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=head1 NAME |
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|
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AnyEvent::MP - multi-processing/message-passing framework |
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|
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=head1 SYNOPSIS |
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|
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use AnyEvent::MP; |
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|
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NODE # returns this node identifier |
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$NODE # contains this node identifier |
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|
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snd $port, type => data...; |
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|
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rcv $port, smartmatch => $cb->($port, @msg); |
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|
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# examples: |
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rcv $port2, ping => sub { snd $_[0], "pong"; 0 }; |
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rcv $port1, pong => sub { warn "pong received\n" }; |
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snd $port2, ping => $port1; |
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|
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# more, smarter, matches (_any_ is exported by this module) |
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rcv $port, [child_died => $pid] => sub { ... |
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rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
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|
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=head1 DESCRIPTION |
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|
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This module (-family) implements a simple message passing framework. |
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|
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Despite its simplicity, you can securely message other processes running |
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on the same or other hosts. |
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|
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At the moment, this module family is severly brokena nd underdocumented, |
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so do not use. This was uploaded mainly to resreve the CPAN namespace - |
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stay tuned! |
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|
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=head1 CONCEPTS |
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|
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=over 4 |
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|
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=item port |
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|
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A port is something you can send messages to with the C<snd> function, and |
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you can register C<rcv> handlers with. All C<rcv> handlers will receive |
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messages they match, messages will not be queued. |
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|
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=item port id - C<noderef#portname> |
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|
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A port id is always the noderef, a hash-mark (C<#>) as separator, followed |
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by a port name (a printable string of unspecified format). |
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|
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=item node |
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|
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A node is a single process containing at least one port - the node |
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port. You can send messages to node ports to let them create new ports, |
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among other things. |
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|
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Initially, nodes are either private (single-process only) or hidden |
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(connected to a master node only). Only when they epxlicitly "become |
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public" can you send them messages from unrelated other nodes. |
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|
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=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
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|
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A noderef is a string that either uniquely identifies a given node (for |
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private and hidden nodes), or contains a recipe on how to reach a given |
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node (for public nodes). |
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|
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=back |
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|
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=head1 VARIABLES/FUNCTIONS |
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|
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=over 4 |
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|
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=cut |
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|
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package AnyEvent::MP; |
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|
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use AnyEvent::MP::Base; |
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|
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use common::sense; |
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|
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use Carp (); |
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|
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use AE (); |
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|
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use base "Exporter"; |
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|
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our $VERSION = '0.02'; |
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our @EXPORT = qw( |
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NODE $NODE $PORT snd rcv _any_ |
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create_port create_port_on |
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create_miniport |
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become_slave become_public |
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); |
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|
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=item NODE / $NODE |
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|
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The C<NODE ()> function and the C<$NODE> variable contain the noderef of |
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the local node. The value is initialised by a call to C<become_public> or |
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C<become_slave>, after which all local port identifiers become invalid. |
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|
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=item snd $portid, type => @data |
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|
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=item snd $portid, @msg |
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|
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Send the given message to the given port ID, which can identify either |
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a local or a remote port, and can be either a string or soemthignt hat |
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stringifies a sa port ID (such as a port object :). |
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|
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While the message can be about anything, it is highly recommended to use a |
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string as first element (a portid, or some word that indicates a request |
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type etc.). |
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|
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The message data effectively becomes read-only after a call to this |
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function: modifying any argument is not allowed and can cause many |
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problems. |
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|
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The type of data you can transfer depends on the transport protocol: when |
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JSON is used, then only strings, numbers and arrays and hashes consisting |
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of those are allowed (no objects). When Storable is used, then anything |
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that Storable can serialise and deserialise is allowed, and for the local |
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node, anything can be passed. |
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|
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=item $local_port = create_port |
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|
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Create a new local port object. See the next section for allowed methods. |
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|
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=cut |
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|
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sub create_port { |
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my $id = "$AnyEvent::MP::Base::UNIQ." . $AnyEvent::MP::Base::ID++; |
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|
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my $self = bless { |
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id => "$NODE#$id", |
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names => [$id], |
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}, "AnyEvent::MP::Port"; |
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|
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$AnyEvent::MP::Base::PORT{$id} = sub { |
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unshift @_, $self; |
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|
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for (@{ $self->{rc0}{$_[1]} }) { |
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$_ && &{$_->[0]} |
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&& undef $_; |
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} |
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|
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for (@{ $self->{rcv}{$_[1]} }) { |
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$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
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&& &{$_->[0]} |
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&& undef $_; |
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} |
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|
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for (@{ $self->{any} }) { |
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$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
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&& &{$_->[0]} |
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&& undef $_; |
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} |
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}; |
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|
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$self |
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} |
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|
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=item $portid = miniport { my @msg = @_; $finished } |
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|
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Creates a "mini port", that is, a very lightweight port without any |
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pattern matching behind it, and returns its ID. |
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|
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The block will be called for every message received on the port. When the |
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callback returns a true value its job is considered "done" and the port |
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will be destroyed. Otherwise it will stay alive. |
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|
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The message will be passed as-is, no extra argument (i.e. no port id) will |
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be passed to the callback. |
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|
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If you need the local port id in the callback, this works nicely: |
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|
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my $port; $port = miniport { |
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snd $otherport, reply => $port; |
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}; |
