ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent-Fork/README
(Generate patch)

Comparing AnyEvent-Fork/README (file contents):
Revision 1.7 by root, Sun Apr 21 12:26:00 2013 UTC vs.
Revision 1.9 by root, Wed Sep 25 11:05:30 2013 UTC

… …
304 $cv->end; 304 $cv->end;
305 }); 305 });
306 } 306 }
307 $cv->recv; 307 $cv->recv;
308 308
309 lhead1 CONCEPTS 309CONCEPTS
310
311 This module can create new processes either by executing a new perl 310 This module can create new processes either by executing a new perl
312 process, or by forking from an existing "template" process. 311 process, or by forking from an existing "template" process.
313 312
314 All these processes are called "child processes" (whether they are 313 All these processes are called "child processes" (whether they are
315 direct children or not), while the process that manages them is called 314 direct children or not), while the process that manages them is called
… …
440 You should use "new" whenever possible, except when having a 439 You should use "new" whenever possible, except when having a
441 template process around is unacceptable. 440 template process around is unacceptable.
442 441
443 The path to the perl interpreter is divined using various methods - 442 The path to the perl interpreter is divined using various methods -
444 first $^X is investigated to see if the path ends with something 443 first $^X is investigated to see if the path ends with something
445 that sounds as if it were the perl interpreter. Failing this, the 444 that looks as if it were the perl interpreter. Failing this, the
446 module falls back to using $Config::Config{perlpath}. 445 module falls back to using $Config::Config{perlpath}.
446
447 The path to perl can also be overriden by setting the global
448 variable $AnyEvent::Fork::PERL - it's value will be used for all
449 subsequent invocations.
447 450
448 $pid = $proc->pid 451 $pid = $proc->pid
449 Returns the process id of the process *iff it is a direct child of 452 Returns the process id of the process *iff it is a direct child of
450 the process running AnyEvent::Fork*, and "undef" otherwise. 453 the process running AnyEvent::Fork*, and "undef" otherwise. As a
454 general rule (that you cannot rely upon), processes created via
455 "new_exec", AnyEvent::Fork::Early or AnyEvent::Fork::Template are
456 direct children, while all other processes are not.
451 457
452 Normally, only processes created via "AnyEvent::Fork->new_exec" and 458 Or in other words, you do not normally have to take care of zombies
453 AnyEvent::Fork::Template are direct children, and you are 459 for processes created via "new", but when in doubt, or zombies are a
454 responsible to clean up their zombies when they die. 460 problem, you need to check whether a process is a diretc child by
455 461 calling this method, and possibly creating a child watcher or reap
456 All other processes are not direct children, and will be cleaned up 462 it manually.
457 by AnyEvent::Fork itself.
458 463
459 $proc = $proc->eval ($perlcode, @args) 464 $proc = $proc->eval ($perlcode, @args)
460 Evaluates the given $perlcode as ... Perl code, while setting @_ to 465 Evaluates the given $perlcode as ... Perl code, while setting @_ to
461 the strings specified by @args, in the "main" package. 466 the strings specified by @args, in the "main" package.
462 467
… …
544 Even if not used otherwise, the socket can be a good indicator for 549 Even if not used otherwise, the socket can be a good indicator for
545 the existence of the process - if the other process exits, you get a 550 the existence of the process - if the other process exits, you get a
546 readable event on it, because exiting the process closes the socket 551 readable event on it, because exiting the process closes the socket
547 (if it didn't create any children using fork). 552 (if it didn't create any children using fork).
548 553
554 Compatibility to AnyEvent::Fork::Remote
555 If you want to write code that works with both this module and
556 AnyEvent::Fork::Remote, you need to write your code so that it
