diff options
| -rw-r--r-- | guix/build/syscalls.scm | 69 | ||||
| -rw-r--r-- | guix/nar.scm | 4 | ||||
| -rw-r--r-- | guix/utils.scm | 75 | ||||
| -rw-r--r-- | tests/syscalls.scm | 88 | ||||
| -rw-r--r-- | tests/utils.scm | 82 |
5 files changed, 160 insertions, 158 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index a9cd6e93c8..86723c23c7 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -65,6 +65,7 @@ processes mkdtemp! pivot-root + fcntl-flock CLONE_CHILD_CLEARTID CLONE_CHILD_SETTID @@ -639,6 +640,74 @@ system to PUT-OLD." ;;; +;;; Advisory file locking. +;;; + +(define %struct-flock + ;; 'struct flock' from <fcntl.h>. + (list short ; l_type + short ; l_whence + size_t ; l_start + size_t ; l_len + int)) ; l_pid + +(define F_SETLKW + ;; On Linux-based systems, this is usually 7, but not always + ;; (exceptions include SPARC.) On GNU/Hurd, it's 9. + (cond ((string-contains %host-type "sparc") 9) ; sparc-*-linux-gnu + ((string-contains %host-type "linux") 7) ; *-linux-gnu + (else 9))) ; *-gnu* + +(define F_SETLK + ;; Likewise: GNU/Hurd and SPARC use 8, while the others typically use 6. + (cond ((string-contains %host-type "sparc") 8) ; sparc-*-linux-gnu + ((string-contains %host-type "linux") 6) ; *-linux-gnu + (else 8))) ; *-gnu* + +(define F_xxLCK + ;; The F_RDLCK, F_WRLCK, and F_UNLCK constants. + (cond ((string-contains %host-type "sparc") #(1 2 3)) ; sparc-*-linux-gnu + ((string-contains %host-type "hppa") #(1 2 3)) ; hppa-*-linux-gnu + ((string-contains %host-type "linux") #(0 1 2)) ; *-linux-gnu + (else #(1 2 3)))) ; *-gnu* + +(define fcntl-flock + (let ((proc (syscall->procedure int "fcntl" `(,int ,int *)))) + (lambda* (fd-or-port operation #:key (wait? #t)) + "Perform locking OPERATION on the file beneath FD-OR-PORT. OPERATION +must be a symbol, one of 'read-lock, 'write-lock, or 'unlock. When WAIT? is +true, block until the lock is acquired; otherwise, thrown an 'flock-error' +exception if it's already taken." + (define (operation->int op) + (case op + ((read-lock) (vector-ref F_xxLCK 0)) + ((write-lock) (vector-ref F_xxLCK 1)) + ((unlock) (vector-ref F_xxLCK 2)) + (else (error "invalid fcntl-flock operation" op)))) + + (define fd + (if (port? fd-or-port) + (fileno fd-or-port) + fd-or-port)) + + ;; XXX: 'fcntl' is a vararg function, but here we happily use the + ;; standard ABI; crossing fingers. + (let ((err (proc fd + (if wait? + F_SETLKW ; lock & wait + F_SETLK) ; non-blocking attempt + (make-c-struct %struct-flock + (list (operation->int operation) + SEEK_SET + 0 0 ; whole file + 0))))) + (or (zero? err) + + ;; Presumably we got EAGAIN or so. + (throw 'flock-error (errno))))))) + + +;;; ;;; Network interfaces. ;;; diff --git a/guix/nar.scm b/guix/nar.scm index 43e5210752..739d3d3a57 100644 --- a/guix/nar.scm +++ b/guix/nar.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2012, 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2014 Mark H Weaver <mhw@netris.org> ;;; ;;; This file is part of GNU Guix. @@ -18,8 +18,8 @@ ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. (define-module (guix nar) - #:use-module (guix utils) #:use-module (guix serialization) + #:use-module (guix build syscalls) #:use-module ((guix build utils) #:select (delete-file-recursively with-directory-excursion)) #:use-module (guix store) diff --git a/guix/utils.scm b/guix/utils.scm index f18bbd19ac..d924e434bd 100644 --- a/guix/utils.scm +++ b/guix/utils.scm @@ -34,7 +34,7 @@ #:use-module ((rnrs bytevectors) #:select (bytevector-u8-set!)) #:use-module (guix combinators) #:use-module ((guix build utils) #:select (dump-port)) - #:use-module ((guix build syscalls) #:select (errno mkdtemp!)) + #:use-module ((guix build syscalls) #:select (mkdtemp!)) #:use-module (ice-9 