[ViewVC] Diff of: cvs/AnyEvent-MP/MP.pm

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.120 by root, Sun Feb 26 11:12:54 2012 UTC vs.
Revision 1.128 by root, Sun Mar 4 14:28:44 2012 UTC

…		…
82		82
83	Ports are represented by (printable) strings called "port IDs".	83	Ports are represented by (printable) strings called "port IDs".
84		84
85	=item port ID - C<nodeid#portname>	85	=item port ID - C<nodeid#portname>
86		86
87	A port ID is the concatenation of a node ID, a hash-mark (C<#>) as	87	A port ID is the concatenation of a node ID, a hash-mark (C<#>)
88	separator, and a port name (a printable string of unspecified format).	88	as separator, and a port name (a printable string of unspecified
		89	format created by AnyEvent::MP).
89		90
90	=item node	91	=item node
91		92
92	A node is a single process containing at least one port - the node port,	93	A node is a single process containing at least one port - the node port,
93	which enables nodes to manage each other remotely, and to create new	94	which enables nodes to manage each other remotely, and to create new
…		…
175		176
176	=cut	177	=cut
177		178
178	package AnyEvent::MP;	179	package AnyEvent::MP;
179		180
		181	use AnyEvent::MP::Config ();
180	use AnyEvent::MP::Kernel;	182	use AnyEvent::MP::Kernel;
		183	use AnyEvent::MP::Kernel qw(%NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID);
181		184
182	use common::sense;	185	use common::sense;
183		186
184	use Carp ();	187	use Carp ();
185		188
186	use AE ();	189	use AE ();
		190	use Guard ();
187		191
188	use base "Exporter";	192	use base "Exporter";
189		193
190	our $VERSION = '1.30';	194	our $VERSION = $AnyEvent::MP::Config::VERSION;
191		195
192	our @EXPORT = qw(	196	our @EXPORT = qw(
193	NODE $NODE *SELF node_of after	197	NODE $NODE *SELF node_of after
194	configure	198	configure
195	snd rcv mon mon_guard kil psub peval spawn cal	199	snd rcv mon mon_guard kil psub peval spawn cal
196	port	200	port
		201	db_set db_del db_reg
		202	db_mon db_family db_keys db_values
197	);	203	);
198		204
199	our $SELF;	205	our $SELF;
200		206
201	sub _self_die() {	207	sub _self_die() {
…		…
221	Before a node can talk to other nodes on the network (i.e. enter	227	Before a node can talk to other nodes on the network (i.e. enter
222	"distributed mode") it has to configure itself - the minimum a node needs	228	"distributed mode") it has to configure itself - the minimum a node needs
223	to know is its own name, and optionally it should know the addresses of	229	to know is its own name, and optionally it should know the addresses of
224	some other nodes in the network to discover other nodes.	230	some other nodes in the network to discover other nodes.
225		231
226	The key/value pairs are basically the same ones as documented for the
227	F<aemp> command line utility (sans the set/del prefix).
228
229	This function configures a node - it must be called exactly once (or	232	This function configures a node - it must be called exactly once (or
230	never) before calling other AnyEvent::MP functions.	233	never) before calling other AnyEvent::MP functions.
		234
		235	The key/value pairs are basically the same ones as documented for the
		236	F<aemp> command line utility (sans the set/del prefix), with these additions:
		237
		238	=over 4
		239
		240	=item norc => $boolean (default false)
		241
		242	If true, then the rc file (e.g. F<~/.perl-anyevent-mp>) will I<not>
		243	be consulted - all configuraiton options must be specified in the
		244	C<configure> call.
		245
		246	=item force => $boolean (default false)
		247
		248	IF true, then the values specified in the C<configure> will take
		249	precedence over any values configured via the rc file. The default is for
		250	the rc file to override any options specified in the program.
		251
		252	=item secure => $pass->($nodeid)
		253
		254	In addition to specifying a boolean, you can specify a code reference that
		255	is called for every remote execution attempt - the execution request is
		256	granted iff the callback returns a true value.
		257
		258	See F<semp setsecure> for more info.
		259
		260	=back
231		261
232	=over 4	262	=over 4
233		263
234	=item step 1, gathering configuration from profiles	264	=item step 1, gathering configuration from profiles
235		265
…		…
249	That means that the values specified in the profile have highest priority	279	That means that the values specified in the profile have highest priority
250	and the values specified directly via C<configure> have lowest priority,	280	and the values specified directly via C<configure> have lowest priority,
251	and can only be used to specify defaults.	281	and can only be used to specify defaults.
252		282
253	If the profile specifies a node ID, then this will become the node ID of	283	If the profile specifies a node ID, then this will become the node ID of
254	this process. If not, then the profile name will be used as node ID. The	284	this process. If not, then the profile name will be used as node ID, with
255	special node ID of C<anon/> will be replaced by a random node ID.	285	a unique randoms tring (C</%u>) appended.
		286
		287	The node ID can contain some C<%> sequences that are expanded: C<%n>
		288	is expanded to the local nodename, C<%u> is replaced by a random
		289	strign to make the node unique. For example, the F<aemp> commandline
		290	utility uses C<aemp/%n/%u> as nodename, which might expand to
		291	C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>.
256		292
257	=item step 2, bind listener sockets	293	=item step 2, bind listener sockets
258		294
259	The next step is to look up the binds in the profile, followed by binding	295	The next step is to look up the binds in the profile, followed by binding
260	aemp protocol listeners on all binds specified (it is possible and valid	296	aemp protocol listeners on all binds specified (it is possible and valid
…		…
277	Example: become a distributed node using the local node name as profile.	313	Example: become a distributed node using the local node name as profile.
278	This should be the most common form of invocation for "daemon"-type nodes.	314	This should be the most common form of invocation for "daemon"-type nodes.
279		315
280	configure	316	configure
281		317
282	Example: become an anonymous node. This form is often used for commandline	318	Example: become a semi-anonymous node. This form is often used for
283	clients.	319	commandline clients.
284		320
285	configure nodeid => "anon/";	321	configure nodeid => "myscript/%n/%u";
286		322
287	Example: configure a node using a profile called seed, which is suitable	323	Example: configure a node using a profile called seed, which is suitable
288	for a seed node as it binds on all local addresses on a fixed port (4040,	324	for a seed node as it binds on all local addresses on a fixed port (4040,
289	customary for aemp).	325	customary for aemp).
290		326
291	# use the aemp commandline utility	327	# use the aemp commandline utility
292	# aemp profile seed nodeid anon/ binds '*:4040'	328	# aemp profile seed binds '*:4040'
293		329
294	# then use it	330	# then use it
295	configure profile => "seed";	331	configure profile => "seed";
296		332
297	# or simply use aemp from the shell again:	333	# or simply use aemp from the shell again:
…		…
367	sub _kilme {	403	sub _kilme {
368	die "received message on port without callback";	404	die "received message on port without callback";
369	}	405	}
370		406
371	sub port(;&) {	407	sub port(;&) {
372	my $id = "$UNIQ." . $ID++;	408	my $id = $UNIQ . ++$ID;
373	my $port = "$NODE#$id";	409	my $port = "$NODE#$id";
374		410
375	rcv $port, shift \|\| \&_kilme;	411	rcv $port, shift \|\| \&_kilme;
376		412
377	$port	413	$port
…		…
650	}	686	}
651		687
652	$node->monitor ($port, $cb);	688	$node->monitor ($port, $cb);
653		689
654	defined wantarray	690	defined wantarray
655	and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) })	691	and ($cb += 0, Guard::guard { $node->unmonitor ($port, $cb) })
656	}	692	}
657		693
658	=item $guard = mon_guard $port, $ref, $ref...	694	=item $guard = mon_guard $port, $ref, $ref...
659		695
660	Monitors the given C<$port> and keeps the passed references. When the port	696	Monitors the given C<$port> and keeps the passed references. When the port
…		…
764	}	800	}
765		801
766	sub spawn(@) {	802	sub spawn(@) {
767	my ($nodeid, undef) = split /#/, shift, 2;	803	my ($nodeid, undef) = split /#/, shift, 2;
768		804
769	my $id = "$RUNIQ." . $ID++;	805	my $id = $RUNIQ . ++$ID;
770		806
771	$_[0] =~ /::/	807	$_[0] =~ /::/
772	or Carp::croak "spawn init function must be a fully-qualified name, caught";	808	or Carp::croak "spawn init function must be a fully-qualified name, caught";
773		809
774	snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_;	810	snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_;
775		811
776	"$nodeid#$id"	812	"$nodeid#$id"
777	}	813	}
		814
778		815
779	=item after $timeout, @msg	816	=item after $timeout, @msg
780		817
781	=item after $timeout, $callback	818	=item after $timeout, $callback
782		819
…		…
852	$port	889	$port
853	}	890	}
854		891
855	=back	892	=back
856		893
		894	=head1 DISTRIBUTED DATABASE
		895
		896	AnyEvent::MP comes with a simple distributed database. The database will
		897	be mirrored asynchronously at all global nodes. Other nodes bind to one of
		898	the global nodes for their needs.