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|
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=cut |
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|
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sub miniport(&) { |
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my $cb = shift; |
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my $id = "$AnyEvent::MP::Base::UNIQ." . $AnyEvent::MP::Base::ID++; |
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|
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$AnyEvent::MP::Base::PORT{$id} = sub { |
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&$cb |
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and delete $AnyEvent::MP::Base::PORT{$id}; |
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}; |
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|
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"$NODE#$id" |
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} |
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|
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package AnyEvent::MP::Port; |
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|
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=back |
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|
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=head1 METHODS FOR PORT OBJECTS |
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|
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=over 4 |
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|
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=item "$port" |
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|
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A port object stringifies to its port ID, so can be used directly for |
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C<snd> operations. |
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|
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=cut |
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|
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use overload |
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'""' => sub { $_[0]{id} }, |
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fallback => 1; |
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|
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=item $port->rcv (type => $callback->($port, @msg)) |
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|
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=item $port->rcv ($smartmatch => $callback->($port, @msg)) |
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|
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=item $port->rcv ([$smartmatch...] => $callback->($port, @msg)) |
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|
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Register a callback on the given port. |
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|
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The callback has to return a true value when its work is done, after |
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which is will be removed, or a false value in which case it will stay |
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registered. |
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|
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If the match is an array reference, then it will be matched against the |
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first elements of the message, otherwise only the first element is being |
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matched. |
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|
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Any element in the match that is specified as C<_any_> (a function |
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exported by this module) matches any single element of the message. |
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|
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While not required, it is highly recommended that the first matching |
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element is a string identifying the message. The one-string-only match is |
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also the most efficient match (by far). |
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|
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=cut |
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|
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sub rcv($@) { |
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my ($self, $match, $cb) = @_; |
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|
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if (!ref $match) { |
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push @{ $self->{rc0}{$match} }, [$cb]; |
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} elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
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my ($type, @match) = @$match; |
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@match |
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? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
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: push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
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} else { |
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push @{ $self->{any} }, [$cb, $match]; |
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} |
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} |
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|
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=item $port->register ($name) |
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|
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Registers the given port under the well known name C<$name>. If the name |
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already exists it is replaced. |
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|
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A port can only be registered under one well known name. |
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|
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=cut |
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|
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sub register { |
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my ($self, $name) = @_; |
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|
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$self->{wkname} = $name; |
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$AnyEvent::MP::Base::WKP{$name} = "$self"; |
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} |
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|
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=item $port->destroy |
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|
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Explicitly destroy/remove/nuke/vaporise the port. |
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|
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Ports are normally kept alive by there mere existance alone, and need to |
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be destroyed explicitly. |
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|
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=cut |
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|
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sub destroy { |
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my ($self) = @_; |
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|
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delete $AnyEvent::MP::Base::WKP{ $self->{wkname} }; |
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|
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delete $AnyEvent::MP::Base::PORT{$_} |
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for @{ $self->{names} }; |
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} |
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|
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=back |
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|
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=head1 FUNCTIONS FOR NODES |
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|
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=over 4 |
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|
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=item mon $noderef, $callback->($noderef, $status, $) |
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|
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Monitors the given noderef. |
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|
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=item become_public endpoint... |
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|
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Tells the node to become a public node, i.e. reachable from other nodes. |
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|
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If no arguments are given, or the first argument is C<undef>, then |
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AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the |
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local nodename resolves to. |
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|
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Otherwise the first argument must be an array-reference with transport |
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endpoints ("ip:port", "hostname:port") or port numbers (in which case the |
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local nodename is used as hostname). The endpoints are all resolved and |
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will become the node reference. |
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|
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=cut |
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|
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=back |
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|
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=head1 NODE MESSAGES |
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|
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Nodes understand the following messages sent to them. Many of them take |
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arguments called C<@reply>, which will simply be used to compose a reply |
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message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
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the remaining arguments are simply the message data. |
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|
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=over 4 |
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|
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=cut |
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|
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=item wkp => $name, @reply |
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|
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Replies with the port ID of the specified well-known port, or C<undef>. |
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|
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=item devnull => ... |
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|
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Generic data sink/CPU heat conversion. |
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|
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=item relay => $port, @msg |
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|
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Simply forwards the message to the given port. |
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|
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=item eval => $string[ @reply] |
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|
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Evaluates the given string. If C<@reply> is given, then a message of the |
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form C<@reply, $@, @evalres> is sent. |
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|
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Example: crash another node. |
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|
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snd $othernode, eval => "exit"; |
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|
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=item time => @reply |
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|
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Replies the the current node time to C<@reply>. |
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|
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Example: tell the current node to send the current time to C<$myport> in a |
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C<timereply> message. |
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|
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snd $NODE, time => $myport, timereply => 1, 2; |
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# => snd $myport, timereply => 1, 2, <time> |
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|
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=back |
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|
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=head1 SEE ALSO |
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|
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L<AnyEvent>. |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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|
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=cut |
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|
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1 |
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|
