readwrit.h

来自「Windows多线程编码随书源码」· C头文件 代码 · 共 50 行

/*
 * ReadWrit.h
 *
 * Sample code for Multithreading Applications in Win32
 * This is from Chapter 7, Listing 7-1
 *
 * Demonstrates an implementation of the
 * Readers/Writers algorithm. This version
 * gives preference to readers.
 */

///////////////////////////////////////////////////////

//
// Structure definition
//

typedef struct _RWLock
{
    // Handle to a mutex that allows
    // a single reader at a time access
    // to the reader counter.
    HANDLE	hMutex;

    // Handle to a semaphore that keeps
    // the data locked for either the
    // readers or the writers.
    HANDLE	hDataLock;

    // The count of the number of readers.
    // Can legally be zero or one while
    // a writer has the data locked.
	int		nReaderCount;
} RWLock;

//
// Reader/Writer prototypes
//

BOOL InitRWLock(RWLock *pLock);
BOOL DestroyRWLock(RWLock *pLock);
BOOL AcquireReadLock(RWLock *pLock);
int ReleaseReadLock(RWLock *pLock);
BOOL AcquireWriteLock(RWLock *pLock);
int ReleaseWriteLock(RWLock *pLock);
BOOL ReadOK(RWLock *pLock);
BOOL WriteOK(RWLock *pLock);

BOOL FatalError(char *s);