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

Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.26 by root, Sat Apr 6 08:58:51 2013 UTC vs.
Revision 1.44 by root, Thu Apr 18 10:49:59 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, ">&", $output or die;
…		…
309	my ($fork_fh) = @_;	337	my ($fork_fh) = @_;
310	});	338	});
311		339
312	=back	340	=back
313		341
314	=head1 FUNCTIONS	342	=head1 THE C<AnyEvent::Fork> CLASS
		343
		344	This module exports nothing, and only implements a single class -
		345	C<AnyEvent::Fork>.
		346
		347	There are two class constructors that both create new processes - C<new>
		348	and C<new_exec>. The C<fork> method creates a new process by forking an
		349	existing one and could be considered a third constructor.
		350
		351	Most of the remaining methods deal with preparing the new process, by
		352	loading code, evaluating code and sending data to the new process. They
		353	usually return the process object, so you can chain method calls.
		354
		355	If a process object is destroyed before calling its C<run> method, then
		356	the process simply exits. After C<run> is called, all responsibility is
		357	passed to the specified function.
		358
		359	As long as there is any outstanding work to be done, process objects
		360	resist being destroyed, so there is no reason to store them unless you
		361	need them later - configure and forget works just fine.
315		362
316	=over 4	363	=over 4
317		364
318	=cut	365	=cut
319		366
…		…
326	use AnyEvent;	373	use AnyEvent;
327	use AnyEvent::Util ();	374	use AnyEvent::Util ();
328		375
329	use IO::FDPass;	376	use IO::FDPass;
330		377
331	our $VERSION = 0.5;	378	our $VERSION = 0.6;
332
333	our $PERL; # the path to the perl interpreter, deduces with various forms of magic
334
335	=item my $pool = new AnyEvent::Fork key => value...
336
337	Create a new process pool. The following named parameters are supported:
338
339	=over 4
340
341	=back
342
343	=cut
344		379
345	# the early fork template process	380	# the early fork template process
346	our $EARLY;	381	our $EARLY;
347		382
348	# the empty template process	383	# the empty template process
349	our $TEMPLATE;	384	our $TEMPLATE;
		385
		386	sub QUEUE() { 0 }
		387	sub FH() { 1 }
		388	sub WW() { 2 }
		389	sub PID() { 3 }
		390	sub CB() { 4 }
		391
		392	sub _new {
		393	my ($self, $fh, $pid) = @_;
		394
		395	AnyEvent::Util::fh_nonblocking $fh, 1;
		396
		397	$self = bless [
		398	[], # write queue - strings or fd's
		399	$fh,
		400	undef, # AE watcher
		401	$pid,
		402	], $self;
		403
		404	$self
		405	}
350		406
351	sub _cmd {	407	sub _cmd {
352	my $self = shift;	408	my $self = shift;
353		409
354	# ideally, we would want to use "a (w/a)*" as format string, but perl	410	# ideally, we would want to use "a (w/a)*" as format string, but perl
355	# versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack	411	# versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack
356	# it.	412	# it.
357	push @{ $self->[2] }, pack "a L/a*", $_[0], $_[1];	413	push @{ $self->[QUEUE] }, pack "a L/a*", $_[0], $_[1];
358		414
359	$self->[3] \|\|= AE::io $self->[1], 1, sub {	415	$self->[WW] \|\|= AE::io $self->[FH], 1, sub {
360	do {	416	do {
361	# send the next "thing" in the queue - either a reference to an fh,	417	# send the next "thing" in the queue - either a reference to an fh,
362	# or a plain string.	418	# or a plain string.
