flom  1.5.22
About: FLoM is a simple lock manager that can be used to avoid shell tricks and safely execute different task that cannot run at the same time (inside a single system or a network of IP communicating systems). Development version.
  Fossies Dox: flom-1.5.22.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  

flom Documentation

Some Fossies usage hints in advance:

  1. To see the Doxygen generated documentation please click on one of the items in the steelblue colored "quick index" bar above or use the side panel at the left which displays a hierarchical tree-like index structure and is adjustable in width.
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 _____ _          __  __ 
|  ___| |    ___ |  \/  |  FLoM
| |_  | |   / _ \| |\/| |  Free Lock Manager
|  _| | |__| (_) | |  | |  a free and open source lock manager
|_|   |_____\___/|_|  |_|

FLoM (Free Lock Manager) is an open source and free lock manager designed to
serialize and synchronize shell command execution and custom programs
developed in C, C++, Java, Perl, PHP, Python.
Official web site is http://www.tiian.org/flom/
Both GitHub https://github.com/tiian/flom and 
SourceForge https://sourceforge.net/projects/flom/ host FLoM source code.
Basic usage examples are in doc/examples directory (default installation path 
is /usr/local/share/doc/flom/examples/)
API documentation is distributed in directory doc/html/ (default installation
path is /usr/local/share/doc/flom/html/) and on the web at http://www.tiian.org/flom/API/C/globals_func.html
FLoM is implemented using state of the art reactive programming:
independent non blocking threads reach unparalleled scalability and C language
source code guarantee the best performance. The usage of mutexes is reduced to
trifling functions: FLoM can be considered a "lock free lock manager".

A list of implemented use cases is listed at this URL: 
This is a brief list of the available features:
- synchronization of shell commands to avoid conflicts on files, directories,
  abstract resources
- enforcement of command order execution to avoid one command is executed
  before another one
- resource utilization leveling to avoid too many similar tasks run at the
  same time 
- all the synchronization features are available inside a single host or in
  a distributed environment using TCP/IP networking (both IPv4 and IPv6 are
- an autodiscovery feature is available to reduce deployment complexity in a
  cloud environment (every node at any time may become a "server" for
  the others node)
- easy API (Application Programming Interface) to synchronize your own
  programs with shell executed flom commands. These languages have a ready
  to use binding: C, C++, Java, Perl, PHP, Python.
- TLS (Transport Layer Security) support to protect network communication and
  to supply peer to peer mutual authentication based on X.509 certificates
- a large spectrum of different resources:
  1. simple: basic locking using DLM semantic
  2. hierarchical: HFS like semantic
  3. numerical: pools of undifferentiated resources
  4. set: sets of differentiated resources
  5. sequence: arrays of transactional (or non transactional) sequences
  6. timestamp: arrays of unique timestamp sequences

FLoM central documentation site is hosted by SourceForge Wiki: 

 * FLoM is free software: you can redistribute it and/or modify under the terms
 * of GNU General Public License version 2 as published by the Free Software
 * Foundation.
 * FLoM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * GNU General Public License for more details.

Download the tarball from SourceForge: https://sourceforge.net/projects/flom/
and install FLoM using standard GNU build chain: 
    tar xvzf flom-X.Y.Z.tar.gz
    cd flom-X.Y.Z
    sudo make install

Python 3 support: if you want to compile the API for Python 3, use:
    PYTHON_VERSION=3 ./configure
    sudo make install

If you are using a Red Hat derivative you will probably use
    make install
instead of "sudo make install".

Take a look to file INSTALL for more details.

man flom 
to read man page and pick up Internet relevant URLs for FLOM project.

make check
to perform package automatic tests.
NOTE: do *NOT* run tests on a system that's using flom because some tests
      need to kill all FLoM running instances and this is not acceptable if
      you are playing production workloads. DO USE A TEST SYSTEM!
NOTE: tests needs the system is NOT overloaded because they stick on timing
      and timing breaks if the system is overloaded.
NOTE: FLoM must be installed with "sudo make install" before tests can 
      proceed (this is a library path issue...)
NOTE: if you are not interested in C++ API library support, specify
      "--disable-cpp" at configure time; example:
      ./configure --disable-cpp
NOTE: if you are not interested in Java API library support, specify
      "--disable-java" at configure time; example:
      ./configure --disable-java
NOTE: if you are not interested in Perl API library support, specify
      "--disable-perl" at configure time; example:
      ./configure --disable-php
NOTE: if you are not interested in PHP API library support, specify
      "--disable-php" at configure time; example:
      ./configure --disable-php
NOTE: if you are not interested in Python API library support, specify
      "--disable-python" at configure time; example:
      ./configure --disable-python

Issues related to multicast and internal Linux firewalling:
the easiest way is to completely disable the internal firewall with
	systemctl stop firewalld 
	systemctl disable firewalld 
or alternatively
	service ipchains stop
	service iptables stop
	chkconfig ipchains off
	chkconfig iptables off
If you cannot disable the firewall and you want to use FLoM autodiscovery
feature (IP multicast based), you will have to configure the internal
firewall allowing FLoM multicast packets.

If you need some help (usage tricks, hints, etc...) please post a message in
the forum: http://sourceforge.net/p/flom/discussion/
If you think you have discovered a bug, please open an issue here:

Dependencies report:
O.S.		Feature		Packages
Ubuntu		Basic		make gcc libglib2.0-dev dbus libdbus-1-dev libssl-dev pkg-config automake
Ubuntu		C++ API		g++
Ubuntu		Perl API	swig libperl-dev
Ubuntu		PHP API		swig php5-cli php5-dev
Ubuntu	16.04	PHP API		swig php-cli php-dev
Ubuntu  18.04   PHP API         swig php-cli php-dev
Ubuntu		Python API	swig python-dev
Ubuntu	10.04	Java API	openjdk-6-jdk
Ubuntu	12.04	Java API	default-jdk (openjdk 6)
Ubuntu	14.04	Java API	default-jdk (openjdk 7)
Ubuntu	16.04	Java API	default-jdk (openjdk 8)
Ubuntu	18.04	Java API	default-jdk (openjdk 10)
CentOS		Basic		gcc glib2-devel dbus dbus-devel autoconf openssl-devel make
CentOS		C++ API		gcc-c++
CentOS		Perl API	swig perl-devel
CentOS		PHP API		swig php-devel
CentOS  6.x	Python API	swig python-devel
CentOS  7.x	Python 2 API	swig python-devel
CentOS  7.x	Python 3 API	swig python3-devel
CentOS  8.x	Python 3 API	swig python3-devel
CentOS	6.x	Java API	java-1.6.0-openjdk* or java-1.7.0-openjdk*
CentOS	7.x	Java API	java-1.8.0-openjdk*
CentOS	8.x	Java API	java-11-openjdk*

* Support not available for PHP 7.0 due to SWIG version, see also 

Enjoy FLoM!