/*

 * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// Mutexes used in the VM.

extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code

extern Monitor* SystemDictionary_lock;           // a lock on the system dictonary

extern Mutex*   PackageTable_lock;               // a lock on the class loader package table

extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access

extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer

extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment

extern Mutex*   JNIGlobalHandle_lock;            // a lock on creating JNI global handles

extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list

extern Mutex*   JNICachedItableIndex_lock;       // a lock on caching an itable index during JNI invoke

extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers

extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers

extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in

extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data

extern Monitor* JvmtiPendingEvent_lock;          // a lock on the JVMTI pending events list

extern Monitor* Heap_lock;                       // a lock on the heap

extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap

extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary

extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary

extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs

extern Mutex*   SymbolTable_lock;                // a lock on the symbol table

extern Mutex*   StringTable_lock;                // a lock on the interned string table

extern Mutex*   CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx

extern Mutex*   MethodData_lock;                 // a lock on installation of method data

extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data

extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table

extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute

extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate

extern Monitor* Safepoint_lock;                  // a lock used by the safepoint abstraction

extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads

                                                 // (also used by Safepoints too to block threads creation/destruction)

extern Monitor* CGC_lock;                        // used for coordination between

                                                 // fore- & background GC threads.

extern Mutex*   STS_init_lock;                   // coordinate initialization of SuspendibleThreadSets.

extern Monitor* SLT_lock;                        // used in CMS GC for acquiring PLL

extern Monitor* iCMS_lock;                       // CMS incremental mode start/stop notification

extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc

extern Monitor* CMark_lock;                      // used for concurrent mark thread coordination

extern Monitor* ZF_mon;                          // used for G1 conc zero-fill.

extern Monitor* Cleanup_mon;                     // used for G1 conc cleanup.

extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q

                                                 // buffer free list.

extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q

                                                 // completed buffer queue.

extern Mutex*   Shared_SATB_Q_lock;              // Lock protecting SATB

                                                 // queue shared by

                                                 // non-Java threads.

extern Mutex*   DirtyCardQ_FL_lock;              // Protects dirty card Q

                                                 // buffer free list.

extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q

                                                 // completed buffer queue.

extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card

                                                 // queue shared by

                                                 // non-Java threads.

                                                 // (see option ExplicitGCInvokesConcurrent)

extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.

extern Mutex*   EvacFailureStack_lock;           // guards the evac failure scan stack

extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)

extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued

#ifdef TIERED

extern Monitor* C1_lock;                         // a lock to ensure on single c1 compile is ever active

#endif // TIERED

extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization

extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated

extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics

extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays

extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm

extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks

extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm

extern Monitor* Interrupt_lock;                  // a lock used for condition variable mediated interrupt processing

extern Monitor* ProfileVM_lock;                  // a lock used for profiling the VMThread

extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles

extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates

extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues

#ifndef PRODUCT

extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe

#endif

extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing

extern Mutex*   Debug2_lock;                     // down synchronization related bugs!

extern Mutex*   Debug3_lock;

extern Mutex*   RawMonitor_lock;

extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data

extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources

extern Mutex*   ParkerFreeList_lock;

extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches

extern Mutex*   MMUTracker_lock;                 // protects the MMU

                                                 // tracker data structures

extern Mutex*   HotCardCache_lock;               // protects the hot card cache

extern Mutex*   Management_lock;                 // a lock used to serialize JVM management

extern Monitor* LowMemory_lock;                  // a lock used for low memory detection

// A MutexLocker provides mutual exclusion with respect to a given mutex

// for the scope which contains the locker.  The lock is an OS lock, not

// an object lock, and the two do not interoperate.  Do not use Mutex-based

// locks to lock on Java objects, because they will not be respected if a

// that object is locked using the Java locking mechanism.

//

//                NOTE WELL!!

//

// See orderAccess.hpp.  We assume throughout the VM that MutexLocker's

// and friends constructors do a fence, a lock and an acquire *in that

// order*.  And that their destructors do a release and unlock, in *that*

// order.  If their implementations change such that these assumptions

// are violated, a whole lot of code will break.

