I'm using Strawberry Perl in a Windows 8 environment. I have a scheduler I have written in Perl that I have been using for a couple of years. Its a threaded application that runs more than 1500 jobs every night, so its doing a lot of the same thing over and over.

The main engine spawns worker threads to run the individual jobs and reports some progress to STDOUT. I have had issues in the past where STDOUT would somehow get corrupted and the engine would stop reporting progress but continue to run and I would eventually find my progress messages in one of the job log files.

I haven't seen that issue in a while, but lately I find the engine has simply hung. It writes messages to both STDOUT and to a log file, and I've been adding debugging left and right, and it simply appears to be hanging on prints to STDOUT.

Autoflush is on and I can see single character updates, but here's an example: 

sub message {
    if ($options{verbose} && $options{verbose} >= ($_[1] || 0)) {
        if ($inprogress) { print "\n"; $inprogress = 0; }
        print "<";
        my @time = localtime;
        print ">";
        printf "%04d-%02d-%02d %02d:%02d:%02d %s\n", $time[5] + 1900,
            $time[4] + 1, $time[3], $time[2], $time[1], $time[0],
            $_[0];
    }
}

[download]
$_[0] is the message I want to print. I thought maybe I was hanging trying to get the local time, but no. I put the < and > prints on either side of the localtime, but it hung between the > and the printf of the message.

Has anyone had experience with this?

In reply to Hang on STDOUT by DanEllison

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