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
#include
#include
#include
#include
// 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
#include
#include
#include
#include
// 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
#include
#include
#include
#include
// 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
#include
#include
#include
#include
// 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;
}