mutexLocker.hpp revision 6014:8a9bb7821e28 
1/*
2 * Copyright (c) 1997, 2013, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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#ifdef TARGET_OS_FAMILY_aix
40# include "os_aix.inline.hpp"
41#endif
42#ifdef TARGET_OS_FAMILY_bsd
43# include "os_bsd.inline.hpp"
44#endif
45
46// Mutexes used in the VM.
47
48extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
49extern Monitor* SystemDictionary_lock;           // a lock on the system dictionary
50extern Mutex*   PackageTable_lock;               // a lock on the class loader package table
51extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
52extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
53extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
54extern Mutex*   JNIGlobalHandle_lock;            // a lock on creating JNI global handles
55extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
56extern Mutex*   MemberNameTable_lock;            // a lock on the MemberNameTable updates
57extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
58extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
59extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
60extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
61extern Monitor* JvmtiPendingEvent_lock;          // a lock on the JVMTI pending events list
62extern Monitor* Heap_lock;                       // a lock on the heap
63extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
64extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
65extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
66extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
67extern Mutex*   SymbolTable_lock;                // a lock on the symbol table
68extern Mutex*   StringTable_lock;                // a lock on the interned string table
69extern Mutex*   CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
70extern Mutex*   MethodData_lock;                 // a lock on installation of method data
71extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
72extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table
73extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
74extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
75extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction
76extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
77                                                 // (also used by Safepoints too to block threads creation/destruction)
78extern Monitor* CGC_lock;                        // used for coordination between
79                                                 // fore- & background GC threads.
80extern Mutex*   STS_init_lock;                   // coordinate initialization of SuspendibleThreadSets.
81extern Monitor* SLT_lock;                        // used in CMS GC for acquiring PLL
82extern Monitor* iCMS_lock;                       // CMS incremental mode start/stop notification
83extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
84extern Monitor* CMark_lock;                      // used for concurrent mark thread coordination
85extern Mutex*   CMRegionStack_lock;              // used for protecting accesses to the CM region stack
86extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
87                                                 // buffer free list.
88extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
89                                                 // completed buffer queue.
90extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB
91                                                 // queue shared by
92                                                 // non-Java threads.
93
94extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q
95                                                 // buffer free list.
96extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
97                                                 // completed buffer queue.
98extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
99                                                 // queue shared by
100                                                 // non-Java threads.
101                                                 // (see option ExplicitGCInvokesConcurrent)
102extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
103extern Mutex*   EvacFailureStack_lock;           // guards the evac failure scan stack
104extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
105extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
106extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
107extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
108extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
109extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
110extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
111extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
112extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
113extern Monitor* Interrupt_lock;                  // a lock used for condition variable mediated interrupt processing
114extern Monitor* ProfileVM_lock;                  // a lock used for profiling the VMThread
115extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
116extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
117extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
118
119#ifndef PRODUCT
120extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
121#endif // PRODUCT
122extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
123extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
124extern Mutex*   Debug3_lock;
125
126extern Mutex*   RawMonitor_lock;
127extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
128extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
129extern Mutex*   ParkerFreeList_lock;
130extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
131
132extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
133extern Monitor* SecondaryFreeList_lock;          // protects the secondary free region list
134extern Mutex*   OldSets_lock;                    // protects the old region sets
135extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
136extern Mutex*   MMUTracker_lock;                 // protects the MMU
137                                                 // tracker data structures
138extern Mutex*   HotCardCache_lock;               // protects the hot card cache
139
140extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
141extern Monitor* Service_lock;                    // a lock used for service thread operation
142extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
143
144#ifdef INCLUDE_TRACE
145extern Mutex*   JfrStacktrace_lock;              // used to guard access to the JFR stacktrace table
146extern Monitor* JfrMsg_lock;                     // protects JFR messaging
147extern Mutex*   JfrBuffer_lock;                  // protects JFR buffer operations
148extern Mutex*   JfrStream_lock;                  // protects JFR stream access
149extern Mutex*   JfrThreadGroups_lock;            // protects JFR access to Thread Groups
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.