363		419
364	if (ref $self->[2][0]) {	420	if (ref $self->[QUEUE][0]) {
365	# send fh	421	# send fh
366	unless (IO::FDPass::send fileno $self->[1], fileno ${ $self->[2][0] }) {	422	unless (IO::FDPass::send fileno $self->[FH], fileno ${ $self->[QUEUE][0] }) {
367	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;	423	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;
368	undef $self->[3];	424	undef $self->[WW];
369	die "AnyEvent::Fork: file descriptor send failure: $!";	425	die "AnyEvent::Fork: file descriptor send failure: $!";
370	}	426	}
371		427
372	shift @{ $self->[2] };	428	shift @{ $self->[QUEUE] };
373		429
374	} else {	430	} else {
375	# send string	431	# send string
376	my $len = syswrite $self->[1], $self->[2][0];	432	my $len = syswrite $self->[FH], $self->[QUEUE][0];
377		433
378	unless ($len) {	434	unless ($len) {
379	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;	435	return if $! == Errno::EAGAIN \|\| $! == Errno::EWOULDBLOCK;
380	undef $self->[3];	436	undef $self->[3];
381	die "AnyEvent::Fork: command write failure: $!";	437	die "AnyEvent::Fork: command write failure: $!";
382	}	438	}
383		439
384	substr $self->[2][0], 0, $len, "";	440	substr $self->[QUEUE][0], 0, $len, "";
385	shift @{ $self->[2] } unless length $self->[2][0];	441	shift @{ $self->[QUEUE] } unless length $self->[QUEUE][0];
386	}	442	}
387	} while @{ $self->[2] };	443	} while @{ $self->[QUEUE] };
388		444
389	# everything written	445	# everything written
390	undef $self->[3];	446	undef $self->[WW];
391		447
392	# invoke run callback, if any	448	# invoke run callback, if any
393	$self->[4]->($self->[1]) if $self->[4];	449	$self->[CB]->($self->[FH]) if $self->[CB];
394	};	450	};
395		451
396	() # make sure we don't leak the watcher	452	() # make sure we don't leak the watcher
397	}
398
399	sub _new {
400	my ($self, $fh, $pid) = @_;
401
402	AnyEvent::Util::fh_nonblocking $fh, 1;
403
404	$self = bless [
405	$pid,
406	$fh,
407	[], # write queue - strings or fd's
408	undef, # AE watcher
409	], $self;
410
411	$self
412	}	453	}
413		454
414	# fork template from current process, used by AnyEvent::Fork::Early/Template	455	# fork template from current process, used by AnyEvent::Fork::Early/Template
415	sub _new_fork {	456	sub _new_fork {
416	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;	457	my ($fh, $slave) = AnyEvent::Util::portable_socketpair;
…		…
421	if ($pid eq 0) {	462	if ($pid eq 0) {
422	require AnyEvent::Fork::Serve;	463	require AnyEvent::Fork::Serve;
423	$AnyEvent::Fork::Serve::OWNER = $parent;	464	$AnyEvent::Fork::Serve::OWNER = $parent;
424	close $fh;	465	close $fh;
425	$0 = "$_[1] of $parent";	466	$0 = "$_[1] of $parent";
426	$SIG{CHLD} = 'IGNORE';
427	AnyEvent::Fork::Serve::serve ($slave);	467	AnyEvent::Fork::Serve::serve ($slave);
428	exit 0;	468	exit 0;
429	} elsif (!$pid) {	469	} elsif (!$pid) {
430	die "AnyEvent::Fork::Early/Template: unable to fork template process: $!";	470	die "AnyEvent::Fork::Early/Template: unable to fork template process: $!";
431	}	471	}
…		…
438	Create a new "empty" perl interpreter process and returns its process	478	Create a new "empty" perl interpreter process and returns its process
439	object for further manipulation.	479	object for further manipulation.
440		480
441	The new process is forked from a template process that is kept around	481	The new process is forked from a template process that is kept around
442	for this purpose. When it doesn't exist yet, it is created by a call to	482	for this purpose. When it doesn't exist yet, it is created by a call to
443	C<new_exec> and kept around for future calls.	483	C<new_exec> first and then stays around for future calls.
444
445	When the process object is destroyed, it will release the file handle
446	that connects it with the new process. When the new process has not yet
447	called C<run>, then the process will exit. Otherwise, what happens depends
448	entirely on the code that is executed.
449		484
450	=cut	485	=cut
451		486
452	sub new {	487	sub new {
453	my $class = shift;	488	my $class = shift;
…		…
543	}	578	}
544		579
545	=item $pid = $proc->pid	580	=item $pid = $proc->pid
546		581
547	Returns the process id of the process I<iff it is a direct child of the	582	Returns the process id of the process I<iff it is a direct child of the
548	process> running AnyEvent::Fork, and C<undef> otherwise.	583	process running AnyEvent::Fork>, and C<undef> otherwise.
549		584
550	Normally, only processes created via C<< AnyEvent::Fork->new_exec >> and	585	Normally, only processes created via C<< AnyEvent::Fork->new_exec >> and
551	L<AnyEvent::Fork::Template> are direct children, and you are responsible	586	L<AnyEvent::Fork::Template> are direct children, and you are responsible
552	to clean up their zombies when they die.	587	to clean up their zombies when they die.
553		588
554	All other processes are not direct children, and will be cleaned up by	589	All other processes are not direct children, and will be cleaned up by
555	AnyEvent::Fork.	590	AnyEvent::Fork itself.
556		591
557	=cut	592	=cut
558		593
559	sub pid {	594	sub pid {
560	$_[0][0]	595	$_[0][PID]
561	}	596	}
562		597
563	=item $proc = $proc->eval ($perlcode, @args)	598	=item $proc = $proc->eval ($perlcode, @args)
564		599
565	Evaluates the given C<$perlcode> as ... perl code, while setting C<@_> to	600	Evaluates the given C<$perlcode> as ... Perl code, while setting C<@_> to
566	the strings specified by C<@args>, in the "main" package.	601	the strings specified by C<@args>, in the "main" package.
567		602
568	This call is meant to do any custom initialisation that might be required	603	This call is meant to do any custom initialisation that might be required
569	(for example, the C<require> method uses it). It's not supposed to be used	604	(for example, the C<require> method uses it). It's not supposed to be used
570	to completely take over the process, use C<run> for that.	605	to completely take over the process, use C<run> for that.
571		606
572	The code will usually be executed after this call returns, and there is no	607	The code will usually be executed after this call returns, and there is no
573	way to pass anything back to the calling process. Any evaluation errors	608	way to pass anything back to the calling process. Any evaluation errors
574	will be reported to stderr and cause the process to exit.	609	will be reported to stderr and cause the process to exit.
575		610
576	If you want to execute some code to take over the process (see the	611	If you want to execute some code (that isn't in a module) to take over the
577	"fork+exec" example in the SYNOPSIS), you should compile a function via	612	process, you should compile a function via C<eval> first, and then call
578	C<eval> first, and then call it via C<run>. This also gives you access to	613	it via C<run>. This also gives you access to any arguments passed via the
579	any arguments passed via the C<send_xxx> methods, such as file handles.	614	C<send_xxx> methods, such as file handles. See the L<use AnyEvent::Fork as
		615	a faster fork+exec> example to see it in action.
580		616
581	Returns the process object for easy chaining of method calls.	617	Returns the process object for easy chaining of method calls.
582		618
583	=cut	619	=cut
584		620
…		…
610	=item $proc = $proc->send_fh ($handle, ...)	646	=item $proc = $proc->send_fh ($handle, ...)
611		647
612	Send one or more file handles (I<not> file descriptors) to the process,	648	Send one or more file handles (I<not> file descriptors) to the process,
613	to prepare a call to C<run>.	649	to prepare a call to C<run>.
614		650
615	The process object keeps a reference to the handles until this is done,	651	The process object keeps a reference to the handles until they have
616	so you must not explicitly close the handles. This is most easily	652	been passed over to the process, so you must not explicitly close the
617	accomplished by simply not storing the file handles anywhere after passing	653	handles. This is most easily accomplished by simply not storing the file
618	them to this method.	654	handles anywhere after passing them to this method - when AnyEvent::Fork
		655	is finished using them, perl will automatically close them.
619		656
620	Returns the process object for easy chaining of method calls.	657	Returns the process object for easy chaining of method calls.
621		658
622	Example: pass a file handle to a process, and release it without	659	Example: pass a file handle to a process, and release it without
623	closing. It will be closed automatically when it is no longer used.	660	closing. It will be closed automatically when it is no longer used.
…		…
630	sub send_fh {	667	sub send_fh {
631	my ($self, @fh) = @_;	668	my ($self, @fh) = @_;
632		669
633	for my $fh (@fh) {	670	for my $fh (@fh) {
634	$self->_cmd ("h");	671	$self->_cmd ("h");
635	push @{ $self->[2] }, \$fh;	672	push @{ $self->[QUEUE] }, \$fh;
636	}	673	}
637		674
638	$self	675	$self
639	}	676	}
640		677
641	=item $proc = $proc->send_arg ($string, ...)	678	=item $proc = $proc->send_arg ($string, ...)
642		679
643	Send one or more argument strings to the process, to prepare a call to	680	Send one or more argument strings to the process, to prepare a call to
644	C<run>. The strings can be any octet string.	681	C<run>. The strings can be any octet strings.
645		682
646	The protocol is optimised to pass a moderate number of relatively short	683	The protocol is optimised to pass a moderate number of relatively short
647	strings - while you can pass up to 4GB of data in one go, this is more	684	strings - while you can pass up to 4GB of data in one go, this is more
648	meant to pass some ID information or other startup info, not big chunks of	685	meant to pass some ID information or other startup info, not big chunks of
649	data.	686	data.
