Linux-non-blocking socket programming to handle EAGAIN errors

Linux-non-blocking socket programming to handle EAGAIN errors-Linux general technology-Linux programming and kernel information, the following is a detailed description. Resource temporarily unavailable often occurs when a non-blocking socket in linux receives data. The errno code is 11 (EAGAIN). What does this mean?

This indicates that you have called the blocking operation in non-blocking mode. If the operation is not completed, this error is returned. This error will not damage the synchronization of the socket, the next cycle is followed by recv. For a non-blocking socket, EAGAIN is not an error. On VxWorks and Windows, EAGAIN is named EWOULDBLOCK.

In addition, if EINTR is returned, that is, errno is 4, and the error description is Interrupted system call, the Operation should continue.

Finally, if the returned value of recv is 0, it indicates that the connection has been disconnected and our receiving operation should also end.