Win32 实现读写锁

Win32中没有为Xp提供读写锁机制（只为Vista提供了）， 由于工作需求，所以自己实现了一个简单的读写锁，具体实现如下：

头文件：rwlocker.h

#ifndef _RWLOCKER_H_#define _RWLOCKER_H_#include <windows.h>namespace Locker{class RWLocker{private:unsigned long rcount;//readersCRITICAL_SECTION cs;HANDLE mutex;public:RWLocker() ;~RWLocker();void rlock();void runlock();void wlock();void wunlock();};}#endif

cpp文件：rwlocker.cpp

#include "rwlocker.h"namespace Locker{RWLocker::RWLocker(){rcount = 0;InitializeCriticalSection(&cs);mutex = CreateMutex(NULL, FALSE, NULL);}RWLocker::~RWLocker(){rcount = 0;ReleaseMutex(mutex);DeleteCriticalSection(&cs);}void RWLocker::rlock(){DWORD dwWaitResult;dwWaitResult = WaitForSingleObject(mutex, INFINITE);switch (dwWaitResult) {// The thread got ownership of the mutexcase WAIT_OBJECT_0: __try { if (++rcount == 1)EnterCriticalSection(&cs);} __finally { // Release ownership of the mutex objectReleaseMutex(mutex);} break; // The thread got ownership of an abandoned mutexcase WAIT_ABANDONED: break ;}}void RWLocker::runlock(){DWORD dwWaitResult;dwWaitResult = WaitForSingleObject(mutex, INFINITE);switch (dwWaitResult) {// The thread got ownership of the mutexcase WAIT_OBJECT_0: __try { if (--rcount == 0)LeaveCriticalSection(&cs);} __finally { // Release ownership of the mutex objectReleaseMutex(mutex);} break; // The thread got ownership of an abandoned mutexcase WAIT_ABANDONED: break ;}}void RWLocker::wlock(){EnterCriticalSection(&cs);}void RWLocker::wunlock(){LeaveCriticalSection(&cs);}}