Linux之多路I/O复用

 

一、select

• int select(int maxfdp1, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *tvptr); //成功则返回已准备好的文件描述符个数，超时则返回0，出错则返回-1
• int FD_ZERO(fd_set *fdset);
• int FD_SET(int fd, fd_set *fdset);
• int FD_CLR(int fd, fd_set *fdset);
• int FD_ISSET(int fd, fd_set *fdset);

 

 1 #include <sys/select.h>
 2 #include <unistd.h>
 3 
 4 int main(int argc, char *argv[])
 5 {
 6     fd_set readset, writeset;
 7     int ret = 0;
 8     FD_ZERO(&readset);
 9     FD_ZERO(&writeset);
10     FD_SET(3, &readset);
11     FD_SET(5, &writeset);
12 
13     ret = select(6, &readset, &writeset, NULL, NULL);
14     switch (ret)
15     {
16     case -1: //error
17         break;
18     case 0: //timeout
19         break;
20     default: //success
21         if(FD_ISSET(3, &readset))
22         {
23             ;//read fd(3)
24         }
25         if(FD_ISSET(5, &writeset))
26         {
27             ;//write fd(5)
28         }
29         break;
30     }
31     return 0;
32 }

二、poll

• int poll(struct pollfd fdarray[], nfds_t nfds, int timeout);

三、epoll

 

来源：https://www.cnblogs.com/bo1990/p/11385977.html