557 assumes there are two file handles for communications, which
558 might not be unix domain sockets. The "run" function should
559 start like this:
560
561 sub run {
562 my ($rfh, @args) = @_; # @args is your normal arguments
563 my $wfh = fileno $rfh ? $rfh : *STDOUT;
564
565 # now use $rfh for reading and $wfh for writing
566 }
567
568 This checks whether the passed file handle is, in fact, the
569 process "STDIN" handle. If it is, then the function was invoked
570 visa AnyEvent::Fork::Remote, so STDIN should be used for reading
571 and "STDOUT" should be used for writing.
572
573 In all other cases, the function was called via this module, and
574 there is only one file handle that should be sued for reading
575 and writing.
576
549 Example: create a template for a process pool, pass a few strings, 577 Example: create a template for a process pool, pass a few strings,
550 some file handles, then fork, pass one more string, and run some 578 some file handles, then fork, pass one more string, and run some
551 code. 579 code.
552 580
553 my $pool = AnyEvent::Fork 581 my $pool = AnyEvent::Fork
… …
576 my ($fh, $str1, $str2, $fh1, $fh2, $str3) = @_; 604 my ($fh, $str1, $str2, $fh1, $fh2, $str3) = @_;
577 605
578 print scalar <$fh>; # prints "hi #1\n" and "hi #2\n" in any order 606 print scalar <$fh>; # prints "hi #1\n" and "hi #2\n" in any order
579 } 607 }
580 608
609 EXPERIMENTAL METHODS
610 These methods might go away completely or change behaviour, at any time.
611
581 $proc->to_fh ($cb->($fh)) # EXPERIMENTAL, MIGHT BE REMOVED 612 $proc->to_fh ($cb->($fh)) # EXPERIMENTAL, MIGHT BE REMOVED
582 Flushes all commands out to the process and then calls the callback 613 Flushes all commands out to the process and then calls the callback
583 with the communications socket. 614 with the communications socket.
584 615
585 The process object becomes unusable on return from this function - 616 The process object becomes unusable on return from this function -
586 any further method calls result in undefined behaviour. 617 any further method calls result in undefined behaviour.
587 618
588 The point of this method is to give you a file handle thta you cna 619 The point of this method is to give you a file handle that you can
589 pass to another process. In that other process, you can call 620 pass to another process. In that other process, you can call
590 "new_from_fh AnyEvent::Fork" to create a new "AnyEvent::Fork" object 621 "new_from_fh AnyEvent::Fork $fh" to create a new "AnyEvent::Fork"
591 from it, thereby effectively passing a fork object to another 622 object from it, thereby effectively passing a fork object to another
592 process. 623 process.
593 624
594 new_from_fh AnyEvent::Fork $fh # EXPERIMENTAL, MIGHT BE REMOVED 625 new_from_fh AnyEvent::Fork $fh # EXPERIMENTAL, MIGHT BE REMOVED
595 Takes a file handle originally rceeived by the "to_fh" method and 626 Takes a file handle originally rceeived by the "to_fh" method and
596 creates a new "AnyEvent:Fork" object. The child process itself will 627 creates a new "AnyEvent:Fork" object. The child process itself will
… …
741 (part of this distribution). 772 (part of this distribution).
742 773
743 AnyEvent::Fork::Template, to create a process by forking the main 774 AnyEvent::Fork::Template, to create a process by forking the main
744 program at a convenient time (part of this distribution). 775 program at a convenient time (part of this distribution).
745 776
777 AnyEvent::Fork::Remote, for another way to create processes that is
778 mostly compatible to this module and modules building on top of it, but
779 works better with remote processes.
780
746 AnyEvent::Fork::RPC, for simple RPC to child processes (on CPAN). 781 AnyEvent::Fork::RPC, for simple RPC to child processes (on CPAN).
747 782
748 AnyEvent::Fork::Pool, for simple worker process pool (on CPAN). 783 AnyEvent::Fork::Pool, for simple worker process pool (on CPAN).
749 784
750AUTHOR AND CONTACT INFORMATION 785AUTHOR AND CONTACT INFORMATION

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines