--- Coro/Coro.pm	2001/07/15 02:35:52	1.9
+++ Coro/Coro.pm	2001/09/16 00:44:05	1.33
@@ -16,10 +16,20 @@
     # 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 + 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;
@@ -28,15 +38,17 @@
 
 use base Exporter;
 
-$VERSION = 0.04;
+$VERSION = 0.49;
 
-@EXPORT = qw(async yield schedule);
-@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 {
@@ -48,17 +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
@@ -69,7 +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).
 
@@ -82,6 +98,8 @@
 
 our $current = $main;
 
+sub current() { $current }
+
 =item $idle
 
 The coroutine to switch to when no other coroutine is running. The default
@@ -95,8 +113,15 @@
    exit(51);
 };
 
-# we really need priorities...
-my @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.
 
@@ -106,16 +131,27 @@
 
 =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.
 
+   # 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(&) {
-   (new Coro $_[0])->ready;
+sub async(&@) {
+   my $pid = new Coro @_;
+   $manager->ready; # this ensures that the stack is cloned from the manager
+   $pid->ready;
+   $pid;
 }
 
 =item schedule
@@ -126,34 +162,26 @@
 
 =cut
 
-my $prev;
+=item cede
 
-sub schedule {
-   # should be done using priorities :(
-   ($prev, $current) = ($current, shift @ready || $idle);
-   Coro::State::transfer($prev, $current);
-}
-
-=item yield
-
-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.
 
+Future versions of this function will allow result arguments.
+
 =cut
 
 sub terminate {
+   $current->cancel;
    &schedule;
+   die; # NORETURN
 }
 
 =back
@@ -166,19 +194,25 @@
 
 =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;
 }
 
@@ -188,8 +222,55 @@
 
 =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;
+}
+
+=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
@@ -198,10 +279,19 @@
 
 1;
 
+=head1 BUGS/LIMITATIONS
+
+ - 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::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
+L<Coro::Handle>, L<Coro::Socket>.
 
 =head1 AUTHOR