#!/usr/bin/perl
use strict;
use warnings;
use threads;
use threads::shared;
use POSIX;

# on linux, watch with "ps -T uxww" to see threads

# daemonize
if(1) {
exit if fork;
POSIX::setsid();
}

# script goes here
open (FH,">$0.out")or die "$!\n"; #prints go to FH
select(*FH);
$| = 1; # Turn on autoflush for FH


my %shash;
my @to_be_processed = ('a'..'z');
my @ready:shared = ();

my $numworkers = 10;

foreach my $dthread(1..$numworkers){
  share $shash{$dthread}{'go'};
  $shash{$dthread}{'go'} = 0;
  
  share $shash{$dthread}{'fileno'}; #in case you want 
  $shash{$dthread}{'fileno'} = '';  #shared filehandles
  
  share $shash{$dthread}{'data'};
  $shash{$dthread}{'data'} = '';
  
  share $shash{$dthread}{'pid'};
  $shash{$dthread}{'pid'} = -1;
  
  share $shash{$dthread}{'die'};
  $shash{$dthread}{'die'} = 0;
  
  $shash{$dthread}{'thread'} = threads->new(\&worker, $dthread);
  push @ready, $dthread;   
}

#print "\t\t",scalar @ready," threads ready.......press a key to start threads\n";
#<>;

RUN:
print FH "Running again\n";

@to_be_processed = ('a'..'z'); #reload fake data

while (my $t = shift(@ready)){
     $shash{$t}{'data'} = shift @to_be_processed;
     $shash{$t}{'go'} = 1; 
}


while(1){

    if( scalar @ready > 0 ){

         if( my $data = shift @to_be_processed ){
            my $t = shift(@ready);
            $shash{$t}{'data'} = $data;
            $shash{$t}{'go'} = 1; 
            #print "thread $t restarting\n";
          }else{ print  "out of input\n"; goto WAIT;  }
     }
}

WAIT:

#print "at end loop\n";

print FH "sleeping\n";
for(1..10){ sleep(1) }

print "restarting another  run\n"; 

goto RUN;


###############################################3


sub worker{
   my $thr_num = shift;
   #print "$thr_num started\n"; 
   my $count;
START:  
   while(1){
      
      if( $shash{$thr_num}{'die'} ){
             #print "thread $thr_num finishing\n"; 
             return} 
      #wait for $go_control  
      if($shash{$thr_num}{'go'}){      
          
                 if($shash{$thr_num}{'die'}){
                    #print "thread finishing\n"; 
                           return} 
               
               $count++;            
               my $str = '    'x$thr_num; #printout spacer
               #print  $str.$thr_num.'->'.$count.$shash{$thr_num}{'data'},"\n";
	      
	       if ($count > 10){ goto RECYCLE; }
	
	       select(undef,undef,undef,.1);
               #sleep rand 5
        
        }else{ 
         $count = 0;
         select(undef,undef,undef,.1); }# sleep until awakened 
   } #end while(1)

RECYCLE:
$shash{$thr_num}{'go'} = 0;
#print "$thr_num done....going back to sleep\n";
$shash{$thr_num}{'data'} = '';
$count = 0;
push @ready, $thr_num;
#print "pushing $thr_num\n";
goto START;
return;
}