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This document describes MCE version 1.608.

 Many-Core Engine (MCE) for Perl helps enable a new level of performance by
 maximizing all available cores. MCE spawns a pool of workers and therefore
 does not fork a new process per each element of data. Instead, MCE follows
 a bank queuing model. Imagine the line being the data and bank-tellers the
 parallel workers. MCE enhances that model by adding the ability to chunk
 the next n elements from the input stream to the next available worker.

 MCE uses domain sockets for IPC versus pipes. One day, a physical box will
 have hundreds of cores. MCE can spawn 960 workers (via fork) for ulimit re-
 porting 1024 allowed for max user processes. Other parallel implementations
 using pipes cannot do this (only about half of ulimit -u).

Chunking in MCE.

 Input data is optional in MCE. Thus, input data is not required to run MCE.

 MCE iterates over input data in chunks. Workers can be spawned prior to
 creating or obtaining data. MCE is a chunking engine. It does not divide
 the input equally by the number of workers. Instead, it chunks from
 start till end.

 Imagine input data as a highway. Now think of MCE (automobile) on the
 highway. Basically, data can be larger than physical memory allows.
 The chunking nature of MCE makes this possible.

    input_data => '/path/to/file',  ## process a file in parallel
    input_data => \@array,          ## process an array in parallel
    input_data => \*FileHandle,     ## process a filehandle in parallel
    input_data => \$scalar,         ## treated like a memory-based file
    input_data => \&iterator,       ## allows for custom input iterator

 MCE can iterate over a sequence of numbers mathematically if all you need
 is a numeric iterator. Check out forseq.pl and seq_demo.pl.

    sequence => { begin => 1, end => 100, step => 2 },
    chunk_size => 20,      ## Worker receives the next 20 sequences

Use Cases for MCE.

 1. Perl is not compiled with threads support and wanting something similar
    to Thread::Queue. Check out MCE::Flow and MCE::Queue.

 2. Wanting multiple roles and each role uniquely configured with number of
    workers and function to execute. Check out flow_demo.pl and step_demo.pl.

 3. Wanting to process rows from a database in parallel. Check out sampledb
    under the examples directory.

 4. MCE can be used to process a single (large) file or process many (small)
    files in parallel. Take bin/mce_grep, a wrapper around the grep binary,
    for a test drive. MCE also includes egrep.pl for a pure Perl grep
    implementation.

 5. A large telecom company wanting to poll millions of devices via SNMP.
    This is possible with MCE, AnyEvent::SNMP, and Net::SNMP. Think of
    having 200 workers and each worker connecting to 300 devices with
    AnyEvent. Each worker processes 300 devices simultaneously.

 6. Wanting to access many hosts in parallel via SSH or TCP/IP.

 ...

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INSTALLATION

 To install this module type the following:

    MCE_INSTALL_TOOLS=1 perl Makefile.PL   (e.g. bin/mce_grep)

    (or) perl Makefile.PL

    make
    make test
    make install

DEPENDENCIES

 This module requires Perl 5.8.0 or later to run.

    MCE spawns child processes by default, not threads.

    However, MCE supports threads via 2 threading libraries if threads
    is desired.

    The use of threads in MCE requires that you include threads support
    prior to loading MCE. The use_threads option defaults to 1 when a
    thread library is loaded. Threads is loaded automatically for
    $^O eq 'MSWin32'.

    use threads;                use forks;
    use threads::shared;  (or)  use forks::shared;
    use MCE;                    use MCE;

 MCE utilizes the following modules:

    bytes
    constant
    Carp
    Fcntl
    File::Path
    IO::Handle
    Scalar::Util
    Socket
    Storable 2.04+
    Symbol
    Test::More 0.45+ (for testing only via make test)
    Time::HiRes

COPYRIGHT AND LICENCE

 Copyright (C) 2012-2015 by Mario E. Roy <marioeroy AT gmail DOT com>

 This program is free software; you can redistribute it and/or modify it
 under the terms of either: the GNU General Public License as published
 by the Free Software Foundation; or the Artistic License.

 See L<http://dev.perl.org/licenses/> for more information.

USAGE

 The source is hosted at http://code.google.com/p/many-core-engine-perl/

 https://metacpan.org/module/MCE::Signal
 https://metacpan.org/module/MCE

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Enjoy MCE !!!

 - Mario

