1 /*
   2  * Copyright (c) 1997, 2010, 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_VM_RUNTIME_MUTEXLOCKER_HPP
  26 #define SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/mutex.hpp"
  30 #ifdef TARGET_OS_FAMILY_linux
  31 # include "os_linux.inline.hpp"
  32 #endif
  33 #ifdef TARGET_OS_FAMILY_solaris
  34 # include "os_solaris.inline.hpp"
  35 #endif
  36 #ifdef TARGET_OS_FAMILY_windows
  37 # include "os_windows.inline.hpp"
  38 #endif
  39 
  40 // Mutexes used in the VM.
  41 
  42 extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
  43 extern Monitor* SystemDictionary_lock;           // a lock on the system dictonary
  44 extern Mutex*   PackageTable_lock;               // a lock on the class loader package table
  45 extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
  46 extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
  47 extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
  48 extern Mutex*   JNIGlobalHandle_lock;            // a lock on creating JNI global handles
  49 extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
  50 extern Mutex*   JNICachedItableIndex_lock;       // a lock on caching an itable index during JNI invoke
  51 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
  52 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
  53 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
  54 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
  55 extern Monitor* JvmtiPendingEvent_lock;          // a lock on the JVMTI pending events list
  56 extern Monitor* Heap_lock;                       // a lock on the heap
  57 extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
  58 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
  59 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
  60 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
  61 extern Mutex*   SymbolTable_lock;                // a lock on the symbol table
  62 extern Mutex*   StringTable_lock;                // a lock on the interned string table
  63 extern Mutex*   CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
  64 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
  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* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
  68 extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
  69 extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction
  70 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
  71                                                  // (also used by Safepoints too to block threads creation/destruction)
  72 extern Monitor* CGC_lock;                        // used for coordination between
  73                                                  // fore- & background GC threads.
  74 extern Mutex*   STS_init_lock;                   // coordinate initialization of SuspendibleThreadSets.
  75 extern Monitor* SLT_lock;                        // used in CMS GC for acquiring PLL
  76 extern Monitor* iCMS_lock;                       // CMS incremental mode start/stop notification
  77 extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
  78 extern Monitor* CMark_lock;                      // used for concurrent mark thread coordination
  79 extern Monitor* ZF_mon;                          // used for G1 conc zero-fill.
  80 extern Monitor* Cleanup_mon;                     // used for G1 conc cleanup.
  81 extern Mutex*   CMRegionStack_lock;              // used for protecting accesses to the CM region stack
  82 extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
  83                                                  // buffer free list.
  84 extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
  85                                                  // completed buffer queue.
  86 extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB
  87                                                  // queue shared by
  88                                                  // non-Java threads.
  89 
  90 extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q
  91                                                  // buffer free list.
  92 extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
  93                                                  // completed buffer queue.
  94 extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
  95                                                  // queue shared by
  96                                                  // non-Java threads.
  97                                                  // (see option ExplicitGCInvokesConcurrent)
  98 extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
  99 extern Mutex*   EvacFailureStack_lock;           // guards the evac failure scan stack
 100 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
 101 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
 102 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
 103 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
 104 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
 105 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
 106 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 107 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
 108 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
 109 extern Monitor* Interrupt_lock;                  // a lock used for condition variable mediated interrupt processing
 110 extern Monitor* ProfileVM_lock;                  // a lock used for profiling the VMThread
 111 extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
 112 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
 113 extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
 114 
 115 #ifndef PRODUCT
 116 extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
 117 #endif
 118 extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
 119 extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
 120 extern Mutex*   Debug3_lock;
 121 
 122 extern Mutex*   RawMonitor_lock;
 123 extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
 124 extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
 125 extern Mutex*   ParkerFreeList_lock;
 126 extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
 127 
 128 extern Mutex*   MMUTracker_lock;                 // protects the MMU
 129                                                  // tracker data structures
 130 extern Mutex*   HotCardCache_lock;               // protects the hot card cache
 131 
 132 extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
 133 extern Monitor* LowMemory_lock;                  // a lock used for low memory detection
 134 
 135 // A MutexLocker provides mutual exclusion with respect to a given mutex
 136 // for the scope which contains the locker.  The lock is an OS lock, not
 137 // an object lock, and the two do not interoperate.  Do not use Mutex-based
 138 // locks to lock on Java objects, because they will not be respected if a
 139 // that object is locked using the Java locking mechanism.
 140 //
 141 //                NOTE WELL!!
 142 //
 143 // See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
 144 // and friends constructors do a fence, a lock and an acquire *in that
 145 // order*.  And that their destructors do a release and unlock, in *that*
 146 // order.  If their implementations change such that these assumptions
 147 // are violated, a whole lot of code will break.
 148 
 149 // Print all mutexes/monitors that are currently owned by a thread; called
 150 // by fatal error handler.
 151 void print_owned_locks_on_error(outputStream* st);
 152 
 153 char *lock_name(Mutex *mutex);
 154 
 155 class MutexLocker: StackObj {
 156  private:
 157   Monitor * _mutex;
 158  public:
 159   MutexLocker(Monitor * mutex) {
 160     assert(mutex->rank() != Mutex::special,
 161       "Special ranked mutex should only use MutexLockerEx");
 162     _mutex = mutex;
 163     _mutex->lock();
 164   }
 165 
 166   // Overloaded constructor passing current thread
 167   MutexLocker(Monitor * mutex, Thread *thread) {
 168     assert(mutex->rank() != Mutex::special,
 169       "Special ranked mutex should only use MutexLockerEx");
 170     _mutex = mutex;
 171     _mutex->lock(thread);
 172   }
 173 
 174   ~MutexLocker() {
 175     _mutex->unlock();
 176   }
 177 
 178 };
 179 
 180 // for debugging: check that we're already owning this lock (or are at a safepoint)
 181 #ifdef ASSERT
 182 void assert_locked_or_safepoint(const Monitor * lock);
 183 void assert_lock_strong(const Monitor * lock);
 184 #else
 185 #define assert_locked_or_safepoint(lock)
 186 #define assert_lock_strong(lock)
 187 #endif
 188 
 189 // A MutexLockerEx behaves like a MutexLocker when its constructor is
 190 // called with a Mutex.  Unlike a MutexLocker, its constructor can also be
 191 // called with NULL, in which case the MutexLockerEx is a no-op.  There
 192 // is also a corresponding MutexUnlockerEx.  We want to keep the
 193 // basic MutexLocker as fast as possible.  MutexLockerEx can also lock
 194 // without safepoint check.
 195 
 196 class MutexLockerEx: public StackObj {
 197  private:
 198   Monitor * _mutex;
 199  public:
 200   MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 201     _mutex = mutex;
 202     if (_mutex != NULL) {
 203       assert(mutex->rank() > Mutex::special || no_safepoint_check,
 204         "Mutexes with rank special or lower should not do safepoint checks");
 205       if (no_safepoint_check)
 206         _mutex->lock_without_safepoint_check();
 207       else
 208         _mutex->lock();
 209     }
 210   }
 211 
 212   ~MutexLockerEx() {
 213     if (_mutex != NULL) {
 214       _mutex->unlock();
 215     }
 216   }
 217 };
 218 
 219 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
 220 // a possibly null Monitor, and allows wait/notify as well which are
 221 // delegated to the underlying Monitor.
 222 
 223 class MonitorLockerEx: public MutexLockerEx {
 224  private:
 225   Monitor * _monitor;
 226  public:
 227   MonitorLockerEx(Monitor* monitor,
 228                   bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
 229     MutexLockerEx(monitor, no_safepoint_check),
 230     _monitor(monitor) {
 231     // Superclass constructor did locking
 232   }
 233 
 234   ~MonitorLockerEx() {
 235     #ifdef ASSERT
 236       if (_monitor != NULL) {
 237         assert_lock_strong(_monitor);
 238       }
 239     #endif  // ASSERT
 240     // Superclass destructor will do unlocking
 241   }
 242 
 243   bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
 244             long timeout = 0,
 245             bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
 246     if (_monitor != NULL) {
 247       return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
 248     }
 249     return false;
 250   }
 251 
 252   bool notify_all() {
 253     if (_monitor != NULL) {
 254       return _monitor->notify_all();
 255     }
 256     return true;
 257   }
 258 
 259   bool notify() {
 260     if (_monitor != NULL) {
 261       return _monitor->notify();
 262     }
 263     return true;
 264   }
 265 };
 266 
 267 
 268 
 269 // A GCMutexLocker is usually initialized with a mutex that is
 270 // automatically acquired in order to do GC.  The function that
 271 // synchronizes using a GCMutexLocker may be called both during and between
 272 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
 273 // if GC is in progress (since the mutex is already held on its behalf.)
 274 
 275 class GCMutexLocker: public StackObj {
 276 private:
 277   Monitor * _mutex;
 278   bool _locked;
 279 public:
 280   GCMutexLocker(Monitor * mutex);
 281   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
 282 };
 283 
 284 
 285 
 286 // A MutexUnlocker temporarily exits a previously
 287 // entered mutex for the scope which contains the unlocker.
 288 
 289 class MutexUnlocker: StackObj {
 290  private:
 291   Monitor * _mutex;
 292 
 293  public:
 294   MutexUnlocker(Monitor * mutex) {
 295     _mutex = mutex;
 296     _mutex->unlock();
 297   }
 298 
 299   ~MutexUnlocker() {
 300     _mutex->lock();
 301   }
 302 };
 303 
 304 // A MutexUnlockerEx temporarily exits a previously
 305 // entered mutex for the scope which contains the unlocker.
 306 
 307 class MutexUnlockerEx: StackObj {
 308  private:
 309   Monitor * _mutex;
 310   bool _no_safepoint_check;
 311 
 312  public:
 313   MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 314     _mutex = mutex;
 315     _no_safepoint_check = no_safepoint_check;
 316     _mutex->unlock();
 317   }
 318 
 319   ~MutexUnlockerEx() {
 320     if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
 321       _mutex->lock_without_safepoint_check();
 322     } else {
 323       _mutex->lock();
 324     }
 325   }
 326 };
 327 
 328 #ifndef PRODUCT
 329 //
 330 // A special MutexLocker that allows:
 331 //   - reentrant locking
 332 //   - locking out of order
 333 //
 334 // Only too be used for verify code, where we can relaxe out dead-lock
 335 // dection code a bit (unsafe, but probably ok). This code is NEVER to
 336 // be included in a product version.
 337 //
 338 class VerifyMutexLocker: StackObj {
 339  private:
 340   Monitor * _mutex;
 341   bool   _reentrant;
 342  public:
 343   VerifyMutexLocker(Monitor * mutex) {
 344     _mutex     = mutex;
 345     _reentrant = mutex->owned_by_self();
 346     if (!_reentrant) {
 347       // We temp. diable strict safepoint checking, while we require the lock
 348       FlagSetting fs(StrictSafepointChecks, false);
 349       _mutex->lock();
 350     }
 351   }
 352 
 353   ~VerifyMutexLocker() {
 354     if (!_reentrant) {
 355       _mutex->unlock();
 356     }
 357   }
 358 };
 359 
 360 #endif
 361 
 362 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP