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

Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.28 by root, Sat Apr 6 09:06:43 2013 UTC vs.
Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC

…		…
27		27
28	Special care has been taken to make this module useful from other modules,	28	Special care has been taken to make this module useful from other modules,
29	while still supporting specialised environments such as L<App::Staticperl>	29	while still supporting specialised environments such as L<App::Staticperl>
30	or L<PAR::Packer>.	30	or L<PAR::Packer>.
31		31
32	=head1 WHAT THIS MODULE IS NOT	32	=head2 WHAT THIS MODULE IS NOT
33		33
34	This module only creates processes and lets you pass file handles and	34	This module only creates processes and lets you pass file handles and
35	strings to it, and run perl code. It does not implement any kind of RPC -	35	strings to it, and run perl code. It does not implement any kind of RPC -
36	there is no back channel from the process back to you, and there is no RPC	36	there is no back channel from the process back to you, and there is no RPC
37	or message passing going on.	37	or message passing going on.
38		38
39	If you need some form of RPC, you can either implement it yourself	39	If you need some form of RPC, you could use the L<AnyEvent::Fork::RPC>
40	in whatever way you like, use some message-passing module such	40	companion module, which adds simple RPC/job queueing to a process created
41	as L<AnyEvent::MP>, some pipe such as L<AnyEvent::ZeroMQ>, use	41	by this module.
42	L<AnyEvent::Handle> on both sides to send e.g. JSON or Storable messages,
43	and so on.
44		42
		43	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
		45	L<AnyEvent::ZeroMQ>, use L<AnyEvent::Handle> on both sides to send
		46	e.g. JSON or Storable messages, and so on.
		47
		48	=head2 COMPARISON TO OTHER MODULES
		49
		50	There is an abundance of modules on CPAN that do "something fork", such as
		51	L<Parallel::ForkManager>, L<AnyEvent::ForkManager>, L<AnyEvent::Worker>
		52	or L<AnyEvent::Subprocess>. There are modules that implement their own
		53	process management, such as L<AnyEvent::DBI>.
		54
		55	The problems that all these modules try to solve are real, however, none
		56	of them (from what I have seen) tackle the very real problems of unwanted
		57	memory sharing, efficiency, not being able to use event processing or
		58	similar modules in the processes they create.
		59
		60	This module doesn't try to replace any of them - instead it tries to solve
		61	the problem of creating processes with a minimum of fuss and overhead (and
		62	also luxury). Ideally, most of these would use AnyEvent::Fork internally,
		63	except they were written before AnyEvent:Fork was available, so obviously
		64	had to roll their own.
		65
45	=head1 PROBLEM STATEMENT	66	=head2 PROBLEM STATEMENT
46		67
47	There are two traditional ways to implement parallel processing on UNIX	68	There are two traditional ways to implement parallel processing on UNIX
48	like operating systems - fork and process, and fork+exec and process. They	69	like operating systems - fork and process, and fork+exec and process. They
49	have different advantages and disadvantages that I describe below,	70	have different advantages and disadvantages that I describe below,
50	together with how this module tries to mitigate the disadvantages.	71	together with how this module tries to mitigate the disadvantages.
…		…
152		173
153	# now $master_filehandle is connected to the	174	# now $master_filehandle is connected to the
154	# $slave_filehandle in the new process.	175	# $slave_filehandle in the new process.
155	});	176	});
156		177
157	# MyModule::worker might look like this	178	C<MyModule> might look like this:
		179
		180	package MyModule;
		181
158	sub MyModule::worker {	182	sub worker {
159	my ($slave_filehandle) = @_;	183	my ($slave_filehandle) = @_;
160		184
161	# now $slave_filehandle is connected to the $master_filehandle	185	# now $slave_filehandle is connected to the $master_filehandle
162	# in the original prorcess. have fun!	186	# in the original prorcess. have fun!
163	}	187	}
…		…
182	}	206	}
183		207
184	# now do other things - maybe use the filehandle provided by run	208	# now do other things - maybe use the filehandle provided by run
185	# to wait for the processes to die. or whatever.	209	# to wait for the processes to die. or whatever.
