mutexLocker.hpp revision 342:37f87013dfd8 
1/*
2 * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25// Mutexes used in the VM.
26
27extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
28extern Monitor* SystemDictionary_lock;           // a lock on the system dictonary
29extern Mutex*   PackageTable_lock;               // a lock on the class loader package table
30extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
31extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
32extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
33extern Mutex*   JNIGlobalHandle_lock;            // a lock on creating JNI global handles
34extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
35extern Mutex*   JNICachedItableIndex_lock;       // a lock on caching an itable index during JNI invoke
36extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
37extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
38extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
39extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
40extern Monitor* JvmtiPendingEvent_lock;          // a lock on the JVMTI pending events list
41extern Monitor* Heap_lock;                       // a lock on the heap
42extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
43extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
44extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
45extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
46extern Mutex*   SymbolTable_lock;                // a lock on the symbol table
47extern Mutex*   StringTable_lock;                // a lock on the interned string table
48extern Mutex*   CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
49extern Mutex*   MethodData_lock;                 // a lock on installation of method data
50extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
51extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table
52extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
53extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
54extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction
55extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
56                                                 // (also used by Safepoints too to block threads creation/destruction)
57extern Monitor* CGC_lock;                        // used for coordination between
58                                                 // fore- & background GC threads.
59extern Mutex*   STS_init_lock;                   // coordinate initialization of SuspendibleThreadSets.
60extern Monitor* SLT_lock;                        // used in CMS GC for acquiring PLL
61extern Monitor* iCMS_lock;                       // CMS incremental mode start/stop notification
62extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
63extern Monitor* CMark_lock;                      // used for concurrent mark thread coordination
64extern Monitor* ZF_mon;                          // used for G1 conc zero-fill.
65extern Monitor* Cleanup_mon;                     // used for G1 conc cleanup.
66extern Monitor* G1ConcRefine_mon;                // used for G1 conc-refine
67                                                 // coordination.
68
69extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
70                                                 // buffer free list.
71extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
72                                                 // completed buffer queue.
73extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB
74                                                 // queue shared by
75                                                 // non-Java threads.
76
77extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q
78                                                 // buffer free list.
79extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
80                                                 // completed buffer queue.
81extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
82                                                 // queue shared by
83                                                 // non-Java threads.
84                                                 // (see option ExplicitGCInvokesConcurrent)
85extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
86extern Mutex*   EvacFailureStack_lock;           // guards the evac failure scan stack
87extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
88extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
89#ifdef TIERED
90extern Monitor* C1_lock;                         // a lock to ensure on single c1 compile is ever active
91#endif // TIERED
92extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
93extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
94extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
95extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
96extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
97extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
98extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
99extern Monitor* Interrupt_lock;                  // a lock used for condition variable mediated interrupt processing
100extern Monitor* ProfileVM_lock;                  // a lock used for profiling the VMThread
101extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
102extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
103extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
104
105#ifndef PRODUCT
106extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
107#endif
108extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
109extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
110extern Mutex*   Debug3_lock;
111
112extern Mutex*   RawMonitor_lock;
113extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
114extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
115extern Mutex*   ParkerFreeList_lock;
116extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
117
118extern Mutex*   MMUTracker_lock;                 // protects the MMU
119                                                 // tracker data structures
120extern Mutex*   HotCardCache_lock;               // protects the hot card cache
121
122extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
123extern Monitor* LowMemory_lock;                  // a lock used for low memory detection
124
125// A MutexLocker provides mutual exclusion with respect to a given mutex
126// for the scope which contains the locker.  The lock is an OS lock, not
127// an object lock, and the two do not interoperate.  Do not use Mutex-based
128// locks to lock on Java objects, because they will not be respected if a
129// that object is locked using the Java locking mechanism.
130//
131//                NOTE WELL!!
132//
133// See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
134// and friends constructors do a fence, a lock and an acquire *in that
135// order*.  And that their destructors do a release and unlock, in *that*
136// order.  If their implementations change such that these assumptions
137// are violated, a whole lot of code will break.
138
139// Print all mutexes/monitors that are currently owned by a thread; called
140// by fatal error handler.
141void print_owned_locks_on_error(outputStream* st);
142
143char *lock_name(Mutex *mutex);
144
145class MutexLocker: StackObj {
146 private:
147  Monitor * _mutex;
148 public:
149  MutexLocker(Monitor * mutex) {
150    assert(mutex->rank() != Mutex::special,
151      "Special ranked mutex should only use MutexLockerEx");
152    _mutex = mutex;
153    _mutex->lock();
154  }
155
156  // Overloaded constructor passing current thread
157  MutexLocker(Monitor * mutex, Thread *thread) {
158    assert(mutex->rank() != Mutex::special,
159      "Special ranked mutex should only use MutexLockerEx");
160    _mutex = mutex;
161    _mutex->lock(thread);
162  }
163
164  ~MutexLocker() {
165    _mutex->unlock();
166  }
167
168};
169
170// for debugging: check that we're already owning this lock (or are at a safepoint)
171#ifdef ASSERT
172void assert_locked_or_safepoint(const Monitor * lock);
173void assert_lock_strong(const Monitor * lock);
174#else
175#define assert_locked_or_safepoint(lock)
176#define assert_lock_strong(lock)
177#endif
178
179// A MutexLockerEx behaves like a MutexLocker when its constructor is
180// called with a Mutex.  Unlike a MutexLocker, its constructor can also be
181// called with NULL, in which case the MutexLockerEx is a no-op.  There
182// is also a corresponding MutexUnlockerEx.  We want to keep the
183// basic MutexLocker as fast as possible.  MutexLockerEx can also lock
184// without safepoint check.
