diff options
Diffstat (limited to 'guix/build/syscalls.scm')
| -rw-r--r-- | guix/build/syscalls.scm | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index 58c23f2844..5aae1530f4 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -656,6 +656,36 @@ mounted at FILE." (define CLONE_NEWPID #x20000000) (define CLONE_NEWNET #x40000000) +(cond-expand + (guile-2.2 + (define %set-automatic-finalization-enabled?! + (let ((proc (pointer->procedure int + (dynamic-func + "scm_set_automatic_finalization_enabled" + (dynamic-link)) + (list int)))) + (lambda (enabled?) + "Switch on or off automatic finalization in a separate thread. +Turning finalization off shuts down the finalization thread as a side effect." + (->bool (proc (if enabled? 1 0)))))) + + (define-syntax-rule (without-automatic-finalization exp) + "Turn off automatic finalization within the dynamic extent of EXP." + (let ((enabled? #t)) + (dynamic-wind + (lambda () + (set! enabled? (%set-automatic-finalization-enabled?! #f))) + (lambda () + exp) + (lambda () + (%set-automatic-finalization-enabled?! enabled?)))))) + + (else + (define-syntax-rule (without-automatic-finalization exp) + ;; Nothing to do here: Guile 2.0 does not have a separate finalization + ;; thread. + exp))) + ;; The libc interface to sys_clone is not useful for Scheme programs, so the ;; low-level system call is wrapped instead. The 'syscall' function is ;; declared in <unistd.h> as a variadic function; in practice, it expects 6 @@ -678,10 +708,17 @@ mounted at FILE." Unlike the fork system call, clone accepts FLAGS that specify which resources are shared between the parent and child processes." (let-values (((ret err) - (proc syscall-id flags - %null-pointer ;child stack - %null-pointer %null-pointer ;ptid & ctid - %null-pointer))) ;unused + ;; Guile 2.2 runs a finalization thread. 'primitive-fork' + ;; takes care of shutting it down before forking, and we + ;; must do the same here. Failing to do that, if the + ;; child process calls 'primitive-fork', it will hang + ;; while trying to pthread_join the finalization thread + ;; since that thread does not exist. + (without-automatic-finalization + (proc syscall-id flags + %null-pointer ;child stack + %null-pointer %null-pointer ;ptid & ctid + %null-pointer)))) ;unused (if (= ret -1) (throw 'system-error "clone" "~d: ~A" (list flags (strerror err)) |