guix/tests/cache.scm
Ludovic Courtès d921c742b7
cache: Avoid cache cleanup storms from concurrent processes.
Reported by Christopher Baines <guix@cbaines.net>.

* guix/cache.scm (maybe-remove-expired-cache-entries): Define
‘expiry-port’; create it with ‘lock-file’.  Change ‘last-expiry-date’
accordingly.  Write timestamp straight to ‘expiry-port’.
* tests/cache.scm ("maybe-remove-expired-cache-entries, cleanup needed
but lock taken"): New test.

Change-Id: I22441d9d2c4a339d3d3878de131864db5a0ae826
2024-08-21 00:52:39 +02:00

124 lines
4.4 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017, 2020, 2024 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2022 Simon Tournier <zimon.toutoune@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (test-cache)
#:use-module (guix cache)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-19)
#:use-module (srfi srfi-64)
#:use-module ((guix build syscalls) #:select (lock-file))
#:use-module ((guix utils) #:select (call-with-temporary-directory))
#:use-module ((rnrs io ports) #:select (get-string-all))
#:use-module (ice-9 match))
(test-begin "cache")
(test-equal "remove-expired-cache-entries"
'("o" "l" "d")
(let* ((removed '())
(now (time-second (current-time time-monotonic)))
(ttl 100)
(stamp (match-lambda
((or "n" "e" "w") (+ now 100))
((or "o" "l" "d") (- now 100))))
(delete (lambda (entry)
(set! removed (cons entry removed)))))
(remove-expired-cache-entries (reverse '("n" "e" "w"
"o" "l" "d"))
#:entry-expiration stamp
#:delete-entry delete)
removed))
(define-syntax-rule (test-cache-cleanup cache exp ...)
(call-with-temporary-directory
(lambda (cache)
(let* ((deleted '())
(delete! (lambda (entry)
(set! deleted (cons entry deleted)))))
exp ...
(maybe-remove-expired-cache-entries cache
(const '("a" "b" "c"))
#:entry-expiration (const 0)
#:delete-entry delete!)
(reverse deleted)))))
(test-equal "maybe-remove-expired-cache-entries, first cleanup"
'("a" "b" "c")
(test-cache-cleanup cache))
(test-equal "maybe-remove-expired-cache-entries, no cleanup needed"
'()
(test-cache-cleanup cache
(call-with-output-file (string-append cache "/last-expiry-cleanup")
(lambda (port)
(display (+ (time-second (current-time time-monotonic)) 100)
port)))))
(test-equal "maybe-remove-expired-cache-entries, cleanup needed"
'("a" "b" "c")
(test-cache-cleanup cache
(call-with-output-file (string-append cache "/last-expiry-cleanup")
(lambda (port)
(display 0 port)))))
(let ((pid #f))
(test-equal "maybe-remove-expired-cache-entries, cleanup needed but lock taken"
'()
(test-cache-cleanup cache
(let ((in+out (pipe)))
(match (primitive-fork)
(0 (dynamic-wind
(const #t)
(lambda ()
(close-port (car in+out))
(let ((port (lock-file
(string-append cache "/last-expiry-cleanup"))))
(display 0 port)
(display "done!\n" (cdr in+out))
(close-port (cdr in+out))
(sleep 100)))
(lambda ()
(primitive-exit 0))))
(n
(set! pid n)
(close-port (cdr in+out))
(pk 'chr (get-string-all (car in+out)))
(close-port (car in+out)))))))
(when pid (kill pid SIGKILL)))
(test-equal "maybe-remove-expired-cache-entries, empty cache"
'("a" "b" "c")
(test-cache-cleanup cache
(call-with-output-file (string-append cache "/last-expiry-cleanup")
(lambda (port)
(display "" port)))))
(test-equal "maybe-remove-expired-cache-entries, corrupted cache"
'("a" "b" "c")
(test-cache-cleanup cache
(call-with-output-file (string-append cache "/last-expiry-cleanup")
(lambda (port)
(display "1\"34657890" port)))))
(test-end "cache")
;;; Local Variables:
;;; eval: (put 'test-cache-cleanup 'scheme-indent-function 1)
;;; End: