diff options
| -rw-r--r-- | guix/build/syscalls.scm | 14 | ||||
| -rw-r--r-- | tests/syscalls.scm | 13 |
2 files changed, 22 insertions, 5 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index 39bcffd516..2c20edf058 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -1398,14 +1398,18 @@ exception if it's already taken." ;; Presumably we got EAGAIN or so. (throw 'flock-error err)))))) -(define* (lock-file file #:key (wait? #t)) - "Wait and acquire an exclusive lock on FILE. Return an open port." - (let ((port (open-file file "w0"))) - (fcntl-flock port 'write-lock #:wait? wait?) +(define* (lock-file file #:optional (mode "w0") + #:key (wait? #t)) + "Wait and acquire an exclusive lock on FILE. Return an open port according +to MODE." + (let ((port (open-file file mode))) + (fcntl-flock port + (if (output-port? port) 'write-lock 'read-lock) + #:wait? wait?) port)) (define (unlock-file port) - "Unlock PORT, a port returned by 'lock-file'." + "Unlock PORT, a port returned by 'lock-file', and close it." (fcntl-flock port 'unlock) (close-port port) #t) diff --git a/tests/syscalls.scm b/tests/syscalls.scm index 7cf67c060d..13f4f11721 100644 --- a/tests/syscalls.scm +++ b/tests/syscalls.scm @@ -383,6 +383,19 @@ (close-port file) result))))))))) +(test-equal "lock-file + unlock-file" + 'hello + (call-with-temporary-directory + (lambda (directory) + (let* ((file (in-vicinity directory "lock")) + (out (lock-file file #:wait? #f))) + (display "hello" out) + (unlock-file out) + (let* ((in (lock-file file "r0")) + (content (read in))) + (unlock-file in) + content))))) + (test-equal "set-thread-name" "Syscall Test" (let ((name (thread-name))) |