NAME
    Parallel::Prefork - A simple prefork server framework

SYNOPSIS
      use Parallel::Prefork;
  
      my $pm = Parallel::Prefork->new({
        max_workers  => 10,
        trap_signals => {
          TERM => 'TERM',
          HUP  => 'TERM',
          USR1 => undef,
        }
      });
  
      while ($pm->signal_received ne 'TERM') {
        load_config();
        $pm->start and next;
    
        ... do some work within the child process ...
    
        $pm->finish;
      }
  
      $pm->wait_all_children();

DESCRIPTION
    "Parallel::Prefork" is much like "Parallel::ForkManager", but supports
    graceful shutdown and run-time reconfiguration.

METHODS
  new
    instantiation. Takes a hashref as an argument. Recognized attributes are
    as follows.

   max_workers
    number of worker processes (default: 10)

   spawn_interval
    interval in seconds between spawning child processes unless a child
    process exits abnormally (default: 0)

   err_respawn_interval
    number of seconds to deter spawning of child processes after a worker
    exits abnormally (default: 1)

   trap_signals
    hashref of signals to be trapped. Manager process will trap the signals
    listed in the keys of the hash, and send the signal specified in the
    associated value (if any) to all worker processes. If the associated
    value is a scalar then it is treated as the name of the signal to be
    sent immediately to all the worker processes. If the value is an
    arrayref the first value is treated the name of the signal and the
    second value is treated as the interval (in seconds) between sending the
    signal to each worker process.

   on_child_reap
    coderef that is called when a child is reaped. Receives the instance to
    the current Paralle::Prefork, the child's pid, and its exit status.

  start
    The main routine. Returns undef in child processes. Returns a true value
    within manager process upon receiving a signal specified in the
    "trap_signals" hashref.

  finish
    Child processes should call this function for termination. Takes exit
    code as an optional argument. Only usable from child processes.

  signal_all_children
    Sends signal to all worker processes. Only usable from manager process.

  wait_all_children
    Blocks until all worker processes exit. Only usable from manager
    process.

AUTHOR
    Kazuho Oku

LICENSE
    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

    See http://www.perl.com/perl/misc/Artistic.html

