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Removing manager locking

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svn: r6618
This commit is contained in:
Jay McCarthy 2007-06-13 01:22:46 +00:00
parent 72ec6342ea
commit 5c0698e07d
6 changed files with 61 additions and 93 deletions
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26
collects/web-server/dispatchers/dispatch-servlets.ss
View File

@ -99,16 +99,10 @@
(define manager (servlet-manager the-servlet))
(parameterize ([current-execution-context (make-execution-context req)])
(define instance-id ((manager-create-instance manager) (make-servlet-instance-data servlet-mutex) (exit-handler)))
; XXX Locking is broken
((manager-instance-lock! manager) instance-id)
(parameterize ([current-servlet-instance-id instance-id]
[exit-handler (lambda (v)
((manager-instance-unlock! manager) instance-id)
(exit v))])
(begin0 (with-handlers ([(lambda (x) #t)
(make-servlet-exception-handler)])
((servlet-handler the-servlet) req))
((manager-instance-unlock! manager) instance-id))))))))
(parameterize ([current-servlet-instance-id instance-id])
(with-handlers ([(lambda (x) #t)
(make-servlet-exception-handler)])
((servlet-handler the-servlet) req))))))))
servlet-prompt)))))
(output-response conn response))
@ -138,11 +132,16 @@
(define the-servlet (cached-load servlet-path))
(define manager (servlet-manager the-servlet))
(define data ((manager-instance-lookup-data manager) instance-id))
(define _v ((manager-instance-lock! manager) instance-id))
(define response
(parameterize ([current-servlet the-servlet]
[current-directory (get-servlet-base-dir servlet-path)]
[current-servlet-instance-id instance-id]
[current-custodian (servlet-custodian the-servlet)])
[current-custodian (servlet-custodian the-servlet)]
[current-namespace (servlet-namespace the-servlet)]
[exit-handler
(lambda (v)
(kill-connection! conn)
(custodian-shutdown-all (servlet-custodian the-servlet)))])
(with-handlers ([exn:fail:servlet-manager:no-instance?
(lambda (the-exn)
((exn:fail:servlet-manager:no-instance-expiration-handler the-exn) req))]
@ -161,8 +160,7 @@
(define kcb ((manager-continuation-lookup manager) instance-id k-id salt))
((custodian-box-value kcb) req))
servlet-prompt)))))))
(output-response conn response)
((manager-instance-unlock! manager) instance-id))
(output-response conn response))
;; cached-load : path -> script, namespace
;; timestamps are no longer checked for performance. The cache must be explicitly

5
collects/web-server/docs/reference/managers.scrbl
View File

@ -22,8 +22,6 @@ the users and implementers of managers.
@defstruct[manager ([create-instance (any/c (-> void) . -> . number?)]
[adjust-timeout! (number? number? . -> . void)]
[instance-lookup-data (number? . -> . any/c)]
[instance-lock! (number? . -> . void)]
[instance-unlock! (number? . -> . void)]
[clear-continuations! (number? . -> . void)]
[continuation-store! (number? any/c expiration-handler? . -> . (list/c number? number?))]
[continuation-lookup (number? number? number? . -> . any/c)])]{
@ -40,9 +38,6 @@ the users and implementers of managers.
@scheme[instance-lookup-data] accesses the arbitrary data passed into
@scheme[create-instance] match by the given instance-id.
@scheme[instance-lock!] and @scheme[instance-unlock!] lock and unlock
access to a particular instance.
@scheme[clear-continuations!] expires all the continuations of an instance.
@scheme[continuation-store!] is given an instance-id, a continuation value,

