Coro/Coro.pm

=head1 NAME

Coro - coroutine process abstraction

=head1 SYNOPSIS

 use Coro;

 async {
    # some asynchronous thread of execution
 };

 # alternatively create an async process like this:

 sub some_func : Coro {
    # some more async code
 }

 yield;

=head1 DESCRIPTION

=cut

package Coro;

use Coro::State;

use base Exporter;

$VERSION = 0.05;

@EXPORT = qw(async yield schedule terminate);
@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 $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
      *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
         my ($package, $ref) = (shift, shift);
         my @attrs;
         for (@_) {
            if ($_ eq "Coro") {
               push @async, $ref;
            } else {
               push @attrs, @_;
            }
         }
         return $old ? $old->($package, $name, @attrs) : @attrs;
      };
   }

   sub INIT {
      async pop @async while @async;
   }
}

=item $main

This coroutine represents the main program.

=cut

our $main = new Coro;

=item $current

The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).

=cut

# maybe some other module used Coro::Specific before...
if ($current) {
   $main->{specific} = $current->{specific};
}

our $current = $main;

=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; #d#
our @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 { ... } [@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(&@) {
   my $pid = new Coro @_;
   $pid->ready;
   $pid;
}

=item schedule

Calls the scheduler. Please note that the current process will not be put
into the ready queue, so calling this function usually means you will
never be called again.

=cut

my $prev;

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>.

=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->{_results} = [@_];
   &schedule;
}

=back

# dynamic methods

=head2 PROCESS METHODS

These are the methods you can call on process objects.

=over 4

=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;
   bless {
      _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
   }, $class;
}

=item $process->ready

Put the current process into the ready queue.

=cut

sub ready {
   push @ready, $_[0];
}

=back

=cut

1;

=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>
 http://www.goof.com/pcg/marc/

