1 /*
   2  * Copyright (c) 1997, 2015, 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 #include "precompiled.hpp"
  26 #include "runtime/mutexLocker.hpp"
  27 #include "runtime/os.inline.hpp"
  28 #include "runtime/safepoint.hpp"
  29 #include "runtime/thread.inline.hpp"
  30 #include "runtime/threadLocalStorage.hpp"
  31 #include "runtime/vmThread.hpp"
  32 
  33 // Mutexes used in the VM (see comment in mutexLocker.hpp):
  34 //
  35 // Note that the following pointers are effectively final -- after having been
  36 // set at JVM startup-time, they should never be subsequently mutated.
  37 // Instead of using pointers to malloc()ed monitors and mutexes we should consider
  38 // eliminating the indirection and using instances instead.
  39 // Consider using GCC's __read_mostly.
  40 
  41 Mutex*   Patching_lock                = NULL;
  42 Monitor* SystemDictionary_lock        = NULL;
  43 Mutex*   PackageTable_lock            = NULL;
  44 Mutex*   CompiledIC_lock              = NULL;
  45 Mutex*   InlineCacheBuffer_lock       = NULL;
  46 Mutex*   VMStatistic_lock             = NULL;
  47 Mutex*   JNIGlobalHandle_lock         = NULL;
  48 Mutex*   JNIHandleBlockFreeList_lock  = NULL;
  49 Mutex*   MemberNameTable_lock         = NULL;
  50 Mutex*   JmethodIdCreation_lock       = NULL;
  51 Mutex*   JfieldIdCreation_lock        = NULL;
  52 Monitor* JNICritical_lock             = NULL;
  53 Mutex*   JvmtiThreadState_lock        = NULL;
  54 Monitor* JvmtiPendingEvent_lock       = NULL;
  55 Monitor* Heap_lock                    = NULL;
  56 Mutex*   ExpandHeap_lock              = NULL;
  57 Mutex*   AdapterHandlerLibrary_lock   = NULL;
  58 Mutex*   SignatureHandlerLibrary_lock = NULL;
  59 Mutex*   VtableStubs_lock             = NULL;
  60 Mutex*   SymbolTable_lock             = NULL;
  61 Mutex*   StringTable_lock             = NULL;
  62 Monitor* StringDedupQueue_lock        = NULL;
  63 Mutex*   StringDedupTable_lock        = NULL;
  64 Monitor* CodeCache_lock               = NULL;
  65 Mutex*   MethodData_lock              = NULL;
  66 Mutex*   RetData_lock                 = NULL;
  67 Monitor* VMOperationQueue_lock        = NULL;
  68 Monitor* VMOperationRequest_lock      = NULL;
  69 Monitor* Safepoint_lock               = NULL;
  70 Monitor* SerializePage_lock           = NULL;
  71 Monitor* Threads_lock                 = NULL;
  72 Monitor* CGC_lock                     = NULL;
  73 Monitor* STS_lock                     = NULL;
  74 Monitor* SLT_lock                     = NULL;
  75 Monitor* FullGCCount_lock             = NULL;
  76 Monitor* CMark_lock                   = NULL;
  77 Mutex*   CMRegionStack_lock           = NULL;
  78 Mutex*   SATB_Q_FL_lock               = NULL;
  79 Monitor* SATB_Q_CBL_mon               = NULL;
  80 Mutex*   Shared_SATB_Q_lock           = NULL;
  81 Mutex*   DirtyCardQ_FL_lock           = NULL;
  82 Monitor* DirtyCardQ_CBL_mon           = NULL;
  83 Mutex*   Shared_DirtyCardQ_lock       = NULL;
  84 Mutex*   ParGCRareEvent_lock          = NULL;
  85 Mutex*   EvacFailureStack_lock        = NULL;
  86 Mutex*   DerivedPointerTableGC_lock   = NULL;
  87 Mutex*   Compile_lock                 = NULL;
  88 Monitor* MethodCompileQueue_lock      = NULL;
  89 Monitor* CompileThread_lock           = NULL;
  90 Monitor* Compilation_lock             = NULL;
  91 Mutex*   CompileTaskAlloc_lock        = NULL;
  92 Mutex*   CompileStatistics_lock       = NULL;
  93 Mutex*   MultiArray_lock              = NULL;
  94 Monitor* Terminator_lock              = NULL;
  95 Monitor* BeforeExit_lock              = NULL;
  96 Monitor* Notify_lock                  = NULL;
  97 Monitor* Interrupt_lock               = NULL;
  98 Monitor* ProfileVM_lock               = NULL;
  99 Mutex*   ProfilePrint_lock            = NULL;
 100 Mutex*   ExceptionCache_lock          = NULL;
 101 Monitor* ObjAllocPost_lock            = NULL;
 102 Mutex*   OsrList_lock                 = NULL;
 103 #ifndef PRODUCT
 104 Mutex*   FullGCALot_lock              = NULL;
 105 #endif
 106 
 107 Mutex*   Debug1_lock                  = NULL;
 108 Mutex*   Debug2_lock                  = NULL;
 109 Mutex*   Debug3_lock                  = NULL;
 110 
 111 Mutex*   tty_lock                     = NULL;
 112 
 113 Mutex*   RawMonitor_lock              = NULL;
 114 Mutex*   PerfDataMemAlloc_lock        = NULL;
 115 Mutex*   PerfDataManager_lock         = NULL;
 116 Mutex*   OopMapCacheAlloc_lock        = NULL;
