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

Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC vs.
Revision 1.57 by root, Sun Aug 25 17:38:43 2013 UTC

…		…
38		38
39	If you need some form of RPC, you could use the L<AnyEvent::Fork::RPC>	39	If you need some form of RPC, you could use the L<AnyEvent::Fork::RPC>
40	companion module, which adds simple RPC/job queueing to a process created	40	companion module, which adds simple RPC/job queueing to a process created
41	by this module.	41	by this module.
42		42
		43	And if you need some automatic process pool management on top of
		44	L<AnyEvent::Fork::RPC>, you can look at the L<AnyEvent::Fork::Pool>
		45	companion module.
		46
43	Or you can implement it yourself in whatever way you like, use some	47	Or you can implement it yourself in whatever way you like: use some
44	message-passing module such as L<AnyEvent::MP>, some pipe such as	48	message-passing module such as L<AnyEvent::MP>, some pipe such as
45	L<AnyEvent::ZeroMQ>, use L<AnyEvent::Handle> on both sides to send	49	L<AnyEvent::ZeroMQ>, use L<AnyEvent::Handle> on both sides to send
46	e.g. JSON or Storable messages, and so on.	50	e.g. JSON or Storable messages, and so on.
47		51
48	=head2 COMPARISON TO OTHER MODULES	52	=head2 COMPARISON TO OTHER MODULES
…		…
250	->send_arg ("/bin/echo", "hi")	254	->send_arg ("/bin/echo", "hi")
251	->run ("run", my $cv = AE::cv);	255	->run ("run", my $cv = AE::cv);
252		256
253	my $stderr = $cv->recv;	257	my $stderr = $cv->recv;
254		258
		259	=head2 For stingy users: put the worker code into a C<DATA> section.
		260
		261	When you want to be stingy with files, you cna put your code into the
		262	C<DATA> section of your module (or program):
		263
		264	use AnyEvent::Fork;
		265
		266	AnyEvent::Fork
		267	->new
		268	->eval (do { local $/; <DATA> })
		269	->run ("doit", sub { ... });
		270
		271	__DATA__
		272
		273	sub doit {
		274	... do something!
		275	}
		276
		277	=head2 For stingy standalone programs: do not rely on external files at
		278	all.
		279
		280	For single-file scripts it can be inconvenient to rely on external
		281	files - even when using < C<DATA> section, you still need to C<exec>
		282	an external perl interpreter, which might not be available when using
		283	L<App::Staticperl>, L<Urlader> or L<PAR::Packer> for example.
		284
		285	Two modules help here - L<AnyEvent::Fork::Early> forks a template process
		286	for all further calls to C<new_exec>, and L<AnyEvent::Fork::Template>
		287	forks the main program as a template process.
		288
		289	Here is how your main program should look like:
		290
		291	#! perl
		292
		293	# optional, as the very first thing.
		294	# in case modules want to create their own processes.
		295	use AnyEvent::Fork::Early;
		296
		297	# next, load all modules you need in your template process
		298	use Example::My::Module
		299	use Example::Whatever;
		300
		301	# next, put your run function definition and anything else you
		302	# need, but do not use code outside of BEGIN blocks.
		303	sub worker_run {
		304	my ($fh, @args) = @_;
		305	...
		306	}
		307
		308	# now preserve everything so far as AnyEvent::Fork object
		309	# in §TEMPLATE.
		310	use AnyEvent::Fork::Template;
		311
		312	# do not put code outside of BEGIN blocks until here
		313
		314	# now use the $TEMPLATE process in any way you like
		315
		316	# for example: create 10 worker processes
		317	my @worker;
		318	my $cv = AE::cv;
		319	for (1..10) {
		320	$cv->begin;
		321	$TEMPLATE->fork->send_arg ($_)->run ("worker_run", sub {
		322	push @worker, shift;
		323	$cv->end;
		324	});
		325	}
		326	$cv->recv;
		327
255	=head1 CONCEPTS	328	=head1 CONCEPTS
256		329
257	This module can create new processes either by executing a new perl	330	This module can create new processes either by executing a new perl
258	process, or by forking from an existing "template" process.	331	process, or by forking from an existing "template" process.
259		332
…		…
377	use AnyEvent;	450	use AnyEvent;
378	use AnyEvent::Util ();	451	use AnyEvent::Util ();
379		452
380	use IO::FDPass;	453	use IO::FDPass;
381		454
382	our $VERSION = 0.6;	455	our $VERSION = 1.1;
383		456
384	# the early fork template process	457	# the early fork template process
385	our $EARLY;	458	our $EARLY;
386		459
387	# the empty template process	460	# the empty template process
…		…
435	# send string	508	# send string
436	my $len = syswrite $self->[FH], $self->[QUEUE][0];	509	my $len = syswrite $self->[FH], $self->[QUEUE][0];
437		510
438	unless ($len) {	511	unless ($len) {
439	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;	512	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;
440	undef $self->[3];	513	undef $self->[WW];
441	die "AnyEvent::Fork: command write failure: $!";	514	die "AnyEvent::Fork: command write failure: $!";
442	}	515	}
443		516
444	substr $self->[QUEUE][0], 0, $len, "";	517	substr $self->[QUEUE][0], 0, $len, "";
445	shift @{ $self->[QUEUE] } unless length $self->[QUEUE][0];	518	shift @{ $self->[QUEUE] } unless length $self->[QUEUE][0];
…		…
448		521
449	# everything written	522	# everything written
450	undef $self->[WW];	523	undef $self->[WW];
451		524
452	# invoke run callback, if any	525	# invoke run callback, if any
		526	if ($self->[CB]) {
453	$self->[CB]->($self->[FH]) if $self->[CB];	527	$self->[CB]->($self->[FH]);
		528	@$self = ();
		529	}
454	};	530	};
455		531
456	() # make sure we don't leak the watcher	532	() # make sure we don't leak the watcher
457	}	533	}
458		534
…		…
529		605
530	You should use C<new> whenever possible, except when having a template	606	You should use C<new> whenever possible, except when having a template
531	process around is unacceptable.	607	process around is unacceptable.
532		608
533	The path to the perl interpreter is divined using various methods - first	609	The path to the perl interpreter is divined using various methods - first
534	C<$^X> is investigated to see if the path ends with something that sounds	610	C<$^X> is investigated to see if the path ends with something that looks
535	as if it were the perl interpreter. Failing this, the module falls back to	611	as if it were the perl interpreter. Failing this, the module falls back to
536	using C<$Config::Config{perlpath}>.	612	using C<$Config::Config{perlpath}>.
537		613
		614	The path to perl can also be overriden by setting the global variable
		615	C<$AnyEvent::Fork::PERL> - it's value will be used for all subsequent
		616	invocations.
		617
538	=cut	618	=cut
		619
		620	our $PERL;
539		621
540	sub new_exec {	622	sub new_exec {
541	my ($self) = @_;	623	my ($self) = @_;
542		624
543	return $EARLY->fork	625	return $EARLY->fork
544	if $EARLY;	626	if $EARLY;
545		627
		628	unless (defined $PERL) {
546	# first find path of perl	629	# first find path of perl
547	my $perl = $;	630	my $perl = $;
548		631
549	# first we try $^X, but the path must be absolute (always on win32), and end in sth.	632	# first we try $^X, but the path must be absolute (always on win32), and end in sth.
550	# that looks like perl. this obviously only works for posix and win32	633	# that looks like perl. this obviously only works for posix and win32
551	unless (	634	unless (
552	($^O eq "MSWin32" \|\| $perl =~ m%^/%)	635	($^O eq "MSWin32" \|\| $perl =~ m%^/%)
553	&& $perl =~ m%[/\\]perl(?:[0-9]+(\.[0-9]+)+)?(\.exe)?$%i	636	&& $perl =~ m%[/\\]perl(?:[0-9]+(\.[0-9]+)+)?(\.exe)?$%i
554	) {	637	) {
555	# if it doesn't look perlish enough, try Config	638	# if it doesn't look perlish enough, try Config
556	require Config;	639	require Config;
557	$perl = $Config::Config{perlpath};	640	$perl = $Config::Config{perlpath};
558	$perl =~ s/(?:\Q$Config::Config{_exe}\E)?$/$Config::Config{_exe}/;	641	$perl =~ s/(?:\Q$Config::Config{_exe}\E)?$/$Config::Config{_exe}/;
		642	}
		643
		644	$PERL = $perl;
559	}	645	}
560		646
561	require Proc::FastSpawn;	647	require Proc::FastSpawn;
562		648
563	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;	649	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;
…		…
571	#local $ENV{PERL5LIB} = join ":", grep !ref, @INC;	657	#local $ENV{PERL5LIB} = join ":", grep !ref, @INC;
572	my %env = %ENV;	658	my %env = %ENV;
573	$env{PERL5LIB} = join +($^O eq "MSWin32" ? ";" : ":"), grep !ref, @INC;	659	$env{PERL5LIB} = join +($^O eq "MSWin32" ? ";" : ":"), grep !ref, @INC;
574		660
575	my $pid = Proc::FastSpawn::spawn (	661	my $pid = Proc::FastSpawn::spawn (
576	$perl,	662	$PERL,
577	["perl", "-MAnyEvent::Fork::Serve", "-e", "AnyEvent::Fork::Serve::me", fileno $slave, $$],	663	["perl", "-MAnyEvent::Fork::Serve", "-e", "AnyEvent::Fork::Serve::me", fileno $slave, $$],
578	[map "$_=$env{$_}", keys %env],	664	[map "$_=$env{$_}", keys %env],
579	) or die "unable to spawn AnyEvent::Fork server: $!";	665	) or die "unable to spawn AnyEvent::Fork server: $!";
580		666
581	$self->_new ($fh, $pid)	667	$self->_new ($fh, $pid)
…		…
773	$self->_cmd (r => $func);	859	$self->_cmd (r => $func);
774	}	860	}
775		861
776	=back	862	=back
777		863
		864	=head2 EXPERIMENTAL METHODS
		865
		866	These methods might go away completely or change behaviour, at any time.
		867
		868	=over 4
		869
		870	=item $proc->to_fh ($cb->($fh)) # EXPERIMENTAL, MIGHT BE REMOVED
		871
		872	Flushes all commands out to the process and then calls the callback with
		873	the communications socket.
		874
		875	The process object becomes unusable on return from this function - any
		876	further method calls result in undefined behaviour.
		877
		878	The point of this method is to give you a file handle thta you cna pass
		879	to another process. In that other process, you can call C<new_from_fh
		880	AnyEvent::Fork> to create a new C<AnyEvent::Fork> object from it, thereby
		881	effectively passing a fork object to another process.
		882
		883	=cut
		884
		885	sub to_fh {
		886	my ($self, $cb) = @_;
		887
		888	$self->[CB] = $cb;
		889
		890	unless ($self->[WW]) {
		891	$self->[CB]->($self->[FH]);
		892	@$self = ();
		893	}
		894	}
		895
		896	=item new_from_fh AnyEvent::Fork $fh # EXPERIMENTAL, MIGHT BE REMOVED
		897
		898	Takes a file handle originally rceeived by the C<to_fh> method and creates
		899	a new C<AnyEvent:Fork> object. The child process itself will not change in
		900	any way, i.e. it will keep all the modifications done to it before calling
		901	C<to_fh>.
		902
		903	The new object is very much like the original object, except that the
		904	C<pid> method will return C<undef> even if the process is a direct child.
		905
		906	=cut
		907
		908	sub new_from_fh {
		909	my ($class, $fh) = @_;
		910
		911	$class->_new ($fh)
		912	}
		913
		914	=back
		915
778	=head1 PERFORMANCE	916	=head1 PERFORMANCE
779		917
780	Now for some unscientific benchmark numbers (all done on an amd64	918	Now for some unscientific benchmark numbers (all done on an amd64
781	GNU/Linux box). These are intended to give you an idea of the relative	919	GNU/Linux box). These are intended to give you an idea of the relative
782	performance you can expect, they are not meant to be absolute performance	920	performance you can expect, they are not meant to be absolute performance
…		…
788		926
789	2079 new processes per second, using manual socketpair + fork	927	2079 new processes per second, using manual socketpair + fork
790		928
791	Then I did the same thing, but instead of calling fork, I called	929	Then I did the same thing, but instead of calling fork, I called
792	AnyEvent::Fork->new->run ("CORE::exit") and then again waited for the	930	AnyEvent::Fork->new->run ("CORE::exit") and then again waited for the
793	socket form the child to close on exit. This does the same thing as manual	931	socket from the child to close on exit. This does the same thing as manual
794	socket pair + fork, except that what is forked is the template process	932	socket pair + fork, except that what is forked is the template process
795	(2440kB), and the socket needs to be passed to the server at the other end	933	(2440kB), and the socket needs to be passed to the server at the other end
796	of the socket first.	934	of the socket first.
797		935
798	2307 new processes per second, using AnyEvent::Fork->new	936	2307 new processes per second, using AnyEvent::Fork->new
…		…
905	to make it so, mostly due to the bloody broken perl that nobody seems to	1043	to make it so, mostly due to the bloody broken perl that nobody seems to
906	care about. The fork emulation is a bad joke - I have yet to see something	1044	care about. The fork emulation is a bad joke - I have yet to see something
907	useful that you can do with it without running into memory corruption	1045	useful that you can do with it without running into memory corruption
908	issues or other braindamage. Hrrrr.	1046	issues or other braindamage. Hrrrr.
909		1047
		1048	Since fork is endlessly broken on win32 perls (it doesn't even remotely
		1049	work within it's documented limits) and quite obviously it's not getting
		1050	improved any time soon, the best way to proceed on windows would be to
		1051	always use C<new_exec> and thus never rely on perl's fork "emulation".
		1052
910	Cygwin perl is not supported at the moment due to some hilarious	1053	Cygwin perl is not supported at the moment due to some hilarious
911	shortcomings of its API - see L<IO::FDPoll> for more details.	1054	shortcomings of its API - see L<IO::FDPoll> for more details. If you never
		1055	use C<send_fh> and always use C<new_exec> to create processes, it should
		1056	work though.
912		1057
913	=head1 SEE ALSO	1058	=head1 SEE ALSO
914		1059
915	L<AnyEvent::Fork::Early>, to avoid executing a perl interpreter at all	1060	L<AnyEvent::Fork::Early>, to avoid executing a perl interpreter at all
916	(part of this distribution).	1061	(part of this distribution).
917		1062
918	L<AnyEvent::Fork::Template>, to create a process by forking the main	1063	L<AnyEvent::Fork::Template>, to create a process by forking the main
919	program at a convenient time (part of this distribution).	1064	program at a convenient time (part of this distribution).
920		1065
		1066	L<AnyEvent::Fork::Remote>, for another way to create processes that is
		1067	mostly compatible to this module and modules building on top of it, but
		1068	works better with remote processes.
		1069
921	L<AnyEvent::Fork::RPC>, for simple RPC to child processes (on CPAN).	1070	L<AnyEvent::Fork::RPC>, for simple RPC to child processes (on CPAN).
		1071
		1072	L<AnyEvent::Fork::Pool>, for simple worker process pool (on CPAN).
922		1073
923	=head1 AUTHOR AND CONTACT INFORMATION	1074	=head1 AUTHOR AND CONTACT INFORMATION
924		1075
925	Marc Lehmann <schmorp@schmorp.de>	1076	Marc Lehmann <schmorp@schmorp.de>
926	http://software.schmorp.de/pkg/AnyEvent-Fork	1077	http://software.schmorp.de/pkg/AnyEvent-Fork

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Comparing AnyEvent-Fork/Fork.pm (file contents): Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC vs. Revision 1.57 by root, Sun Aug 25 17:38:43 2013 UTC

Diff Legend

Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC vs.
Revision 1.57 by root, Sun Aug 25 17:38:43 2013 UTC