168void print_owned_locks_on_error(outputStream* st);
169
170char *lock_name(Mutex *mutex);
171
172class MutexLocker: StackObj {
173 private:
174  Monitor * _mutex;
175 public:
176  MutexLocker(Monitor * mutex) {
177    assert(mutex->rank() != Mutex::special,
178      "Special ranked mutex should only use MutexLockerEx");
179    _mutex = mutex;
180    _mutex->lock();
181  }
182
183  // Overloaded constructor passing current thread
184  MutexLocker(Monitor * mutex, Thread *thread) {
185    assert(mutex->rank() != Mutex::special,
186      "Special ranked mutex should only use MutexLockerEx");
187    _mutex = mutex;
188    _mutex->lock(thread);
189  }
190
191  ~MutexLocker() {
192    _mutex->unlock();
193  }
194
195};
196
197// for debugging: check that we're already owning this lock (or are at a safepoint)
198#ifdef ASSERT
199void assert_locked_or_safepoint(const Monitor * lock);
200void assert_lock_strong(const Monitor * lock);
201#else
202#define assert_locked_or_safepoint(lock)
203#define assert_lock_strong(lock)
204#endif
205
206// A MutexLockerEx behaves like a MutexLocker when its constructor is
207// called with a Mutex.  Unlike a MutexLocker, its constructor can also be
208// called with NULL, in which case the MutexLockerEx is a no-op.  There
209// is also a corresponding MutexUnlockerEx.  We want to keep the
210// basic MutexLocker as fast as possible.  MutexLockerEx can also lock
211// without safepoint check.
212
213class MutexLockerEx: public StackObj {
214 private:
215  Monitor * _mutex;
216 public:
217  MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
218    _mutex = mutex;
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();
224      else
225        _mutex->lock();
226    }
227  }
228
229  ~MutexLockerEx() {
230    if (_mutex != NULL) {
231      _mutex->unlock();
232    }
233  }
234};
235
236// A MonitorLockerEx is like a MutexLockerEx above, except it takes
237// a possibly null Monitor, and allows wait/notify as well which are
238// delegated to the underlying Monitor.
239
240class MonitorLockerEx: public MutexLockerEx {
241 private:
242  Monitor * _monitor;
243 public:
244  MonitorLockerEx(Monitor* monitor,
245                  bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
246    MutexLockerEx(monitor, no_safepoint_check),
247    _monitor(monitor) {
248    // Superclass constructor did locking
249  }
250
251  ~MonitorLockerEx() {
252    #ifdef ASSERT
253      if (_monitor != NULL) {
254        assert_lock_strong(_monitor);
255      }
256    #endif  // ASSERT
257    // Superclass destructor will do unlocking
258  }
259
260  bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
261            long timeout = 0,
262            bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
263    if (_monitor != NULL) {
264      return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
265    }
266    return false;
267  }
268
269  bool notify_all() {
270    if (_monitor != NULL) {
271      return _monitor->notify_all();
272    }
273    return true;
274  }
275
276  bool notify() {
277    if (_monitor != NULL) {
278      return _monitor->notify();
279    }
280    return true;
281  }
282};
283
284
285
286// A GCMutexLocker is usually initialized with a mutex that is
287// automatically acquired in order to do GC.  The function that
288// synchronizes using a GCMutexLocker may be called both during and between
289// GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
290// if GC is in progress (since the mutex is already held on its behalf.)
291
292class GCMutexLocker: public StackObj {
293private:
294  Monitor * _mutex;
295  bool _locked;
296public:
297  GCMutexLocker(Monitor * mutex);
298  ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
299};
300
301
302
303// A MutexUnlocker temporarily exits a previously
304// entered mutex for the scope which contains the unlocker.
305
306class MutexUnlocker: StackObj {
307 private:
308  Monitor * _mutex;
309
310 public:
311  MutexUnlocker(Monitor * mutex) {
312    _mutex = mutex;
313    _mutex->unlock();
314  }
315
316  ~MutexUnlocker() {
317    _mutex->lock();
318  }
319};
320
321// A MutexUnlockerEx temporarily exits a previously
322// entered mutex for the scope which contains the unlocker.
323
324class MutexUnlockerEx: StackObj {
325 private:
326  Monitor * _mutex;
327  bool _no_safepoint_check;
328
329 public:
330  MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
331    _mutex = mutex;
332    _no_safepoint_check = no_safepoint_check;
333    _mutex->unlock();
334  }
335
336  ~MutexUnlockerEx() {
337    if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
338      _mutex->lock_without_safepoint_check();
339    } else {
340      _mutex->lock();
341    }
342  }
343};
344
345#ifndef PRODUCT
346//
347// A special MutexLocker that allows:
348//   - reentrant locking
349//   - locking out of order
350//
351// Only to be used for verify code, where we can relax out dead-lock
352// detection code a bit (unsafe, but probably ok). This code is NEVER to
353// be included in a product version.
354//
355class VerifyMutexLocker: StackObj {
356 private:
357  Monitor * _mutex;
358  bool   _reentrant;
359 public:
360  VerifyMutexLocker(Monitor * mutex) {
361    _mutex     = mutex;
362    _reentrant = mutex->owned_by_self();
363    if (!_reentrant) {
364      // We temp. disable strict safepoint checking, while we require the lock
365      FlagSetting fs(StrictSafepointChecks, false);
366      _mutex->lock();
367    }
368  }
369
370  ~VerifyMutexLocker() {
371    if (!_reentrant) {
372      _mutex->unlock();
373    }
374  }
375};
376
377#endif
378
379#endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP
380