Re^4: DBI and fork() on Win32

I'm ready to just give up... Got rid of the fork() and replaced with

system(1, "perl", "child-script", $job);
[download]

This crashes too, even when 'child-script' contains just two lines:

print "hello world\n";
exit;
[download]

Comment on Re^4: DBI and fork() on Win32 Select or Download Code

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Re^5: DBI and fork() on Win32 by Corion (Patriarch) on Feb 10, 2009 at 15:46 UTC
You need to be a bit more precise because the following Works On My Machine: `#!perl -w use strict; use DBI; my $dsn = 'dbi:SQLite:dbname=tmp.sqlite'; while (1) { my $dbh = DBI->connect($dsn,undef,undef,{RaiseError => 1}); # Parent + connecting # .. get a job list .. my @jobs = qw(Corion FloydATC FloydATD); $dbh->disconnect(); # <-- NB! foreach my $job (@jobs) { my @cmd = ($^X, '-le', q{"print 'Processing ', join '_', @ARGV"}, +$job); system(1, @cmd); } sleep 1; } print "Done.";` [download] Of course, I'm not really doing anything with the DBI handle, but maybe you can try my version and then work your way up to your version.	[reply] [d/l]
Re^6: DBI and fork() on Win32 by jand (Friar) on Feb 10, 2009 at 19:50 UTC
This will only start up to 63 child processes before `system(1, ...)` will start failing. You could either capture the return value of the `system(1, ...)` call, which is a PID, or more generally just use the sample code from the waitpid() documentation before calling `system(1, ...)` to reap all zombie processes. This is necessary because Perl keeps these PIDs together with the PIDs returned by the fork() emulation in a single table that has a limit of 63 entries. This somewhat arbitrary number comes from the `WaitForMultipleObjects()` Windows API that is used in the implementation of `wait()`.	[reply] [d/l] [select]
Re^7: DBI and fork() on Win32 by FloydATC (Deacon) on Feb 10, 2009 at 21:42 UTC
Yup after the not-so-subtle hint in the direction of perlport I read up on this ugly thing that is system(1, ...) and figured as much. Thanks :-)	[reply]
Re^6: DBI and fork() on Win32 by FloydATC (Deacon) on Feb 10, 2009 at 17:35 UTC
Indeed, it works now, I was tripped by a typo. Now for the next interesting challenge... `The process cannot access the file because it is being used by another + process.` [download] And people actually PAY for this operating system.	[reply] [d/l]