* code reformatting

* use kw.ss instead of opt-lambda
* moved a debugging comment into an `if'

svn: r4273
This commit is contained in:
Eli Barzilay 2006-09-07 19:55:41 +00:00
parent a0ccd557f5
commit a0c4d3b454

View File

@ -1,9 +1,9 @@
(module thread mzscheme
(require "etc.ss" "contract.ss")
(require "kw.ss" "contract.ss")
(provide run-server
consumer-thread)
consumer-thread)
#|
t accepts a function, f, and creates a thread. It returns the thread and a
@ -12,194 +12,188 @@
block.
|#
(define consumer-thread
(case-lambda
[(f) (consumer-thread f void)]
[(f init)
(unless (procedure? f) (raise-type-error 'consumer-thread "procedure" f))
(let ([sema (make-semaphore 0)]
[protect (make-semaphore 1)]
[front-state null]
[back-state null])
(values
(thread
(letrec ([loop
(lambda ()
(semaphore-wait sema)
(let ([local-state
(begin
(semaphore-wait protect)
(if (null? back-state)
(let ([new-front (reverse front-state)])
(set! back-state (cdr new-front))
(set! front-state null)
(semaphore-post protect)
(car new-front))
(begin0
(car back-state)
(set! back-state (cdr back-state))
(semaphore-post protect))))])
(apply f local-state))
(loop))])
(lambda ()
(init)
(loop))))
(lambda new-state
(let ([num (length new-state)])
(unless (procedure-arity-includes? f num)
(raise
(make-exn:fail:contract:arity
(string->immutable-string
(format "<procedure-from-consumer-thread>: consumer procedure arity is ~e; provided ~s argument~a"
(procedure-arity f) num (if (= 1 num) "" "s")))
(current-continuation-marks)))))
(semaphore-wait protect)
(set! front-state (cons new-state front-state))
(semaphore-post protect)
(semaphore-post sema))))]))
(define/kw (consumer-thread f #:optional [init void])
(unless (procedure? f) (raise-type-error 'consumer-thread "procedure" f))
(let ([sema (make-semaphore 0)]
[protect (make-semaphore 1)]
[front-state null]
[back-state null])
(values
(thread
(letrec ([loop
(lambda ()
(semaphore-wait sema)
(let ([local-state
(begin
(semaphore-wait protect)
(if (null? back-state)
(let ([new-front (reverse front-state)])
(set! back-state (cdr new-front))
(set! front-state null)
(semaphore-post protect)
(car new-front))
(begin0
(car back-state)
(set! back-state (cdr back-state))
(semaphore-post protect))))])
(apply f local-state))
(loop))])
(lambda ()
(init)
(loop))))
(lambda new-state
(let ([num (length new-state)])
(unless (procedure-arity-includes? f num)
(raise
(make-exn:fail:contract:arity
(string->immutable-string
(format "<procedure-from-consumer-thread>: consumer procedure arity is ~e; provided ~s argument~a"
(procedure-arity f) num (if (= 1 num) "" "s")))
(current-continuation-marks)))))
(semaphore-wait protect)
(set! front-state (cons new-state front-state))
(semaphore-post protect)
(semaphore-post sema)))))
(define run-server
(opt-lambda (port-number
handler
connection-timeout
[handle-exn void]
[tcp-listen tcp-listen]
[tcp-close tcp-close]
[tcp-accept tcp-accept]
[tcp-accept/enable-break tcp-accept/enable-break])
(let ([l (tcp-listen port-number 5 #t)]
[can-break? (break-enabled)])
(dynamic-wind
void
(lambda ()
;; All connections should use the same parameterization,
;; to facilitate transferring continuations from one
;; connection to another:
(let ([paramz (current-parameterization)])
;; Loop to handle connections:
(let loop ()
(with-handlers ([exn:fail:network? handle-exn])
;; Make a custodian for the next session:
(let ([c (make-custodian)])
(parameterize ([current-custodian c])
;; disable breaks during session set-up...
(parameterize-break #f
;; ... but enable breaks while blocked on an accept:
(let-values ([(r w) ((if can-break?
tcp-accept/enable-break
tcp-accept)
l)])
;; Handler thread:
(let ([t (thread (lambda ()
;; First, install the parameterization
;; used for all connections:
(call-with-parameterization
paramz
(lambda ()
;; Install this connection's custodian
;; for this thread in the shared
;; parameterization:
(current-custodian c)
;; Enable breaking:
(when can-break?
(break-enabled #t))
;; Call the handler
(handler r w)))))])
;; Clean-up and timeout thread:
(thread (lambda ()
(sync/timeout connection-timeout t)
(when (thread-running? t)
;; Only happens if connection-timeout is not #f
(break-thread t))
(sync/timeout connection-timeout t)
(custodian-shutdown-all c)))))))))
(loop))))
(lambda () (tcp-close l))))))
(define/kw (run-server port-number handler connection-timeout
#:optional
[handle-exn void]
[tcp-listen tcp-listen]
[tcp-close tcp-close]
[tcp-accept tcp-accept]
[tcp-accept/enable-break tcp-accept/enable-break])
(let ([l (tcp-listen port-number 5 #t)]
[can-break? (break-enabled)])
(dynamic-wind
void
(lambda ()
;; All connections should use the same parameterization,
;; to facilitate transferring continuations from one
;; connection to another:
(let ([paramz (current-parameterization)])
;; Loop to handle connections:
(let loop ()
(with-handlers ([exn:fail:network? handle-exn])
;; Make a custodian for the next session:
(let ([c (make-custodian)])
(parameterize ([current-custodian c])
;; disable breaks during session set-up...
(parameterize-break #f
;; ... but enable breaks while blocked on an accept:
(let-values ([(r w) ((if can-break?
tcp-accept/enable-break
tcp-accept)
l)])
;; Handler thread:
(let ([t (thread (lambda ()
;; First, install the parameterization
;; used for all connections:
(call-with-parameterization
paramz
(lambda ()
;; Install this connection's custodian
;; for this thread in the shared
;; parameterization:
(current-custodian c)
;; Enable breaking:
(when can-break?
(break-enabled #t))
;; Call the handler
(handler r w)))))])
;; Clean-up and timeout thread:
(thread (lambda ()
(sync/timeout connection-timeout t)
(when (thread-running? t)
;; Only happens if connection-timeout is not #f
(break-thread t))
(sync/timeout connection-timeout t)
(custodian-shutdown-all c)))))))))
(loop))))
(lambda () (tcp-close l)))))
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Couroutine
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; An X-coroutine-object is
;; An X-coroutine-object is
;; (make-coroutine-object thread semaphore channel channel X)
(define-struct coroutine-object (worker can-stop-lock done-ch ex-ch result))
;; coroutine : ((bool ->) -> X) -> X-coroutine-object
(define (coroutine f)
;;(printf "2. new coroutine~n")
(let* ((can-stop-lock (make-semaphore 1))
(done-ch (make-channel))
(ex-ch (make-channel))
(proceed-sema (make-semaphore))
(stop-enabled? #t)
(enable-stop
(let* ([can-stop-lock (make-semaphore 1)]
[done-ch (make-channel)]
[ex-ch (make-channel)]
[proceed-sema (make-semaphore)]
[stop-enabled? #t]
[enable-stop
(lambda (enable?)
;;(printf "3. enabling ~a~n" enable?)
(cond
((and enable? (not stop-enabled?))
(semaphore-post can-stop-lock)
(set! stop-enabled? #t))
((and (not enable?) stop-enabled?)
(semaphore-wait can-stop-lock)
(set! stop-enabled? #f)))
[(and enable? (not stop-enabled?))
(semaphore-post can-stop-lock)
(set! stop-enabled? #t)]
[(and (not enable?) stop-enabled?)
(semaphore-wait can-stop-lock)
(set! stop-enabled? #f)])
;;(printf "3. finished enabling~n")
))
(tid (thread (lambda ()
(semaphore-wait proceed-sema)
;;(printf "3. creating coroutine thread~n")
(with-handlers (((lambda (exn) #t)
(lambda (exn)
(enable-stop #t)
(channel-put ex-ch exn))))
(let ([v (f enable-stop)])
(enable-stop #t)
(channel-put done-ch v)))))))
(begin0
(make-coroutine-object tid can-stop-lock done-ch ex-ch #f)
(thread-suspend tid)
(semaphore-post proceed-sema))))
)]
[tid (thread (lambda ()
(semaphore-wait proceed-sema)
;;(printf "3. creating coroutine thread~n")
(with-handlers ([(lambda (exn) #t)
(lambda (exn)
(enable-stop #t)
(channel-put ex-ch exn))])
(let ([v (f enable-stop)])
(enable-stop #t)
(channel-put done-ch v)))))])
(begin0 (make-coroutine-object tid can-stop-lock done-ch ex-ch #f)
(thread-suspend tid)
(semaphore-post proceed-sema))))
;; coroutine : real-number X-coroutine-object -> bool
(define (coroutine-run timeout w)
(if (coroutine-object-worker w)
#;(printf "2. starting coroutine~n")
(let ((can-stop-lock (coroutine-object-can-stop-lock w))
(worker (coroutine-object-worker w)))
(thread-resume worker)
(dynamic-wind
void
;; Let the co-routine run...
(lambda ()
(sync (choice-evt (wrap-evt (alarm-evt (+ timeout (current-inexact-milliseconds)))
(lambda (x)
#;(printf "2. alarm-evt~n")
(semaphore-wait can-stop-lock)
(thread-suspend worker)
(semaphore-post can-stop-lock)
#f))
(wrap-evt (coroutine-object-done-ch w)
(lambda (res)
#;(printf "2. coroutine-done-evt~n")
(set-coroutine-object-result! w res)
(coroutine-kill w)
#t))
(wrap-evt (coroutine-object-ex-ch w)
(lambda (exn)
#;(printf "2. ex-evt~n")
(coroutine-kill w)
(raise exn))))))
;; In case we escape through a break:
(lambda ()
(when (thread-running? worker)
(semaphore-wait can-stop-lock)
(thread-suspend worker)
(semaphore-post can-stop-lock)))))
#t))
(let ([can-stop-lock (coroutine-object-can-stop-lock w)]
[worker (coroutine-object-worker w)])
#;(printf "2. starting coroutine~n")
(thread-resume worker)
(dynamic-wind
void
;; Let the co-routine run...
(lambda ()
(sync (choice-evt (wrap-evt (alarm-evt (+ timeout (current-inexact-milliseconds)))
(lambda (x)
#;(printf "2. alarm-evt~n")
(semaphore-wait can-stop-lock)
(thread-suspend worker)
(semaphore-post can-stop-lock)
#f))
(wrap-evt (coroutine-object-done-ch w)
(lambda (res)
#;(printf "2. coroutine-done-evt~n")
(set-coroutine-object-result! w res)
(coroutine-kill w)
#t))
(wrap-evt (coroutine-object-ex-ch w)
(lambda (exn)
#;(printf "2. ex-evt~n")
(coroutine-kill w)
(raise exn))))))
;; In case we escape through a break:
(lambda ()
(when (thread-running? worker)
(semaphore-wait can-stop-lock)
(thread-suspend worker)
(semaphore-post can-stop-lock)))))
#t))
;; coroutine-result : X-coroutine-object -> X
(define (coroutine-result w)
(coroutine-object-result w))
;; coroutine-kill : X-coroutine-object ->
(define (coroutine-kill w)
(set-coroutine-object-can-stop-lock! w #f)
@ -213,9 +207,8 @@
(coroutine-object? x))
(provide coroutine?)
(provide/contract
(provide/contract
(coroutine (((any/c . -> . any) . -> . any) . -> . coroutine?))
(coroutine-run (real? coroutine? . -> . boolean?))
(coroutine-result (coroutine? . -> . any))
(coroutine-kill (coroutine? . -> . any))))