--- Coro/Coro.pm	2001/07/14 22:14:21	1.8
+++ Coro/Coro.pm	2001/07/22 03:24:10	1.21
@@ -20,6 +20,22 @@
 
 =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.
+
 =cut
 
 package Coro;
@@ -28,14 +44,12 @@
 
 use base Exporter;
 
-$VERSION = 0.03;
+$VERSION = 0.10;
 
-@EXPORT = qw(async yield schedule);
+@EXPORT = qw(async yield schedule terminate current);
 @EXPORT_OK = qw($current);
 
 {
-   use subs 'async';
-
    my @async;
 
    # this way of handling attributes simply is NOT scalable ;()
@@ -49,31 +63,27 @@
             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;
    }
 }
 
-my $idle = new Coro sub {
-   &yield while 1;
-};
-
 =item $main
 
 This coroutine represents the main program.
 
 =cut
 
-$main = new Coro;
+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).
 
@@ -84,10 +94,25 @@
    $main->{specific} = $current->{specific};
 }
 
-$current = $main;
+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.
+
+=cut
+
+# should be done using priorities :(
+our $idle = new Coro sub {
+   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.
 
@@ -97,16 +122,26 @@
 
 =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 @_;
+   $pid->ready;
+   $pid;
 }
 
 =item schedule
@@ -120,7 +155,8 @@
 my $prev;
 
 sub schedule {
-   ($prev, $current) = ($current, shift @ready);
+   # should be done using priorities :(
+   ($prev, $current) = ($current, shift @ready || $idle);
    Coro::State::transfer($prev, $current);
 }
 
@@ -140,9 +176,13 @@
 
 Terminates the current process.
 
+Future versions of this function will allow result arguments.
+
 =cut
 
 sub terminate {
+   $current->{_results} = [@_];
+   delete $current->{_coro_state};
    &schedule;
 }
 
@@ -156,19 +196,25 @@
 
 =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;
 }
 
@@ -188,6 +234,25 @@
 
 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::Event>.
+
 =head1 AUTHOR
 
  Marc Lehmann <pcg@goof.com>