关键段：
关键段类型CRITICAL_SECTION
1.初始化关键段： void InitializeCriticalSection(LPCRITICAL_SECTION lpCriticalSection); 2.销毁关键段： void DeleleCriticalSection(LPCRITICAL_SECTION lpCriticalSection); 3.进入关键段： void EnterCriticalSection(LPCRITICAL_SECTION lpCriticalSection); 4.离开关键段： void LeaveCriticalSection(LPCRITICAL_SECTION lpCriticalSection);关键段解决线程互斥问题测试代码如下：
#include <stdio.h> #include <process.h> #include <Windows.h> #define THREAD_NUM 10 CRITICAL_SECTION g_csThreadParameter; CRITICAL_SECTION g_csThreadCode; unsigned long g_nNum; unsigned int __stdcall ThreadFun(void *pM) { int nThreadNum = *(int *)pM; //离开子线程的关键区域 LeaveCriticalSection(&g_csThreadParameter); Sleep(50); //进入子线程互斥区域 EnterCriticalSection(&g_csThreadCode); g_nNum++; Sleep(0); printf("线程编号为%d, 全局资源值为%d\n", nThreadNum, g_nNum); //离开各自线程互斥区域 LeaveCriticalSection(&g_csThreadCode); return 0; } int main(int argc, char *argv[]) { HANDLE handle[THREAD_NUM]; int i = 0; printf("--------------------经典线程同步：关键段--------------------\n"); //初始化关键段 InitializeCriticalSection(&g_csThreadParameter); InitializeCriticalSection(&g_csThreadCode); g_nNum = 0; while(i < THREAD_NUM) { //进入子线程关键段区域 EnterCriticalSection(&g_csThreadParameter); handle[i] = (HANDLE)_beginthreadex(NULL, 0, ThreadFun, &i, 0, NULL); ++i; } WaitForMultipleObjects(THREAD_NUM, handle, 1, INFINITE); //删除关键段 DeleteCriticalSection(&g_csThreadCode); DeleteCriticalSection(&g_csThreadParameter); system("pause"); return 0; }以上代码在Visual Studio 2010中的5次运行结果如下：
如上图所示，该段使用关键段的测试代码的确解决了线程互斥的问题，但是并没有解决线程同步的问题，因此我们需要其他方法，解决线程同步问题。
