Removing connection mutex

svn: r6656

collects/web-server/bench/NOTES

@@ -1,3 +1,13 @@
+* data/1181788603.ss
+
+	Removing all references to semaphores doesn't change much.
+
+* data/1181787772.ss
+
+	Removing the semaphores on connections---no longer needed---
+	seems to improve the average case. 12ms were cut off. The
+	memory usage seems strange.
+
 * data/1181686382.ss
 
 	The memory-usage data implies that there is a leak

collects/web-server/bench/data/1181787772.ss

@@ -0,0 +1 @@
+(benchmark (cmd "ab -c 10 -t 120 -e /tmp/mztmp1181787597671591189 http://localhost:9480/file") (timing (start 1181787597) (stop 1181787717) (shutdown 1181787772)) (memory-usage (mzscheme (before 15501312) (after 271469624) (after-gc 240140744)) (server (before 11486956) (after 11767936) (after-gc 11737348))) (response-times (1.0 5.0 5.0 6.0 6.0 7.0 7.0 7.0 8.0 8.0 8.0 9.0 9.0 9.0 10.0 10.0 10.0 11.0 11.0 11.0 12.0 12.0 12.0 13.0 13.0 13.0 14.0 14.0 14.0 15.0 15.0 15.0 16.0 16.0 17.0 17.0 17.0 18.0 18.0 18.0 19.0 19.0 20.0 20.0 20.0 21.0 21.0 21.0 22.0 22.0 23.0 23.0 24.0 24.0 25.0 25.0 26.0 26.0 27.0 27.0 28.0 28.0 29.0 29.0 29.0 30.0 30.0 31.0 31.0 32.0 33.0 33.0 34.0 35.0 35.0 36.0 37.0 38.0 38.0 39.0 40.0 41.0 42.0 42.0 43.0 45.0 46.0 47.0 49.0 50.0 51.0 53.0 55.0 58.0 61.0 64.0 69.0 78.0 99.0 284.0)))

collects/web-server/bench/data/1181788603.ss

@@ -0,0 +1 @@
+(benchmark (cmd "ab -c 10 -t 120 -e /tmp/mztmp1181788425672419526 http://localhost:9480/file") (timing (start 1181788425) (stop 1181788546) (shutdown 1181788603)) (memory-usage (mzscheme (before 15474656) (after 256099040) (after-gc 246890536)) (server (before 11476576) (after 238827648) (after-gc 239474740))) (response-times (1.0 5.0 5.0 6.0 6.0 7.0 7.0 7.0 8.0 8.0 8.0 8.0 9.0 9.0 9.0 10.0 10.0 10.0 10.0 11.0 11.0 11.0 12.0 12.0 12.0 13.0 13.0 14.0 14.0 14.0 15.0 15.0 15.0 16.0 16.0 17.0 17.0 17.0 18.0 18.0 19.0 19.0 19.0 20.0 20.0 21.0 21.0 22.0 22.0 22.0 23.0 23.0 24.0 24.0 25.0 25.0 26.0 26.0 27.0 27.0 28.0 28.0 29.0 29.0 29.0 30.0 30.0 31.0 31.0 32.0 32.0 33.0 34.0 34.0 35.0 36.0 37.0 38.0 38.0 39.0 40.0 41.0 41.0 42.0 43.0 44.0 46.0 47.0 48.0 50.0 51.0 53.0 55.0 57.0 60.0 63.0 68.0 77.0 104.0 291.0)))

collects/web-server/docs/reference/private.scrbl

@@ -66,12 +66,11 @@ for doing this.
 @defstruct[connection
            ([timer timer?]
             [i-port input-port?] [o-port output-port?] [custodian custodian?]
-            [close? boolean?] [mutex semaphore?])]{
+            [close? boolean?])]{
  A connection is a pair of ports (@scheme[i-port] and @scheme[o-port]) that is
  ready to close after the current job if @scheme[close?] is @scheme[#t]. Resources
- associated with the connection should be allocated under @scheme[custodian] and
+ associated with the connection should be allocated under @scheme[custodian].
- locked by @scheme[mutex]---including access to the ports. The connection will last
+ The connection will last until @scheme[timer] triggers.
- until @scheme[timer] triggers.
 }
   
 @; XXX Don't pass in parent-cust

collects/web-server/private/connection-manager.ss

@@ -2,14 +2,11 @@
   (require (lib "contract.ss")
            "timer.ss")
   
-  (define-struct connection (timer i-port o-port custodian close? mutex)
+  (define-struct connection (timer i-port o-port custodian close?))
-    (make-inspector))
   
   (provide/contract
    [struct connection
-           ([timer timer?]
+           ([timer timer?] [i-port input-port?] [o-port output-port?] [custodian custodian?] [close? boolean?])]
-            [i-port input-port?] [o-port output-port?] [custodian custodian?]
-            [close? boolean?] [mutex semaphore?])]
    [start-connection-manager (custodian? . -> . void)]
    [new-connection (number? input-port? output-port? custodian? boolean? . -> . connection?)]
    [kill-connection! (connection? . -> . void)]
@@ -27,8 +24,7 @@
               (make-connection
                (start-timer time-to-live
                             (lambda () (kill-connection! conn)))
-               i-port o-port cust close?
+               i-port o-port cust close?)])
-               (make-semaphore 1))])
       conn))
   
   ;; kill-connection!: connection -> void

collects/web-server/private/request.ss

@@ -16,9 +16,6 @@
   ;; read the request line, and the headers, determine if the connection should
   ;; be closed after servicing the request and build a request structure
   (define (read-request conn host-port port-addresses)
-    (call-with-semaphore
-     (connection-mutex conn)
-     (lambda ()
     (define ip 
       (connection-i-port conn))
     (define-values (method uri major minor)
@@ -41,7 +38,7 @@
      (make-request method uri headers bindings raw-post-data
                    host-ip host-port client-ip)
      (close-connection? headers major minor
-                           client-ip host-ip)))))
+                        client-ip host-ip)))
   
   ;; **************************************************
   ;; close-connection?

collects/web-server/private/response.ss

@@ -176,10 +176,8 @@
           (with-handlers ([exn? (lambda (exn)
                                   (kill-connection! conn)
                                   (raise exn))])
-            (call-with-semaphore (connection-mutex conn)
-                                 (lambda ()
             (apply f conn args)
-                                   (flush-output (connection-o-port conn))))))))
+            (flush-output (connection-o-port conn))))))
   
   (define ext:output-response
     (ext:wrap output-response))

collects/web-server/tests/private/request-test.ss

@@ -19,7 +19,7 @@
            [ip (open-input-bytes b)]
            [op (open-output-bytes)])
       (values (make-connection (make-timer ip +inf.0 (lambda () (void)))
-                               ip op (make-custodian) #f (make-semaphore))
+                               ip op (make-custodian) #f)
               headers)))
   
   (define (get-bindings post-data)

collects/web-server/tests/util.ss

@@ -31,7 +31,7 @@
     (define ip (open-input-bytes ib))
     (define op (open-output-bytes))
     (values (make-connection (make-timer never-evt +inf.0 (lambda () (void)))
-                             ip op (current-custodian) #f (make-semaphore 1))
+                             ip op (current-custodian) #f)
             ip
             op))