…		…
665	Enter the function specified by the function name in C<$func> in the	702	Enter the function specified by the function name in C<$func> in the
666	process. The function is called with the communication socket as first	703	process. The function is called with the communication socket as first
667	argument, followed by all file handles and string arguments sent earlier	704	argument, followed by all file handles and string arguments sent earlier
668	via C<send_fh> and C<send_arg> methods, in the order they were called.	705	via C<send_fh> and C<send_arg> methods, in the order they were called.
669		706
		707	The process object becomes unusable on return from this function - any
		708	further method calls result in undefined behaviour.
		709
670	The function name should be fully qualified, but if it isn't, it will be	710	The function name should be fully qualified, but if it isn't, it will be
671	looked up in the main package.	711	looked up in the C<main> package.
672		712
673	If the called function returns, doesn't exist, or any error occurs, the	713	If the called function returns, doesn't exist, or any error occurs, the
674	process exits.	714	process exits.
675		715
676	Preparing the process is done in the background - when all commands have	716	Preparing the process is done in the background - when all commands have
677	been sent, the callback is invoked with the local communications socket	717	been sent, the callback is invoked with the local communications socket
678	as argument. At this point you can start using the socket in any way you	718	as argument. At this point you can start using the socket in any way you
679	like.	719	like.
680
681	The process object becomes unusable on return from this function - any
682	further method calls result in undefined behaviour.
683		720
684	If the communication socket isn't used, it should be closed on both sides,	721	If the communication socket isn't used, it should be closed on both sides,
685	to save on kernel memory.	722	to save on kernel memory.
686		723
687	The socket is non-blocking in the parent, and blocking in the newly	724	The socket is non-blocking in the parent, and blocking in the newly
…		…
726	=cut	763	=cut
727		764
728	sub run {	765	sub run {
729	my ($self, $func, $cb) = @_;	766	my ($self, $func, $cb) = @_;
730		767
731	$self->[4] = $cb;	768	$self->[CB] = $cb;
732	$self->_cmd (r => $func);	769	$self->_cmd (r => $func);
733	}	770	}
734		771
735	=back	772	=back
736		773
…		…
762	479 vfork+execs per second, using AnyEvent::Fork->new_exec	799	479 vfork+execs per second, using AnyEvent::Fork->new_exec
763		800
764	So how can C<< AnyEvent->new >> be faster than a standard fork, even	801	So how can C<< AnyEvent->new >> be faster than a standard fork, even
765	though it uses the same operations, but adds a lot of overhead?	802	though it uses the same operations, but adds a lot of overhead?
766		803
767	The difference is simply the process size: forking the 6MB process takes	804	The difference is simply the process size: forking the 5MB process takes
768	so much longer than forking the 2.5MB template process that the overhead	805	so much longer than forking the 2.5MB template process that the extra
769	introduced is canceled out.	806	overhead is canceled out.
770		807
771	If the benchmark process grows, the normal fork becomes even slower:	808	If the benchmark process grows, the normal fork becomes even slower:
772		809
773	1340 new processes, manual fork in a 20MB process	810	1340 new processes, manual fork of a 20MB process
774	731 new processes, manual fork in a 200MB process	811	731 new processes, manual fork of a 200MB process
775	235 new processes, manual fork in a 2000MB process	812	235 new processes, manual fork of a 2000MB process
776		813
777	What that means (to me) is that I can use this module without having a	814	What that means (to me) is that I can use this module without having a bad
778	very bad conscience because of the extra overhead required to start new	815	conscience because of the extra overhead required to start new processes.
779	processes.
780		816
781	=head1 TYPICAL PROBLEMS	817	=head1 TYPICAL PROBLEMS
782		818
783	This section lists typical problems that remain. I hope by recognising	819	This section lists typical problems that remain. I hope by recognising
784	them, most can be avoided.	820	them, most can be avoided.
785		821
786	=over 4	822	=over 4
787		823
788	=item "leaked" file descriptors for exec'ed processes	824	=item leaked file descriptors for exec'ed processes
789		825
790	POSIX systems inherit file descriptors by default when exec'ing a new	826	POSIX systems inherit file descriptors by default when exec'ing a new
791	process. While perl itself laudably sets the close-on-exec flags on new	827	process. While perl itself laudably sets the close-on-exec flags on new
792	file handles, most C libraries don't care, and even if all cared, it's	828	file handles, most C libraries don't care, and even if all cared, it's
793	often not possible to set the flag in a race-free manner.	829	often not possible to set the flag in a race-free manner.
