546 lines
14 KiB
C++
546 lines
14 KiB
C++
//+---------------------------------------------------------------------------
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//
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// Microsoft Windows
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// Copyright (C) Microsoft Corporation, 1991 - 2000.
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//
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// File: CiSem.Hxx
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//
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// Contents: Semaphore classes
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//
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// Classes: CMutexSem - Mutex semaphore class
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// CStaticMutexSem - statically allocated Mutex semaphore class
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// CEventSem - Event semaphore
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//
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// History: 21-Jun-91 AlexT Created.
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//
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//----------------------------------------------------------------------------
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#pragma once
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//+---------------------------------------------------------------------------
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//
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// Class: CMutexSem (mxs)
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//
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// Purpose: Mutex Semaphore services
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//
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// Interface: Request - acquire semaphore
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// Release - release semaphore
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//
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// History: 14-Jun-91 AlexT Created.
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// 30-oct-91 SethuR 32 bit implementation
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//
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// Notes: This class wraps a mutex semaphore. Mutex semaphores protect
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// access to resources by only allowing one client through at a
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// time. The client Requests the semaphore before accessing the
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// resource and Releases the semaphore when it is done. The
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// same client can Request the semaphore multiple times (a nest
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// count is maintained).
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//
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//----------------------------------------------------------------------------
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class CMutexSem
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{
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public:
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CMutexSem()
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{
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InitializeCriticalSection( &_cs );
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_fInitedCS = TRUE;
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}
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CMutexSem(BOOL fInit)
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{
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if (fInit)
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{
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InitializeCriticalSection( &_cs );
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_fInitedCS = TRUE;
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}
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else
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{
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memset( &_cs, 0, sizeof _cs );
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_fInitedCS = FALSE;
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}
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}
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~CMutexSem()
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{
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if (_fInitedCS)
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{
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DeleteCriticalSection( &_cs );
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_fInitedCS = FALSE;
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}
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}
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void Init()
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{
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InitializeCriticalSection(&_cs);
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_fInitedCS = TRUE;
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}
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void Request()
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{
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#if DBG == 1
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if (!_fInitedCS)
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DbgPrint( "CMutexSem not initialized!\n" );
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#endif
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EnterCriticalSection( &_cs );
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}
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void Release()
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{
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LeaveCriticalSection( &_cs );
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}
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BOOL Try()
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{
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return TryEnterCriticalSection( &_cs );
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}
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BOOL IsHeld()
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{
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return ( LongToHandle( GetCurrentThreadId() ) == _cs.OwningThread );
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}
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protected:
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BOOL _fInitedCS;
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CRITICAL_SECTION _cs;
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};
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//+---------------------------------------------------------------------------
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//
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// Class: CStaticMutexSem
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//
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// Purpose: Mutex Semaphore services
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//
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// Interface: Init - initializer (two-step)
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// Request - acquire semaphore
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// Release - release semaphore
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//
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// History: 20 May 99 AlawW Created.
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//
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// Notes: Like a CMutexSem, but initialization is deferred. Useful
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// for statically allocated critical sections where there is
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// the (unlikely) potential to get a STATUS_NO_MEMORY exception
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// thrown from the InitializeCriticalSection call.
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//
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//----------------------------------------------------------------------------
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class CStaticMutexSem : public CMutexSem
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{
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public:
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CStaticMutexSem( ) : CMutexSem( FALSE ) {}
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};
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//+---------------------------------------------------------------------------
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//
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// Class: CLock (lck)
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//
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// Purpose: Lock using a Mutex Semaphore
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//
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// History: 02-Oct-91 BartoszM Created.
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//
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// Notes: Simple lock object to be created on the stack.
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// The constructor acquires the semaphor, the destructor
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// (called when lock is going out of scope) releases it.
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//
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//----------------------------------------------------------------------------
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class CLock
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{
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public:
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CLock( CMutexSem& mxs ) : _mxs ( mxs )
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{
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_mxs.Request();
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}
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~CLock()
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{
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_mxs.Release();
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}
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private:
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CMutexSem & _mxs;
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};
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#define CPriLock CLock
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//+---------------------------------------------------------------------------
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//
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// Class: CReleasableLock
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//
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// Purpose: Lock using a Mutex Semaphore that can be released/requested
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//
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// History: 16-Sep-96 dlee Created.