186		210
187	# My::Server::run might look like this	211	C<My::Server> might look like this:
188	sub My::Server::run {	212
		213	package My::Server;
		214
		215	sub run {
189	my ($slave, $listener, $id) = @_;	216	my ($slave, $listener, $id) = @_;
190		217
191	close $slave; # we do not use the socket, so close it to save resources	218	close $slave; # we do not use the socket, so close it to save resources
192		219
193	# we could go ballistic and use e.g. AnyEvent here, or IO::AIO,	220	# we could go ballistic and use e.g. AnyEvent here, or IO::AIO,
…		…
197	}	224	}
198	}	225	}
199		226
200	=head2 use AnyEvent::Fork as a faster fork+exec	227	=head2 use AnyEvent::Fork as a faster fork+exec
201		228
202	This runs /bin/echo hi, with stdout redirected to /tmp/log and stderr to	229	This runs C</bin/echo hi>, with standard output redirected to F</tmp/log>
203	the communications socket. It is usually faster than fork+exec, but still	230	and standard error redirected to the communications socket. It is usually
204	let's you prepare the environment.	231	faster than fork+exec, but still lets you prepare the environment.
205		232
206	open my $output, ">/tmp/log" or die "$!";	233	open my $output, ">/tmp/log" or die "$!";
207		234
208	AnyEvent::Fork	235	AnyEvent::Fork
209	->new	236	->new
210	->eval ('	237	->eval ('
		238	# compile a helper function for later use
211	sub run {	239	sub run {
212	my ($fh, $output, @cmd) = @_;	240	my ($fh, $output, @cmd) = @_;
213		241
214	# perl will clear close-on-exec on STDOUT/STDERR	242	# perl will clear close-on-exec on STDOUT/STDERR
215	open STDOUT, ">&", $output or die;	243	open STDOUT, ">&", $output or die;
…		…
226		254
227	=head1 CONCEPTS	255	=head1 CONCEPTS
228		256
229	This module can create new processes either by executing a new perl	257	This module can create new processes either by executing a new perl
230	process, or by forking from an existing "template" process.	258	process, or by forking from an existing "template" process.
		259
		260	All these processes are called "child processes" (whether they are direct
		261	children or not), while the process that manages them is called the
		262	"parent process".
231		263
232	Each such process comes with its own file handle that can be used to	264	Each such process comes with its own file handle that can be used to
233	communicate with it (it's actually a socket - one end in the new process,	265	communicate with it (it's actually a socket - one end in the new process,
234	one end in the main process), and among the things you can do in it are	266	one end in the main process), and among the things you can do in it are
235	load modules, fork new processes, send file handles to it, and execute	267	load modules, fork new processes, send file handles to it, and execute
…		…
326		358
327	If a process object is destroyed before calling its C<run> method, then	359	If a process object is destroyed before calling its C<run> method, then
328	the process simply exits. After C<run> is called, all responsibility is	360	the process simply exits. After C<run> is called, all responsibility is
329	passed to the specified function.	361	passed to the specified function.
330		362
		363	As long as there is any outstanding work to be done, process objects
		364	resist being destroyed, so there is no reason to store them unless you
		365	need them later - configure and forget works just fine.
