Ovid has asked for the wisdom of the Perl Monks concerning the following question:
I'm sure there's an easy way around this with fork, but rather than guess at the answer, I'll just present the problem (I've been trying to solve this for a bit).
#!/usr/bin/perl use strict; use warnings; eval { local $SIG{ALRM} = sub { die "alarm\n" }; alarm 2; system("perl -e '1 while 1'") == 0 or die "Cannot do infinite loop: $!"; alarm 0; }; die $@ unless $@ eq "alarm\n"; # the following lines let me do a 'ps awux|grep perl' # while this is running print 'Hanging ...'; <STDIN>;
I don't do a huge amount of work with process management, so this is giving me fits. Basically, I sometimes need call code code which may never return but I have no way of knowing in advance if this is the case. I want an alarm to catch when that happens. However, when I do that, the proces is hanging around in the process table. How can I ensure that when the system times out that the process is reaped? I'm making about 10,000 system calls and this is rapidly killing my system.
Update:
I forgot that this isn't a real example of what I need. I also need the result, if any, of the command I execute. My actual code looks like this:
sub timeout { my ( $package, $timeout, $code ) = @_; my $result; eval { local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required alarm $timeout; $result = $code->(); alarm 0; }; if ($@) { die "Could not make $package: $@" unless $@ eq "alarm\n"; # + propagate unexpected errors # timed out } return $result; } timeout( $package, 10, sub {`perl $make_prog 2>&1`} );
Cheers,
Ovid
New address of my CGI Course.
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Replies are listed 'Best First'. | |
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Re: Killing a hanging child process
by liverpole (Monsignor) on Sep 11, 2006 at 23:33 UTC | |
Re: Killing a hanging child process
by sgifford (Prior) on Sep 11, 2006 at 22:21 UTC | |
Re: Killing a hanging child process
by ozone (Friar) on Sep 11, 2006 at 22:15 UTC | |
Re: Killing a hanging child process
by andyford (Curate) on Sep 11, 2006 at 22:09 UTC | |
Re: Killing a hanging child process
by zentara (Archbishop) on Sep 12, 2006 at 12:52 UTC | |
Re: Killing a hanging child process
by bluto (Curate) on Sep 12, 2006 at 19:21 UTC | |
Re: Killing a hanging child process
by sgt (Deacon) on Sep 13, 2006 at 22:43 UTC | |
by chb (Deacon) on Dec 22, 2006 at 08:36 UTC |