suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

db: fix mysql close-on-exec slowdown (TCP issue)

Browse Source
This commit is contained in:
Ryan Culpepper 2012-03-15 23:10:23 -06:00
parent 6b02b507a9
commit c10bf245c5
1 changed files with 9 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
collects/db/private/mysql/connection.rkt
View File

@ -55,7 +55,6 @@
(define next-msg-num 0)
(define/private (fresh-exchange)
(set! msg-buffer null)
(set! next-msg-num 0))
;; buffer-message : message -> void
@ -68,6 +67,7 @@
(define/private (flush-message-buffer)
(for ([msg+num (in-list (reverse msg-buffer))])
(write-packet outport (car msg+num) (cdr msg+num)))
(set! msg-buffer null)
(flush-output outport))
;; send-message : message -> void
@ -264,18 +264,15 @@
(classify-my-sql stmt)])])
(check-statement/tx fsym stmt-type)
(begin0 (query1 fsym stmt cursor? #t)
(when #f ;; DISABLED!
;; For some reason, *really* slow; the concurrent tests slow
;; down by over an order of magnitude when this is enabled.
(statement:after-exec stmt #f))))))])
(statement:after-exec stmt #f)))))])
(query1:process-result fsym result)))
;; query1 : symbol Statement -> QueryResult
(define/private (query1 fsym stmt cursor? warnings?)
(let ([delenda (check/invalidate-cache stmt)])
;; Don't do anything with delenda; too slow!
;; (See comment in query method above.)
(void))
(when delenda
(for ([(_sql pst) (in-hash delenda)])
(free-statement pst #f))))
(let ([wbox (and warnings? (box 0))])
(fresh-exchange)
(query1:enqueue stmt cursor?)
@ -425,12 +422,15 @@
(define/public (get-base) this)
(define/public (free-statement pst need-lock?)
;; Important: *buffer* statement-close message, but do not send (ie, flush).
;; That way, message included in same TCP packet as next query message, avoiding
;; write-write-read TCP packet sequence, Nagle's algorithm & delayed ACK issue.
(define (do-free-statement)
(let ([id (send pst get-handle)])
(when (and id outport) ;; outport = connected?
(send pst set-handle #f)
(fresh-exchange)
(send-message (make-command:statement-packet 'statement-close id)))))
(buffer-message (make-command:statement-packet 'statement-close id)))))
(if need-lock?
(call-with-lock* 'free-statement do-free-statement void #f)
(do-free-statement)))