中断被阻止的读取

我的程序经历了这样一个循环:

... while(1){ read(sockfd,buf,sizeof(buf)); ... } 

读取function在等待input时阻塞,恰好来自套接字。 我想处理SIGINT,基本上告诉它如果正在读取,然后调用任意函数,则停止读取函数。 做这个的最好方式是什么?

Solutions Collecting From Web of "中断被阻止的读取"

read(2)

  EINTR The call was interrupted by a signal before any data was read; see signal(7). 

如果你修改你的代码看起来更像是:

 cont = 1; while (1 && cont) { ret = read(sockfd, buf, sizeof(buf)); if (ret < 0 && errno == EINTR) cont = arbitrary_function(); } 

这使得arbitrary_function()决定read(2)是否应该重试。

更新

您需要处理信号以便从read(2)获得EINTR行为:

 #include<unistd.h> #include<stdio.h> #include<stdlib.h> #include<signal.h> #include<errno.h> int interrupted; void handle_int(num) { interrupted = 1; } int main(void){ char buf[9001]; struct sigaction int_handler = {.sa_handler=handle_int}; sigaction(SIGINT,&int_handler,0); while(!interrupted){ printf("interrupted: %d\n", interrupted); if(read(0,buf,sizeof(buf))<0){ if(errno==EINTR){ puts("eintr"); }else{ printf("%d\n",errno); } puts("."); } } puts("end"); return 0; } 

给出输出:

 $ ./foo interrupted: 0 hello interrupted: 0 ^Ceintr . end 

当你的进程收到一个信号时, read()将返回, errno的值将被设置为EINTR