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Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.10 by root, Sun Jul 15 02:36:54 2001 UTC vs.
Revision 1.89 by root, Mon Nov 27 02:01:33 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
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
31$VERSION = 0.04; 46our $VERSION = '3.0';
32 47
33@EXPORT = qw(async yield schedule); 48our @EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}
87
88=over 4
63 89
64=item $main 90=item $main
65 91
66This coroutine represents the main program. 92This coroutine represents the main program.
67 93
68=cut 94=cut
69 95
70our $main = new Coro; 96$main = new Coro;
71 97
72=item $current 98=item $current (or as function: current)
73 99
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
75 106
76=cut 107=cut
77 108
78# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
79if ($current) { 110if ($current) {
80 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
81} 112}
82 113
83our $current = $main; 114$current = $main;
115
116sub current() { $current }
84 117
85=item $idle 118=item $idle
86 119
87The coroutine to switch to when no other coroutine is running. The default 120A callback that is called whenever the scheduler finds no ready coroutines
88implementation prints "FATAL: deadlock detected" and exits. 121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
89 123
90=cut 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.
91 127
92# should be done using priorities :( 128=cut
93our $idle = new Coro sub { 129
130$idle = sub {
94 print STDERR "FATAL: deadlock detected\n"; 131 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 132 exit (51);
96}; 133};
97 134
98# we really need priorities... 135# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 136# cannot destroy itself.
137my @destroy;
138my $manager; $manager = new Coro sub {
139 while () {
140 # by overwriting the state object with the manager we destroy it
141 # while still being able to schedule this coroutine (in case it has
142 # been readied multiple times. this is harmless since the manager
143 # can be called as many times as neccessary and will always
144 # remove itself from the runqueue
145 while (@destroy) {
146 my $coro = pop @destroy;
147 $coro->{status} ||= [];
148 $_->ready for @{delete $coro->{join} || []};
149
150 # the next line destroys the coro state, but keeps the
151 # process itself intact (we basically make it a zombie
152 # process that always runs the manager thread, so it's possible
153 # to transfer() to this process).
154 $coro->_clone_state_from ($manager);
155 }
156 &schedule;
157 }
158};
100 159
101# static methods. not really. 160# static methods. not really.
102 161
162=back
163
103=head2 STATIC METHODS 164=head2 STATIC METHODS
104 165
105Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
106 167
107=over 4 168=over 4
108 169
109=item async { ... }; 170=item async { ... } [@args...]
110 171
111Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
113terminated. 174terminated.
114 175
115=cut 176Calling C<exit> in a coroutine will not work correctly, so do not do that.
116 177
178When the coroutine dies, the program will exit, just as in the main
179program.
180
181 # create a new coroutine that just prints its arguments
182 async {
183 print "@_\n";
184 } 1,2,3,4;
185
186=cut
187
117sub async(&) { 188sub async(&@) {
118 (new Coro $_[0])->ready; 189 my $pid = new Coro @_;
190 $pid->ready;
191 $pid
119} 192}
120 193
121=item schedule 194=item schedule
122 195
123Calls 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
124into the ready queue, so calling this function usually means you will 197into the ready queue, so calling this function usually means you will
125never be called again. 198never be called again.
126 199
127=cut 200=cut
128 201
129my $prev;
130
131sub schedule {
132 # should be done using priorities :(
133 ($prev, $current) = ($current, shift @ready || $idle);
134 Coro::State::transfer($prev, $current);
135}
136
137=item yield 202=item cede
138 203
139Yield to other processes. This function puts the current process into the 204"Cede" to other processes. This function puts the current process into the
140ready 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.
141 207
142=cut 208=cut
143 209
144sub yield {
145 $current->ready;
146 &schedule;
147}
148
149=item terminate 210=item terminate [arg...]