vlist) #:use-module (ice-9 format) #:autoload (ice-9 popen) (open-pipe*) @@ -47,7 +47,6 @@ #:export (bytevector->base16-string base16-string->bytevector - fcntl-flock strip-keyword-arguments default-keyword-arguments substitute-keyword-arguments @@ -340,78 +339,6 @@ This procedure returns #t on success." ;;; -;;; Advisory file locking. -;;; - -(define %struct-flock - ;; 'struct flock' from <fcntl.h>. - (list short ; l_type - short ; l_whence - size_t ; l_start - size_t ; l_len - int)) ; l_pid - -(define F_SETLKW - ;; On Linux-based systems, this is usually 7, but not always - ;; (exceptions include SPARC.) On GNU/Hurd, it's 9. - (compile-time-value - (cond ((string-contains %host-type "sparc") 9) ; sparc-*-linux-gnu - ((string-contains %host-type "linux") 7) ; *-linux-gnu - (else 9)))) ; *-gnu* - -(define F_SETLK - ;; Likewise: GNU/Hurd and SPARC use 8, while the others typically use 6. - (compile-time-value - (cond ((string-contains %host-type "sparc") 8) ; sparc-*-linux-gnu - ((string-contains %host-type "linux") 6) ; *-linux-gnu - (else 8)))) ; *-gnu* - -(define F_xxLCK - ;; The F_RDLCK, F_WRLCK, and F_UNLCK constants. - (compile-time-value - (cond ((string-contains %host-type "sparc") #(1 2 3)) ; sparc-*-linux-gnu - ((string-contains %host-type "hppa") #(1 2 3)) ; hppa-*-linux-gnu - ((string-contains %host-type "linux") #(0 1 2)) ; *-linux-gnu - (else #(1 2 3))))) ; *-gnu* - -(define fcntl-flock - (let* ((ptr (dynamic-func "fcntl" (dynamic-link))) - (proc (pointer->procedure int ptr `(,int ,int *)))) - (lambda* (fd-or-port operation #:key (wait? #t)) - "Perform locking OPERATION on the file beneath FD-OR-PORT. OPERATION -must be a symbol, one of 'read-lock, 'write-lock, or 'unlock. When WAIT? is -true, block until the lock is acquired; otherwise, thrown an 'flock-error' -exception if it's already taken." - (define (operation->int op) - (case op - ((read-lock) (vector-ref F_xxLCK 0)) - ((write-lock) (vector-ref F_xxLCK 1)) - ((unlock) (vector-ref F_xxLCK 2)) - (else (error "invalid fcntl-flock operation" op)))) - - (define fd - (if (port? fd-or-port) - (fileno fd-or-port) - fd-or-port)) - - ;; XXX: 'fcntl' is a vararg function, but here we happily use the - ;; standard ABI; crossing fingers. - (let ((err (proc fd - (if wait? - F_SETLKW ; lock & wait - F_SETLK) ; non-blocking attempt - (make-c-struct %struct-flock - (list (operation->int operation) - SEEK_SET - 0 0 ; whole file - 0))))) - (or (zero? err) - - ;; Presumably we got EAGAIN or so. - (throw 'flock-error (errno))))))) - - -;;; ;;; Keyword arguments. ;;; diff --git a/tests/syscalls.scm b/tests/syscalls.scm index 0b73fb4b0c..73fa8a7acf 100644 --- a/tests/syscalls.scm +++ b/tests/syscalls.scm @@ -29,6 +29,10 @@ ;; Test the (guix build syscalls) module, although there's not much that can ;; actually be tested without being root. +(define temp-file + (string-append "t-utils-" (number->string (getpid)))) + + (test-begin "syscalls") (test-equal "mount, ENOENT" @@ -172,6 +176,88 @@ (status:exit-val status)))) (eq? #t result)))))))) +(false-if-exception (delete-file temp-file)) +(test-equal "fcntl-flock wait" + 42 ; the child's exit status + (let ((file (open-file temp-file "w0b"))) + ;; Acquire an exclusive lock. + (fcntl-flock file 'write-lock) + (match (primitive-fork) + (0 + (dynamic-wind + (const #t) + (lambda () + ;; Reopen FILE read-only so we can have a read lock. + (let ((file (open-file temp-file "r0b"))) + ;; Wait until we can acquire the lock. + (fcntl-flock file 'read-lock) + (primitive-exit (read file))) + (primitive-exit 1)) + (lambda () + (primitive-exit 2)))) + (pid + ;; Write garbage and wait. + (display "hello, world!" file) + (force-output file) + (sleep 1) + + ;; Write the real answer. + (seek file 0 SEEK_SET) + (truncate-file file 0) + (write 42 file) + (force-output file) + + ;; Unlock, which should let the child continue. + (fcntl-flock file 'unlock) + + (match (waitpid pid) + ((_ . status) + (let ((result (status:exit-val status))) + (close-port file) + result))))))) + +(test-equal "fcntl-flock non-blocking" + EAGAIN ; the child's exit status + (match (pipe) + ((input . output) + (match (primitive-fork) + (0 + (dynamic-wind + (const #t) + (lambda () + (close-port output) + + ;; Wait for the green light. + (read-char input) + + ;; Open FILE read-only so we can have a read lock. + (let ((file (open-file temp-file "w0"))) + (catch 'flock-error + (lambda () + ;; This attempt should throw EAGAIN. + (fcntl-flock file 'write-lock #:wait? #f)) + (lambda (key errno) + (primitive-exit (pk 'errno errno))))) + (primitive-exit -1)) + (lambda () + (primitive-exit -2)))) + (pid + (close-port input) + (let ((file (open-file temp-file "w0"))) + ;; Acquire an exclusive lock. + (fcntl-flock file 'write-lock) + + ;; Tell the child to continue. + (write 'green-light output) + (force-output output) + + (match (waitpid pid) + ((_ . status) + (let ((result (status:exit-val status))) + (fcntl-flock file 'unlock) + (close-port file) + result))))))))) + (test-assert "all-network-interface-names" (match (all-network-interface-names) (((? string? names) ..1) @@ -303,3 +389,5 @@ 0)) (test-end) + +(false-if-exception (delete-file temp-file)) diff --git a/tests/utils.scm b/tests/utils.scm index a54482e94c..6590ed91cf 100644 --- a/tests/utils.scm +++ b/tests/utils.scm @@ -168,88 +168,6 @@ (call-with-decompressed-port 'xz (open-file temp-file "r0b") get-bytevector-all)))) -(false-if-exception (delete-file temp-file)) -(test-equal "fcntl-flock wait" - 42 ; the child's exit status - (let ((file (open-file temp-file "w0b"))) - ;; Acquire an exclusive lock. - (fcntl-flock file 'write-lock) - (match (primitive-fork) - (0 - (dynamic-wind - (const #t) - (lambda () - ;; Reopen FILE read-only so we can have a read lock. - (let ((file (open-file temp-file "r0b"))) - ;; Wait until we can acquire the lock. - (fcntl-flock file 'read-lock) - (primitive-exit (read file))) - (primitive-exit 1)) - (lambda () - (primitive-exit 2)))) - (pid - ;; Write garbage and wait. - (display "hello, world!" file) - (force-output file) - (sleep 1) - - ;; Write the real answer. - (seek file 0 SEEK_SET) - (truncate-file file 0) - (write 42 file) - (force-output file) - - ;; Unlock, which should let the child continue. - (fcntl-flock file 'unlock) - - (match (waitpid pid) - ((_ . status) - (let ((result (status:exit-val status))) - (close-port file) - result))))))) - -(test-equal "fcntl-flock non-blocking" - EAGAIN ; the child's exit status - (match (pipe) - ((input . output) - (match (primitive-fork) - (0 - (dynamic-wind - (const #t) - (lambda () - (close-port output) - - ;; Wait for the green light. - (read-char input) - - ;; Open FILE read-only so we can have a read lock. - (let ((file (open-file temp-file "w0"))) - (catch 'flock-error - (lambda () - ;; This attempt should throw EAGAIN. - (fcntl-flock file 'write-lock #:wait? #f)) - (lambda (key errno) - (primitive-exit (pk 'errno errno))))) - (primitive-exit -1)) - (lambda () - (primitive-exit -2)))) - (pid - (close-port input) - (let ((file (open-file temp-file "w0"))) - ;; Acquire an exclusive lock. - (fcntl-flock file 'write-lock) - - ;; Tell the child to continue. - (write 'green-light output) - (force-output output) - - (match (waitpid pid) - ((_ . status) - (let ((result (status:exit-val status))) - (fcntl-flock file 'unlock) - (close-port file) - result))))))))) - ;; This is actually in (guix store). (test-equal "store-path-package-name" "bash-4.2-p24" |