90
collects/web-server/managers/lru.ss
View File

@ -25,16 +25,17 @@
#:key
[initial-count 1]
[inform-p (lambda _ (void))])
(define lock (make-semaphore 1))
;; Instances
(define instances (make-hash-table))
(define next-instance-id (make-counter))
(define-struct instance (data k-table use-count))
(define-struct instance (data k-table))
(define (create-instance data expire-fn)
(define instance-id (next-instance-id))
(hash-table-put! instances
instance-id
(make-instance data (create-k-table) 0))
(make-instance data (create-k-table)))
instance-id)
(define (adjust-timeout! instance-id secs)
(void))
@ -49,15 +50,6 @@
instance-expiration-handler)))))
instance)
(define (instance-lock! instance-id)
(define instance (instance-lookup instance-id))
(set-instance-use-count! instance
(add1 (instance-use-count instance))))
(define (instance-unlock! instance-id)
(define instance (instance-lookup instance-id))
(set-instance-use-count! instance
(sub1 (instance-use-count instance))))
;; Continuation table
(define-struct k-table (next-id-fn htable))
(define (create-k-table)
@ -69,7 +61,7 @@
(define (clear-continuations! instance-id)
(match (instance-lookup instance-id)
[(struct instance (data (and k-table (struct k-table (next-id-fn htable))) locked?))
[(struct instance (data (and k-table (struct k-table (next-id-fn htable)))))
(hash-table-for-each
htable
(match-lambda*
@ -79,7 +71,7 @@
(define (continuation-store! instance-id k expiration-handler)
(match (instance-lookup instance-id)
[(struct instance (data (struct k-table (next-id-fn htable)) _))
[(struct instance (data (struct k-table (next-id-fn htable))))
(define k-id (next-id-fn))
(define salt (random 100000000))
(hash-table-put! htable
@ -88,7 +80,7 @@
(list k-id salt)]))
(define (continuation-lookup instance-id a-k-id a-salt)
(match (instance-lookup instance-id)
[(struct instance (data (struct k-table (next-id-fn htable)) _))
[(struct instance (data (struct k-table (next-id-fn htable))))
(match
(hash-table-get htable a-k-id
(lambda ()
@ -109,15 +101,17 @@
instance-expiration-handler)))
k)])]))
(define (wrap f)
(lambda args
(call-with-semaphore lock (lambda () (apply f args)))))
(define the-manager
(make-LRU-manager create-instance
(make-LRU-manager (wrap create-instance)
adjust-timeout!
instance-lookup-data
instance-lock!
instance-unlock!
clear-continuations!
continuation-store!
continuation-lookup
(wrap instance-lookup-data)
(wrap clear-continuations!)
(wrap continuation-store!)
(wrap continuation-lookup)
; Specific
instance-expiration-handler
; Private
@ -126,32 +120,34 @@
; Collector
(define (collect just-go?)
(define removed (box 0))
(hash-table-for-each
instances
(match-lambda*
[(list instance-id (struct instance (_ (struct k-table (next-id-fn htable)) use-count)))
(define empty? (box #t))
(hash-table-for-each
htable
(match-lambda*
[(list k-id (list s k eh count))
(if (zero? count)
(begin (set-box! removed (add1 (unbox removed)))
(hash-table-remove! htable k-id))
(begin (set-box! empty? #f)
(hash-table-put! htable k-id
(list s k eh (sub1 count)))))]))
(when (and (unbox empty?)
; XXX race condition
(zero? use-count))
(set-box! removed (add1 (unbox removed)))
(hash-table-remove! instances instance-id))]))
(when (or just-go?
(not (zero? (unbox removed))))
(inform-p (unbox removed))
(collect-garbage)
(collect-garbage)))
(call-with-semaphore
lock
(lambda ()
(define removed (box 0))
(hash-table-for-each
instances
(match-lambda*
[(list instance-id (struct instance (_ (struct k-table (next-id-fn htable)))))
(define empty? (box #t))
(hash-table-for-each
htable
(match-lambda*
[(list k-id (list s k eh count))
(if (zero? count)
(begin (set-box! removed (add1 (unbox removed)))
(hash-table-remove! htable k-id))
(begin (set-box! empty? #f)
(hash-table-put! htable k-id
(list s k eh (sub1 count)))))]))
(when (unbox empty?)
(set-box! removed (add1 (unbox removed)))
(hash-table-remove! instances instance-id))]))
(when (or just-go?
(not (zero? (unbox removed))))
(inform-p (unbox removed))
(collect-garbage)
(collect-garbage)))))
(define manager-thread
(thread
(lambda ()

4
collects/web-server/managers/manager.ss
View File

@ -5,8 +5,6 @@
(define-struct manager (create-instance
adjust-timeout!
instance-lookup-data
instance-lock!
instance-unlock!
clear-continuations!
continuation-store!
continuation-lookup))
@ -18,8 +16,6 @@
[struct manager ([create-instance (any/c (any/c . -> . void) . -> . number?)]
[adjust-timeout! (number? number? . -> . void)]
[instance-lookup-data (number? . -> . any/c)]
[instance-lock! (number? . -> . void)]
[instance-unlock! (number? . -> . void)]
[clear-continuations! (number? . -> . void)]
[continuation-store! (number? any/c expiration-handler? . -> . (list/c number? number?))]
[continuation-lookup (number? number? number? . -> . any/c)])]

7
collects/web-server/managers/none.ss
View File

@ -22,11 +22,6 @@
(current-continuation-marks)
instance-expiration-handler)))
(define (instance-lock! instance-id)
(void))
(define (instance-unlock! instance-id)
(void))
(define (instance-lookup-data instance-id)
(thread-cell-ref the-data))
@ -41,8 +36,6 @@
(make-none-manager create-instance
adjust-timeout!
instance-lookup-data
instance-lock!
instance-unlock!
clear-continuations!
continuation-store!
continuation-lookup

22
collects/web-server/managers/timeouts.ss
View File

@ -28,7 +28,7 @@
(define instances (make-hash-table))
(define next-instance-id (make-counter))
(define-struct instance (data k-table timer locked?))
(define-struct instance (data k-table timer))
(define (create-instance data expire-fn)
(define instance-id (next-instance-id))
(hash-table-put! instances
@ -38,8 +38,7 @@
(start-timer instance-timer-length
(lambda ()
(expire-fn)
(hash-table-remove! instances instance-id)))
#t))
(hash-table-remove! instances instance-id)))))
instance-id)
(define (adjust-timeout! instance-id secs)
(reset-timer! (instance-timer (instance-lookup instance-id))
@ -56,14 +55,7 @@
(increment-timer! (instance-timer instance)
instance-timer-length)
instance)
(define (instance-lock! instance-id)
(define instance (instance-lookup instance-id))
(set-instance-locked?! instance #t))
(define (instance-unlock! instance-id)
(define instance (instance-lookup instance-id))
(set-instance-locked?! instance #f))
;; Continuation table
(define-struct k-table (next-id-fn htable))
(define (create-k-table)
@ -75,7 +67,7 @@
(define (clear-continuations! instance-id)
(match (instance-lookup instance-id)
[(struct instance (data (and k-table (struct k-table (next-id-fn htable))) instance-timer locked?))
[(struct instance (data (and k-table (struct k-table (next-id-fn htable))) instance-timer))
(hash-table-for-each
htable
(match-lambda*
@ -85,7 +77,7 @@
(define (continuation-store! instance-id k expiration-handler)
(match (instance-lookup instance-id)
[(struct instance (data (struct k-table (next-id-fn htable)) instance-timer locked?))
[(struct instance (data (struct k-table (next-id-fn htable)) instance-timer))
(define k-id (next-id-fn))
(define salt (random 100000000))
(hash-table-put! htable
@ -99,7 +91,7 @@
(list k-id salt)]))
(define (continuation-lookup instance-id a-k-id a-salt)
(match (instance-lookup instance-id)
[(struct instance (data (struct k-table (next-id-fn htable)) instance-timer locked?))
[(struct instance (data (struct k-table (next-id-fn htable)) instance-timer))
(match
(hash-table-get htable a-k-id
(lambda ()
@ -123,8 +115,6 @@
(make-timeout-manager create-instance
adjust-timeout!
instance-lookup-data
instance-lock!
instance-unlock!
clear-continuations!
continuation-store!
continuation-lookup