34 lines
1000 B
C++
34 lines
1000 B
C++
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#ifndef _CRW_H
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#define _CRW_H
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#include <limits.h>
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//
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// This class contains the meat - does actual locking etc...
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//
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class CShareLock {
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private :
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long cReadLock ; // Number of Readers who have passed through the lock OR
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// the number of readers waiting for the lock (will be negative).
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// A value of 0 means nobody in the lock
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long cOutRdrs ; // The number of readers remainin in the lock if
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// there is a writer waiting. This can become temporarily negative
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CRITICAL_SECTION critWriters ; // Critical section to allow only one writer into the lock at a time
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HANDLE hWaitingWriters ; // Semaphore for waiting writers to block on (Only 1 ever, others will
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// be queued on critWriters)
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HANDLE hWaitingReaders ; // Semaphore for waiting readers to block on
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public :
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CShareLock( ) ;
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~CShareLock( ) ;
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void ShareLock( ) ;
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void ShareUnlock( ) ;
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void ExclusiveLock( ) ;
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void ExclusiveUnlock( ) ;
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} ;
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#endif
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