// Print all mutexes/monitors that are currently owned by a thread; called

// by fatal error handler.

void print_owned_locks_on_error(outputStream* st);

char *lock_name(Mutex *mutex);

class MutexLocker: StackObj {

 private:

  Monitor * _mutex;

 public:

  MutexLocker(Monitor * mutex) {

    assert(mutex->rank() != Mutex::special,

      "Special ranked mutex should only use MutexLockerEx");

    _mutex = mutex;

    _mutex->lock();

  }

  // Overloaded constructor passing current thread

  MutexLocker(Monitor * mutex, Thread *thread) {

    assert(mutex->rank() != Mutex::special,

      "Special ranked mutex should only use MutexLockerEx");

    _mutex = mutex;

    _mutex->lock(thread);

  }

  ~MutexLocker() {

    _mutex->unlock();

  }

};

// for debugging: check that we're already owning this lock (or are at a safepoint)

#ifdef ASSERT

void assert_locked_or_safepoint(const Monitor * lock);

void assert_lock_strong(const Monitor * lock);

#else

#define assert_locked_or_safepoint(lock)

#define assert_lock_strong(lock)

#endif

// A MutexLockerEx behaves like a MutexLocker when its constructor is

// called with a Mutex.  Unlike a MutexLocker, its constructor can also be

// called with NULL, in which case the MutexLockerEx is a no-op.  There

// is also a corresponding MutexUnlockerEx.  We want to keep the

// basic MutexLocker as fast as possible.  MutexLockerEx can also lock

// without safepoint check.

class MutexLockerEx: public StackObj {

 private:

  Monitor * _mutex;

 public:

  MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {

    _mutex = mutex;

    if (_mutex != NULL) {

      assert(mutex->rank() > Mutex::special || no_safepoint_check,

        "Mutexes with rank special or lower should not do safepoint checks");

      if (no_safepoint_check)

        _mutex->lock_without_safepoint_check();

      else

        _mutex->lock();

    }

  }

  ~MutexLockerEx() {

    if (_mutex != NULL) {

      _mutex->unlock();

    }

  }

};

// A MonitorLockerEx is like a MutexLockerEx above, except it takes

// a possibly null Monitor, and allows wait/notify as well which are

// delegated to the underlying Monitor.

class MonitorLockerEx: public MutexLockerEx {

 private:

  Monitor * _monitor;

 public:

  MonitorLockerEx(Monitor* monitor,

                  bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):

    MutexLockerEx(monitor, no_safepoint_check),

    _monitor(monitor) {

    // Superclass constructor did locking

  }

  ~MonitorLockerEx() {

    #ifdef ASSERT

      if (_monitor != NULL) {

        assert_lock_strong(_monitor);

      }

    #endif  // ASSERT

    // Superclass destructor will do unlocking

  }

  bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,

            long timeout = 0,

            bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {

    if (_monitor != NULL) {

      return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);

    }

    return false;

  }

  bool notify_all() {

    if (_monitor != NULL) {

      return _monitor->notify_all();

    }

    return true;

  }

  bool notify() {

    if (_monitor != NULL) {

      return _monitor->notify();

    }

    return true;

  }

};

// A GCMutexLocker is usually initialized with a mutex that is

// automatically acquired in order to do GC.  The function that

// synchronizes using a GCMutexLocker may be called both during and between

// GC's.  Thus, it must acquire the mutex if GC is not in progress, but not

// if GC is in progress (since the mutex is already held on its behalf.)

class GCMutexLocker: public StackObj {

private:

  Monitor * _mutex;

  bool _locked;

public:

  GCMutexLocker(Monitor * mutex);

  ~GCMutexLocker() { if (_locked) _mutex->unlock(); }

};

// A MutexUnlocker temporarily exits a previously

// entered mutex for the scope which contains the unlocker.

class MutexUnlocker: StackObj {

 private:

  Monitor * _mutex;

 public:

  MutexUnlocker(Monitor * mutex) {

    _mutex = mutex;

    _mutex->unlock();

  }

  ~MutexUnlocker() {

    _mutex->lock();

  }

};

// A MutexUnlockerEx temporarily exits a previously

// entered mutex for the scope which contains the unlocker.

class MutexUnlockerEx: StackObj {

 private:

  Monitor * _mutex;

  bool _no_safepoint_check;

 public:

  MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {

    _mutex = mutex;

    _no_safepoint_check = no_safepoint_check;

    _mutex->unlock();

  }

  ~MutexUnlockerEx() {

    if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {

      _mutex->lock_without_safepoint_check();

    } else {

      _mutex->lock();

    }

  }

};

#ifndef PRODUCT

//

// A special MutexLocker that allows:

//   - reentrant locking

//   - locking out of order

//

// Only too be used for verify code, where we can relaxe out dead-lock

// dection code a bit (unsafe, but probably ok). This code is NEVER to

// be included in a product version.

//

class VerifyMutexLocker: StackObj {

 private:

  Monitor * _mutex;

  bool   _reentrant;

 public:

  VerifyMutexLocker(Monitor * mutex) {

    _mutex     = mutex;

    _reentrant = mutex->owned_by_self();

    if (!_reentrant) {

      // We temp. diable strict safepoint checking, while we require the lock

      FlagSetting fs(StrictSafepointChecks, false);

      _mutex->lock();

    }

  }

  ~VerifyMutexLocker() {

    if (!_reentrant) {

      _mutex->unlock();

    }

  }

};

#endif