|Perl Monk, Perl Meditation|
Re^4: Perl Signalsby afoken (Parson)
|on Nov 17, 2011 at 16:51 UTC||Need Help??|
[...] the requirement to re-install a signal handler is some super ancient (many decades ago) stuff. [...] I would think that the Perl docs should be updated.
So do I.
this while() loop in the reaper is definitely needed
I have no problem with the while loop in the reaper, it is properly explained in perlipc.
On the other hand, so is the problem with old SysV behaviour:
But that will be problematic for the more complicated handlers that need to reinstall themselves. Because Perl's signal mechanism is currently based on the signal(3) function from the C library, you may sometimes be so unfortunate as to run on systems where that function is "broken"; that is, it behaves in the old unreliable SysV way rather than the newer, more reasonable BSD and POSIX fashion. So you'll see defensive people writing signal handlers like this:
I think the paragraph cited above and the two examples following it should be moved into a new section "Signal Handlers on Ancient Systems" ("pre-POSIX systems"?), and be replaced with text and examples that concentrate on handling SIGCHLD / wait / waitpid instead of working around ancient API problems.
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)