLUDE_NMT
 135 extern Mutex*   NMTQuery_lock;                   // serialize NMT Dcmd queries
 136 #endif
 137 #if INCLUDE_CDS
 138 #if INCLUDE_JVMTI
 139 extern Mutex*   CDSClassFileStream_lock;         // FileMapInfo::open_stream_for_jvmti
 140 #endif
 141 extern Mutex*   DumpTimeTable_lock;              // SystemDictionaryShared::find_or_allocate_info_for
 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 Mutex*   JfrStream_lock;                  // protects JFR stream access
 148 extern Monitor* JfrThreadSampler_lock;           // used to suspend/resume JFR thread sampler
 149 #endif
 150 
 151 #ifndef SUPPORTS_NATIVE_CX8
 152 extern Mutex*   UnsafeJlong_lock;                // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
 153 #endif
 154 
 155 extern Mutex*   MetaspaceExpand_lock;            // protects Metaspace virtualspace and chunk expansions
 156 extern Mutex*   ClassLoaderDataGraph_lock;       // protects CLDG list, needed for concurrent unloading
 157 
 158 
 159 extern Monitor* CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.
 160                                                  // Only used locally in PrintCodeCacheLayout processing.
 161 
 162 #if INCLUDE_JVMCI
 163 extern Monitor* JVMCI_lock;                      // Monitor to control initialization of JVMCI
 164 #endif
 165 
 166 // A MutexLocker provides mutual exclusion with respect to a given mutex
 167 // for the scope which contains the locker.  The lock is an OS lock, not
 168 // an object lock, and the two do not interoperate.  Do not use Mutex-based
 169 // locks to lock on Java objects, because they will not be respected if a
 170 // that object is locked using the Java locking mechanism.
 171 //
 172 //                NOTE WELL!!
 173 //
 174 // See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
 175 // and friends constructors do a fence, a lock and an acquire *in that
 176 // order*.  And that their destructors do a release and unlock, in *that*
 177 // order.  If their implementations change such that these assumptions
 178 // are violated, a whole lot of code will break.
 179 
 180 // Print all mutexes/monitors that are currently owned by a thread; called
 181 // by fatal error handler.
 182 void print_owned_locks_on_error(outputStream* st);
 183 
 184 char *lock_name(Mutex *mutex);
 185 
 186 // for debugging: check that we're already owning this lock (or are at a safepoint)
 187 #ifdef ASSERT
 188 void assert_locked_or_safepoint(const Monitor * lock);
 189 void assert_locked_or_safepoint_weak(const Monitor * lock);
 190 void assert_lock_strong(const Monitor * lock);
 191 #else
 192 #define assert_locked_or_safepoint(lock)
 193 #define assert_locked_or_safepoint_weak(lock)
 194 #define assert_lock_strong(lock)
 195 #endif
 196 
 197 class MutexLocker: public StackObj {
 198  protected:
 199   Monitor* _mutex;
 200  private:
 201  public:
 202   MutexLocker(Monitor* mutex, 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();
 210       } else {
 211         _mutex->lock();
 212       }
 213     }
 214   }
 215 
 216   MutexLocker(Monitor* mutex, Thread* thread, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 217     _mutex(mutex) {
 218     bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag;
 219     if (_mutex != NULL) {
 220       assert(_mutex->rank() > Mutex::special || no_safepoint_check,
 221              "Mutexes with rank special or lower should not do safepoint checks");
 222       if (no_safepoint_check) {
 223         _mutex->lock_without_safepoint_check(thread);
 224       } else {
 225         _mutex->lock(thread);
 226       }
 227     }
 228   }
 229 
 230   ~MutexLocker() {
 231     if (_mutex != NULL) {
 232       assert_lock_strong(_mutex);
 233       _mutex->unlock();
 234     }
 235   }
 236 };
 237 
 238 // A MonitorLocker is like a MutexLocker above, except it allows
 239 // wait/notify as well which are delegated to the underlying Monitor.
 240 // It also disallows NULL.
 241 
 242 class MonitorLocker: public MutexLocker {
 243   Mutex::SafepointCheckFlag _flag;
 244  public:
 245   MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 246     MutexLocker(monitor, flag), _flag(flag) {
 247     // Superclass constructor did locking
 248     assert(_mutex != NULL, "NULL monitor not allowed");
 249   }
 250 
 251   MonitorLocker(Monitor* monitor, Thread* thread, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 252     MutexLocker(monitor, thread, flag), _flag(flag)  {
 253     // Superclass constructor did locking
 254     assert(_mutex != NULL, "NULL monitor not allowed");
 255   }
 256 
 257   bool wait(long timeout = 0,
 258             bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
 259     if (_flag == Mutex::_safepoint_check_flag) {
 260       return _mutex->wait(timeout, as_suspend_equivalent);
 261     } else {
 262       return _mutex->wait_without_safepoint_check(timeout);
 263     }
 264     return false;
 265   }
 266 
 267   void notify_all() {
 268     _mutex->notify_all();
 269   }
 270 
 271   void notify() {
 272     _mutex->notify();
 273   }
 274 };
 275 
 276 
 277 // A GCMutexLocker is usually initialized with a mutex that is
 278 // automatically acquired in order to do GC.  The function that
 279 // synchronizes using a GCMutexLocker may be called both during and between
 280 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
 281 // if GC is in progress (since the mutex is already held on its behalf.)
 282 
 283 class GCMutexLocker: public StackObj {
 284 private:
 285   Monitor* _mutex;
 286   bool _locked;
 287 public:
 288   GCMutexLocker(Monitor* mutex);
 289   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
 290 };
 291 
 292 // A MutexUnlocker temporarily exits a previously
 293 // entered mutex for the scope which contains the unlocker.
 294 
 295 class MutexUnlocker: StackObj {
 296  private:
 297   Monitor* _mutex;
 298   bool _no_safepoint_check;
 299 
 300  public:
 301   MutexUnlocker(Monitor* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) :
 302     _mutex(mutex),
 303     _no_safepoint_check(flag) {
 304     _mutex->unlock();
 305   }
 306 
 307   ~MutexUnlocker() {
 308     if (_no_safepoint_check) {
 309       _mutex->lock_without_safepoint_check();
 310     } else {
 311       _mutex->lock();
 312     }
 313   }
 314 };
 315 
 316 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP