NAME
forks::BerkeleyDB - high-performance drop-in replacement for threads
VERSION
This documentation describes version 0.054.
SYNOPSYS
use forks::BerkeleyDB;
my $thread = threads->new( sub { # or ->create or async()
print "Hello world from a thread\n";
} );
$thread->join;
threads->detach;
$thread->detach;
my $tid = $thread->tid;
my $owntid = threads->tid;
my $self = threads->self;
my $threadx = threads->object( $tidx );
threads->yield();
$_->join foreach threads->list;
unless (fork) {
threads->isthread; # intended to be used in a child-init Apache handler
}
use forks qw(debug);
threads->debug( 1 );
perl -Mforks::BerkeleyDB -Mforks::BerkeleyDB::shared threadapplicationDESCRIPTION
forks::BerkeleyDB is a drop-in replacement for threads, written as an extension of forks. The goal of this module is to improve upon the core performance of forks at a level comparable to native ithreads.
REQUIRED MODULES
BerkeleyDB (0.27)
Devel::Required (0.07)
forks (0.23)
Storable (any)
Tie::Restore (0.11)USAGE
See forks for common usage information.
Environment Variables
forks::BerkeleyDB supports several environment variables.
TMPDIR
forks::BerkeleyDB requires a temporary directory to store all BerkeleyDB environment and database files. This variable is controlled by File::Spec, so the default location for such files (in the case that TMPDIR is unset) will depend on your platform; e.g. File::Spec::Unix checks $ENV{TMPDIR} (unless taint is on) and /tmp.
THREADS_BDB_ENV_CHMOD
Sets the default file and directory permissions of BerkeleyDB environment and database files. If unset, will use the Perl default; e.g. current process (thread) umask with defaults for mkdir and open.
THREADS_BDB_ENV_CHOWN
Sets the default group owner of BerkeleyDB environment and database files. If unset, will use the Perl default; e.g. current process (thread) effective user.
THREADS_BDB_ENV_CHGRP
Sets the default group owner of BerkeleyDB environment and database files. If unset, will use the Perl default; e.g. current process (thread) effective group.
NOTES
If you have forks.pm 0.23 or later installed, all database files created during runtime will be automatically purged when the main thread exits. If you have created a large number of shared variables, you may experience a slight delay during process exit. Note that these files may not be cleaned up if the main thread or process group is terminated using SIGKILL, although existance of these files after exit should not have an adverse affect on other currently running or future forks::BerkeleyDB processes.
Testing has been performed against BerkeleyDB 4.3.x. Full compatibility is expected with BDB 4.x and likely with 3.x as well. Unclear if all tie methods are compatible with 2.x. This module is currently not compatible with BDB 1.x.
CAVIATS
This module defines CORE::GLOBAL::fork to insure BerkeleyDB resources are correctly managed before and after a fork occurs. This insures that processes will be able to safely use threads->isthread. You may encounter issues with your application or other modules it uses also define CORE::GLOBAL::fork. To work around this, you should modify your CORE::GLOBAL::fork to support chaining, like the following
use subs 'fork';
*_oldfork = \&CORE::GLOBAL::fork;
sub fork {
#your code here
...
_oldfork->() if ref(*oldfork) eq 'SUB';
}TODO
See the TODO file in the distribution.
AUTHOR
Eric Rybski <rybskej@yahoo.com>.
COPYRIGHT
Copyright (c) 2006-2008 Eric Rybski <rybskej@yahoo.com>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.