=cut

Revision:	1.13
Committed:	Tue Jul 17 00:24:14 2001 UTC (22 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.12:	+26 -9 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.8	Coro - coroutine process abstraction
4	root	1.1
5			=head1 SYNOPSIS
6
7			use Coro;
8
9	root	1.8	async {
10			# some asynchronous thread of execution
11	root	1.2	};
12
13	root	1.8	# alternatively create an async process like this:
14	root	1.6
15	root	1.8	sub some_func : Coro {
16			# some more async code
17			}
18
19			yield;
20	root	1.2
21	root	1.1	=head1 DESCRIPTION
22
23	root	1.8	=cut
24
25			package Coro;
26
27			use Coro::State;
28
29			use base Exporter;
30
31	root	1.12	$VERSION = 0.05;
32	root	1.8
33	root	1.13	@EXPORT = qw(async yield schedule terminate);
34	root	1.8	@EXPORT_OK = qw($current);
35
36			{
37			use subs 'async';
38
39			my @async;
40
41			# this way of handling attributes simply is NOT scalable ;()
42			sub import {
43			Coro->export_to_level(1, @_);
44			my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
45			*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
46			my ($package, $ref) = (shift, shift);
47			my @attrs;
48			for (@_) {
49			if ($_ eq "Coro") {
50			push @async, $ref;
51			} else {
52			push @attrs, @_;
53			}
54			}
55			return $old ? $old->($package, $name, @attrs) : @attrs;
56			};
57			}
58
59			sub INIT {
60			async pop @async while @async;
61			}
62			}
63
64			=item $main
65	root	1.2
66	root	1.8	This coroutine represents the main program.
67	root	1.1
68			=cut
69
70	root	1.9	our $main = new Coro;
71	root	1.8
72			=item $current
73	root	1.1
74	root	1.8	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75	root	1.1
76	root	1.8	=cut
77
78			# maybe some other module used Coro::Specific before...
79			if ($current) {
80			$main->{specific} = $current->{specific};
81	root	1.1	}
82
83	root	1.9	our $current = $main;
84
85			=item $idle
86
87			The coroutine to switch to when no other coroutine is running. The default
88			implementation prints "FATAL: deadlock detected" and exits.
89
90			=cut
91
92			# should be done using priorities :(
93			our $idle = new Coro sub {
94			print STDERR "FATAL: deadlock detected\n";
95			exit(51);
96			};
97	root	1.8
98			# we really need priorities...
99	root	1.13	## my @ready; #d#
100			our @ready = (); # the ready queue. hehe, rather broken ;)
101	root	1.8
102			# static methods. not really.
103
104			=head2 STATIC METHODS
105
106			Static methods are actually functions that operate on the current process only.
107
108			=over 4
109
110	root	1.13	=item async { ... } [@args...]
111	root	1.8
112			Create a new asynchronous process and return it's process object
113			(usually unused). When the sub returns the new process is automatically
114			terminated.
115
116	root	1.13	# create a new coroutine that just prints its arguments
117			async {
118			print "@_\n";
119			} 1,2,3,4;
120
121			The coderef you submit MUST NOT be a closure that refers to variables
122			in an outer scope. This does NOT work. Pass arguments into it instead.
123
124	root	1.8	=cut
125
126	root	1.13	sub async(&@) {
127			my $pid = new Coro @_;
128	root	1.11	$pid->ready;
129			$pid;
130	root	1.8	}
131	root	1.1
132	root	1.8	=item schedule
133	root	1.6
134	root	1.8	Calls the scheduler. Please note that the current process will not be put
135			into the ready queue, so calling this function usually means you will
136			never be called again.
137	root	1.1
138			=cut
139
140	root	1.8	my $prev;
141
142			sub schedule {
143	root	1.9	# should be done using priorities :(
144			($prev, $current) = ($current, shift @ready \|\| $idle);
145	root	1.8	Coro::State::transfer($prev, $current);
146	root	1.1	}
147
148	root	1.8	=item yield
149	root	1.1
150	root	1.8	Yield to other processes. This function puts the current process into the
151			ready queue and calls C<schedule>.
152	root	1.7
153	root	1.8	=cut
154
155			sub yield {
156			$current->ready;
157			&schedule;
158			}
159	root	1.7
160	root	1.8	=item terminate
161	root	1.7
162	root	1.8	Terminates the current process.
163	root	1.1
164	root	1.13	Future versions of this function will allow result arguments.
165
166	root	1.1	=cut
167
168	root	1.8	sub terminate {
169	root	1.13	$current->{_results} = [@_];
170	root	1.8	&schedule;
171	root	1.1	}
172	root	1.6
173	root	1.8	=back
174
175			# dynamic methods
176
177			=head2 PROCESS METHODS
178
179			These are the methods you can call on process objects.
180	root	1.6
181	root	1.8	=over 4
182
183	root	1.13	=item new Coro \&sub [, @args...]
184	root	1.8
185			Create a new process and return it. When the sub returns the process
186			automatically terminates. To start the process you must first put it into
187			the ready queue by calling the ready method.
188	root	1.6
189	root	1.13	The coderef you submit MUST NOT be a closure that refers to variables
190			in an outer scope. This does NOT work. Pass arguments into it instead.
191
192	root	1.6	=cut
193
194	root	1.13	sub _newcoro {
195			terminate &{+shift};
196			}
197
198	root	1.8	sub new {
199			my $class = shift;
200			bless {
201	root	1.13	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
202	root	1.8	}, $class;
203			}
204	root	1.6
205	root	1.8	=item $process->ready
206	root	1.1
207	root	1.8	Put the current process into the ready queue.
208	root	1.1
209	root	1.8	=cut
210	root	1.1
211	root	1.8	sub ready {
212			push @ready, $_[0];
213			}
214	root	1.1
215	root	1.8	=back
216	root	1.2
217	root	1.8	=cut
218	root	1.2
219	root	1.8	1;
220	root	1.9
221			=head1 SEE ALSO
222
223			L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
224	root	1.10	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
225	root	1.1
226			=head1 AUTHOR
227
228			Marc Lehmann <pcg@goof.com>
229			http://www.goof.com/pcg/marc/
230
231			=cut
232