--- Coro/Coro.pm	2001/07/17 02:21:56	1.14
+++ Coro/Coro.pm	2001/09/24 00:16:30	1.35
@@ -16,7 +16,7 @@
     # some more async code
  }
 
- yield;
+ cede;
 
 =head1 DESCRIPTION
 
@@ -25,6 +25,11 @@
 
 This module is still experimental, see the BUGS section below.
 
+In this module, coroutines are defined as "callchain + lexical variables
++ @_ + $_ + $@ + $^W + C stack), 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.
+
 =cut
 
 package Coro;
@@ -33,15 +38,17 @@
 
 use base Exporter;
 
-$VERSION = 0.05;
+$VERSION = 0.5;
 
-@EXPORT = qw(async yield schedule terminate);
-@EXPORT_OK = qw($current);
+@EXPORT = qw(async cede schedule terminate current);
+%EXPORT_TAGS = (
+      prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
+);
+@EXPORT_OK = @{$EXPORT_TAGS{prio}};
 
 {
-   use subs 'async';
-
    my @async;
+   my $init;
 
    # this way of handling attributes simply is NOT scalable ;()
    sub import {
@@ -53,17 +60,21 @@
          for (@_) {
             if ($_ eq "Coro") {
                push @async, $ref;
+               unless ($init++) {
+                  eval q{
+                     sub INIT {
+                        &async(pop @async) while @async;
+                     }
+                  };
+               }
             } 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;
-   }
 }
 
 =item $main
@@ -74,7 +85,7 @@
 
 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).
 
@@ -87,6 +98,8 @@
 
 our $current = $main;
 
+sub current() { $current }
+
 =item $idle
 
 The coroutine to switch to when no other coroutine is running. The default
@@ -100,9 +113,15 @@
    exit(51);
 };
 
-# we really need priorities...
-## my @ready; #d#
-our @ready = (); # the ready queue. hehe, rather broken ;)
+# this coroutine is necessary because a coroutine
+# cannot destroy itself.
+my @destroy;
+my $manager = new Coro sub {
+   while() {
+      delete ((pop @destroy)->{_coro_state}) while @destroy;
+      &schedule;
+   }
+};
 
 # static methods. not really.
 
@@ -130,6 +149,7 @@
 
 sub async(&@) {
    my $pid = new Coro @_;
+   $manager->ready; # this ensures that the stack is cloned from the manager
    $pid->ready;
    $pid;
 }
@@ -142,26 +162,14 @@
 
 =cut
 
-my $prev;
-
-sub schedule {
-   # should be done using priorities :(
-   ($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
-ready queue and calls C<schedule>.
+"Cede" to other processes. This function puts the current process into the
+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 {
-   $current->ready;
-   &schedule;
-}
-
 =item terminate
 
 Terminates the current process.
@@ -171,8 +179,9 @@
 =cut
 
 sub terminate {
-   $current->{_results} = [@_];
+   $current->cancel;
    &schedule;
+   die; # NORETURN
 }
 
 =back
@@ -213,8 +222,56 @@
 
 =cut
 
-sub ready {
-   push @ready, $_[0];
+=item $process->cancel
+
+Like C<terminate>, but terminates the specified process instead.
+
+=cut
+
+sub cancel {
+   push @destroy, $_[0];
+   $manager->ready;
+   &schedule if $current == $_[0];
+}
+
+=item $oldprio = $process->prio($newprio)
+
+Sets the priority of the process. Higher priority processes get run before
+lower priority processes. Priorities are smalled signed integer (currently
+-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
+tag :prio to get then):
+
+   PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
+       3    >     1     >      0      >    -1    >    -3     >    -4
+
+   # set priority to HIGH
+   current->prio(PRIO_HIGH);
+
+The idle coroutine ($Coro::idle) always has a lower priority than any
+existing coroutine.
+
+Changing the priority of the current process will take effect immediately,
+but changing the priority of processes in the ready queue (but not
+running) will only take effect after the next schedule (of that
+process). This is a bug that will be fixed in some future version.
+
+=cut
+
+sub prio {
+   my $old = $_[0]{prio};
+   $_[0]{prio} = $_[1] if @_ > 1;
+   $old;
+}
+
+=item $newprio = $process->nice($change)
+
+Similar to C<prio>, but subtract the given value from the priority (i.e.
+higher values mean lower priority, just as in unix).
+
+=cut
+
+sub nice {
+   $_[0]{prio} -= $_[1];
 }
 
 =back
@@ -223,18 +280,19 @@
 
 1;
 
-=head1 BUGS
+=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.
+ - you must make very sure that no coro is still active on global destruction.
+   very bad things might happen otherwise (usually segfaults).
+ - 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::Event>.
+L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
+L<Coro::Handle>, L<Coro::Socket>.
 
 =head1 AUTHOR