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Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.83 by root, Fri Nov 24 15:34:33 2006 UTC

… …
14 14
15 sub some_func : Coro { 15 sub some_func : Coro {
16 # some more async code 16 # some more async code
17 } 17 }
18 18
19 yield; 19 cede;
20 20
21=head1 DESCRIPTION 21=head1 DESCRIPTION
22 22
23This module collection manages coroutines. Coroutines are similar to
24threads but don't run in parallel.
25
26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35use strict;
36no warnings "uninitialized";
37
27use Coro::State; 38use Coro::State;
28 39
29use base Exporter; 40use base qw(Coro::State Exporter);
30 41
31$VERSION = 0.03; 42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
32 45
33@EXPORT = qw(async yield schedule); 46our $VERSION = '2.5';
34@EXPORT_OK = qw($current); 47
48our @EXPORT = qw(async cede schedule terminate current);
49our %EXPORT_TAGS = (
50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
51);
52our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
35 53
36{ 54{
37 use subs 'async';
38
39 my @async; 55 my @async;
56 my $init;
40 57
41 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 59 sub import {
60 no strict 'refs';
61
43 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
45 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
46 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
47 my @attrs; 67 my @attrs;
48 for (@_) { 68 for (@_) {
49 if ($_ eq "Coro") { 69 if ($_ eq "Coro") {
50 push @async, $ref; 70 push @async, $ref;
71 unless ($init++) {
72 eval q{
73 sub INIT {
74 &async(pop @async) while @async;
75 }
76 };
77 }
51 } else { 78 } else {
52 push @attrs, @_; 79 push @attrs, $_;
53 } 80 }
54 } 81 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 82 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 83 };
57 } 84 }
58 85
59 sub INIT {
60 async pop @async while @async;
61 }
62} 86}
63 87
64my $idle = new Coro sub { 88=over 4
65 &yield while 1;
66};
67 89
68=item $main 90=item $main
69 91
70This coroutine represents the main program. 92This coroutine represents the main program.
71 93
72=cut 94=cut
73 95
74$main = new Coro; 96$main = new Coro;
75 97
76=item $current 98=item $current (or as function: current)
77 99
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
79 106
80=cut 107=cut
81 108
82# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
83if ($current) { 110if ($current) {
84 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
85} 112}
86 113
87$current = $main; 114$current = $main;
88 115
89# we really need priorities... 116sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 117
118=item $idle
119
120A callback that is called whenever the scheduler finds no ready coroutines
121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
123
124This hook is overwritten by modules such as C<Coro::Timer> and
125C<Coro::Event> to wait on an external event that hopefully wakes up some
126coroutine.
127
128=cut
129
130$idle = sub {
131 print STDERR "FATAL: deadlock detected\n";
132 exit (51);
133};
134
135# this coroutine is necessary because a coroutine
136# cannot destroy itself.
137my @destroy;
138my $manager;
139$manager = new Coro sub {
140 while () {
141 # by overwriting the state object with the manager we destroy it
142 # while still being able to schedule this coroutine (in case it has
143 # been readied multiple times. this is harmless since the manager
144 # can be called as many times as neccessary and will always
145 # remove itself from the runqueue
146 while (@destroy) {
147 my $coro = pop @destroy;
148 $coro->{status} ||= [];
149 $_->ready for @{delete $coro->{join} || []};
150
151 # the next line destroys the coro state, but keeps the
152 # process itself intact (we basically make it a zombie
153 # process that always runs the manager thread, so it's possible
154 # to transfer() to this process).
155 $coro->_clone_state_from ($manager);
156 }
157 &schedule;
158 }
159};
91 160
92# static methods. not really. 161# static methods. not really.
93 162
163=back
164
94=head2 STATIC METHODS 165=head2 STATIC METHODS
95 166
96Static methods are actually functions that operate on the current process only. 167Static methods are actually functions that operate on the current process only.
97 168
98=over 4 169=over 4
99 170
100=item async { ... }; 171=item async { ... } [@args...]
101 172
102Create a new asynchronous process and return it's process object 173Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 174(usually unused). When the sub returns the new process is automatically
104terminated. 175terminated.
105 176
106=cut 177When the coroutine dies, the program will exit, just as in the main
178program.
107 179
180 # create a new coroutine that just prints its arguments
181 async {
182 print "@_\n";
183 } 1,2,3,4;
184
185=cut
186
108sub async(&) { 187sub async(&@) {
109 (new Coro $_[0])->ready; 188 my $pid = new Coro @_;
189 $manager->ready; # this ensures that the stack is cloned from the manager
190 $pid->ready;
191 $pid;
110} 192}
111 193
112=item schedule 194=item schedule
113 195
114Calls the scheduler. Please note that the current process will not be put 196Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 197into the ready queue, so calling this function usually means you will
116never be called again. 198never be called again.
