Question

大侠请留步，急急急，socket 怎样非阻塞是读取数据

Answer 1

设置超时，recv的时候加上超时时间就可以了。
//利用了select函数监听读，写，异常
while (1) {
maxfd = listener;

FD_ZERO(&readset);
FD_ZERO(&writeset);
FD_ZERO(&exset);

FD_SET(listener, &readset);

for (i=0; i < FD_SETSIZE; ++i) {
if (state[i]) {
if (i > maxfd)
maxfd = i;
FD_SET(i, &readset);
if (state[i]->writing) {
FD_SET(i, &writeset);
}
}
}

if (select(maxfd+1, &readset, &writeset, &exset, NULL) < 0) {
perror("select");
return;
}

if (FD_ISSET(listener, &readset)) {
struct sockaddr_storage ss;
socklen_t slen = sizeof(ss);
int fd = accept(listener, (struct sockaddr*)&ss, &slen);
if (fd < 0) {
perror("accept");
} else if (fd > FD_SETSIZE) {
close(fd);
} else {
make_nonblocking(fd);
state[fd] = alloc_fd_state();
assert(state[fd]);/*XXX*/
}
}

for (i=0; i < maxfd+1; ++i) {
int r = 0;
if (i == listener)
continue;

if (FD_ISSET(i, &readset)) {
r = do_read(i, state[i]);
}
if (r == 0 && FD_ISSET(i, &writeset)) {
r = do_write(i, state[i]);
}
if (r) {
free_fd_state(state[i]);
state[i] = NULL;
close(i);
}
}
}