scsh-0.6/scheme/big/socket.scm

118 lines
3.8 KiB
Scheme

; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
; Server interface
; (open-socket [socket-number]) -> socket
; (close-socket socket)
; (socket-accept socket) -> [input-port output-port]
; (get-host-name) -> string
; (socket-port-number socket) -> integer
; Client interface
; (socket-client host-name socket-number) -> [input-port output-port]
; Old calls I would like to get rid off.
; (socket-listen socket) -> [input-port output-port]
; (socket-listen-channels socket) -> [input-channel output-channel]
; (socket-client-channels host-name socket-number) -> [input-channels output-channels]
;--------------------
; Socket type
;
; A socket has a channel (for accepting connections) and a port number.
; These are only used for servers; clients don't need them.
(define-record-type socket :socket
(make-socket channel port-number)
socket?
(channel socket-channel)
(port-number socket-port-number))
(define-record-discloser :socket
(lambda (s) `(socket ,(socket-port-number s))))
(define (close-socket socket)
(close-channel (socket-channel socket)))
; Makes a server socket.
(define (open-socket . maybe-number)
(let ((channel (new-socket #t)))
(bind-socket channel (if (or (null? maybe-number)
(= (car maybe-number) 0)) ; old, crappy spec
#f
(car maybe-number)))
(real-socket-listen channel)
(make-socket channel (socket-number channel))))
(define (socket-accept socket)
(call-with-values
(lambda ()
(socket-listen-channels socket))
(lambda (in out)
(values (input-channel+closer->port in close-socket-input-channel)
(output-channel+closer->port out close-socket-output-channel)))))
(define socket-listen socket-accept)
(define (socket-listen-channels socket)
(let ((channel (socket-channel socket)))
(let loop ()
(disable-interrupts!)
(let ((channels (real-socket-accept channel)))
(cond (channels
(enable-interrupts!)
(values (car channels)
(cdr channels)))
(else
(wait-for-channel channel) ; enables interrupts
(loop)))))))
; Connect to the socket and return input and output ports.
(define (socket-client host-name port-number)
(call-with-values
(lambda ()
(socket-client-channels host-name port-number))
(lambda (in out)
(values (input-channel+closer->port in close-socket-input-channel)
(output-channel+closer->port out close-socket-output-channel)))))
(define (socket-client-channels host-name port-number)
(let ((channel (new-socket #f)))
(let loop ()
(disable-interrupts!)
(let ((output-channel (real-socket-connect channel host-name port-number)))
(cond ((channel? output-channel)
(enable-interrupts!)
(values channel output-channel))
; This should never happen.
((eq? output-channel #t)
(error "client socket already connected" host-name port-number))
(else
(wait-for-channel channel) ; enables interrupts
(loop)))))))
; We need to explicitly close the channel.
(define (close-socket-input-channel channel)
(close-socket-half channel #t)
(close-channel channel))
(define (close-socket-output-channel channel)
(close-socket-half channel #f)
(close-channel channel))
; The C calls we use. These are in c/unix/socket.c.
(import-lambda-definition new-socket (server?) "s48_socket")
(import-lambda-definition bind-socket (socket number) "s48_bind")
(import-lambda-definition socket-number (socket) "s48_socket_number")
(import-lambda-definition real-socket-listen (socket) "s48_listen")
(import-lambda-definition real-socket-accept (socket) "s48_accept")
(import-lambda-definition real-socket-connect (socket machine port-number)
"s48_connect")
(import-lambda-definition close-socket-half (socket input?)
"s48_close_socket_half")
(import-lambda-definition get-host-name () "s48_get_host_name")