I believe the problem occurs when a SIGALRM and SIGCHLD occur very close together. The SIGALRM causes the program to exit the eval block's scope with the die("ALRM EVENT\n").

Could it be the other way around? I see that you're switching off the alarm outside of the eval. Maybe you should switch off the alarm inside the SIGCHLD handler: 

-local $SIG{'CHLD'} = sub { die("CHLD EVENT\n"); };
+local $SIG{'CHLD'} = sub { alarm(0); die("CHLD EVENT\n"); };

[download]
Another approach would be to return to using unsafe signal handlers inside the eval, see POSIX's sigaction() for that.

Liz

Update:
Actually, Perl 5.8.1 introduced a new idiom for temporarily allowing unsafe signals: 

local $ENV{PERL_SIGNALS} = 'unsafe';

[download]
From perl581delta.pod:
Unsafe signals again available
In Perl 5.8.0 the so-called "safe signals" were introduced. This means that Perl no longer handles signals immediately but instead "between opcodes", when it is safe to do so. The earlier immediate handling easily could corrupt the internal state of Perl, resulting in mysteri- ous crashes.

However, the new safer model has its problems too. Because now an opcode, a basic unit of Perl execution, is never interrupted but instead let to run to completion, certain operations that can take a long time now really do take a long time. For example, certain network operations have their own blocking and timeout mechanisms, and being able to interrupt them immediately would be nice.

Therefore perl 5.8.1 introduces a "backdoor" to restore the pre-5.8.0 (pre-5.7.3, really) signal behaviour. Just set the environment vari- able PERL_SIGNALS to "unsafe", and the old immediate (and unsafe) sig- nal handling behaviour returns. See "PERL_SIGNALS" in perlrun and "Deferred Signals (Safe Signals)" in perlipc.

In completely unrelated news, you can now use safe signals with POSIX::SigAction. See "POSIX::SigAction" in POSIX.

In reply to Re: BUG? die() executing outside scope of eval block by liz
in thread BUG! die() executing outside scope of eval block by jdhedden

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