150 211
151Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
152 213
153=cut 214=cut
154 215
155sub terminate { 216sub terminate {
156 &schedule; 217 $current->cancel (@_);
157} 218}
158 219
159=back 220=back
160 221
161# dynamic methods 222# dynamic methods
… …
164 225
165These are the methods you can call on process objects. 226These are the methods you can call on process objects.
166 227
167=over 4 228=over 4
168 229
169=item new Coro \&sub; 230=item new Coro \&sub [, @args...]
170 231
171Create 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
172automatically 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
173the ready queue by calling the ready method. 235by calling the ready method.
174 236
237Calling C<exit> in a coroutine will not work correctly, so do not do that.
238
175=cut 239=cut
240
241sub _new_coro {
242 terminate &{+shift};
243}
176 244
177sub new { 245sub new {
178 my $class = shift; 246 my $class = shift;
179 my $proc = $_[0]; 247
180 bless { 248 $class->SUPER::new (\&_new_coro, @_)
181 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
182 }, $class;
183} 249}
184 250
185=item $process->ready 251=item $process->ready
186 252
187Put the current process into the ready queue. 253Put the given process into the ready queue.
188 254
189=cut 255=cut
190 256
191sub ready { 257=item $process->cancel (arg...)
192 push @ready, $_[0]; 258
259Terminates the given process and makes it return the given arguments as
260status (default: the empty list).
261
262=cut
263
264sub cancel {
265 my $self = shift;
266 $self->{status} = [@_];
267 push @destroy, $self;
268 $manager->ready;
269 &schedule if $current == $self;
270}
271
272=item $process->join
273
274Wait until the coroutine terminates and return any values given to the
275C<terminate> or C<cancel> functions. C<join> can be called multiple times
276from multiple processes.
277
278=cut
279
280sub join {
281 my $self = shift;
282 unless ($self->{status}) {
283 push @{$self->{join}}, $current;
284 &schedule;
285 }
286 wantarray ? @{$self->{status}} : $self->{status}[0];
287}
288
289=item $oldprio = $process->prio ($newprio)
290
291Sets (or gets, if the argument is missing) the priority of the
292process. Higher priority processes get run before lower priority
293processes. Priorities are small signed integers (currently -4 .. +3),
294that you can refer to using PRIO_xxx constants (use the import tag :prio
295to get then):
296
297 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
298 3 > 1 > 0 > -1 > -3 > -4
299
300 # set priority to HIGH
301 current->prio(PRIO_HIGH);
302
303The idle coroutine ($Coro::idle) always has a lower priority than any
304existing coroutine.
305
306Changing the priority of the current process will take effect immediately,
307but changing the priority of processes in the ready queue (but not
308running) will only take effect after the next schedule (of that
309process). This is a bug that will be fixed in some future version.
310
311=item $newprio = $process->nice ($change)
312
313Similar to C<prio>, but subtract the given value from the priority (i.e.
314higher values mean lower priority, just as in unix).
315
316=item $olddesc = $process->desc ($newdesc)
317
318Sets (or gets in case the argument is missing) the description for this
319process. This is just a free-form string you can associate with a process.
320
321=cut
322
323sub desc {
324 my $old = $_[0]{desc};
325 $_[0]{desc} = $_[1] if @_ > 1;
326 $old;
193} 327}
194 328
195=back 329=back
196 330
197=cut 331=cut
198 332
1991; 3331;
200 334
335=head1 BUGS/LIMITATIONS
336
337 - you must make very sure that no coro is still active on global
338 destruction. very bad things might happen otherwise (usually segfaults).
339
340 - this module is not thread-safe. You should only ever use this module
341 from the same thread (this requirement might be losened in the future
342 to allow per-thread schedulers, but Coro::State does not yet allow
343 this).
344
201=head1 SEE ALSO 345=head1 SEE ALSO
202 346
203L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 347Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
204L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 348
349Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
350
351Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
352
353Embedding: L<Coro:MakeMaker>
205 354
206=head1 AUTHOR 355=head1 AUTHOR
207 356
208 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
209 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
210 359
211=cut 360=cut
212 361

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