From f6c9763984dafe5023e171878231cbcc6cc1edfa Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Wed, 27 Apr 2022 17:53:10 +0200 Subject: linux-container: Ensure signal-handling asyncs get a chance to run. Previously we could enter the blocking 'waitpid' call and miss an opportunity to run the signal handler async. * gnu/build/linux-container.scm (call-with-container) [periodically-schedule-asyncs]: New procedure. [install-signal-handlers]: Call it. --- gnu/build/linux-container.scm | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'gnu/build') diff --git a/gnu/build/linux-container.scm b/gnu/build/linux-container.scm index 03c01439ce..1fac8f4b92 100644 --- a/gnu/build/linux-container.scm +++ b/gnu/build/linux-container.scm @@ -327,11 +327,20 @@ process when caught by its parent. Note that if THUNK needs to load any additional Guile modules, the relevant module files must be present in one of the mappings in MOUNTS and the Guile load path must be adjusted as needed." + (define (periodically-schedule-asyncs) + ;; XXX: In Guile there's a time window where a signal-handling async could + ;; be queued without being processed by the time we enter a blocking + ;; syscall like waitpid(2) (info "(guile) Signals"). This terrible hack + ;; ensures pending asyncs get a chance to run periodically. + (sigaction SIGALRM (lambda _ (alarm 1))) + (alarm 1)) + (define (install-signal-handlers pid) ;; Install handlers that forward signals to PID. (define (relay-signal signal) (false-if-exception (kill pid signal))) + (periodically-schedule-asyncs) (for-each (lambda (signal) (sigaction signal relay-signal)) relayed-signals)) -- cgit 1.4.1