		366
331	=over 4	367	=over 4
332		368
333	=cut	369	=cut
334		370
335	package AnyEvent::Fork;	371	package AnyEvent::Fork;
…		…
341	use AnyEvent;	377	use AnyEvent;
342	use AnyEvent::Util ();	378	use AnyEvent::Util ();
343		379
344	use IO::FDPass;	380	use IO::FDPass;
345		381
346	our $VERSION = 0.5;	382	our $VERSION = 0.6;
347
348	our $PERL; # the path to the perl interpreter, deduces with various forms of magic
349
350	=over 4
351
352	=back
353
354	=cut
355		383
356	# the early fork template process	384	# the early fork template process
357	our $EARLY;	385	our $EARLY;
358		386
359	# the empty template process	387	# the empty template process
360	our $TEMPLATE;	388	our $TEMPLATE;
		389
		390	sub QUEUE() { 0 }
		391	sub FH() { 1 }
		392	sub WW() { 2 }
		393	sub PID() { 3 }
		394	sub CB() { 4 }
		395
		396	sub _new {
		397	my ($self, $fh, $pid) = @_;
		398
		399	AnyEvent::Util::fh_nonblocking $fh, 1;
		400
		401	$self = bless [
		402	[], # write queue - strings or fd's
		403	$fh,
		404	undef, # AE watcher
		405	$pid,
		406	], $self;
		407
		408	$self
		409	}
361		410
362	sub _cmd {	411	sub _cmd {
363	my $self = shift;	412	my $self = shift;
364		413
365	# ideally, we would want to use "a (w/a)*" as format string, but perl	414	# ideally, we would want to use "a (w/a)*" as format string, but perl
366	# versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack	415	# versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack
367	# it.	416	# it.
368	push @{ $self->[2] }, pack "a L/a*", $_[0], $_[1];	417	push @{ $self->[QUEUE] }, pack "a L/a*", $_[0], $_[1];
369		418
370	$self->[3] \|\|= AE::io $self->[1], 1, sub {	419	$self->[WW] \|\|= AE::io $self->[FH], 1, sub {
371	do {	420	do {
372	# send the next "thing" in the queue - either a reference to an fh,	421	# send the next "thing" in the queue - either a reference to an fh,
373	# or a plain string.	422	# or a plain string.
374		423
375	if (ref $self->[2][0]) {	424	if (ref $self->[QUEUE][0]) {
376	# send fh	425	# send fh
377	unless (IO::FDPass::send fileno $self->[1], fileno ${ $self->[2][0] }) {	426	unless (IO::FDPass::send fileno $self->[FH], fileno ${ $self->[QUEUE][0] }) {
378	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;	427	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;
379	undef $self->[3];	428	undef $self->[WW];
380	die "AnyEvent::Fork: file descriptor send failure: $!";	429	die "AnyEvent::Fork: file descriptor send failure: $!";
381	}	430	}
382		431
383	shift @{ $self->[2] };	432	shift @{ $self->[QUEUE] };
384		433
385	} else {	434	} else {
386	# send string	435	# send string
387	my $len = syswrite $self->[1], $self->[2][0];	436	my $len = syswrite $self->[FH], $self->[QUEUE][0];
388		437
389	unless ($len) {	438	unless ($len) {
390	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;	439	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;
391	undef $self->[3];	440	undef $self->[3];
392	die "AnyEvent::Fork: command write failure: $!";	441	die "AnyEvent::Fork: command write failure: $!";
393	}	442	}
394		443
395	substr $self->[2][0], 0, $len, "";	444	substr $self->[QUEUE][0], 0, $len, "";
396	shift @{ $self->[2] } unless length $self->[2][0];	445	shift @{ $self->[QUEUE] } unless length $self->[QUEUE][0];
397	}	446	}
398	} while @{ $self->[2] };	447	} while @{ $self->[QUEUE] };
399		448
400	# everything written	449	# everything written
401	undef $self->[3];	450	undef $self->[WW];
402		451
403	# invoke run callback, if any	452	# invoke run callback, if any
404	$self->[4]->($self->[1]) if $self->[4];	453	$self->[CB]->($self->[FH]) if $self->[CB];
405	};	454	};
406		455
407	() # make sure we don't leak the watcher	456	() # make sure we don't leak the watcher
408	}
409
410	sub _new {
411	my ($self, $fh, $pid) = @_;
412
413	AnyEvent::Util::fh_nonblocking $fh, 1;
414
415	$self = bless [
416	$pid,
417	$fh,
418	[], # write queue - strings or fd's
419	undef, # AE watcher
420	], $self;
421
422	$self
423	}	457	}
