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authorLudovic Courtès <ludo@gnu.org>2017-11-17 10:10:30 +0100
committerLudovic Courtès <ludo@gnu.org>2017-11-17 10:10:30 +0100
commit232b3d31016439b5600e47d845ffb7c9a4ee4723 (patch)
tree0a80a65687ad3c675c0bb69567b9cc5ea02fb250
parentef2c6b409568123e760a7dfa22d45fc09e713198 (diff)
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guix-232b3d31016439b5600e47d845ffb7c9a4ee4723.tar.gz
workers: 'pool-idle?' returns true only if the workers are idle.
Fixes <https://bugs.gnu.org/28779>. Reported by Eric Bavier <bavier@cray.com>. * guix/workers.scm (<pool>)[busy]: New field. (worker-thunk): Add #:idle and #:busy and use them. (make-pool): Pass #:busy and #:idle to 'worker-thunk'. Pass a 'busy' value to '%make-pool'. * guix/workers.scm (pool-idle?): Check whether 'pool-busy' returns zero and adjust docstring.
-rw-r--r--guix/workers.scm24
1 files changed, 17 insertions, 7 deletions
diff --git a/guix/workers.scm b/guix/workers.scm
index 846f5e50a9..0f6f54bab0 100644
--- a/guix/workers.scm
+++ b/guix/workers.scm
@@ -45,12 +45,13 @@
;;; Code:
(define-record-type <pool>
- (%make-pool queue mutex condvar workers)
+ (%make-pool queue mutex condvar workers busy)
pool?
(queue pool-queue)
(mutex pool-mutex)
(condvar pool-condition-variable)
- (workers pool-workers))
+ (workers pool-workers)
+ (busy pool-busy))
(define-syntax-rule (without-mutex mutex exp ...)
(dynamic-wind
@@ -62,12 +63,14 @@
(lock-mutex mutex))))
(define* (worker-thunk mutex condvar pop-queue
- #:key (thread-name "guix worker"))
+ #:key idle busy (thread-name "guix worker"))
"Return the thunk executed by worker threads."
(define (loop)
(match (pop-queue)
(#f ;empty queue
- (wait-condition-variable condvar mutex))
+ (idle)
+ (wait-condition-variable condvar mutex)
+ (busy))
((? procedure? proc)
;; Release MUTEX while executing PROC.
(without-mutex mutex
@@ -97,19 +100,24 @@ threads as reported by the operating system."
(let* ((mutex (make-mutex))
(condvar (make-condition-variable))
(queue (make-q))
+ (busy count)
(procs (unfold (cut >= <> count)
(lambda (n)
(worker-thunk mutex condvar
(lambda ()
(and (not (q-empty? queue))
(q-pop! queue)))
+ #:busy (lambda ()
+ (set! busy (+ 1 busy)))
+ #:idle (lambda ()
+ (set! busy (- busy 1)))
#:thread-name thread-name))
1+
0))
(threads (map (lambda (proc)
(call-with-new-thread proc))
procs)))
- (%make-pool queue mutex condvar threads)))
+ (%make-pool queue mutex condvar threads (lambda () busy))))
(define (pool-enqueue! pool thunk)
"Enqueue THUNK for future execution by POOL."
@@ -118,9 +126,11 @@ threads as reported by the operating system."
(signal-condition-variable (pool-condition-variable pool))))
(define (pool-idle? pool)
- "Return true if POOL doesn't have any task in its queue."
+ "Return true if POOL doesn't have any task in its queue and all the workers
+are currently idle (i.e., waiting for a task)."
(with-mutex (pool-mutex pool)
- (q-empty? (pool-queue pool))))
+ (and (q-empty? (pool-queue pool))
+ (zero? ((pool-busy pool))))))
(define-syntax-rule (eventually pool exp ...)
"Run EXP eventually on one of the workers of POOL."