proxmox-mirrors/pve-common
1
0
Fork 0
mirror of https://git.proxmox.com/git/pve-common synced 2025-06-03 17:24:46 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Add run_fork_with_timeout utility

Browse Source 
This runs subroutine in a forked process
and kills it after a timeout
This commit is contained in:
Emmanuel Kasper 2017-06-29 14:48:12 +02:00 committed by Wolfgang Bumiller
parent 61a967bf1f
commit 72fba9114b
1 changed files with 66 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
src/PVE/Tools.pm
View File

@ -839,6 +839,72 @@ sub next_spice_port {
return next_unused_port(61000, 61099, $family, $address);
}
# sigkill after $timeout a $sub running in a fork if it can't write a pipe
# the $sub has to return a single scalar
sub run_fork_with_timeout {
my ($timeout, $sub) = @_;
my $res;
my $error;
my $pipe_out = IO::Pipe->new();
my $pipe_err = IO::Pipe->new();
# disable pending alarms, save their remaining time
my $prev_alarm = alarm 0;
# trap before forking to avoid leaving a zombie if the parent get killed
my $sig_received;
local $SIG{INT} = $SIG{TERM} = $SIG{QUIT} = $SIG{HUP} = $SIG{PIPE} = sub {
$sig_received++;
};
my $child = fork();
if (!defined($child)) {
die "fork failed: $!\n";
return $res;
}
if (!$child) {
$pipe_out->writer();
$pipe_err->writer();
eval {
$res = $sub->();
print {$pipe_out} "$res";
$pipe_out->flush();
};
if (my $err = $@) {
print {$pipe_err} "$err";
$pipe_err->flush();
POSIX::_exit(1);
}
POSIX::_exit(0);
}
$pipe_out->reader();
$pipe_err->reader();
my $readvalues = sub {
local $/ = undef;
$res = <$pipe_out>;
$error = <$pipe_err>;
};
eval {
run_with_timeout($timeout, $readvalues);
};
warn $@ if $@;
$pipe_out->close();
$pipe_err->close();
kill('KILL', $child);
waitpid($child, 0);
alarm $prev_alarm;
die "interrupted by unexpected signal\n" if $sig_received;
die $error if $error;
return $res;
}
# NOTE: NFS syscall can't be interrupted, so alarm does
# not work to provide timeouts.
# from 'man nfs': "Only SIGKILL can interrupt a pending NFS operation"