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Comparing AnyEvent-Fork/Fork.pm (file contents):
Revision 1.36 by root, Sat Apr 6 09:43:15 2013 UTC vs.
Revision 1.39 by root, Sat Apr 6 22:39:37 2013 UTC

… …
27 27
28Special care has been taken to make this module useful from other modules, 28Special care has been taken to make this module useful from other modules,
29while still supporting specialised environments such as L<App::Staticperl> 29while still supporting specialised environments such as L<App::Staticperl>
30or L<PAR::Packer>. 30or L<PAR::Packer>.
31 31
32=head1 WHAT THIS MODULE IS NOT 32=head2 WHAT THIS MODULE IS NOT
33 33
34This module only creates processes and lets you pass file handles and 34This module only creates processes and lets you pass file handles and
35strings to it, and run perl code. It does not implement any kind of RPC - 35strings to it, and run perl code. It does not implement any kind of RPC -
36there is no back channel from the process back to you, and there is no RPC 36there is no back channel from the process back to you, and there is no RPC
37or message passing going on. 37or message passing going on.
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40in whatever way you like, use some message-passing module such 40in whatever way you like, use some message-passing module such
41as L<AnyEvent::MP>, some pipe such as L<AnyEvent::ZeroMQ>, use 41as L<AnyEvent::MP>, some pipe such as L<AnyEvent::ZeroMQ>, use
42L<AnyEvent::Handle> on both sides to send e.g. JSON or Storable messages, 42L<AnyEvent::Handle> on both sides to send e.g. JSON or Storable messages,
43and so on. 43and so on.
44 44
45=head2 COMPARISON TO OTHER MODULES
46
47There is an abundance of modules on CPAN that do "something fork", such as
48L<Parallel::ForkManager>, L<AnyEvent::ForkManager>, L<AnyEvent::Worker>
49or L<AnyEvent::Subprocess>. There are modules that implement their own
50process management, such as L<AnyEvent::DBI>.
51
52The problems that all these modules try to solve are real, however, none
53of them (from what I have seen) tackle the very real problems of unwanted
54memory sharing, efficiency, not being able to use event processing or
55similar modules in the processes they create.
56
57This module doesn't try to replace any of them - instead it tries to solve
58the problem of creating processes with a minimum of fuss and overhead (and
59also luxury). Ideally, most of these would use AnyEvent::Fork internally,
60except they were written before AnyEvent:Fork was available, so obviously
61had to roll their own.
62
45=head1 PROBLEM STATEMENT 63=head2 PROBLEM STATEMENT
46 64
47There are two traditional ways to implement parallel processing on UNIX 65There are two traditional ways to implement parallel processing on UNIX
48like operating systems - fork and process, and fork+exec and process. They 66like operating systems - fork and process, and fork+exec and process. They
49have different advantages and disadvantages that I describe below, 67have different advantages and disadvantages that I describe below,
50together with how this module tries to mitigate the disadvantages. 68together with how this module tries to mitigate the disadvantages.
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849 867
850The solution is to either not load these modules before use'ing 868The solution is to either not load these modules before use'ing
851L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay 869L<AnyEvent::Fork::Early> or L<AnyEvent::Fork::Template>, or to delay
852initialising them, for example, by calling C<init Gtk2> manually. 870initialising them, for example, by calling C<init Gtk2> manually.
853 871
854=item exit runs destructors 872=item exiting calls object destructors
855 873
856This only applies to users of Lc<AnyEvent::Fork:Early> and 874This only applies to users of L<AnyEvent::Fork:Early> and
857L<AnyEvent::Fork::Template>. 875L<AnyEvent::Fork::Template>, or when initialiasing code creates objects
876that reference external resources.
858 877
859When a process created by AnyEvent::Fork exits, it might do so by calling 878When a process created by AnyEvent::Fork exits, it might do so by calling
860exit, or simply letting perl reach the end of the program. At which point 879exit, or simply letting perl reach the end of the program. At which point
861Perl runs all destructors. 880Perl runs all destructors.
862 881

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