…		…
813	libraries or the code that leaks those file descriptors.	849	libraries or the code that leaks those file descriptors.
814		850
815	Fortunately, most of these leaked descriptors do no harm, other than	851	Fortunately, most of these leaked descriptors do no harm, other than
816	sitting on some resources.	852	sitting on some resources.
817		853
818	=item "leaked" file descriptors for fork'ed processes	854	=item leaked file descriptors for fork'ed processes
819		855
820	Normally, L<AnyEvent::Fork> does start new processes by exec'ing them,	856	Normally, L<AnyEvent::Fork> does start new processes by exec'ing them,
821	which closes file descriptors not marked for being inherited.	857	which closes file descriptors not marked for being inherited.
822		858
823	However, L<AnyEvent::Fork::Early> and L<AnyEvent::Fork::Template> offer	859	However, L<AnyEvent::Fork::Early> and L<AnyEvent::Fork::Template> offer
…		…
832		868
833	The solution is to either not load these modules before use'ing	869	The solution is to either not load these modules before use'ing
834	L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay	870	L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay
835	initialising them, for example, by calling C<init Gtk2> manually.	871	initialising them, for example, by calling C<init Gtk2> manually.
836		872
837	=item exit runs destructors	873	=item exiting calls object destructors
838		874
839	This only applies to users of Lc<AnyEvent::Fork:Early> and	875	This only applies to users of L<AnyEvent::Fork:Early> and
840	L<AnyEvent::Fork::Template>.	876	L<AnyEvent::Fork::Template>, or when initialising code creates objects
		877	that reference external resources.
841		878
842	When a process created by AnyEvent::Fork exits, it might do so by calling	879	When a process created by AnyEvent::Fork exits, it might do so by calling
843	exit, or simply letting perl reach the end of the program. At which point	880	exit, or simply letting perl reach the end of the program. At which point
844	Perl runs all destructors.	881	Perl runs all destructors.
845		882
…		…
864	to make it so, mostly due to the bloody broken perl that nobody seems to	901	to make it so, mostly due to the bloody broken perl that nobody seems to
865	care about. The fork emulation is a bad joke - I have yet to see something	902	care about. The fork emulation is a bad joke - I have yet to see something
866	useful that you can do with it without running into memory corruption	903	useful that you can do with it without running into memory corruption
867	issues or other braindamage. Hrrrr.	904	issues or other braindamage. Hrrrr.
868		905
869	Cygwin perl is not supported at the moment, as it should implement fd	906	Cygwin perl is not supported at the moment due to some hilarious
870	passing, but doesn't, and rolling my own is hard, as cygwin doesn't	907	shortcomings of its API - see L<IO::FDPoll> for more details.
871	support enough functionality to do it.
872		908
873	=head1 SEE ALSO	909	=head1 SEE ALSO
874		910
875	L<AnyEvent::Fork::Early> (to avoid executing a perl interpreter),	911	L<AnyEvent::Fork::Early> (to avoid executing a perl interpreter),
876	L<AnyEvent::Fork::Template> (to create a process by forking the main	912	L<AnyEvent::Fork::Template> (to create a process by forking the main
877	program at a convenient time).	913	program at a convenient time), L<AnyEvent::Fork::RPC> (for simple RPC to
		914	child processes).
878		915
879	=head1 AUTHOR	916	=head1 AUTHOR AND CONTACT INFORMATION
880		917
881	Marc Lehmann <schmorp@schmorp.de>	918	Marc Lehmann <schmorp@schmorp.de>
882	http://home.schmorp.de/	919	http://software.schmorp.de/pkg/AnyEvent-Fork
883		920
884	=cut	921	=cut
885		922
886	1	923	1
887		924

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Comparing AnyEvent-Fork/Fork.pm (file contents): Revision 1.26 by root, Sat Apr 6 08:58:51 2013 UTC vs. Revision 1.44 by root, Thu Apr 18 10:49:59 2013 UTC

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Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.26 by root, Sat Apr 6 08:58:51 2013 UTC vs.
Revision 1.44 by root, Thu Apr 18 10:49:59 2013 UTC