Function listen [src]

Prototype

pub fn listen(sock: socket_t, backlog: u31) ListenError!void

Parameters

sock: socket_tbacklog: u31

Possible Errors

AddressInUse

Another socket is already listening on the same port. For Internet domain sockets, the socket referred to by sockfd had not previously been bound to an address and, upon attempting to bind it to an ephemeral port, it was determined that all port numbers in the ephemeral port range are currently in use. See the discussion of /proc/sys/net/ipv4/ip_local_port_range in ip(7).

AlreadyConnected

Already connected

FileDescriptorNotASocket

The file descriptor sockfd does not refer to a socket.

NetworkSubsystemFailed

The network subsystem has failed.

OperationNotSupported

The socket is not of a type that supports the listen() operation.

SocketNotBound

Socket has not been bound yet

SystemResources

Ran out of system resources On Windows it can either run out of socket descriptors or buffer space

Unexpected UnexpectedError

The Operating System returned an undocumented error code.

This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.

When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.

Source

  pub fn listen(sock: socket_t, backlog: u31) ListenError!void {
    if (native_os == .windows) {
        const rc = windows.listen(sock, backlog);
        if (rc == windows.ws2_32.SOCKET_ERROR) {
            switch (windows.ws2_32.WSAGetLastError()) {
                .WSANOTINITIALISED => unreachable, // not initialized WSA
                .WSAENETDOWN => return error.NetworkSubsystemFailed,
                .WSAEADDRINUSE => return error.AddressInUse,
                .WSAEISCONN => return error.AlreadyConnected,
                .WSAEINVAL => return error.SocketNotBound,
                .WSAEMFILE, .WSAENOBUFS => return error.SystemResources,
                .WSAENOTSOCK => return error.FileDescriptorNotASocket,
                .WSAEOPNOTSUPP => return error.OperationNotSupported,
                .WSAEINPROGRESS => unreachable,
                else => |err| return windows.unexpectedWSAError(err),
            }
        }
        return;
    } else {
        const rc = system.listen(sock, backlog);
        switch (errno(rc)) {
            .SUCCESS => return,
            .ADDRINUSE => return error.AddressInUse,
            .BADF => unreachable,
            .NOTSOCK => return error.FileDescriptorNotASocket,
            .OPNOTSUPP => return error.OperationNotSupported,
            else => |err| return unexpectedErrno(err),
        }
    }
}  