 117 
 118 Mutex*   FreeList_lock                = NULL;
 119 Monitor* SecondaryFreeList_lock       = NULL;
 120 Mutex*   OldSets_lock                 = NULL;
 121 Monitor* RootRegionScan_lock          = NULL;
 122 Mutex*   MMUTracker_lock              = NULL;
 123 
 124 Monitor* GCTaskManager_lock           = NULL;
 125 
 126 Mutex*   Management_lock              = NULL;
 127 Monitor* Service_lock                 = NULL;
 128 Monitor* PeriodicTask_lock            = NULL;
 129 
 130 #ifdef INCLUDE_TRACE
 131 Mutex*   JfrStacktrace_lock           = NULL;
 132 Monitor* JfrMsg_lock                  = NULL;
 133 Mutex*   JfrBuffer_lock               = NULL;
 134 Mutex*   JfrStream_lock               = NULL;
 135 Mutex*   JfrThreadGroups_lock         = NULL;
 136 #endif
 137 
 138 #ifndef SUPPORTS_NATIVE_CX8
 139 Mutex*   UnsafeJlong_lock             = NULL;
 140 #endif
 141 
 142 #define MAX_NUM_MUTEX 128
 143 static Monitor * _mutex_array[MAX_NUM_MUTEX];
 144 static int _num_mutex;
 145 
 146 #ifdef ASSERT
 147 void assert_locked_or_safepoint(const Monitor * lock) {
 148   // check if this thread owns the lock (common case)
 149   if (IgnoreLockingAssertions) return;
 150   assert(lock != NULL, "Need non-NULL lock");
 151   if (lock->owned_by_self()) return;
 152   if (SafepointSynchronize::is_at_safepoint()) return;
 153   if (!Universe::is_fully_initialized()) return;
 154   // see if invoker of VM operation owns it
 155   VM_Operation* op = VMThread::vm_operation();
 156   if (op != NULL && op->calling_thread() == lock->owner()) return;
 157   fatal(err_msg("must own lock %s", lock->name()));
 158 }
 159 
 160 // a stronger assertion than the above
 161 void assert_lock_strong(const Monitor * lock) {
 162   if (IgnoreLockingAssertions) return;
 163   assert(lock != NULL, "Need non-NULL lock");
 164   if (lock->owned_by_self()) return;
 165   fatal(err_msg("must own lock %s", lock->name()));
 166 }
 167 #endif
 168 
 169 #define def(var, type, pri, vm_block, safepoint_check_allowed ) {      \
 170   var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
 171   assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX");        \
 172   _mutex_array[_num_mutex++] = var;                                      \
 173 }
 174 
 175 void mutex_init() {
 176   def(tty_lock                     , Mutex  , event,       true,  Monitor::_safepoint_check_never);      // allow to lock in VM
 177 
 178   def(CGC_lock                     , Monitor, special,     true,  Monitor::_safepoint_check_never);      // coordinate between fore- and background GC
 179   def(STS_lock                     , Monitor, leaf,        true,  Monitor::_safepoint_check_never);
 180 
 181   if (UseConcMarkSweepGC || UseG1GC) {
 182     def(FullGCCount_lock           , Monitor, leaf,        true,  Monitor::_safepoint_check_never);      // in support of ExplicitGCInvokesConcurrent
 183   }
 184   if (UseG1GC) {
 185 
 186     def(CMark_lock                 , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);      // coordinate concurrent mark thread
 187     def(CMRegionStack_lock         , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
 188     def(SATB_Q_FL_lock             , Mutex  , special,     true,  Monitor::_safepoint_check_never);
 189     def(SATB_Q_CBL_mon             , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);
 190     def(Shared_SATB_Q_lock         , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
 191 
 192     def(DirtyCardQ_FL_lock         , Mutex  , special,     true,  Monitor::_safepoint_check_never);
 193     def(DirtyCardQ_CBL_mon         , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);
 194     def(Shared_DirtyCardQ_lock     , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
 195 
 196     def(FreeList_lock              , Mutex,   leaf     ,   true,  Monitor::_safepoint_check_never);
 197     def(SecondaryFreeList_lock     , Monitor, leaf     ,   true,  Monitor::_safepoint_check_never);
 198     def(OldSets_lock               , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_never);
 199     def(RootRegionScan_lock        , Monitor, leaf     ,   true,  Monitor::_safepoint_check_never);
 200     def(MMUTracker_lock            , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_never);
 201     def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true,  Monitor::_safepoint_check_never);
 202 
