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Comparing Coro/Coro.pm (file contents):
Revision 1.14 by root, Tue Jul 17 02:21:56 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 23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel. 24threads but don't run in parallel.
25 25
26This module is still experimental, see the BUGS section below. 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.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35use strict;
36no warnings "uninitialized";
37
32use Coro::State; 38use Coro::State;
33 39
34use base Exporter; 40use base qw(Coro::State Exporter);
35 41
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
36$VERSION = 0.05; 46our $VERSION = '3.0';
37 47
38@EXPORT = qw(async yield schedule terminate); 48our @EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($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}};
40 53
41{ 54{
42 use subs 'async';
43
44 my @async; 55 my @async;
56 my $init;
45 57
46 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 59 sub import {
60 no strict 'refs';
61
48 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
50 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
51 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
52 my @attrs; 67 my @attrs;
53 for (@_) { 68 for (@_) {
54 if ($_ eq "Coro") { 69 if ($_ eq "Coro") {
55 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 }
56 } else { 78 } else {
57 push @attrs, @_; 79 push @attrs, $_;
58 } 80 }
59 } 81 }
60 return $old ? $old->($package, $name, @attrs) : @attrs; 82 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 83 };
62 } 84 }
63 85
64 sub INIT {
65 async pop @async while @async;
66 }
67} 86}
87
88=over 4
68 89
69=item $main 90=item $main
70 91
71This coroutine represents the main program. 92This coroutine represents the main program.
72 93
73=cut 94=cut
74 95
75our $main = new Coro; 96$main = new Coro;
76 97
77=item $current 98=item $current (or as function: current)
78 99
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
80 106
81=cut 107=cut
82 108
83# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
84if ($current) { 110if ($current) {
85 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
86} 112}
87 113
88our $current = $main; 114$current = $main;
115
116sub current() { $current }
89 117
90=item $idle 118=item $idle
91 119
92The coroutine to switch to when no other coroutine is running. The default 120A callback that is called whenever the scheduler finds no ready coroutines
93implementation prints "FATAL: deadlock detected" and exits. 121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
94 123
95=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.
96 127
97# should be done using priorities :( 128=cut
98our $idle = new Coro sub { 129
130$idle = sub {
99 print STDERR "FATAL: deadlock detected\n"; 131 print STDERR "FATAL: deadlock detected\n";
100 exit(51); 132 exit (51);
101}; 133};
102 134
103# we really need priorities... 135# this coroutine is necessary because a coroutine
104## my @ready; #d# 136# cannot destroy itself.
105our @ready = (); # the ready queue. hehe, rather broken ;) 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};
106 159
107# static methods. not really. 160# static methods. not really.
161
162=back
108 163
109=head2 STATIC METHODS 164=head2 STATIC METHODS
110 165
111Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
112 167
… …
115=item async { ... } [@args...] 170=item async { ... } [@args...]
116 171
117Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
118(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
119terminated. 174terminated.
175
176Calling C<exit> in a coroutine will not work correctly, so do not do that.
177
178When the coroutine dies, the program will exit, just as in the main
179program.
120 180
121 # create a new coroutine that just prints its arguments 181 # create a new coroutine that just prints its arguments
122 async { 182 async {
123 print "@_\n"; 183 print "@_\n";
124 } 1,2,3,4; 184 } 1,2,3,4;
125 185
126The coderef you submit MUST NOT be a closure that refers to variables
127in an outer scope. This does NOT work. Pass arguments into it instead.
128
129=cut 186=cut
130 187
131sub async(&@) { 188sub async(&@) {
132 my $pid = new Coro @_; 189 my $pid = new Coro @_;
133 $pid->ready; 190 $pid->ready;
134 $pid; 191 $pid
135} 192}
136 193
137=item schedule 194=item schedule
138 195
139Calls 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
140into the ready queue, so calling this function usually means you will 197into the ready queue, so calling this function usually means you will
141never be called again. 198never be called again.
142 199
143=cut 200=cut
144 201
145my $prev;
146
147sub schedule {
148 # should be done using priorities :(
149 ($prev, $current) = ($current, shift @ready || $idle);
150 Coro::State::transfer($prev, $current);
151}
152
153=item yield 202=item cede
154 203
155Yield to other processes. This function puts the current process into the 204"Cede" to other processes. This function puts the current process into the
156ready 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.
157 207
158=cut 208=cut
159 209
160sub yield {
161 $current->ready;
162 &schedule;
163}
164
165=item terminate 210=item terminate [arg...]
166 211
167Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
168
169Future versions of this function will allow result arguments.
170 213
171=cut 214=cut
172 215
173sub terminate { 216sub terminate {
174 $current->{_results} = [@_]; 217 $current->cancel (@_);
175 &schedule;
176} 218}
177 219
178=back 220=back
179 221
180# dynamic methods 222# dynamic methods
… …
186=over 4 228=over 4
187 229
188=item new Coro \&sub [, @args...] 230=item new Coro \&sub [, @args...]
189 231
190Create 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
191automatically 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
192the ready queue by calling the ready method. 235by calling the ready method.
193 236
194The coderef you submit MUST NOT be a closure that refers to variables 237Calling C<exit> in a coroutine will not work correctly, so do not do that.
195in an outer scope. This does NOT work. Pass arguments into it instead.
196 238
197=cut 239=cut
198 240
199sub _newcoro { 241sub _new_coro {
200 terminate &{+shift}; 242 terminate &{+shift};
201} 243}
202 244
203sub new { 245sub new {
204 my $class = shift; 246 my $class = shift;
205 bless { 247
206 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 248 $class->SUPER::new (\&_new_coro, @_)
207 }, $class;
208} 249}
209 250
210=item $process->ready 251=item $process->ready
211 252
212Put the current process into the ready queue. 253Put the given process into the ready queue.
213 254
214=cut 255=cut
215 256
216sub ready { 257=item $process->cancel (arg...)
217 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;
218} 327}
219 328
220=back 329=back
221 330
222=cut 331=cut
223 332
2241; 3331;
225 334
226=head1 BUGS 335=head1 BUGS/LIMITATIONS
227 336
228 - could be faster, especially when the core would introduce special 337 - you must make very sure that no coro is still active on global
229 support for coroutines (like it does for threads). 338 destruction. very bad things might happen otherwise (usually segfaults).
230 - there is still a memleak on coroutine termination that I could not 339
231 identify. Could be as small as a single SV. 340 - this module is not thread-safe. You should only ever use this module
232 - this module is not well-tested. 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).
233 344
234=head1 SEE ALSO 345=head1 SEE ALSO
235 346
236L<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>.
237L<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>
238 354
239=head1 AUTHOR 355=head1 AUTHOR
240 356
241 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
242 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
243 359
244=cut 360=cut
245 361

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