GetExitCodeThread()

 

BOOL   GetExitCodeThread (

       HANDLE         hThread,                  // in,线程handle,也就是CreateThread()的返回值

       LPDWORD      lpExitCode               //out,存储线程结束代码,也就是线程的返回值

);

说明: 此函数调用成功返回TRUE,失败返回FALSE,只表示这个函数是否调用成功而己.

        不能根据返回值来判断一个线程是否结束,而要根据 lpExitCode的值来确定,

        lpExitCode  值STILL_ACTIVE 表示线程正在运行.

            若线程己经结束,则lpExitCode中存储指定线程的返回值.

例:

/* * ExitCode.c * * Sample code for "Multithreading Applications in Win32" * This is from Chapter 2, Listing 2-2 * * Start two threads and try to exit * when the user presses a key. */ #define WIN32_LEAN_AND_MEAN #include <stdio.h> #include <stdlib.h> #include <windows.h> #include <conio.h> DWORD WINAPI ThreadFunc(LPVOID); int main() { HANDLE hThrd1; HANDLE hThrd2; DWORD exitCode1 = 0; DWORD exitCode2 = 0; DWORD threadId; //创建成功,返回一个HANDLE,对于此线程的操作函数,几乎都使用此HANDLE hThrd1 = CreateThread(NULL, 0, //堆栈大小,0取默认值1MB ThreadFunc, //线程函数地址 (LPVOID)1, //线程的传入参数 0, //0 表示线程一旦创建 立即执行 &threadId ); //线程ID,一般为 向线程发送消息时用, if (hThrd1) printf("Thread 1 launched/n"); // hThrd2 = CreateThread(NULL, 0, ThreadFunc, (LPVOID)2, 0, &threadId ); if (hThrd2) printf("Thread 2 launched/n"); // Keep waiting until both calls to // GetExitCodeThread succeed AND // neither of them returns STILL_ACTIVE. // This method is not optimal - we'll // see the correct way in Chapter 3. for (;;) { printf("Press any key to exit../n"); getch(); // 按任意键继续 // 刺探 指定线程(通过线程的HANDLE) 是否己经结束, //exitCode1中存储线程状态,若正在运行,值为STILL_ACTIVE //若己经结束,值为 线程的返回值(即 return 后的值) GetExitCodeThread(hThrd1, &exitCode1); GetExitCodeThread(hThrd2, &exitCode2); if ( exitCode1 == STILL_ACTIVE ) puts("Thread 1 is still running!"); if ( exitCode2 == STILL_ACTIVE ) puts("Thread 2 is still running!"); if ( exitCode1 != STILL_ACTIVE && exitCode2 != STILL_ACTIVE ) break; } CloseHandle(hThrd1); //线程核心对象的引用计数 减1 CloseHandle(hThrd2); printf("Thread 1 returned %d/n", exitCode1); printf("Thread 2 returned %d/n", exitCode2); return EXIT_SUCCESS; } /* * Take the startup value, do some simple math on it, * and return the calculated value. */ DWORD WINAPI ThreadFunc(LPVOID n) { Sleep((DWORD)n*1000*2); return (DWORD)n * 10; }