[ViewVC] Diff of: cvs/Coro/Coro.pm

Comparing Coro/Coro.pm (file contents):
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC vs.
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC

  sub some_func : Coro {
     # some more async code
  }
- yield;
+ cede;
 =head1 DESCRIPTION
+This module collection manages coroutines. Coroutines are similar to
+Threads but don't run in parallel.
+This module is still experimental, see the BUGS section below.
+In this module, coroutines are defined as "callchain + lexical variables
++ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's
+own set of lexicals and it's own set of perl's most important global
+variables.
+WARNING: When using this module, make sure that, at program end, no
+coroutines are still running OR just call exit before falling off the
+end. The reason for this is that some coroutine of yours might have called
+into a C function, and falling off the end of main:: results in returning
+to that C function instead if to the main C interpreter.
+WARNING: Unless you really know what you are doing, do NOT do context
+switches inside callbacks from the XS level. The reason for this is
+similar to the reason above:  A callback calls a perl function, this
+perl function does a context switch, some other callback is called, the
+original function returns from it - to what? To the wrong XS function,
+with totally different return values. Unfortunately, this includes
+callbacks done by perl itself (tie'd variables!).
+The only workaround for this is to do coroutines on C level.
 =cut
 package Coro;
 use Coro::State;
 use base Exporter;
-$VERSION = 0.04;
+$VERSION = 0.10;
-@EXPORT = qw(async yield schedule);
+@EXPORT = qw(async cede schedule terminate current);
 @EXPORT_OK = qw($current);
 {
-   use subs 'async';
    my @async;
    # this way of handling attributes simply is NOT scalable ;()
    sub import {
       Coro->export_to_level(1, @_);
          my @attrs;
          for (@_) {
             if ($_ eq "Coro") {
                push @async, $ref;
             } else {
-               push @attrs, @_;
+               push @attrs, $_;
             }
          }
-         return $old ? $old->($package, $name, @attrs) : @attrs;
+         return $old ? $old->($package, $ref, @attrs) : @attrs;
       };
    }
    sub INIT {
-      async pop @async while @async;
+      &async(pop @async) while @async;
    }
 }
 =item $main
 =cut
 our $main = new Coro;
-=item $current
+=item $current (or as function: current)
 The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
 =cut
 if ($current) {
    $main->{specific} = $current->{specific};
 }
 our $current = $main;
+sub current() { $current }
 =item $idle
 The coroutine to switch to when no other coroutine is running. The default
 implementation prints "FATAL: deadlock detected" and exits.
    print STDERR "FATAL: deadlock detected\n";
    exit(51);
 };
 # we really need priorities...
-my @ready = (); # the ready queue. hehe, rather broken ;)
+my @ready; # the ready queue. hehe, rather broken ;)
 # static methods. not really.
 =head2 STATIC METHODS
 Static methods are actually functions that operate on the current process only.
 =over 4
-=item async { ... };
+=item async { ... } [@args...]
 Create a new asynchronous process and return it's process object
 (usually unused). When the sub returns the new process is automatically
 terminated.
-=cut
+   # create a new coroutine that just prints its arguments
+   async {
+      print "@_\n";
+   } 1,2,3,4;
+The coderef you submit MUST NOT be a closure that refers to variables
+in an outer scope. This does NOT work. Pass arguments into it instead.
+=cut
-sub async(&) {
+sub async(&@) {
-   (new Coro $_[0])->ready;
+   my $pid = new Coro @_;
+   $pid->ready;
+   $pid;
 }
 =item schedule
 Calls the scheduler. Please note that the current process will not be put
    # should be done using priorities :(
    ($prev, $current) = ($current, shift @ready || $idle);
    Coro::State::transfer($prev, $current);
 }
-=item yield
+=item cede
-Yield to other processes. This function puts the current process into the
+"Cede" to other processes. This function puts the current process into the
-ready queue and calls C<schedule>.
+ready queue and calls C<schedule>, which has the effect of giving up the
+current "timeslice" to other coroutines of the same or higher priority.
 =cut
-sub yield {
+sub cede {
    $current->ready;
    &schedule;
 }
 =item terminate
 Terminates the current process.
+Future versions of this function will allow result arguments.
 =cut
 sub terminate {
-   &schedule;
+   my $self = $current;
+   $self->{_results} = [@_];
+   $current = shift @ready || $idle;
+   Coro::State::transfer(delete $self->{_coro_state}, $current);
+   # cannot return
+   die;
 }
 =back
 # dynamic methods
 These are the methods you can call on process objects.
 =over 4
-=item new Coro \&sub;
+=item new Coro \&sub [, @args...]
 Create a new process and return it. When the sub returns the process
 automatically terminates. To start the process you must first put it into
 the ready queue by calling the ready method.
+The coderef you submit MUST NOT be a closure that refers to variables
+in an outer scope. This does NOT work. Pass arguments into it instead.
 =cut
+sub _newcoro {
+   terminate &{+shift};
+}
 sub new {
    my $class = shift;
-   my $proc = $_[0];
    bless {
-      _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
+      _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
    }, $class;
 }
 =item $process->ready
 =cut
 1;
+=head1 BUGS/LIMITATIONS
+ - could be faster, especially when the core would introduce special
+   support for coroutines (like it does for threads).
+ - there is still a memleak on coroutine termination that I could not
+   identify. Could be as small as a single SV.
+ - this module is not well-tested.
+ - if variables or arguments "disappear" (become undef) or become
+   corrupted please contact the author so he cen iron out the
+   remaining bugs.
+ - this module is not thread-safe. You must only ever use this module from
+   the same thread (this requirement might be loosened in the future to
+   allow per-thread schedulers, but Coro::State does not yet allow this).
 =head1 SEE ALSO
 L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
-L<Coro::Signal>, L<Coro::State>.
+L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
 =head1 AUTHOR
  Marc Lehmann <pcg@goof.com>
  http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC vs. Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC vs.
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC