module net import time // no_deadline should be given to functions when no deadline is wanted (i.e. all functions // return instantly) const no_deadline = time.Time{ unix: 0 } // no_timeout should be given to functions when no timeout is wanted (i.e. all functions // return instantly) pub const no_timeout = time.Duration(0) // infinite_timeout should be given to functions when an infinite_timeout is wanted (i.e. functions // only ever return with data) pub const infinite_timeout = time.infinite // Shutdown shutsdown a socket and closes it fn shutdown(handle int) ? { $if windows { C.shutdown(handle, C.SD_BOTH) socket_error(C.closesocket(handle))? } $else { C.shutdown(handle, C.SHUT_RDWR) socket_error(C.close(handle))? } } // Select waits for an io operation (specified by parameter `test`) to be available fn @select(handle int, test Select, timeout time.Duration) ?bool { set := C.fd_set{} C.FD_ZERO(&set) C.FD_SET(handle, &set) seconds := timeout / time.second microseconds := time.Duration(timeout - (seconds * time.second)).microseconds() mut tt := C.timeval{ tv_sec: u64(seconds) tv_usec: u64(microseconds) } mut timeval_timeout := &tt // infinite timeout is signaled by passing null as the timeout to // select if timeout == net.infinite_timeout { timeval_timeout = &C.timeval(0) } match test { .read { socket_error(C.@select(handle + 1, &set, C.NULL, C.NULL, timeval_timeout))? } .write { socket_error(C.@select(handle + 1, C.NULL, &set, C.NULL, timeval_timeout))? } .except { socket_error(C.@select(handle + 1, C.NULL, C.NULL, &set, timeval_timeout))? } } return C.FD_ISSET(handle, &set) } [inline] fn select_deadline(handle int, test Select, deadline time.Time) ?bool { // if we have a 0 deadline here then the timeout that was passed was infinite... infinite := deadline.unix_time() == 0 for infinite || time.now() <= deadline { timeout := if infinite { net.infinite_timeout } else { deadline - time.now() } ready := @select(handle, test, timeout) or { if err.code() == 4 { // Spurious wakeup from signal, keep waiting continue } // NOT a spurious wakeup return err } return ready } // Deadline elapsed return false } // wait_for_common wraps the common wait code fn wait_for_common(handle int, deadline time.Time, timeout time.Duration, test Select) ? { // Convert timeouts to deadlines real_deadline := if timeout == net.infinite_timeout { time.unix(0) } else if timeout == 0 { // No timeout set, so assume deadline deadline } else if timeout < 0 { // TODO(emily): Do something nicer here :) panic('invalid negative timeout') } else { // timeout time.now().add(timeout) } ready := select_deadline(handle, test, real_deadline)? if ready { return } return err_timed_out } // wait_for_write waits for a write io operation to be available fn wait_for_write(handle int, deadline time.Time, timeout time.Duration) ? { return wait_for_common(handle, deadline, timeout, .write) } // wait_for_read waits for a read io operation to be available fn wait_for_read(handle int, deadline time.Time, timeout time.Duration) ? { return wait_for_common(handle, deadline, timeout, .read) }