diff options
| -rw-r--r-- | guix/scripts/offload.scm | 50 |
1 files changed, 19 insertions, 31 deletions
diff --git a/guix/scripts/offload.scm b/guix/scripts/offload.scm index f90f9e92fa..30fe69ad6d 100644 --- a/guix/scripts/offload.scm +++ b/guix/scripts/offload.scm @@ -260,13 +260,6 @@ instead of '~a' of type '~a'~%") (lambda () (unlock-file port))))) -(define-syntax-rule (with-machine-lock machine hint exp ...) - "Wait to acquire MACHINE's exclusive lock for HINT, and evaluate EXP in that -context." - (with-file-lock (machine-lock-file machine hint) - exp ...)) - - (define (machine-slot-file machine slot) "Return the file name of MACHINE's file for SLOT." ;; For each machine we have a bunch of files representing each build slot. @@ -284,23 +277,25 @@ the slot, or #f if none is available. This mechanism allows us to set a hard limit on the number of simultaneous connections allowed to MACHINE." (mkdir-p (dirname (machine-slot-file machine 0))) - (with-machine-lock machine 'slots - (any (lambda (slot) - (let ((port (open-file (machine-slot-file machine slot) - "w0"))) - (catch 'flock-error - (lambda () - (fcntl-flock port 'write-lock #:wait? #f) - ;; Got it! - (format (current-error-port) - "process ~a acquired build slot '~a'~%" - (getpid) (port-filename port)) - port) - (lambda args - ;; PORT is already locked by another process. - (close-port port) - #f)))) - (iota (build-machine-parallel-builds machine))))) + + ;; When several 'guix offload' processes run in parallel, there's a race + ;; among them, but since they try the slots in the same order, we're fine. + (any (lambda (slot) + (let ((port (open-file (machine-slot-file machine slot) + "w0"))) + (catch 'flock-error + (lambda () + (fcntl-flock port 'write-lock #:wait? #f) + ;; Got it! + (format (current-error-port) + "process ~a acquired build slot '~a'~%" + (getpid) (port-filename port)) + port) + (lambda args + ;; PORT is already locked by another process. + (close-port port) + #f)))) + (iota (build-machine-parallel-builds machine)))) (define (release-build-slot slot) "Release SLOT, a build slot as returned as by 'acquire-build-slot'." @@ -447,12 +442,6 @@ of free disk space on '~a'~%") normalized) load)) -(define (machine-lock-file machine hint) - "Return the name of MACHINE's lock file for HINT." - (string-append %state-directory "/offload/" - (build-machine-name machine) - "." (symbol->string hint) ".lock")) - (define (random-seed) (logxor (getpid) (car (gettimeofday)))) @@ -827,7 +816,6 @@ This tool is meant to be used internally by 'guix-daemon'.\n")) (leave (G_ "invalid arguments: ~{~s ~}~%") x)))) ;;; Local Variables: -;;; eval: (put 'with-machine-lock 'scheme-indent-function 2) ;;; eval: (put 'with-file-lock 'scheme-indent-function 1) ;;; eval: (put 'with-error-to-port 'scheme-indent-function 1) ;;; eval: (put 'with-timeout 'scheme-indent-function 2) |