Created: 2012-03-25 04:13
Updated: 2017-07-05 23:15


IPC::Transit - A framework for high performance message passing


The serialization is currently hard-coded to


use strict;
use IPC::Transit;
IPC::Transit::send(qname => 'test', message => { a => 'b' });

#...the same or a different process on the same machine
my $message = IPC::Transit::receive(qname => 'test');

#remote transit
remote-transitd &  #run 'outgoing' transitd gateway
IPC::Transit::send(qname => 'test', message => { a => 'b' }, destination => '');

#On '':
plackup --port 9816 $(which remote-transit-gateway.psgi) &  #run 'incoming' transitd gateway
my $message = IPC::Transit::receive(qname => 'test');


This queue framework has the following goals:

  • Serverless
  • High Throughput
  • Usually Low Latency
  • Relatively Good Reliability
  • CPU and Memory efficient
  • Cross UNIX Implementation
  • Multiple Language Compability
  • Very few module dependencies
  • Supports old version of Perl
  • Feature stack is modular and optional

This queue framework has the following anti-goals:

  • Guaranteed Delivery


send(qname => 'some_queue', message => $hashref, [destination => $destination, serializer => 'some serializer', crypto => 1 ])

This sends $hashref to 'some_queue'. some_queue may be on the local box, or it may be in the same process space as the caller.

This call will block until the destination queue has enough space to handle the serialized message.

The destination argument is optional. If defined, it is the remote host will receive the message.

The serialize argument is optional, and defaults to Sereal. It is over-ridden with the IPC_TRANSIT_DEFAULT_SERIALIZER environmental variable. The following serializers are available:

serial, json, yaml, storable, dumper

NB: there is no need to define the serialization type in receive. It is automatically detected and utilized.

The crypto argument is optional. See below for details.

receive(qname => 'some_queue', nonblock => [0|1], override_local => [0|1])

This function fetches a hash reference from 'some_queue' and returns it. By default, it will block until a reference is available. Setting nonblock to a true value will cause this to return immediately with 'undef' is no messages are available.

override_local defaults to false; if set to true, the receive will always do a non-process local receive.

stat(qname => 'some_queue')

Returns various stats about the passed queue name, per IPC::Msg::stat:

print Dumper IPC::Transit::stat(qname => 'test');
$VAR1 = {
         'ctime' => 1335141770,
         'cuid' => 1000,
         'lrpid' => 0,
         'uid' => 1000,
         'lspid' => 0,
         'mode' => 438,
         'qnum' => 0,
         'cgid' => 1000,
         'rtime' => 0,
         'qbytes' => 16384,
         'stime' => 0,
         'gid' => 1000


Return an array of hash references, each containing the information obtained by the stat() call, one entry for each queue on the system.


On send(), if the crypto argument is set, IPC::Transit will sign and encrypt the message before it is sent. The necessary configs, including relevant keys, are set in some global variables.

See an actual example of this in action under ex/

Please note that this module does not directly assist with the always onerous task of key distribution.


If not set, this defaults to the output of the module Sys::Hostname. This value is placed into the message by the sender, and used by the receiver to lookup the public key of the sender.


This is a hash reference initially populated, in the attribute 'default', with the private half of a default key pair. For actual secure communication, a new key pair must be generated on both sides, and the sender's private key needs to be placed here:

$IPC::Transit::my_keys->{private} = $real_private_key


As above, this is a hash reference initially populated, in the attribute 'default', with the public half of a default key pair. For actual secure communication, a new key pair must be generated on both sides, and the receiver's public key needs to be placed here:

$IPC::Transit::public_keys->{$receiver_hostname} = $real_public_key_from_receiver

$receiver_hostname must exactly match what is passed into the 'destination' field of send().

All of these keys must be base 64 encoded 32 byte primes, as used by the Crypto::Sodium package.


This returns a two element array representing a public/privte key pair, properly base64 encoded for use in $IPC::Transit::my_keys and $IPC::Transit::public_keys


A zillion other queueing systems.


Implement nonblock flag for send()


Patches, flames, opinions, enhancement ideas are all welcome.

I am not satisfied with not supporting Windows, but it is considered secondary. I am open to the possibility of adding abstractions for this kind of support as long as it doesn't impact the primary goals.


Copyright (c) 2012, 2013, 2016 Dana M. Diederich. All Rights Reserved.


This module is free software. It may be used, redistributed and/or modified under the terms of the Perl Artistic License (see


Dana M. Diederich <>

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