… | |
… | |
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 = 0.7; |
455 | our $VERSION = '1.0'; |
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 |
… | |
… | |
412 | my $self = shift; |
485 | my $self = shift; |
413 | |
486 | |
414 | # ideally, we would want to use "a (w/a)*" as format string, but perl |
487 | # ideally, we would want to use "a (w/a)*" as format string, but perl |
415 | # versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack |
488 | # versions from at least 5.8.9 to 5.16.3 are all buggy and can't unpack |
416 | # it. |
489 | # it. |
417 | push @{ $self->[QUEUE] }, pack "a L/a*", $_[0], $_[1]; |
490 | push @{ $self->[QUEUE] }, pack "a N/a*", $_[0], $_[1]; |
418 | |
491 | |
419 | $self->[WW] ||= AE::io $self->[FH], 1, sub { |
492 | $self->[WW] ||= AE::io $self->[FH], 1, sub { |
420 | do { |
493 | do { |
421 | # send the next "thing" in the queue - either a reference to an fh, |
494 | # send the next "thing" in the queue - either a reference to an fh, |
422 | # or a plain string. |
495 | # or a plain string. |
… | |
… | |
774 | |
847 | |
775 | $self->[CB] = $cb; |
848 | $self->[CB] = $cb; |
776 | $self->_cmd (r => $func); |
849 | $self->_cmd (r => $func); |
777 | } |
850 | } |
778 | |
851 | |
|
|
852 | =back |
|
|
853 | |
|
|
854 | =head2 ADVANCED METHODS |
|
|
855 | |
|
|
856 | =over 4 |
|
|
857 | |
|
|
858 | =item new_from_stdio AnyEvent::Fork $fh |
|
|
859 | |
|
|
860 | Assume that you have a perl interpreter running (without any special |
|
|
861 | options or a program) somewhere and it has it's STDIN and STDOUT connected |
|
|
862 | to the C<$fh> somehow. I.e. exactly the state perl is in when you start it |
|
|
863 | without any arguments: |
|
|
864 | |
|
|
865 | perl |
|
|
866 | |
|
|
867 | Then you can create an C<AnyEvent::Fork> object out of this perl |
|
|
868 | interpreter with this constructor. |
|
|
869 | |
|
|
870 | When the usefulness of this isn't immediately clear, imagine you manage to |
|
|
871 | run a perl interpreter remotely (F<ssh remotemachine perl>), then you can |
|
|
872 | manage it mostly like a local C<AnyEvent::Fork> child. |
|
|
873 | |
|
|
874 | This works without any module support, i.e. the remote F<perl> does not |
|
|
875 | need to have any special modules installed. |
|
|
876 | |
|
|
877 | There are a number of limitations though: C<send_fh> will only work if the |
|
|
878 | L<IO::FDPass> module is loadable by the remote perl and the two processes |
|
|
879 | are connected in a way that let's L<IO::FDPass> do it's work. |
|
|
880 | |
|
|
881 | This will therefore not work over a network connection. From this follows |
|
|
882 | that C<fork> will also not work under these circumstances, as it relies on |
|
|
883 | C<send_fh> internally. |
|
|
884 | |
|
|
885 | Although not a limitation of this module, keep in mind that the |
|
|
886 | "communications socket" is simply C<STDIN>, and depending on how you |
|
|
887 | started F<perl> (e.g. via F<ssh>), it might only be half-duplex. This is |
|
|
888 | fine for C<AnyEvent::Fork>, but your C<run> function might want to use |
|
|
889 | C<STDIN> (or the "communications socket") for input and C<STDOUT> for |
|
|
890 | output. |
|
|
891 | |
|
|
892 | You can support both cases by checking the C<fileno> of the handle passed |
|
|
893 | to your run function: |
|
|
894 | |
|
|
895 | sub run { |
|
|
896 | my ($rfh) = @_; |
|
|
897 | |
|
|