185
186class MutexLockerEx: public StackObj {
187 private:
188  Monitor * _mutex;
189 public:
190  MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
191    _mutex = mutex;
192    if (_mutex != NULL) {
193      assert(mutex->rank() > Mutex::special || no_safepoint_check,
194        "Mutexes with rank special or lower should not do safepoint checks");
195      if (no_safepoint_check)
196        _mutex->lock_without_safepoint_check();
197      else
198        _mutex->lock();
199    }
200  }
201
202  ~MutexLockerEx() {
203    if (_mutex != NULL) {
204      _mutex->unlock();
205    }
206  }
207};
208
209// A MonitorLockerEx is like a MutexLockerEx above, except it takes
210// a possibly null Monitor, and allows wait/notify as well which are
211// delegated to the underlying Monitor.
212
213class MonitorLockerEx: public MutexLockerEx {
214 private:
215  Monitor * _monitor;
216 public:
217  MonitorLockerEx(Monitor* monitor,
218                  bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
219    MutexLockerEx(monitor, no_safepoint_check),
220    _monitor(monitor) {
221    // Superclass constructor did locking
222  }
223
224  ~MonitorLockerEx() {
225    #ifdef ASSERT
226      if (_monitor != NULL) {
227        assert_lock_strong(_monitor);
228      }
229    #endif  // ASSERT
230    // Superclass destructor will do unlocking
231  }
232
233  bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
234            long timeout = 0,
235            bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
236    if (_monitor != NULL) {
237      return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
238    }
239    return false;
240  }
241
242  bool notify_all() {
243    if (_monitor != NULL) {
244      return _monitor->notify_all();
245    }
246    return true;
247  }
248
249  bool notify() {
250    if (_monitor != NULL) {
251      return _monitor->notify();
252    }
253    return true;
254  }
255};
256
257
258
259// A GCMutexLocker is usually initialized with a mutex that is
260// automatically acquired in order to do GC.  The function that
261// synchronizes using a GCMutexLocker may be called both during and between
262// GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
263// if GC is in progress (since the mutex is already held on its behalf.)
264
265class GCMutexLocker: public StackObj {
266private:
267  Monitor * _mutex;
268  bool _locked;
269public:
270  GCMutexLocker(Monitor * mutex);
271  ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
272};
273
274
275
276// A MutexUnlocker temporarily exits a previously
277// entered mutex for the scope which contains the unlocker.
278
279class MutexUnlocker: StackObj {
280 private:
281  Monitor * _mutex;
282
283 public:
284  MutexUnlocker(Monitor * mutex) {
285    _mutex = mutex;
286    _mutex->unlock();
287  }
288
289  ~MutexUnlocker() {
290    _mutex->lock();
291  }
292};
293
294// A MutexUnlockerEx temporarily exits a previously
295// entered mutex for the scope which contains the unlocker.
296
297class MutexUnlockerEx: StackObj {
298 private:
299  Monitor * _mutex;
300  bool _no_safepoint_check;
301
302 public:
303  MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
304    _mutex = mutex;
305    _no_safepoint_check = no_safepoint_check;
306    _mutex->unlock();
307  }
308
309  ~MutexUnlockerEx() {
310    if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
311      _mutex->lock_without_safepoint_check();
312    } else {
313      _mutex->lock();
314    }
315  }
316};
317
318#ifndef PRODUCT
319//
320// A special MutexLocker that allows:
321//   - reentrant locking
322//   - locking out of order
323//
324// Only too be used for verify code, where we can relaxe out dead-lock
325// dection code a bit (unsafe, but probably ok). This code is NEVER to
326// be included in a product version.
327//
328class VerifyMutexLocker: StackObj {
329 private:
330  Monitor * _mutex;
331  bool   _reentrant;
332 public:
333  VerifyMutexLocker(Monitor * mutex) {
334    _mutex     = mutex;
335    _reentrant = mutex->owned_by_self();
336    if (!_reentrant) {
337      // We temp. diable strict safepoint checking, while we require the lock
338      FlagSetting fs(StrictSafepointChecks, false);
339      _mutex->lock();
340    }
341  }
342
343  ~VerifyMutexLocker() {
344    if (!_reentrant) {
345      _mutex->unlock();
346    }
347  }
348};
349
350#endif
351