 203     def(StringDedupQueue_lock      , Monitor, leaf,        true,  Monitor::_safepoint_check_never);
 204     def(StringDedupTable_lock      , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
 205   }
 206   def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_sometimes);
 207   def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
 208   def(CodeCache_lock               , Mutex  , special,     true,  Monitor::_safepoint_check_never);
 209   def(Interrupt_lock               , Monitor, special,     true,  Monitor::_safepoint_check_never);      // used for interrupt processing
 210   def(RawMonitor_lock              , Mutex,   special,     true,  Monitor::_safepoint_check_never);
 211   def(OopMapCacheAlloc_lock        , Mutex,   leaf,        true,  Monitor::_safepoint_check_always);     // used for oop_map_cache allocation.
 212 
 213   def(Patching_lock                , Mutex  , special,     true,  Monitor::_safepoint_check_never);      // used for safepointing and code patching.
 214   def(ObjAllocPost_lock            , Monitor, special,     false, Monitor::_safepoint_check_never);
 215   def(Service_lock                 , Monitor, special,     true,  Monitor::_safepoint_check_never);      // used for service thread operations
 216   def(JmethodIdCreation_lock       , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for creating jmethodIDs.
 217 
 218   def(SystemDictionary_lock        , Monitor, leaf,        true,  Monitor::_safepoint_check_always);     // lookups done by VM thread
 219   def(PackageTable_lock            , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
 220   def(InlineCacheBuffer_lock       , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);
 221   def(VMStatistic_lock             , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
 222   def(ExpandHeap_lock              , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // Used during compilation by VM thread
 223   def(JNIHandleBlockFreeList_lock  , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);      // handles are used by VM thread
 224   def(SignatureHandlerLibrary_lock , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
 225   def(SymbolTable_lock             , Mutex  , leaf+2,      true,  Monitor::_safepoint_check_always);
 226   def(StringTable_lock             , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);
 227   def(ProfilePrint_lock            , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
 228   def(ExceptionCache_lock          , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
 229   def(OsrList_lock                 , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
 230   def(Debug1_lock                  , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
 231 #ifndef PRODUCT
 232   def(FullGCALot_lock              , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // a lock to make FullGCALot MT safe
 233 #endif
 234   def(BeforeExit_lock              , Monitor, leaf,        true,  Monitor::_safepoint_check_always);
 235   def(PerfDataMemAlloc_lock        , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for allocating PerfData memory for performance data
 236   def(PerfDataManager_lock         , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for synchronized access to PerfDataManager resources
 237 
 238   // CMS_modUnionTable_lock                   leaf
 239   // CMS_bitMap_lock                          leaf 1
 240   // CMS_freeList_lock                        leaf 2
 241 
 242   def(Safepoint_lock               , Monitor, safepoint,   true,  Monitor::_safepoint_check_sometimes);  // locks SnippetCache_lock/Threads_lock
 243 
 244   def(Threads_lock                 , Monitor, barrier,     true,  Monitor::_safepoint_check_sometimes);
 245 
 246   def(VMOperationQueue_lock        , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);  // VM_thread allowed to block on these
 247   def(VMOperationRequest_lock      , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
 248   def(RetData_lock                 , Mutex  , nonleaf,     false, Monitor::_safepoint_check_always);
 249   def(Terminator_lock              , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
 250   def(VtableStubs_lock             , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
 251   def(Notify_lock                  , Monitor, nonleaf,     true,  Monitor::_safepoint_check_always);