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//
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//----------------------------------------------------------------------------
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class CReleasableLock
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{
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public:
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CReleasableLock( CMutexSem& mxs, BOOL fHeld = TRUE ) :
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_fHeld( fHeld ), _mxs(mxs)
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{
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if ( fHeld )
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_mxs.Request();
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}
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~CReleasableLock()
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{
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if ( _fHeld )
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_mxs.Release();
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}
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void Release()
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{
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Win4Assert( _fHeld );
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_mxs.Release();
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_fHeld = FALSE;
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}
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void Request()
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{
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Win4Assert( !_fHeld );
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_mxs.Request();
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_fHeld = TRUE;
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}
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BOOL Try()
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{
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Win4Assert( !_fHeld );
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return ( _fHeld = _mxs.Try() );
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}
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BOOL IsHeld() const { return _fHeld; }
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private:
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CMutexSem & _mxs;
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BOOL _fHeld;
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};
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//+---------------------------------------------------------------------------
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//
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// Class: CEventSem (evs)
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//
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// Purpose: Event Semaphore services
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//
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// Interface: Wait - wait for semaphore to be signalled
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// Set - set signalled state
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// Reset - clear signalled state
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// Pulse - set and clear semaphore
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//
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// History: 21-Jun-91 AlexT Created.
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// 27-Feb-92 BartoszM Use exceptions for errors
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//
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// Notes: Used for communication between consumers and producers.
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// Consumer threads block by calling Wait. A producer
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// calls Set waking up all the consumers who go ahead
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// and consume until there's nothing left. They call
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// Reset, release whatever lock protected the resources,
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// and call Wait. There has to be a separate lock
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// to protect the shared resources.
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// Remember: call Reset under lock.
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// don't call Wait under lock.
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//
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//----------------------------------------------------------------------------
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class CEventSem
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{
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public:
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inline CEventSem( BOOL fInitState=FALSE, const LPSECURITY_ATTRIBUTES lpsa=NULL );
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inline CEventSem( HANDLE hEvent );
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inline CEventSem( DWORD dwMustBeZero, WCHAR const * pwszName,
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DWORD dwAccess = EVENT_ALL_ACCESS | EVENT_MODIFY_STATE | SYNCHRONIZE );
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inline CEventSem( WCHAR const * pwszName,
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BOOL fInitState = FALSE,
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const LPSECURITY_ATTRIBUTES lpsa = NULL );
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HANDLE AcquireHandle()
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{
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HANDLE hVal = _hEvent;
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_hEvent = 0;
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return hVal;
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}
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void Create()
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{
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Win4Assert( 0 == _hEvent );
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_hEvent = CreateEventW( 0, TRUE, FALSE, 0 );
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if ( 0 == _hEvent )
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THROW( CException() );
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}
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inline ~CEventSem();
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inline ULONG Wait(DWORD dwMilliseconds = INFINITE,
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BOOL fAlertable = FALSE );
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inline void Set();
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inline void Reset();
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inline void Pulse();
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inline const HANDLE GetHandle() const { return _hEvent; }
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private:
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HANDLE _hEvent;
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};
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//+---------------------------------------------------------------------------
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//
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// Class: CAutoEventSem
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//
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// Purpose: Auto-reset version of CEventSem
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//
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// History: 16-Sep-96 dlee Created.
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//
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//----------------------------------------------------------------------------
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class CAutoEventSem
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{
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public:
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CAutoEventSem()
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{
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_hEvent = CreateEventW( 0, FALSE, FALSE, 0 );
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if ( 0 == _hEvent )
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THROW( CException() );
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}
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~CAutoEventSem()
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{
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if ( 0 != _hEvent )
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{
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BOOL f = CloseHandle ( _hEvent );
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Win4Assert( f && "can't close event handle" );
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}
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}
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void Set()
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{
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if ( !SetEvent ( _hEvent ) )
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THROW( CException() );
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}
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void Wait()
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{
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WaitForSingleObject( _hEvent, INFINITE );
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}
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const HANDLE GetHandle() const { return _hEvent; }
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private:
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HANDLE _hEvent;
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};
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//+---------------------------------------------------------------------------
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//
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// Class: CEventSetter
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//
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// Purpose: Sets an event when exiting scope
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//
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// History: 16-Sep-96 dlee Created.
