NAME

Test::Stream::IPC - Enable concurrency in Test::Stream.

EXPERIMENTAL CODE WARNING

This is an experimental release! Test-Stream, and all its components are still in an experimental phase. This dist has been released to cpan in order to allow testers and early adopters the chance to write experimental new tools with it, or to add experimental support for it into old tools.

PLEASE DO NOT COMPLETELY CONVERT OLD TOOLS YET. This experimental release is very likely to see a lot of code churn. API's may break at any time. Test-Stream should NOT be depended on by any toolchain level tools until the experimental phase is over.

SYNOPSIS

    use Test::Stream::IPC qw/poll cull/;

    ...

    cull();

    ...

CLASS METHODS

$class->import

$subclass->import

$class_or_subclass->import('cull', 'poll', 'no_fatal')

This is called whenever you load this module, or any IPC driver. If called on an IPC driver it will add that driver to the list of available drivers.

All arguments are optional. All arguments should work just fine when provided to drivers instead of Test::Stream::IPC itself.

The 'cull' argument will cause the cull() function to be exported to your namespace. This function will find the current hub and cull all IPC events that are waiting.

The 'poll' argument will add a global init hook for Test::Stream::Context objects that will cull all events for a hub when a context is obtained. Use this if you want events to come in frequently without calling cull() yourself all over the place.

The 'no_fatal' argument will cause fatal IPC errors to be warnings instead of forcing an exit. This argument exists solely for some legacy Test::Builder based tools that do naughty things.

@drivers = $class->drivers

Obtain the list of drivers that have been loaded, in the order they were loaded. If no driver has been loaded this will load and return Test::Stream::IPC::Files.

$class->abort($msg)

If an IPC encounters a fatal error it should use this. This will print the message to STDERR with 'IPC Fatal Error: ' prefixed to it, then it will forcefully exit 255. IPC errors may occur in threads or processes other than the main one, this method provides the best chance of the harness noticing the error.

$class->abort_trace($msg)

This is the same as $ipc->abort($msg) except that it uses Carp::longmess to add a stack trace to the message.

LOADING DRIVERS

Test::Stream::IPC has an import() method. All drivers inherit this import method. This import method registers the driver with the main IPC module.

In most cases you just need to load the desired IPC driver to make it work. You should load this driver as early as possible. A warning will be issued if you load it too late for it to be effective.

    use Test::Stream::IPC::MyDriver;
    ...

WRITING DRIVERS

    package My::IPC::Driver;
    use strict;
    use warnings;

    use base 'Test::Stream::IPC';

    sub is_viable {
        return 0 if $^O eq 'win32'; # Will not work on windows.
        return 1;
    }

    sub add_hub {
        my $self = shift;
        my ($hid) = @_;

        ... # Make it possible to contact the hub
    }

    sub drop_hub {
        my $self = shift;
        my ($hid) = @_;

        ... # Nothing should try to reach the hub anymore.
    }

    sub send {
        my $self = shift;
        my ($hid, $e) = @_;

        ... # Send the event to the proper hub.
    }

    sub cull {
        my $self = shift;
        my ($hid) = @_;

        my @events = ...; # Here is where you get the events for the hub

        return @events;
    }

    sub waiting {
        my $self = shift;

        ... # Notify all listening procs and threads that the main
        ... # process/thread is waiting for them to finish.
    }

    1;

METHODS SUBCLASSES MUST IMPLEMENT

$ipc->is_viable

This should return true if the driver works in the current environment. This should return false if it does not.

$ipc->add_hub($hid)

This is used to alert the driver that a new hub is expecting events. The driver should keep track of the process and thread ids, the hub should only be dropped by the proc+thread that started it.

    sub add_hub {
        my $self = shift;
        my ($hid) = @_;

        ... # Make it possible to contact the hub
    }

$ipc->drop_hub($hid)

This is used to alert the driver that a hub is no longer accepting events. The driver should keep track of the process and thread ids, the hub should only be dropped by the proc+thread that started it (This is the drivers responsibility to enforce).

    sub drop_hub {
        my $self = shift;
        my ($hid) = @_;

        ... # Nothing should try to reach the hub anymore.
    }

$ipc->send($hid, $event);

Used to send events from the current process/thread to the specified hub in its process+thread.

    sub send {
        my $self = shift;
        my ($hid, $e) = @_;

        ... # Send the event to the proper hub.
    }

@events = $ipc->cull($hid)

Used to collect events that have been sent to the specified hub.

    sub cull {
        my $self = shift;
        my ($hid) = @_;

        my @events = ...; # Here is where you get the events for the hub

        return @events;
    }

$ipc->waiting()

This is called in the parent process when it is complete and waiting for all child processes and threads to complete.

    sub waiting {
        my $self = shift;

        ... # Notify all listening procs and threads that the main
        ... # process/thread is waiting for them to finish.
    }

SOURCE

The source code repository for Test::Stream can be found at http://github.com/Test-More/Test-Stream/.

MAINTAINERS

Chad Granum <exodist@cpan.org>

AUTHORS

Chad Granum <exodist@cpan.org>

COPYRIGHT

Copyright 2015 Chad Granum <exodist7@gmail.com>.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html