Time out TCP relay process if peers don't show up

This commit is contained in:
Tony Garnock-Jones 2014-06-21 11:55:05 -04:00
parent c4b14b3331
commit 7456e2efec
1 changed files with 27 additions and 19 deletions

46
tcp.rkt
View File

@ -109,28 +109,36 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Relay between kernel-level and user-level
(define relay-peer-wait-time-msec 5000)
(define ((spawn-relay local-user-addr) remote-addr local-tcp-addr)
(define timer-name (list 'spawn-relay local-tcp-addr remote-addr))
(define local-peer-traffic (pub (tcp-channel remote-addr local-user-addr ?) #:level 1))
(define remote-peer-traffic (sub (tcp-channel remote-addr local-tcp-addr ?) #:level 1))
(spawn (lambda (e state)
(match e
[(routing-update g)
(define local-peer-absent? (gestalt-empty? (gestalt-filter g local-peer-traffic)))
(define remote-peer-absent? (gestalt-empty? (gestalt-filter g remote-peer-traffic)))
(define new-state (+ (if local-peer-absent? 0 1) (if remote-peer-absent? 0 1)))
(transition new-state (when (< new-state state) (quit)))]
[(message (tcp-channel (== local-user-addr) (== remote-addr) bs) _ _)
(transition state (send (tcp-channel local-tcp-addr remote-addr bs)))]
[(message (tcp-channel (== remote-addr) (== local-tcp-addr) bs) _ _)
(transition state (send (tcp-channel remote-addr local-user-addr bs)))]
[_ #f]))
0
(gestalt-union local-peer-traffic
remote-peer-traffic
(sub (tcp-channel remote-addr local-tcp-addr ?))
(sub (tcp-channel local-user-addr remote-addr ?))
(pub (tcp-channel remote-addr local-user-addr ?))
(pub (tcp-channel local-tcp-addr remote-addr ?)))))
(list
(send (set-timer timer-name relay-peer-wait-time-msec 'relative))
(spawn (lambda (e state)
(match e
[(routing-update g)
(define local-peer-absent? (gestalt-empty? (gestalt-filter g local-peer-traffic)))
(define remote-peer-absent? (gestalt-empty? (gestalt-filter g remote-peer-traffic)))
(define new-state (+ (if local-peer-absent? 0 1) (if remote-peer-absent? 0 1)))
(transition new-state (when (< new-state state) (quit)))]
[(message (tcp-channel (== local-user-addr) (== remote-addr) bs) _ _)
(transition state (send (tcp-channel local-tcp-addr remote-addr bs)))]
[(message (tcp-channel (== remote-addr) (== local-tcp-addr) bs) _ _)
(transition state (send (tcp-channel remote-addr local-user-addr bs)))]
[(message (timer-expired _ _) _ _)
(error 'spawn-relay "TCP relay process timed out waiting for peer")]
[_ #f]))
0
(gestalt-union local-peer-traffic
remote-peer-traffic
(sub (tcp-channel remote-addr local-tcp-addr ?))
(sub (tcp-channel local-user-addr remote-addr ?))
(pub (tcp-channel remote-addr local-user-addr ?))
(pub (tcp-channel local-tcp-addr remote-addr ?))
(sub (timer-expired timer-name ?))))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Codec & kernel-level driver