____ ____ ______ ____ ___ ____
!! ! | \ / | T \ / \| \ !!!!
!!! | o Y o | | D Y Y _ l ! !!!
!!!! | _/| l_ __j | O | | | !!!!
!!: | | | _ | | | | \| | | | !: :!
:!: | | | | | | | | . l ! | | : ::
:: l__j l__j__j l__j l__j\_j\___/l__j__j : :
--- '( A B S T R A C T ) -------------------------------------------------------
Patron is a multi-consumer/multi-producer thread pooling library written in
Common Lisp with flexibility and performance in mind. You simply create a
`PATRON' with a job queue of fixed size, specify a fixed number of `WORKER'
threads and start submitting your `JOB's into the work queue.
While Patron is written in portable Common Lisp in mind, because of some
platform specific features[1] used, it currently works on SBCL[2] and CCL[3]
platforms. As a side note, Patron currently depends on bordeaux-threads[4]
library for common threading functionalities.
[1] Semaphores, missing threading features (`THREAD-JOIN', `WITHOUT-INTERRUPTS',
etc.) in bordeaux-threads, `WITH-TIMEOUT' macro.
[2] Steel Bank Common Lisp (http://www.sbcl.org/)
[3] Clozure Common Lisp (http://openmcl.clozure.com/)
[4] http://common-lisp.net/project/bordeaux-threads/
--- '( E X A M P L E ) ---------------------------------------------------------
Below basic example should get you to a point where you can start creating
thread pools in minutes.
(defvar *stream* *standard-output*)
(defvar *stream-lock* (patron:make-lock))
(defun safe-format (fmt &rest args)
(patron:with-lock *stream-lock*
(apply #'format *stream* fmt args)))
(defun thread-stats (patron)
(safe-format
"Keepers: ~{~A~^ ~}~%Workers: ~{~A~^ ~}~%"
(map 'list #'patron:thread-alive-p (patron::keepers-of patron))
(map 'list #'patron:thread-alive-p (patron::workers-of patron))))
(let ((state (make-random-state)))
(defun job ()
(let ((duration (random 5 state)))
(safe-format " ~S => Sleeping... [~A]~%" (patron:current-thread) duration)
(sleep duration)
(safe-format " ~S => Done!~%" (patron:current-thread)))))
(defun report-result (job)
(safe-format "RESULT: JOB: ~S~%" job))
(defun patron-test ()
(let* ((patron
(make-instance
'patron:patron
:worker-capacity 3
:job-capacity 32
:worker-timeout-duration 3)))
(safe-format "Starting...~%")
(patron:start-patron patron)
(sleep 1.0)
(thread-stats patron)
(safe-format "Submitting jobs...~%")
(loop repeat 5
do (patron:submit-job
patron
(make-instance
'patron:job
:function #'job
:result-report-function #'report-result)))
(safe-format "Submitted.~%")
(safe-format "Stopping...~%")
(patron:stop-patron patron :wait t)
(safe-format "Stopped.~%")
(thread-stats patron)))
; Starting...
; Keepers: T T
; Workers: T T T
; Submitting jobs...
; Submitted.
; Stopping...
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8D21}> => Sleeping... [2]
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8F71}> => Sleeping... [2]
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040EA1D1}> => Sleeping... [3]
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8D21}> => Done!
; RESULT: JOB: #<PATRON:JOB :FUNCTION #<FUNCTION TEST::JOB> :START-TIME "2009-04-30 14:41:49" :FINISH-TIME "2009-04-30 14:41:51" {1004155561}>
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8D21}> => Sleeping... [3]
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8F71}> => Done!
; RESULT: JOB: #<PATRON:JOB :FUNCTION #<FUNCTION TEST::JOB> :START-TIME "2009-04-30 14:41:49" :FINISH-TIME "2009-04-30 14:41:51" {1004155891}>
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8F71}> => Sleeping... [2]
; 2009-04-30 14:41:52 - #<PATRON:JOB :FUNCTION #<FUNCTION TEST::JOB> :START-TIME "2009-04-30 14:41:49" :CONDITION #<PATRON::TIMEOUT-CONDITION :DURATION 3 :TIME "2009-04-30 14:41:52"> {1004155BC1}>
; #<SB-THREAD:THREAD "Anonymous" RUNNING {10040E8F71}> => Done!