		899
		900	The database consists of a two-level hash - a hash contains a hash which
		901	contains values.
		902
		903	The top level hash key is called "family", and the second-level hash key
		904	is called "subkey" or simply "key".
		905
		906	The family must be alphanumeric, i.e. start with a letter and consist
		907	of letters, digits, underscores and colons (C<[A-Za-z][A-Za-z0-9_:]*>,
		908	pretty much like Perl module names.
		909
		910	As the family namespace is global, it is recommended to prefix family names
		911	with the name of the application or module using it.
		912
		913	The subkeys must be non-empty strings, with no further restrictions.
		914
		915	The values should preferably be strings, but other perl scalars should
		916	work as well (such as undef, arrays and hashes).
		917
		918	Every database entry is owned by one node - adding the same family/subkey
		919	combination on multiple nodes will not cause discomfort for AnyEvent::MP,
		920	but the result might be nondeterministic, i.e. the key might have
		921	different values on different nodes.
		922
		923	Different subkeys in the same family can be owned by different nodes
		924	without problems, and in fact, this is the common method to create worker
		925	pools. For example, a worker port for image scaling might do this:
		926
		927	db_set my_image_scalers => $port;
		928
		929	And clients looking for an image scaler will want to get the
		930	C<my_image_scalers> keys:
		931
		932	db_keys "my_image_scalers" => 60 => sub {
		933	#d##TODO#
		934
		935	=over
		936
		937	=item db_set $family => $subkey [=> $value]
		938
		939	Sets (or replaces) a key to the database - if C<$value> is omitted,
		940	C<undef> is used instead.
		941
		942	=item db_del $family => $subkey
		943
		944	Deletes a key from the database.
		945
		946	=item $guard = db_reg $family => $subkey [=> $value]
		947
		948	Sets the key on the database and returns a guard. When the guard is
		949	destroyed, the key is deleted from the database. If C<$value> is missing,
		950	then C<undef> is used.
		951
		952	=item $guard = db_mon $family => $cb->($familyhash, \@subkeys...)
		953
		954	Creates a monitor on the given database family. Each time a key is set or
		955	or is deleted the callback is called with a hash containing the database
		956	family and an arrayref with subkeys that have changed.
		957
		958	Specifically, if one of the passed subkeys exists in the $familyhash, then
		959	it is currently set to the value in the $familyhash. Otherwise, it has
		960	been deleted.
		961
		962	The first call will be with the current contents of the family and all
		963	keys, as if they were just added.
		964
		965	It is possible that the callback is called with a change event even though
		966	the subkey is already present and the value has not changed.
		967
		968	The monitoring stops when the guard object is destroyed.
		969
		970	Example: on every change to the family "mygroup", print out all keys.
		971
		972	my $guard = db_mon mygroup => sub {
		973	my ($family, $keys) = @_;
		974	print "mygroup members: ", (join " ", keys %$family), "\n";
		975	};
		976
		977	Exmaple: wait until the family "My::Module::workers" is non-empty.
		978
		979	my $guard; $guard = db_mon My::Module::workers => sub {
		980	my ($family, $keys) = @_;
		981	return unless %$family;
		982	undef $guard;
		983	print "My::Module::workers now nonempty\n";
		984	};
		985
		986	Example: print all changes to the family "AnyRvent::Fantasy::Module".
		987
		988	my $guard = db_mon AnyRvent::Fantasy::Module => sub {
		989	my ($family, $keys) = @_;
		990
		991	for (@$keys) {
		992	print "$_: ",
		993	(exists $family->{$_}
		994	? $family->{$_}
		995	: "(deleted)"),
		996	"\n";
		997	}
		998	};
		999
		1000	=cut
		1001
		1002	=back
		1003
857	=head1 AnyEvent::MP vs. Distributed Erlang	1004	=head1 AnyEvent::MP vs. Distributed Erlang
858		1005
859	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node	1006	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node
860	== aemp node, Erlang process == aemp port), so many of the documents and	1007	== aemp node, Erlang process == aemp port), so many of the documents and
861	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a	1008	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.120 by root, Sun Feb 26 11:12:54 2012 UTC vs. Revision 1.128 by root, Sun Mar 4 14:28:44 2012 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.120 by root, Sun Feb 26 11:12:54 2012 UTC vs.
Revision 1.128 by root, Sun Mar 4 14:28:44 2012 UTC