Greetings Wise monks,

I am trying to make 10 consecutive HTTP calls and then wait for all 10 calls to finish before sending the data. I have found the below simple code I can modify to suit me needs.

My question is (Once i remove the sleeps) does the below method make 10 calls concurrently at the same time and then return the data for all 10 children. Or will this method simply make 10 calls one at a time defeating the purpose handily.

I am new to threads and any help you could give would be greatly appreciated.

Thank you kindly,

Perl Fork example 

 Perl Fork example 
  
 This examples fork 10 child processes. 
 It will wait for all childs to finish before exiting. 
  
 #!/usr/local/roadm/bin/perl 
  
 use strict; 
 use warnings; 
  
 print "Starting main program\n"; 
 my @childs; 
  
 for ( my $count = 1; $count <= 10; $count++) { 
         my $pid = fork(); 
         if ($pid) { 
         # parent    #print "pid is $pid, parent $$\n"; 
         push(@childs, $pid); 
         } elsif ($pid == 0) { 
                 # child 
                 sub1($count); 
                 exit 0; 
         } else { 
                 die "couldnt fork: $!\n"; 
         } 
  
  
  
 } 
  
 foreach (@childs) { 
          my $tmp = waitpid($_, 0); 
          print "done with pid $tmp\n";  ### DONE WITH HTTP CHILD 
  
 } 
  
 print "End of main program\n"; ### RETURN DATA FOR ALL 10 CHILDREN 
  
  
 sub sub1 { 
         my $num = shift; 
         print "started child process for  $num\n"; ### Make my HTTP C
+ALL HERE 
         sleep $num; 
         print "done with child process for $num\n"; ### Return Data f
+or 1 HTTP CHILD 
         return $num; 
 } 
  
  
 Output looks like: 
  
 Starting main program 
 started child process for  1 
 started child process for  2 
 started child process for  3 
 started child process for  4 
 started child process for  5 
 started child process for  6 
 started child process for  9 
 started child process for  10 
 started child process for  7 
 started child process for  8 
 done with child process for 1 
 done with pid 5584 
 done with child process for 2 
 done with pid 5585 
 done with child process for 3 
 done with pid 5586 
 done with child process for 4 
 done with pid 5587 
 done with child process for 5 
 done with pid 5588 
 done with child process for 6 
 done with pid 5589 
 done with child process for 7 
 done with pid 5590 
 done with child process for 8 
 done with pid 5591 
 done with child process for 9 
 done with pid 5593 
 done with child process for 10 
 done with pid 5594 
 End of main program 
  
 Another Version of doing this without fork is below.:: 
 ------------------------------------------------------ 
 ---------------------------------------------------- 
 Below you'll find an example of a multi-threaded Perl program as well
+ as a forked Perl program. 
 Both seem to work fine. A disadvantage of threads is that Perl needs 
+to be compiled with threads support. 
 Not all versions of Perl come with that by default. 
 A Perl Thread example 
  
 #!/usr/local/roadm/bin/perl 
 # This is compiled with threading support 
  
 use strict; 
 use warnings; 
 use threads; 
 use threads::shared; 
  
 print "Starting main program\n"; 
  
 my @threads; 
 for ( my $count = 1; $count <= 10; $count++) { 
         my $t = threads->new(\&sub1, $count); 
         push(@threads,$t); 
 } 
 foreach (@threads) { 
         my $num = $_->join; 
         print "done with $num\n"; 
 } 
 print "End of main program\n"; 
  
 sub sub1 { 
         my $num = shift; 
         print "started thread $num\n"; 
         sleep $num; 
         print "done with thread $num\n"; 
         return $num; 
 } 
  
 Will print: 
  
 Starting main program 
 started thread 1 
 started thread 2 
 started thread 3 
 started thread 4 
 started thread 5 
 started thread 6 
 started thread 7 
 started thread 8 
 started thread 9 
 started thread 10 
 done with thread 1 
 done with 1 
 done with thread 2 
 done with 2 
 done with thread 3 
 done with 3 
 done with thread 4 
 done with 4 
 done with thread 5 
 done with 5 
 done with thread 6 
 done with 6 
 done with thread 7 
 done with 7 
 done with thread 8 
 done with 8 
 done with thread 9 
 done with 9 
 done with thread 10 
 done with 10 
 End of main program

[download]

I had posted a lengthy Thank you for your response but it never posted for some reason. So im posting it again.

Thank you much that cleared it all up for me.

especially the stored internally untill join() part.

In reply to Perl Threads Question. by Monkomatic

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