; RESULT: JOB: #<PATRON:JOB :FUNCTION #<FUNCTION TEST::JOB> :START-TIME "2009-04-30 14:41:51" :FINISH-TIME "2009-04-30 14:41:53" {1004156231}>
; 2009-04-30 14:41:54 - #<PATRON:JOB :FUNCTION #<FUNCTION TEST::JOB> :START-TIME "2009-04-30 14:41:51" :CONDITION #<PATRON::TIMEOUT-CONDITION :DURATION 3 :TIME "2009-04-30 14:41:54"> {1004155EF1}>
; Stopped.
; Keepers: NIL NIL
; Workers: NIL NIL NIL
--- '( D O C U M E N T A T I O N ) ---------------------------------------------
Before going into the syntatical details, here is a general figure about the
inner workings of Patron.
- Queue operations take action in a blocking manner and are wrapped by
`WITH-TIMEOUT' statements.
- There are no busy waits, synchronized access is supplied using semaphores.
- Using a two-lock concurrent queue algorithm, consumer and producer lockings
are separated from each other for performance purposes .
- There are two keeper threads where each keeper is ensuring its partners
existence and first (master) keeper ensuring the existence of specified number
of worker threads.
While Patron source code is fully documented, below you'll find the
documentation excerpts from the source code for exported symbols.
[Condition] timeout-condition (error-condition)
[Slot] time - Time condition instance is created.
[Slot] duration - Elapsed duration before condition is raised.
Condition thrown when the duration specified in the `WITH-TIMEOUT' is
exceeded. (`TIME' slot is inherited from `ERROR-CONDITION'.)
[Function] default-error-report (condition)
Default function for reporting errors.
[Class] thread ()
[Slot] id - Implementation dependent thread identifier.
[Slot] function - Function executed by current thread.
[Function] make-lock ()
[Macro] with-lock (lock &body body)
[Function] thread-start (thread)
[Function] current-thread ()
[Function] thread-alive-p (thread)
[Function] thread-interrupt (thread function)
[Function] thread-join (thread)
[Macro] without-interrupts (&body body)
[Class] job ()
[Slot] function - Function will be called to start the execution.
[Slot] result-report-function - Function will be called to report the result.
[Slot] error-report-function - Function will be called to report an error.
[Slot] submit-time - Job queue entrance time.
[Slot] start-time - Job execution start time.
[Slot] finish-time - Job execution finish time.
[Slot] condition - Signaled condition in case of a failure.
[Slot] result - Job result in case of no failure.
[Class] patron ()
[Slot] error-report-function - Will get called for management related
errors -- e.g when found a dead worker, keeper, etc.
[Slot] job-capacity - Upper limit on the job queue size.
[Slot] worker-capacity - Number of serving `WORKER's.
[Slot] worker-timeout-duration - Time limit on the work processing duration.
[Slot] keeper-timeout-duration - Wait period for keepers.
[Function] submit-job (patron job)
Submit given `JOB' into the job queue of `PATRON'. Function works in a
blocking manner and returns inserted `JOB', or throws a `TIMEOUT-CONDITION'.
[Function] worker-stats (patron)
Returns a property list of minimum, maximum, and average statistics of
`N-FAILURES', `FAIL-DURATION', `BUSY-DURATION', and `IDLE-DURATION' slots
among workers. Function blocks job queue while gathering statistics.
[Function] start-patron (patron)
After switching `STATE' to `:ACTIVE', starts `WORKERS's and `KEEPER's in
order.
[Function] stop-patron (patron &key wait kill)
After switching `STATE' to `:INACTIVE', stops `KEEPER's and `WORKER's in
order. For related effects of keyword arguments see documentation of
`STOP-KEEPERS' and `STOP-WORKERS' functions.