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