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//
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//----------------------------------------------------------------------------
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class CEventSetter
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{
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public:
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CEventSetter( CAutoEventSem &event ) : _event( event )
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{ }
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~CEventSetter() { _event.Set(); }
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private:
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CAutoEventSem & _event;
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};
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::CEventSem
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//
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// Synopsis: Creates an event
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//
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// Arguments: [bInitState] -- TRUE: signaled state, FALSE non-signaled
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// [lpsa] -- security attributes
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline CEventSem::CEventSem ( BOOL bInitState, const LPSECURITY_ATTRIBUTES lpsa )
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{
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_hEvent = CreateEventW( lpsa, TRUE, bInitState, 0 );
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if ( _hEvent == 0 )
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{
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THROW( CException() );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::CEventSem
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//
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// Synopsis: Opens an event
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//
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// Arguments: [hEvent] -- handle of event to open
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// [bInitState] -- TRUE: signaled state, FALSE non-signaled
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//
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// History: 02-Jul-94 DwightKr Created
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//
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//----------------------------------------------------------------------------
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inline CEventSem::CEventSem ( HANDLE hEvent ) : _hEvent( hEvent )
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{
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::CEventSem
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//
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// Synopsis: Constructor to "open" an already existing event sem.
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//
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// Arguments: [dwMustBeZero] - Just to distinguish from the constructor
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// used to "create" named event semaphores.
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// [pwszName] - Name of the semaphore
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// [dwAccess] - Access.
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//
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// History: 2-15-96 srikants Created
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//
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// Notes:
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//
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//----------------------------------------------------------------------------
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inline CEventSem::CEventSem( DWORD dwMustBeZero, WCHAR const * pwszName, DWORD dwAccess )
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{
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Win4Assert( 0 == dwMustBeZero && 0 != pwszName );
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_hEvent = OpenEventW( dwAccess, TRUE, pwszName );
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if ( 0 == _hEvent )
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{
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THROW( CException() );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::CEventSem
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//
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// Synopsis: Constructor to "create" a named event semaphore.
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//
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// Arguments: [pwszName] - Name of the event semaphore.
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// [fInitState] -
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// [lpsa] -
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//
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// History: 2-15-96 srikants Created
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//
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// Notes:
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//
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//----------------------------------------------------------------------------
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inline CEventSem::CEventSem( WCHAR const * pwszName, BOOL fInitState,
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const LPSECURITY_ATTRIBUTES lpsa )
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{
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_hEvent = CreateEventW( lpsa, TRUE, fInitState, pwszName );
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if ( _hEvent == 0 )
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{
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THROW( CException() );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::~CEventSem
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//
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// Synopsis: Releases event
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline CEventSem::~CEventSem ()
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{
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if ( 0 != _hEvent )
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{
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BOOL f = CloseHandle( _hEvent );
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Win4Assert( f && "can't close event handle" );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::Set
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//
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// Synopsis: Set the state to signaled. Wake up waiting threads.
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// For manual events the state remains set
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// until Reset is called
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline void CEventSem::Set()
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{
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if ( !SetEvent ( _hEvent ) )
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{
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THROW( CException() );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::Reset
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//
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// Synopsis: Reset the state to non-signaled. Threads will block.
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline void CEventSem::Reset()
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{
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if ( !ResetEvent ( _hEvent ) )
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{
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THROW( CException() );
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}
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::Wait
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//
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// Synopsis: Block until event set
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline ULONG CEventSem::Wait( DWORD msec, BOOL fAlertable )
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{
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DWORD res = WaitForSingleObjectEx ( _hEvent, msec, fAlertable );
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if ( 0xffffffff == res )
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{
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THROW( CException() );
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}
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return res;
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}
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//+---------------------------------------------------------------------------
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//
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// Member: CEventSem::Pulse
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//
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// Synopsis: Set the state to signaled. Wake up waiting threads.
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//
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// History: 27-Feb-92 BartoszM Created
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//
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//----------------------------------------------------------------------------
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inline void CEventSem::Pulse()
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{
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if ( !PulseEvent ( _hEvent ) )
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{
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THROW( CException() );
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}
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}
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