Perl kill(0, $pid) in Windows always returning 1
- by banshee_walk_sly
I'm trying to make a Perl script that will run a set of other programs in Windows. I need to be able to capture the stdout, stderr, and exit code of the process, and I need to be able to see if a process exceeds it's allotted execution time.
Right now, the pertinent part of my code looks like:
...
$pid = open3($wtr, $stdout, $stderr, $command);
if($time < 0){
waitpid($pid, 0);
$return = $? >> 8;
$death_sig = $? & 127;
$core_dump = $? & 128;
}
else{
# Do timeout stuff, currently not working as planned
print "pid: $pid\n";
my $elapsed = 0;
#THIS LOOP ONLY TERMINATES WHEN $time > $elapsed ...?
while(kill 0, $pid and $time > $elapsed){
Time::HiRes::usleep(1000); # sleep for milliseconds
$elapsed += 1;
$return = $? >> 8;
$death_sig = $? & 127;
$core_dump = $? & 128;
}
if($elapsed >= $time){
$status = "FAIL";
print $log "TIME LIMIT EXCEEDED\n";
}
}
#these lines are needed to grab the stdout and stderr in arrays so
# I may reuse them in multiple logs
if(fileno $stdout){
@stdout = <$stdout>;
}
if(fileno $stderr){
@stderr = <$stderr>;
}
...
Everything is working correctly if $time = -1 (no timeout is needed), but the system thinks that kill 0, $pid is always 1. This makes my loop run for the entirety of the time allowed.
Some extra details just for clarity:
This is being run on Windows.
I know my process does terminate because I have get all the expected output.
Perl version: This is perl, v5.10.1 built for MSWin32-x86-multi-thread
(with 2 registered patches, see perl -V for more detail) Copyright 1987-2009, Larry Wall
Binary build 1007 [291969] provided by ActiveState http://www.ActiveState.com
Built Jan 26 2010 23:15:11
I appreciate your help :D
For that future person who may have a similar issue
I got the code to work, here is the modified code sections:
$pid = open3($wtr, $stdout, $stderr, $command);
close($wtr);
if($time < 0){
waitpid($pid, 0);
}
else{
print "pid: $pid\n";
my $elapsed = 0;
while(waitpid($pid, WNOHANG) <= 0 and $time > $elapsed){
Time::HiRes::usleep(1000); # sleep for milliseconds
$elapsed += 1;
}
if($elapsed >= $time){
$status = "FAIL";
print $log "TIME LIMIT EXCEEDED\n";
}
}
$return = $? >> 8;
$death_sig = $? & 127;
$core_dump = $? & 128;
if(fileno $stdout){
@stdout = <$stdout>;
}
if(fileno $stderr){
@stderr = <$stderr>;
}
close($stdout);
close($stderr);