898 | my $wfh = fileno $rfh ? $rfh : *STDOUT; |
|
|
899 | |
|
|
900 | # now use $rfh for reading and $wfh for writing |
|
|
901 | } |
|
|
902 | |
|
|
903 | =cut |
|
|
904 | |
|
|
905 | sub new_from_stdio { |
|
|
906 | my ($class, $fh) = @_; |
|
|
907 | |
|
|
908 | my $self = $class->_new ($fh); |
|
|
909 | |
|
|
910 | # send startup code |
|
|
911 | push @{ $self->[QUEUE] }, |
|
|
912 | (do "AnyEvent/Fork/serve.pl") |
|
|
913 | . <<'EOF'; |
|
|
914 | |
|
|
915 | $OWNER = "another process"; |
|
|
916 | $0 = "AnyEvent::Fork/stdio of $OWNER"; |
|
|
917 | |
|
|
918 | serve *STDIN; |
|
|
919 | __END__ |
|
|
920 | EOF |
|
|
921 | |
|
|
922 | # the data is only sent when the user requests additional things, which |
|
|
923 | # is likely early enough for our purposes. |
|
|
924 | |
|
|
925 | $self |
|
|
926 | } |
|
|
927 | |
|
|
928 | =back |
|
|
929 | |
|
|
930 | =head2 EXPERIMENTAL METHODS |
|
|
931 | |
|
|
932 | These methods might go away completely or change behaviour, a any time. |
|
|
933 | |
|
|
934 | =over 4 |
|
|
935 | |
779 | =item $proc->to_fh ($cb->($fh)) # EXPERIMENTAL, MIGHT BE REMOVED |
936 | =item $proc->to_fh ($cb->($fh)) # EXPERIMENTAL, MIGHT BE REMOVED |
780 | |
937 | |
781 | Flushes all commands out to the process and then calls the callback with |
938 | Flushes all commands out to the process and then calls the callback with |
782 | the communications socket. |
939 | the communications socket. |
783 | |
940 | |
784 | The process object becomes unusable on return from this function - any |
941 | The process object becomes unusable on return from this function - any |
785 | further method calls result in undefined behaviour. |
942 | further method calls result in undefined behaviour. |
786 | |
943 | |
787 | The point of this method is to give you a file handle thta you cna pass |
944 | The point of this method is to give you a file handle thta you cna pass |
788 | to another process. In that other process, you can call C<new_from_fh |
945 | to another process. In that other process, you can call C<new_from_fh |
789 | AnyEvent::Fork::RPC> to create a new C<AnyEvent::Fork> object from it, |
946 | AnyEvent::Fork> to create a new C<AnyEvent::Fork> object from it, thereby |
790 | thereby effectively passing a fork object to another process. |
947 | effectively passing a fork object to another process. |
791 | |
948 | |
792 | =cut |
949 | =cut |
793 | |
950 | |
794 | sub to_fh { |
951 | sub to_fh { |
795 | my ($self, $cb) = @_; |
952 | my ($self, $cb) = @_; |
… | |
… | |
972 | L<AnyEvent::Fork::Template>, to create a process by forking the main |
1129 | L<AnyEvent::Fork::Template>, to create a process by forking the main |
973 | program at a convenient time (part of this distribution). |
1130 | program at a convenient time (part of this distribution). |
974 | |
1131 | |
975 | L<AnyEvent::Fork::RPC>, for simple RPC to child processes (on CPAN). |
1132 | L<AnyEvent::Fork::RPC>, for simple RPC to child processes (on CPAN). |
976 | |
1133 | |
|
|
1134 | L<AnyEvent::Fork::Pool>, for simple worker process pool (on CPAN). |
|
|
1135 | |
977 | =head1 AUTHOR AND CONTACT INFORMATION |
1136 | =head1 AUTHOR AND CONTACT INFORMATION |
978 | |
1137 | |
979 | Marc Lehmann <schmorp@schmorp.de> |
1138 | Marc Lehmann <schmorp@schmorp.de> |
980 | http://software.schmorp.de/pkg/AnyEvent-Fork |
1139 | http://software.schmorp.de/pkg/AnyEvent-Fork |
981 | |
1140 | |