28.semaphore跨进程通信

• 根据id创建Semaphore,并初始化有一个信号量可用 name类型是char *...;

   HANDLE hsem = CreateSemaphoreA(NULL, 1, , name);

• 关闭句柄

   CloseHandle(hsem);

• 根据id打开semaphore

   HANDLE hsem = OpenSemaphoreA(SEMAPHORE_ALL_ACCESS, TRUE, name);

• 接受Semaphore句柄

   DWORD res = WaitForSingleObject(hsem, );

• 检测是否收到

   switch (res)
       {
       case WAIT_OBJECT_0:
           printf("收到信号-------");
           break;
       case WAIT_TIMEOUT:
           printf("超时没有收到-------");
           break;
       case WAIT_ABANDONED:
           printf("另外一个进程意外终止-------");
           break;
       default:
           break;
  
       }

完整代码:

主信号.c

 #include <stdio.h>
 #include <stdlib.h>
 #include <Windows.h>

 char name[] = "haihualovefang";

 void main()
 {
     HANDLE hsem = CreateSemaphoreA(NULL, , , name);
     printf("创建成功");
     char ch = getch();

     ReleaseSemaphore(hsem, , NULL);
     printf("触发信号量");
     CloseHandle(hsem);

 }

wait.c

 #include <stdio.h>
 #include <stdlib.h>
 #include <Windows.h>

 char name[] = "haihualovefang";

 void main()
 {

     HANDLE hsem = OpenSemaphoreA(SEMAPHORE_ALL_ACCESS, TRUE, name);;
     if (hsem == NULL)
     {
         printf("打开失败");
         system("pause");
         return;
     }
     printf("等待-------");
     DWORD res = WaitForSingleObject(hsem, );
     switch (res)
     {
     case WAIT_OBJECT_0:
         printf("收到信号-------");
         break;
     case WAIT_TIMEOUT:
         printf("超时没有收到-------");
         break;
     case WAIT_ABANDONED:
         printf("另外一个进程意外终止-------");
         break;
     default:
         break;

     }
     CloseHandle(hsem);

     system("pause");
 }