117 199
118=cut 200=cut
119 201
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 202=item cede
128 203
129Yield to other processes. This function puts the current process into the 204"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 205ready queue and calls C<schedule>, which has the effect of giving up the
206current "timeslice" to other coroutines of the same or higher priority.
131 207
132=cut 208=cut
133 209
134sub yield {
135 $current->ready;
136 &schedule;
137}
138
139=item terminate 210=item terminate [arg...]
140 211
141Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
142 213
143=cut 214=cut
144 215
145sub terminate { 216sub terminate {
146 &schedule; 217 $current->cancel (@_);
147} 218}
148 219
149=back 220=back
150 221
151# dynamic methods 222# dynamic methods
… …
154 225
155These are the methods you can call on process objects. 226These are the methods you can call on process objects.
156 227
157=over 4 228=over 4
158 229
159=item new Coro \&sub; 230=item new Coro \&sub [, @args...]
160 231
161Create a new process and return it. When the sub returns the process 232Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 233automatically terminates as if C<terminate> with the returned values were
234called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 235by calling the ready method.
164 236
165=cut 237=cut
238
239sub _newcoro {
240 terminate &{+shift};
241}
166 242
167sub new { 243sub new {
168 my $class = shift; 244 my $class = shift;
169 my $proc = $_[0]; 245
170 bless { 246 $class->SUPER::new (\&_newcoro, @_)
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
172 }, $class;
173} 247}
174 248
175=item $process->ready 249=item $process->ready
176 250
177Put the current process into the ready queue. 251Put the given process into the ready queue.
178 252
179=cut 253=cut
180 254
181sub ready { 255=item $process->cancel (arg...)
182 push @ready, $_[0]; 256
257Terminates the given process and makes it return the given arguments as
258status (default: the empty list).
259
260=cut
261
262sub cancel {
263 my $self = shift;
264 $self->{status} = [@_];
265 push @destroy, $self;
266 $manager->ready;
267 &schedule if $current == $self;
268}
269
270=item $process->join
271
272Wait until the coroutine terminates and return any values given to the
273C<terminate> or C<cancel> functions. C<join> can be called multiple times
274from multiple processes.
275
276=cut
277
278sub join {
279 my $self = shift;
280 unless ($self->{status}) {
281 push @{$self->{join}}, $current;
282 &schedule;
283 }
284 wantarray ? @{$self->{status}} : $self->{status}[0];
285}
286
287=item $oldprio = $process->prio ($newprio)
288
289Sets (or gets, if the argument is missing) the priority of the
290process. Higher priority processes get run before lower priority
291processes. Priorities are small signed integers (currently -4 .. +3),
292that you can refer to using PRIO_xxx constants (use the import tag :prio
293to get then):
294
295 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
296 3 > 1 > 0 > -1 > -3 > -4
297
298 # set priority to HIGH
299 current->prio(PRIO_HIGH);
300
301The idle coroutine ($Coro::idle) always has a lower priority than any
302existing coroutine.
303
304Changing the priority of the current process will take effect immediately,
305but changing the priority of processes in the ready queue (but not
306running) will only take effect after the next schedule (of that
307process). This is a bug that will be fixed in some future version.
308
309=item $newprio = $process->nice ($change)
310
311Similar to C<prio>, but subtract the given value from the priority (i.e.
312higher values mean lower priority, just as in unix).
313
314=item $olddesc = $process->desc ($newdesc)
315
316Sets (or gets in case the argument is missing) the description for this
317process. This is just a free-form string you can associate with a process.
318
319=cut
320
321sub desc {
322 my $old = $_[0]{desc};
323 $_[0]{desc} = $_[1] if @_ > 1;
324 $old;
183} 325}
184 326
185=back 327=back
186 328
187=cut 329=cut
188 330
1891; 3311;
190 332
333=head1 BUGS/LIMITATIONS
334
335 - you must make very sure that no coro is still active on global
336 destruction. very bad things might happen otherwise (usually segfaults).
337
338 - this module is not thread-safe. You should only ever use this module
339 from the same thread (this requirement might be losened in the future
340 to allow per-thread schedulers, but Coro::State does not yet allow
341 this).
342
343=head1 SEE ALSO
344
345Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
346
347Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
348
349Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
350
351Embedding: L<Coro:MakeMaker>
352
191=head1 AUTHOR 353=head1 AUTHOR
192 354
193 Marc Lehmann <pcg@goof.com> 355 Marc Lehmann <schmorp@schmorp.de>
194 http://www.goof.com/pcg/marc/ 356 http://home.schmorp.de/
195 357
196=cut 358=cut
197 359

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