Andrew Johnson
fbda9f3280
Replaced $Id$ and $Header$ keywords with $Revision-Id$ Deleted $Log$ keywords and any log messages
116 lines
3.1 KiB
C++
116 lines
3.1 KiB
C++
/*************************************************************************\
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* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
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* National Laboratory.
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* Copyright (c) 2002 The Regents of the University of California, as
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* Operator of Los Alamos National Laboratory.
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* EPICS BASE Versions 3.13.7
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* and higher are distributed subject to a Software License Agreement found
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* in file LICENSE that is included with this distribution.
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\*************************************************************************/
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#ifndef epicsGuardh
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#define epicsGuardh
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#ifndef assert // allow use of epicsAssert.h
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# include <cassert>
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#endif
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/*
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* $Revision-Id$
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*
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* Author: Jeffrey O. Hill
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*
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*/
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template < class T > class epicsGuardRelease;
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// Automatically applies and releases the mutex.
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// This class is also useful in situations where
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// C++ exceptions are possible.
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template < class T >
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class epicsGuard {
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public:
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epicsGuard ( T & );
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void assertIdenticalMutex ( const T & ) const;
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~epicsGuard ();
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private:
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T * _pTargetMutex;
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epicsGuard ( const epicsGuard & );
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epicsGuard & operator = ( const epicsGuard & );
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friend class epicsGuardRelease < T >;
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};
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// Automatically releases and reapplies the mutex.
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// This class is also useful in situations where
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// C++ exceptions are possible.
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template < class T >
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class epicsGuardRelease {
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public:
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epicsGuardRelease ( epicsGuard < T > & );
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~epicsGuardRelease ();
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private:
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epicsGuard < T > & _guard;
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T * _pTargetMutex;
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epicsGuardRelease ( const epicsGuardRelease & );
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epicsGuardRelease & operator = ( const epicsGuardRelease & );
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};
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// same interface as epicsMutex
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class epicsMutexNOOP {
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public:
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void lock ();
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bool tryLock ();
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void unlock ();
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void show ( unsigned level ) const;
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};
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template < class T >
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inline epicsGuard < T > :: epicsGuard ( T & mutexIn ) :
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_pTargetMutex ( & mutexIn )
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{
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_pTargetMutex->lock ();
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}
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template < class T >
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inline epicsGuard < T > :: ~epicsGuard ()
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{
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_pTargetMutex->unlock ();
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}
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template < class T >
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inline void epicsGuard < T > :: assertIdenticalMutex (
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const T & mutexToVerify ) const
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{
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assert ( _pTargetMutex == & mutexToVerify );
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}
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template < class T >
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inline epicsGuardRelease < T > ::
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epicsGuardRelease ( epicsGuard<T> & guardIn ) :
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_guard ( guardIn ),
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_pTargetMutex ( guardIn._pTargetMutex )
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{
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// Setting the guard's _pTargetMutex to nill will
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// allow assertIdenticalMutex to catch situations
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// where a guard is being used and it has been
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// released, and also situations where ~epicsGuard ()
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// runs and an epicsGuardRelease is still referencing
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// the guard will be detected.
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_guard._pTargetMutex = 0;
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_pTargetMutex->unlock ();
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}
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template < class T >
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inline epicsGuardRelease < T > :: ~epicsGuardRelease ()
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{
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_pTargetMutex->lock ();
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_guard._pTargetMutex = _pTargetMutex;
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}
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inline void epicsMutexNOOP::lock () {}
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inline bool epicsMutexNOOP::tryLock () { return true; }
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inline void epicsMutexNOOP::unlock () {}
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inline void epicsMutexNOOP::show ( unsigned ) const {}
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#endif // epicsGuardh
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