
Forks::Super version 0.22
=========================

Forks::Super provides drop-in replacements for the Perl
fork(), wait(), and waitpid() functions with
additional features for spawning background processes
and managing them, including:

   *  forking to shell command or subroutine

      can specify a shell command or a Perl subroutine
      (name or code reference) to invoke in the child
      process

   *  setting deadlines

      can specify a deadline (in relative or absolute
      time) for a background process to complete. 
      The background process will be killed if it does
      not complete by the deadline.

   *  throttling

      Limiting the number of simultaneous processes.
      Callers can install their own functions to determine
      when the system is too busy to launch another
      job.

   *  dependencies

      Jobs can be specified to wait until other jobs
      have started and/or completed before they can begin.

   *  deferred jobs

      Jobs can be specified to start at some specific time in
      the future, or to be launched under some specific
      future conditions. Arbitrary priorities can be
      assigned to jobs so that more urgent jobs will be
      launched first

   *  access to standard child filehandles

      Parent process can have access to STDIN, STDOUT,
      and STDERR filehandles of child processes to
      facilitate interprocess communication
      
   *  operating system features

      On some operating systems, the priority and CPU affinity
      of the child processes can be set.


INSTALLATION

The typical installation recipe

   perl Makefile.PL
   make
   make test
   make install

usually works. A few of the tests are subject to some
hard-to-investigate race conditions and may fail
intermittently. Running "make test" again or installing
the "Time::HiRes" module may increase the chance of
passing the test phase. Some of the tests are also more
likely to fail on a heavily loaded system.

Tests from the file "t/60-os.t" cover the operating-
system dependent functionality of this module. These
tests may fail on some configurations, but that should
not discourage you from installing this module.


DEPENDENCIES

This module requires these other modules and libraries,
all included with the standard distribution:

    Carp
    Exporter
    POSIX
    File::Path
    IO::Handle

Forks::Super recommends and will make use of the following 
modules if they are installed, but will still be able
to perform all of its functions without using them:

    Time::HiRes

The bg_eval function, to evaluate Perl code in the background,
requires YAML. 

Certain operating system dependent features may not work
(usually failing silently) if these OS-specific modules
are not installed:

    Win32::Process [Windows and Cygwin]
    Win32          [Windows]
    Win32::API     [Windows]
    BSD::Process::Affinity [BSD]

WINDOWS

Some features of this module do not work or work a
little differently with Windows systems. See the
README.windows file included in this distribution
for important information.


COPYRIGHT AND LICENCE

Copyright (c) 2009-2010, Marty O'Brien.

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.8 or,
at your option, any later version of Perl 5 you may have available.