 252   def(JNIGlobalHandle_lock         , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);     // locks JNIHandleBlockFreeList_lock
 253   def(JNICritical_lock             , Monitor, nonleaf,     true,  Monitor::_safepoint_check_always);     // used for JNI critical regions
 254   def(AdapterHandlerLibrary_lock   , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
 255   if (UseConcMarkSweepGC) {
 256     def(SLT_lock                   , Monitor, nonleaf,     false, Monitor::_safepoint_check_never);      // used in CMS GC for locking PLL lock
 257   }
 258 
 259   def(Heap_lock                    , Monitor, nonleaf+1,   false, Monitor::_safepoint_check_sometimes);
 260   def(JfieldIdCreation_lock        , Mutex  , nonleaf+1,   true,  Monitor::_safepoint_check_always);     // jfieldID, Used in VM_Operation
 261   def(MemberNameTable_lock         , Mutex  , nonleaf+1,   false, Monitor::_safepoint_check_always);     // Used to protect MemberNameTable
 262 
 263   def(CompiledIC_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // locks VtableStubs_lock, InlineCacheBuffer_lock
 264   def(CompileTaskAlloc_lock        , Mutex  , nonleaf+2,   true,  Monitor::_safepoint_check_always);
 265   def(CompileStatistics_lock       , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);
 266   def(MultiArray_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // locks SymbolTable_lock
 267 
 268   def(JvmtiThreadState_lock        , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // Used by JvmtiThreadState/JvmtiEventController
 269   def(JvmtiPendingEvent_lock       , Monitor, nonleaf,     false, Monitor::_safepoint_check_never);      // Used by JvmtiCodeBlobEvents
 270   def(Management_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // used for JVM management
 271 
 272   def(Compile_lock                 , Mutex  , nonleaf+3,   true,  Monitor::_safepoint_check_sometimes);
 273   def(MethodData_lock              , Mutex  , nonleaf+3,   false, Monitor::_safepoint_check_always);
 274 
 275   def(MethodCompileQueue_lock      , Monitor, nonleaf+4,   true,  Monitor::_safepoint_check_always);
 276   def(Debug2_lock                  , Mutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
 277   def(Debug3_lock                  , Mutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
 278   def(ProfileVM_lock               , Monitor, special,     false, Monitor::_safepoint_check_never);      // used for profiling of the VMThread
 279   def(CompileThread_lock           , Monitor, nonleaf+5,   false, Monitor::_safepoint_check_always);
 280   def(PeriodicTask_lock            , Monitor, nonleaf+5,   true,  Monitor::_safepoint_check_sometimes);
 281   if (WhiteBoxAPI) {
 282     def(Compilation_lock           , Monitor, leaf,        false, Monitor::_safepoint_check_never);
 283   }
 284 
 285 #ifdef INCLUDE_TRACE
 286   def(JfrMsg_lock                  , Monitor, leaf,        true,  Monitor::_safepoint_check_always);
 287   def(JfrBuffer_lock               , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
 288   def(JfrThreadGroups_lock         , Mutex,   leaf,        true,  Monitor::_safepoint_check_always);
 289   def(JfrStream_lock               , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
 290   def(JfrStacktrace_lock           , Mutex,   special,     true,  Monitor::_safepoint_check_sometimes);
 291 #endif
 292 
 293 #ifndef SUPPORTS_NATIVE_CX8
 294   def(UnsafeJlong_lock             , Mutex,   special,     false, Monitor::_safepoint_check_never);
 295 #endif
 296 }
 297 
 298 GCMutexLocker::GCMutexLocker(Monitor * mutex) {
 299   if (SafepointSynchronize::is_at_safepoint()) {
 300     _locked = false;
 301   } else {
 302     _mutex = mutex;
 303     _locked = true;
 304     _mutex->lock();
 305   }
 306 }
 307 
 308 // Print all mutexes/monitors that are currently owned by a thread; called
 309 // by fatal error handler.
 310 void print_owned_locks_on_error(outputStream* st) {
 311   st->print("VM Mutex/Monitor currently owned by a thread: ");
 312   bool none = true;
 313   for (int i = 0; i < _num_mutex; i++) {
 314      // see if it has an owner
 315      if (_mutex_array[i]->owner() != NULL) {
 316        if (none) {
 317           // print format used by Mutex::print_on_error()
 318           st->print_cr(" ([mutex/lock_event])");
 319           none = false;
 320        }
 321        _mutex_array[i]->print_on_error(st);
 322        st->cr();
 323      }
 324   }
 325   if (none) st->print_cr("None");
 326 }