libev sets sockets to blocking with no timeout - c++

Question

Rant: I really dislike boost::asio, So I've been looking at alternatives and came across libev. Which seems simple enough for me, but is doing a few things I cannot understand. If those are too many questions in one thread, please let me know.
1) I set the listening socket to NON_BLOCK, I also set each accepted incoming connection as NON_BLOCK, yet somewhere in the code the socket(s) turns into BLOCK.
Ex:
bool Server::Start()
{
// Setup event loop
loop = ev_default_loop(EVBACKEND_SELECT); //EVFLAG_AUTO ?
// Create Socket
sockfd = socket(PF_INET, SOCK_STREAM, 0);
addr_len = sizeof(addr)
// Set Socket to non blocking
fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFL) | O_NONBLOCK);
if (fcntl(sockfd, F_GETFL) & O_NONBLOCK) std::cout << "Socket is NONBLOCK" << std::endl;
else std::cout << "Socket is BLOCK" << std::endl;
if (sockfd < 0) {
std::cout << "ERROR opening socket" << std::endl;
return false;
}
bzero((char *)&addr, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = INADDR_ANY;
// Bind port to socket
if (bind(sockfd,(struct sockaddr*)&addr, sizeof(addr))!=0) {
std::cout << "bind error" << std::endl;
return false;
}
// Listen
if (listen(sockfd, 2) < 0) {
std::cout << "listen error" << std::endl;
return false;
}
// Initialize and start a watcher to accepts client requests
ev_io_init(&w_accept, accept_cb, sockfd, EV_READ);
ev_io_start(loop, &w_accept);
return true;
}
I have tried to make the main loop also not to block:
void Server::MainLoop()
{
// Start infinite loop
while (1) {
ev_loop(loop, EVLOOP_NONBLOCK);
}
}
But it doesnt seem to have made a different. PLEASE DO NOT redirect me to the documentation (the only available source of documentation on the internet) I have read it.
I do this for the client socket that has been accepted:
void accept_cb(struct ev_loop *loop, struct ev_io *watcher, int revents)
....
c->client_sd = accept(watcher->fd, (struct sockaddr *)&c->client_addr, &c->client_len);
....
ev_io *w_client = (struct ev_io*) malloc (sizeof(struct ev_io));
ev_io_init(w_client, read_cb, c->client_sd, EV_READ);
ev_io_start(loop, w_client);
fcntl(watcher->fd, F_SETFL, fcntl(watcher->fd, F_GETFL) | O_NONBLOCK);
Yet every time my read callback is executed, the socket is magically set to BLOCK
2) I have tried setting a timeout for the socket:
struct timeval timeout;
timeout.tv_sec = 10;
timeout.tv_usec = 0;
if (setsockopt (sockfd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout,
sizeof(timeout)) < 0)
error("setsockopt failed\n");
if (setsockopt (sockfd, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout,
sizeof(timeout)) < 0)
error("setsockopt failed\n");
(Taken from here: this question)
It simply doesn't work. Is this because the sockets are reset to BLOCKing mode ?
3) I have seen a C++ wrapper for libev. I absolutely hate the fact I have to make the callbacks static functions, it ruins everything for me. Yet all the examples I have seen use:
signal.loop.break_loop();
and
loop.run(0);
which, funnily enough produces:
error: ‘struct ev::loop_ref’ has no member named ‘break_loop’ error:
‘struct ev::default_loop’ has no member named ‘run’
on Debian Squeeze.
So, what I am asking is:
What, who, where is the socket changed from NON_BLOCK to BLOCK ?
How (if) can I set a timeout for the socket (blocking or non-blocking)
What is wrong with ev++.h and why are those nice people using the wrappers I can't use?
Please, bear in mind that I can use the sockets to read and send data, but in a blocking manner, without timeouts. Furthermore, as this is a server, I NEED to keep the code in classes, as I have to save messages per connected clients. Making this static or non-class methods simply ruins it, or forces me to take a very different approach.
PS: Any alternatives to libev ?

Answer 1

You aren't setting the client FD to non-blocking mode. You are setting the listening socket FD.