424		458
425	# fork template from current process, used by AnyEvent::Fork::Early/Template	459	# fork template from current process, used by AnyEvent::Fork::Early/Template
426	sub _new_fork {	460	sub _new_fork {
427	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;	461	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;
…		…
432	if ($pid eq 0) {	466	if ($pid eq 0) {
433	require AnyEvent::Fork::Serve;	467	require AnyEvent::Fork::Serve;
434	$AnyEvent::Fork::Serve::OWNER = $parent;	468	$AnyEvent::Fork::Serve::OWNER = $parent;
435	close $fh;	469	close $fh;
436	$0 = "$_[1] of $parent";	470	$0 = "$_[1] of $parent";
437	$SIG{CHLD} = 'IGNORE';
438	AnyEvent::Fork::Serve::serve ($slave);	471	AnyEvent::Fork::Serve::serve ($slave);
439	exit 0;	472	exit 0;
440	} elsif (!$pid) {	473	} elsif (!$pid) {
441	die "AnyEvent::Fork::Early/Template: unable to fork template process: $!";	474	die "AnyEvent::Fork::Early/Template: unable to fork template process: $!";
442	}	475	}
…		…
449	Create a new "empty" perl interpreter process and returns its process	482	Create a new "empty" perl interpreter process and returns its process
450	object for further manipulation.	483	object for further manipulation.
451		484
452	The new process is forked from a template process that is kept around	485	The new process is forked from a template process that is kept around
453	for this purpose. When it doesn't exist yet, it is created by a call to	486	for this purpose. When it doesn't exist yet, it is created by a call to
454	C<new_exec> and kept around for future calls.	487	C<new_exec> first and then stays around for future calls.
455
456	When the process object is destroyed, it will release the file handle
457	that connects it with the new process. When the new process has not yet
458	called C<run>, then the process will exit. Otherwise, what happens depends
459	entirely on the code that is executed.
460		488
461	=cut	489	=cut
462		490
463	sub new {	491	sub new {
464	my $class = shift;	492	my $class = shift;
…		…
554	}	582	}
555		583
556	=item $pid = $proc->pid	584	=item $pid = $proc->pid
557		585
558	Returns the process id of the process I<iff it is a direct child of the	586	Returns the process id of the process I<iff it is a direct child of the
559	process> running AnyEvent::Fork, and C<undef> otherwise.	587	process running AnyEvent::Fork>, and C<undef> otherwise.
560		588
561	Normally, only processes created via C<< AnyEvent::Fork->new_exec >> and	589	Normally, only processes created via C<< AnyEvent::Fork->new_exec >> and
562	L<AnyEvent::Fork::Template> are direct children, and you are responsible	590	L<AnyEvent::Fork::Template> are direct children, and you are responsible
563	to clean up their zombies when they die.	591	to clean up their zombies when they die.
564		592
565	All other processes are not direct children, and will be cleaned up by	593	All other processes are not direct children, and will be cleaned up by
566	AnyEvent::Fork.	594	AnyEvent::Fork itself.
567		595
568	=cut	596	=cut
569		597
570	sub pid {	598	sub pid {
571	$_[0][0]	599	$_[0][PID]
572	}	600	}
573		601
574	=item $proc = $proc->eval ($perlcode, @args)	602	=item $proc = $proc->eval ($perlcode, @args)
575		603
576	Evaluates the given C<$perlcode> as ... perl code, while setting C<@_> to	604	Evaluates the given C<$perlcode> as ... Perl code, while setting C<@_> to
577	the strings specified by C<@args>, in the "main" package.	605	the strings specified by C<@args>, in the "main" package.
578		606
579	This call is meant to do any custom initialisation that might be required	607	This call is meant to do any custom initialisation that might be required
580	(for example, the C<require> method uses it). It's not supposed to be used	608	(for example, the C<require> method uses it). It's not supposed to be used
581	to completely take over the process, use C<run> for that.	609	to completely take over the process, use C<run> for that.
582		610
583	The code will usually be executed after this call returns, and there is no	611	The code will usually be executed after this call returns, and there is no
584	way to pass anything back to the calling process. Any evaluation errors	612	way to pass anything back to the calling process. Any evaluation errors
585	will be reported to stderr and cause the process to exit.	613	will be reported to stderr and cause the process to exit.
586		614
587	If you want to execute some code to take over the process (see the	615	If you want to execute some code (that isn't in a module) to take over the
588	"fork+exec" example in the SYNOPSIS), you should compile a function via	616	process, you should compile a function via C<eval> first, and then call
589	C<eval> first, and then call it via C<run>. This also gives you access to	617	it via C<run>. This also gives you access to any arguments passed via the
590	any arguments passed via the C<send_xxx> methods, such as file handles.	618	C<send_xxx> methods, such as file handles. See the L<use AnyEvent::Fork as
		619	a faster fork+exec> example to see it in action.
591		620
592	Returns the process object for easy chaining of method calls.	621	Returns the process object for easy chaining of method calls.
593		622
594	=cut	623	=cut
595		624
…		…
621	=item $proc = $proc->send_fh ($handle, ...)	650	=item $proc = $proc->send_fh ($handle, ...)
622		651
623	Send one or more file handles (I<not> file descriptors) to the process,	652	Send one or more file handles (I<not> file descriptors) to the process,
624	to prepare a call to C<run>.	653	to prepare a call to C<run>.
625		654
626	The process object keeps a reference to the handles until this is done,	655	The process object keeps a reference to the handles until they have
627	so you must not explicitly close the handles. This is most easily	656	been passed over to the process, so you must not explicitly close the
628	accomplished by simply not storing the file handles anywhere after passing	657	handles. This is most easily accomplished by simply not storing the file
629	them to this method.	658	handles anywhere after passing them to this method - when AnyEvent::Fork
		659	is finished using them, perl will automatically close them.
630		660
631	Returns the process object for easy chaining of method calls.	661	Returns the process object for easy chaining of method calls.
632		662
633	Example: pass a file handle to a process, and release it without	663	Example: pass a file handle to a process, and release it without
634	closing. It will be closed automatically when it is no longer used.	664	closing. It will be closed automatically when it is no longer used.
…		…
641	sub send_fh {	671	sub send_fh {
642	my ($self, @fh) = @_;	672	my ($self, @fh) = @_;
643		673
644	for my $fh (@fh) {	674	for my $fh (@fh) {
645	$self->_cmd ("h");	675	$self->_cmd ("h");
646	push @{ $self->[2] }, \$fh;	676	push @{ $self->[QUEUE] }, \$fh;
647	}	677	}
648		678
649	$self	679	$self
650	}	680	}
651		681
652	=item $proc = $proc->send_arg ($string, ...)	682	=item $proc = $proc->send_arg ($string, ...)
653		683
654	Send one or more argument strings to the process, to prepare a call to	684	Send one or more argument strings to the process, to prepare a call to
655	C<run>. The strings can be any octet string.	685	C<run>. The strings can be any octet strings.
656		686
657	The protocol is optimised to pass a moderate number of relatively short	687	The protocol is optimised to pass a moderate number of relatively short
658	strings - while you can pass up to 4GB of data in one go, this is more	688	strings - while you can pass up to 4GB of data in one go, this is more
659	meant to pass some ID information or other startup info, not big chunks of	689	meant to pass some ID information or other startup info, not big chunks of
660	data.	690	data.
…		…
676	Enter the function specified by the function name in C<$func> in the	706	Enter the function specified by the function name in C<$func> in the
677	process. The function is called with the communication socket as first	707	process. The function is called with the communication socket as first
678	argument, followed by all file handles and string arguments sent earlier	708	argument, followed by all file handles and string arguments sent earlier
679	via C<send_fh> and C<send_arg> methods, in the order they were called.	709	via C<send_fh> and C<send_arg> methods, in the order they were called.
680		710
		711	The process object becomes unusable on return from this function - any
		712	further method calls result in undefined behaviour.
		713
681	The function name should be fully qualified, but if it isn't, it will be	714	The function name should be fully qualified, but if it isn't, it will be
682	looked up in the main package.	715	looked up in the C<main> package.
683		716
684	If the called function returns, doesn't exist, or any error occurs, the	717	If the called function returns, doesn't exist, or any error occurs, the
685	process exits.	718	process exits.
686		719
687	Preparing the process is done in the background - when all commands have	720	Preparing the process is done in the background - when all commands have
688	been sent, the callback is invoked with the local communications socket	721	been sent, the callback is invoked with the local communications socket
689	as argument. At this point you can start using the socket in any way you	722	as argument. At this point you can start using the socket in any way you
690	like.	723	like.
691
692	The process object becomes unusable on return from this function - any
693	further method calls result in undefined behaviour.
694		724
695	If the communication socket isn't used, it should be closed on both sides,	725	If the communication socket isn't used, it should be closed on both sides,
696	to save on kernel memory.	726	to save on kernel memory.
697		727
698	The socket is non-blocking in the parent, and blocking in the newly	728	The socket is non-blocking in the parent, and blocking in the newly
…		…
737	=cut	767	=cut
738		768
739	sub run {	769	sub run {
740	my ($self, $func, $cb) = @_;	770	my ($self, $func, $cb) = @_;
741		771
742	$self->[4] = $cb;	772	$self->[CB] = $cb;
743	$self->_cmd (r => $func);	773	$self->_cmd (r => $func);
744	}	774	}
745		775
746	=back	776	=back
747		777
…		…
773	479 vfork+execs per second, using AnyEvent::Fork->new_exec	803	479 vfork+execs per second, using AnyEvent::Fork->new_exec
774		804
775	So how can C<< AnyEvent->new >> be faster than a standard fork, even	805	So how can C<< AnyEvent->new >> be faster than a standard fork, even
776	though it uses the same operations, but adds a lot of overhead?	806	though it uses the same operations, but adds a lot of overhead?
777		807
778	The difference is simply the process size: forking the 6MB process takes	808	The difference is simply the process size: forking the 5MB process takes
779	so much longer than forking the 2.5MB template process that the overhead	809	so much longer than forking the 2.5MB template process that the extra
780	introduced is canceled out.	810	overhead is canceled out.
781		811
782	If the benchmark process grows, the normal fork becomes even slower:	812	If the benchmark process grows, the normal fork becomes even slower:
783		813
784	1340 new processes, manual fork in a 20MB process	814	1340 new processes, manual fork of a 20MB process
785	731 new processes, manual fork in a 200MB process	815	731 new processes, manual fork of a 200MB process
786	235 new processes, manual fork in a 2000MB process	816	235 new processes, manual fork of a 2000MB process
787		817
788	What that means (to me) is that I can use this module without having a	818	What that means (to me) is that I can use this module without having a bad
789	very bad conscience because of the extra overhead required to start new	819	conscience because of the extra overhead required to start new processes.
790	processes.
791		820
792	=head1 TYPICAL PROBLEMS	821	=head1 TYPICAL PROBLEMS
793		822
794	This section lists typical problems that remain. I hope by recognising	823	This section lists typical problems that remain. I hope by recognising
795	them, most can be avoided.	824	them, most can be avoided.
796		825
797	=over 4	826	=over 4
798		827
799	=item "leaked" file descriptors for exec'ed processes	828	=item leaked file descriptors for exec'ed processes
800		829
801	POSIX systems inherit file descriptors by default when exec'ing a new	830	POSIX systems inherit file descriptors by default when exec'ing a new
802	process. While perl itself laudably sets the close-on-exec flags on new	831	process. While perl itself laudably sets the close-on-exec flags on new
803	file handles, most C libraries don't care, and even if all cared, it's	832	file handles, most C libraries don't care, and even if all cared, it's
804	often not possible to set the flag in a race-free manner.	833	often not possible to set the flag in a race-free manner.
…		…
824	libraries or the code that leaks those file descriptors.	853	libraries or the code that leaks those file descriptors.
825		854
826	Fortunately, most of these leaked descriptors do no harm, other than	855	Fortunately, most of these leaked descriptors do no harm, other than
827	sitting on some resources.	856	sitting on some resources.
828		857
829	=item "leaked" file descriptors for fork'ed processes	858	=item leaked file descriptors for fork'ed processes
830		859
831	Normally, L<AnyEvent::Fork> does start new processes by exec'ing them,	860	Normally, L<AnyEvent::Fork> does start new processes by exec'ing them,
832	which closes file descriptors not marked for being inherited.	861	which closes file descriptors not marked for being inherited.
833		862
834	However, L<AnyEvent::Fork::Early> and L<AnyEvent::Fork::Template> offer	863	However, L<AnyEvent::Fork::Early> and L<AnyEvent::Fork::Template> offer
…		…
843		872
844	The solution is to either not load these modules before use'ing	873	The solution is to either not load these modules before use'ing
845	L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay	874	L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay
846	initialising them, for example, by calling C<init Gtk2> manually.	875	initialising them, for example, by calling C<init Gtk2> manually.
847		876
848	=item exit runs destructors	877	=item exiting calls object destructors
849		878
850	This only applies to users of Lc<AnyEvent::Fork:Early> and	879	This only applies to users of L<AnyEvent::Fork:Early> and
851	L<AnyEvent::Fork::Template>.	880	L<AnyEvent::Fork::Template>, or when initialising code creates objects
		881	that reference external resources.
852		882
853	When a process created by AnyEvent::Fork exits, it might do so by calling	883	When a process created by AnyEvent::Fork exits, it might do so by calling
854	exit, or simply letting perl reach the end of the program. At which point	884	exit, or simply letting perl reach the end of the program. At which point
855	Perl runs all destructors.	885	Perl runs all destructors.
856		886
…		…
875	to make it so, mostly due to the bloody broken perl that nobody seems to	905	to make it so, mostly due to the bloody broken perl that nobody seems to
876	care about. The fork emulation is a bad joke - I have yet to see something	906	care about. The fork emulation is a bad joke - I have yet to see something
877	useful that you can do with it without running into memory corruption	907	useful that you can do with it without running into memory corruption
878	issues or other braindamage. Hrrrr.	908	issues or other braindamage. Hrrrr.
879		909
880	Cygwin perl is not supported at the moment, as it should implement fd	910	Cygwin perl is not supported at the moment due to some hilarious
881	passing, but doesn't, and rolling my own is hard, as cygwin doesn't	911	shortcomings of its API - see L<IO::FDPoll> for more details.
882	support enough functionality to do it.
883		912
884	=head1 SEE ALSO	913	=head1 SEE ALSO
885		914
886	L<AnyEvent::Fork::Early> (to avoid executing a perl interpreter),	915	L<AnyEvent::Fork::Early>, to avoid executing a perl interpreter at all
		916	(part of this distribution).
		917
887	L<AnyEvent::Fork::Template> (to create a process by forking the main	918	L<AnyEvent::Fork::Template>, to create a process by forking the main
888	program at a convenient time).	919	program at a convenient time (part of this distribution).
889		920
890	=head1 AUTHOR	921	L<AnyEvent::Fork::RPC>, for simple RPC to child processes (on CPAN).
		922
		923	=head1 AUTHOR AND CONTACT INFORMATION
891		924
892	Marc Lehmann <schmorp@schmorp.de>	925	Marc Lehmann <schmorp@schmorp.de>
893	http://home.schmorp.de/	926	http://software.schmorp.de/pkg/AnyEvent-Fork
894		927
895	=cut	928	=cut
896		929
897	1	930	1
898		931

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Comparing AnyEvent-Fork/Fork.pm (file contents): Revision 1.28 by root, Sat Apr 6 09:06:43 2013 UTC vs. Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC

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Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.28 by root, Sat Apr 6 09:06:43 2013 UTC vs.
Revision 1.46 by root, Thu Apr 18 11:18:23 2013 UTC