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author | Ludovic Courtès <ludo@gnu.org> | 2019-04-29 21:42:04 +0200 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2019-04-29 21:54:10 +0200 |
commit | c20d4cac1fb72afe26a3e534b92e9a9691936458 (patch) | |
tree | 01bf7a57b8ea8dd7a9ec6aa26b3020aeb0274ecb | |
parent | c21d912a027056c30ee86c1ce021322e89f474c3 (diff) | |
download | guix-c20d4cac1fb72afe26a3e534b92e9a9691936458.tar guix-c20d4cac1fb72afe26a3e534b92e9a9691936458.tar.gz |
processes: Gracefully handle daemons without clients.
Fixes <https://bugs.gnu.org/34716>.
Reported by Mark H Weaver <mhw@netris.org>.
The problem could be reproduced by running, on one hand:
sh -c 'exec -a guix-daemon sleep 777'
and on the other hand:
guix processes
If there is no process with PID 777, 'guix processes' would barf as it
stumbles upon a <daemon-session> record whose client is #f.
* guix/scripts/processes.scm (daemon-sessions)[child-process->session]:
New procedure, with lambda formerly passed to 'map'. Handle #f returns
from 'lookup-process'.
Call 'child-process->session' within 'filter-map', not just 'map'.
-rw-r--r-- | guix/scripts/processes.scm | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/guix/scripts/processes.scm b/guix/scripts/processes.scm index 2dd3bbf30a..a2ab017490 100644 --- a/guix/scripts/processes.scm +++ b/guix/scripts/processes.scm @@ -158,15 +158,22 @@ active sessions, and the master 'guix-daemon' process." (= pid (process-parent-id process)))) processes)) - (values (map (lambda (process) - (match (process-command process) - ((argv0 (= string->number client) _ ...) - (let ((files (process-open-files process))) - (daemon-session process - (lookup-process client) - (lookup-children (process-id process)) - (filter lock-file? files)))))) - children) + (define (child-process->session process) + (match (process-command process) + ((argv0 (= string->number client) _ ...) + (let ((files (process-open-files process)) + (client (lookup-process client))) + ;; After a client has died, there's a window during which its + ;; corresponding 'guix-daemon' process is still alive, in which + ;; case 'lookup-process' returns #f. In that case ignore the + ;; session. + (and client + (daemon-session process client + (lookup-children + (process-id process)) + (filter lock-file? files))))))) + + (values (filter-map child-process->session children) master))) (define (daemon-session->recutils session port) |