From: Joseph McDonald <joe@...>
Date: 2001-06-29T10:15:44+09:00
Subject: [ruby-talk:17039] Re: sigprocmask


JM> Is there a way to call sigprocmask in ruby?  Here is an
JM> example in perl:

JM> # Block these signals while we're forking.
JM>     $sigset = POSIX::SigSet->new(SIGINT SIGTERM);
JM>     sigprocmask(SIG_BLOCK, $sigset)
JM>         or die "Can't block signals for fork: $!\n";

FYI, the reason sigprocmask is called is because: according to perl
cookbook  recipe 16.20:
http://www.google.com/search?q=cache:x4-36hS5iMM:urth.acsu.buffalo.edu/~pjg/perlcd/cookbook/ch16_21.htm+%22the+most+paranoid+of+programmers+block+signals%22&hl=en&lr=lang_en

"The most paranoid of programmers block signals for a fork to prevent
a signal handler in the child process being called before Perl can
update the child's $$ variable, its process id. If the signal handler
were called immediately and reported $$ in that handler, it could
possibly report its parent's $$, not its own. This issue does not
arise often."

I don't know if this could happen in ruby or not, but this is for a
program that handles thousands of requests per minute and is a forker.
It is currently written in perl, but I'd like that to change... :-)
If this is not a concern for ruby, even better, but I'm not quite sure
how to tell.

I took a look at signal.c in the ruby source and see that it does use
sigprocmask, but I'm not quite sure how to use it via ruby itself.

thanks,
-joe