[pve-devel] [RFC PATCH 1/1] Add run_or_get_killed utility

[Emmanuel Kasper]

This runs subroutine in a forked process
and kills it after a timeout
---
 src/PVE/Tools.pm | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index da7da5d..0bf94ae 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -841,6 +841,49 @@ sub next_spice_port {
     return next_unused_port(61000, 61099, $family, $address);
 }
 
+# sigkill a $sub running in a fork if it can't write a pipe after $timeout
+# the $sub has to return a single scalar
+sub run_or_get_killed {
+    my ($sub, $timeout) = @_;
+
+    my $res;
+
+    my $pipe = IO::Pipe->new();
+    my $child = fork();
+    if (!defined($child)) {
+	warn "fork failed: $!\n";
+	return $res;
+    }
+
+    if (!$child) {
+	$pipe->writer();
+	eval {
+	    $res = $sub->();
+	    print {$pipe} "$res";
+	    $pipe->close();
+	};
+	if (my $err = $@) {
+	    warn $err;
+	    POSIX::_exit(1);
+	}
+	POSIX::_exit(0);
+    }
+
+    $pipe->reader();
+
+    my $readvalues = sub {
+	$res = (<$pipe> =~ /^(.*)$/)[0];
+    };
+    eval {
+	run_with_timeout($timeout, $readvalues);
+    };
+    warn $@ if $@;
+    $pipe->close();
+    kill('KILL', $child);
+    waitpid($child, 0);
+    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"
-- 
2.11.0