BUG/MEDIUM: check/threads: make external checks run exclusively on thread 1
See GH issues #141 for all the context. In short, registered signal
handlers are not inherited by other threads during startup, which is
normally not a problem, except that we need that the same thread as
the one doing the fork() cleans up the old process using waitpid()
once its death is reported via SIGCHLD, as happens in external checks.
The only simple solution to this at the moment is to make sure that
external checks are exclusively run on the first thread, the one
which registered the signal handlers on startup. It will be far more
than enough anyway given that external checks must not require to be
load balanced on multiple threads! A more complex solution could be
designed over the long term to let each thread deal with all signals
but it sounds overkill.
This must be backported as far as 1.8.
(cherry picked from commit 6dd4ac890b5810b0f0fe81725fda05ad3d052849)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed