Windows核心编程之 用户模式下的线程同步 读写锁和条件变量

 读写锁

#include <Windows.h>
#include <tchar.h>
#include <stdio.h>
#include <process.h>
#include <winbase.h>

// 读写锁
SRWLOCK srwLock;

unsigned WINAPI ReadThread1(LPVOID)
{
	while(1)
	{
		AcquireSRWLockShared(&srwLock);
		printf("read 1111\n");
		ReleaseSRWLockShared(&srwLock);
		Sleep(500);
	}


	return 0;
}

unsigned WINAPI ReadThread2(LPVOID)
{

	while(1)
	{
		AcquireSRWLockShared(&srwLock);
		printf("read 2222222222\n");
		ReleaseSRWLockShared(&srwLock);
		Sleep(500);
	}

	return 0;
}

unsigned WINAPI WriteThread(LPVOID)
{
	while(1)
	{
		AcquireSRWLockExclusive(&srwLock);
		printf("write\n");
		ReleaseSRWLockExclusive(&srwLock);

		Sleep(1000);

	}

	return 0;
}
int main()
{
	InitializeSRWLock(&srwLock);

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, ReadThread1, NULL, 0, NULL) );

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, ReadThread2, NULL, 0, NULL) );
	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, WriteThread, NULL, 0, NULL) );

	system("pause");

	return 0;
}

条件变量

SleepConditionVariableSRW 可以递归调用，但是最后需要释放一次

#include <Windows.h>
#include <tchar.h>
#include <stdio.h>
#include <process.h>
#include <winbase.h>

// 读写锁和条件变量
// 关键段和条件变量

CRITICAL_SECTION g_cs;
CONDITION_VARIABLE g_conditionVariable;
unsigned WINAPI TestCS(LPVOID)
{
	EnterCriticalSection(&g_cs);
	printf("11\n");
	SleepConditionVariableCS(&g_conditionVariable,&g_cs,INFINITE);

	printf("aaaa\n");

	LeaveCriticalSection(&g_cs);

	return 0;
}

unsigned WINAPI ttttttt(LPVOID)
{
	EnterCriticalSection(&g_cs);
	printf("2222\n");
	
	printf("333\n");
	LeaveCriticalSection(&g_cs);
	WakeConditionVariable(&g_conditionVariable);

	return 0;
}
int main()
{
	InitializeCriticalSection(&g_cs);
	InitializeConditionVariable(&g_conditionVariable);
	
	HANDLE hThread = (HANDLE)_beginthreadex(NULL, 0, TestCS, NULL, 0, NULL);
	HANDLE hThread1 = (HANDLE)_beginthreadex(NULL, 0, ttttttt, NULL, 0, NULL);

	system("pause");

	return 0;
}

#include <Windows.h>
#include <tchar.h>
#include <stdio.h>
#include <process.h>
#include <winbase.h>

// 读写锁 与条件变量 共享模式

SRWLOCK srwLock;

//条件变量
CONDITION_VARIABLE condition_Var;

unsigned WINAPI ReadThread1(LPVOID)
{
	while(1)
	{
		AcquireSRWLockShared(&srwLock);

		printf("线程1 准备等待条件变量\n");

		SleepConditionVariableSRW(&condition_Var, &srwLock, INFINITE, CONDITION_VARIABLE_LOCKMODE_SHARED);

		printf("线程1 等到了\n");

		ReleaseSRWLockShared(&srwLock);
		Sleep(500);
	}


	return 0;
}

unsigned WINAPI ReadThread2(LPVOID)
{

	while(1)
	{
		AcquireSRWLockShared(&srwLock);

		printf("线程2 准备等待条件变量\n");

		SleepConditionVariableSRW(&condition_Var, &srwLock, INFINITE, CONDITION_VARIABLE_LOCKMODE_SHARED);

		printf("线程2 等到了\n");

		ReleaseSRWLockShared(&srwLock);

		Sleep(500);
	}

	return 0;
}

unsigned WINAPI WriteThread(LPVOID)
{
	while(1)
	{
		AcquireSRWLockExclusive(&srwLock);
		printf("write\n");
		ReleaseSRWLockExclusive(&srwLock);

		Sleep(1000);

	}

	return 0;
}
int main()
{
	InitializeSRWLock(&srwLock);
	InitializeConditionVariable(&condition_Var);

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, ReadThread1, NULL, 0, NULL) );

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, ReadThread2, NULL, 0, NULL) );
// 	CloseHandle(
// 		(HANDLE)_beginthreadex(NULL, 0, WriteThread, NULL, 0, NULL) );

//	Sleep(2000);

	printf("准备激活条件变量\n");

	//如果激活时，没有条件变量在等待，那么激活状态会丢失，就是说只有等待的时候，激活才有用

	WakeAllConditionVariable(&condition_Var);

	Sleep(100);

	printf("main over\n");


	system("pause");

	return 0;
}

下面的代码，介绍了这么使用读写锁和条件变量

#include <Windows.h>
#include <tchar.h>
#include <stdio.h>
#include <process.h>
#include <winbase.h>

// 读写锁 与条件变量 共享模式

//苹果数
LONG volatile gl_apple = 0;

SRWLOCK srwLock;

//条件变量
CONDITION_VARIABLE CV_Eat;
CONDITION_VARIABLE CV_Make;

#define EATTIME 100
#define MAKETIME 200


void PrintApple()
{
	printf("目前还剩 %d apple\n", gl_apple);
}
//吃苹果
unsigned WINAPI AllenEatApple(LPVOID)
{
	while(1)
	{
		AcquireSRWLockShared(&srwLock);

		printf("Allen 准备吃苹果\n");

		while (InterlockedCompareExchange(&gl_apple, 0, 0) <= 0)
		{
			printf("allen 还没有苹果，等等吧\n");

			SleepConditionVariableSRW(&CV_Eat, &srwLock, INFINITE, CONDITION_VARIABLE_LOCKMODE_SHARED);

		}

		InterlockedDecrement(&gl_apple);

		printf("allen 吃完了\n");

		PrintApple();

		ReleaseSRWLockShared(&srwLock);

		WakeConditionVariable(&CV_Make);

		printf("allen say: make apple\n");


		Sleep(EATTIME);
	}


	return 0;
}

unsigned WINAPI LiMeiEatApple(LPVOID)
{

	while(1)
	{
		AcquireSRWLockShared(&srwLock);

		printf("LiMei 准备吃苹果\n");

		while (InterlockedCompareExchange(&gl_apple, 0, 0) <= 0)
		{
			printf("LiMei 还没有苹果，等等吧\n");

			SleepConditionVariableSRW(&CV_Eat, &srwLock, INFINITE, CONDITION_VARIABLE_LOCKMODE_SHARED);

		}

		InterlockedDecrement(&gl_apple);

		printf("LiMei 吃完了\n");

		PrintApple();

		ReleaseSRWLockShared(&srwLock);

		WakeConditionVariable(&CV_Make);

		printf("LiMei say: make apple\n");


		Sleep(EATTIME);
	}

	return 0;
}

unsigned WINAPI MakeApple(LPVOID)
{
	while(1)
	{
		AcquireSRWLockExclusive(&srwLock);

		//只能生产10个
		if(InterlockedCompareExchange(&gl_apple,10,10) >= 10)
		{
			//独占锁 等待消费
			printf("够数了，不生产了\n");

			SleepConditionVariableSRW(&CV_Make, &srwLock, INFINITE, 0);
		}

		InterlockedIncrement(&gl_apple);

		printf("生产了一个，目前共有: %d \n",gl_apple);

		ReleaseSRWLockExclusive(&srwLock);

		WakeAllConditionVariable(&CV_Eat);//告诉他们，可以吃了

		Sleep(MAKETIME);

	}

	return 0;
}
int main()
{
	InitializeSRWLock(&srwLock);

	InitializeConditionVariable(&CV_Eat);

	InitializeConditionVariable(&CV_Make);

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, AllenEatApple, NULL, 0, NULL) );

	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, LiMeiEatApple, NULL, 0, NULL) );
	CloseHandle(
		(HANDLE)_beginthreadex(NULL, 0, MakeApple, NULL, 0, NULL) );

	system("pause");

	return 0;
}