我实现了套接字超时和重试,但为了做到这一点,我不得不将套接字设置为非阻塞套接字。但是,我需要套接字来阻止。这是我对解决这两个问题的尝试。这不起作用。后续发送呼叫阻止但从不发送任何数据。当我没有选择和超时连接时,后续发送呼叫正常工作。套接字超时并删除O_NONBLOCK选项
参考文献:
- C: socket connection timeout
- How to reset a socket back to blocking mode (after I set it to nonblocking mode)?
代码:
fd_set fdset;
struct timeval tv;
fcntl(dsock, F_SETFL, O_NONBLOCK);
tv.tv_sec = theDeviceTimeout;
tv.tv_usec = 0;
int retries=0;
logi(theLogOutput, LOG_INFO, "connecting to device socket num retrys: %i", theDeviceRetry);
for(retries=0;retries<theDeviceRetry;retries++) {
connect(dsock, (struct sockaddr *)&daddr, sizeof daddr);
FD_ZERO(&fdset);
FD_SET(dsock, &fdset);
if (select(dsock + 1, NULL, &fdset, NULL, &tv) == 1) {
int so_error;
socklen_t slen = sizeof so_error;
getsockopt(dsock, SOL_SOCKET, SO_ERROR, &so_error, &slen);
if (so_error == 0) {
logi(theLogOutput, LOG_INFO, "connected to socket on port %i on %s", theDevicePort, theDeviceIP);
break;
} else {
logi(theLogOutput, LOG_WARN, "connect to %i failed on ip %s because %s retries %i", theDevicePort, theDeviceIP, strerror(errno), retries);
logi(theLogOutput, LOG_WARN, "failed to connect to device %s", strerror(errno));
logi(theLogOutput, LOG_WARN, "error: %i %s", so_error, strerror(so_error));
continue;
}
}
}
int opts;
opts = fcntl(dsock,F_GETFL);
logi(theLogOutput, LOG_DEBUG, "clearing nonblock option %i retries %i", opts, retries);
opts ^= O_NONBLOCK;
fcntl(dsock, F_SETFL, opts);
我们需要你发布一个可以编译和运行的完整测试用例。 – zwol 2011-02-22 22:41:05
是否最后一次调用'fcntl'成功(返回值为0)?如果不是,那么将errno设置为? – 2011-02-22 22:45:15
请注意,您应该使用'opts | = O_NONBLOCK',因为XOR不会告诉您它是ON还是OFF。另外......一旦'retries == theDeviceRetry'真的发生了什么? – 2015-12-06 02:27:46