Need threads help

[batavus]

I'm wanting to run 10 threads, doing their thing, and when one finishes, start up another one. Thus keeping 10 going at all times until the end of looping through a list.

For example code below:

#!/usr/bin/perl

use threads;

sub mythread
{
my $arg1 = shift;
my $arg2 = shift;
my $myself = threads->self;
my $threadid = $myself->tid;

print "Thread $threadid with $arg1 and $arg2 to do something...\n";
sleep 30;
}

MYLOOP: foreach (0 ... 100)
{
print "checking thread count...";
if (threads->list == 10) {sleep 30; redo MYLOOP;}
$a=$_;
$b=$_ + 10;
push @threads, threads->create("mythread",($a,$b));
}


When I run this, however, it blows chunks:

# ./threadtest.pl
checking thread count...Thread 1 with 0 and 10 to do something...
Can't call method "tid" without a package or object reference at /usr/opt/perl5/lib/5.8.2/aix-thread-multi/threads.pm line 57.
checking thread count...A thread exited while 2 threads were running.


What am I doing wrong with this approach?

Thanks,

---
Batavus

 

[TrojanWarBlade]

Point 1: Always "use strict;".
Point 2: How can you expect to call a method "tid" on "$myself" when you haven't defined "$myself"?
Point 3: I think you'll find the "tid" is a thread object method and therefore you can only call it from the parent process using the thread object returned to that parent process.


Trojan.

 

[batavus]

Thanks for the response TrojanWarBlade. But, if I take tid call out of my code, it still blows chunks:

#!/usr/bin/perl

use threads;

sub mythread
{
my $arg1 = shift;
my $arg2 = shift;

print "Thread with $arg1 and $arg2 to do something...\n";
system(sleep 30);
}

MYLOOP: foreach (0 ... 100)
{
if (threads->list == 10) {sleep 30; redo MYLOOP;}
$a=$_;
$b=$_ + 10;
$myt = threads->create("mythread",($a,$b));
}


# ./threadtest.pl
Thread with 0 and 10 to do something...
Can't call method "tid" without a package or object reference at /usr/opt/perl5/lib/5.8.2/aix-thread-multi/threads.pm line 57.
A thread exited while 2 threads were running.


Notice where it is failing the method call to "tid", not in my code but un the threads.pm package/module.

What I'm thinking at the moment is to just detach every thread, then somehow keep track of them outside of the threads module. Maybe by creating /tmp empty file entries while the thread is running, then the thread would remove the empty file in /tmp before it returns. Thus the 'parent' program can keep track of threads by checking /tmp for those file entries. Not elaborite, but should work for the single use functionality I'm looking for in this script.

Anyone else have some suggestions?

Thanks,

---
Batavus