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Comparing Coro/Coro.pm (file contents):
Revision 1.18 by root, Sat Jul 21 02:49:09 2001 UTC vs.
Revision 1.85 by root, Sat Nov 25 00:56:35 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35use strict;
36no warnings "uninitialized";
37
32use Coro::State; 38use Coro::State;
33 39
34use base Exporter; 40use base qw(Coro::State Exporter);
35 41
36$VERSION = 0.09; 42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
37 45
46our $VERSION = '2.5';
47
38@EXPORT = qw(async yield schedule terminate); 48our @EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($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, $ref, @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
104my @ready; # the ready queue. hehe, rather broken ;) 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};
105 160
106# static methods. not really. 161# static methods. not really.
162
163=back
107 164
108=head2 STATIC METHODS 165=head2 STATIC METHODS
109 166
110Static methods are actually functions that operate on the current process only. 167Static methods are actually functions that operate on the current process only.
111 168
… …
114=item async { ... } [@args...] 171=item async { ... } [@args...]
115 172
116Create a new asynchronous process and return it's process object 173Create a new asynchronous process and return it's process object
117(usually unused). When the sub returns the new process is automatically 174(usually unused). When the sub returns the new process is automatically
118terminated. 175terminated.
176
177When the coroutine dies, the program will exit, just as in the main
178program.
119 179
120 # create a new coroutine that just prints its arguments 180 # create a new coroutine that just prints its arguments
121 async { 181 async {
122 print "@_\n"; 182 print "@_\n";
123 } 1,2,3,4; 183 } 1,2,3,4;
124 184
125The coderef you submit MUST NOT be a closure that refers to variables
126in an outer scope. This does NOT work. Pass arguments into it instead.
127
128=cut 185=cut
129 186
130sub async(&@) { 187sub async(&@) {
131 my $pid = new Coro @_; 188 my $pid = new Coro @_;
132 $pid->ready; 189 $pid->ready;
133 $pid; 190 $pid
134} 191}
135 192
136=item schedule 193=item schedule
137 194
138Calls the scheduler. Please note that the current process will not be put 195Calls the scheduler. Please note that the current process will not be put
139into the ready queue, so calling this function usually means you will 196into the ready queue, so calling this function usually means you will
140never be called again. 197never be called again.
141 198
142=cut 199=cut
143 200
144my $prev;
145
146sub schedule {
147 # should be done using priorities :(
148 ($prev, $current) = ($current, shift @ready || $idle);
149 Coro::State::transfer($prev, $current);
150}
151
152=item yield 201=item cede
153 202
154Yield to other processes. This function puts the current process into the 203"Cede" to other processes. This function puts the current process into the
155ready queue and calls C<schedule>. 204ready queue and calls C<schedule>, which has the effect of giving up the
205current "timeslice" to other coroutines of the same or higher priority.
156 206
157=cut 207=cut
158 208
159sub yield {
160 $current->ready;
161 &schedule;
162}
163
164=item terminate 209=item terminate [arg...]
165 210
166Terminates the current process. 211Terminates the current process with the given status values (see L<cancel>).
167
168Future versions of this function will allow result arguments.
169 212
170=cut 213=cut
171 214
172sub terminate { 215sub terminate {
173 $current->{_results} = [@_]; 216 $current->cancel (@_);
174 &schedule;
175} 217}
176 218
177=back 219=back
178 220
179# dynamic methods 221# dynamic methods
… …
185=over 4 227=over 4
186 228
187=item new Coro \&sub [, @args...] 229=item new Coro \&sub [, @args...]
188 230
189Create a new process and return it. When the sub returns the process 231Create a new process and return it. When the sub returns the process
190automatically terminates. To start the process you must first put it into 232automatically terminates as if C<terminate> with the returned values were
233called. To make the process run you must first put it into the ready queue
191the ready queue by calling the ready method. 234by calling the ready method.
192 235
193The coderef you submit MUST NOT be a closure that refers to variables
194in an outer scope. This does NOT work. Pass arguments into it instead.
195
196=cut 236=cut
197 237
198sub _newcoro { 238sub _new_coro {
239 $current->_clear_idle_sp; # set the idle sp on the following cede
240 _set_cede_self; # ensures that cede cede's us first
241 cede;
199 terminate &{+shift}; 242 terminate &{+shift};
200} 243}
201 244
202sub new { 245sub new {
203 my $class = shift; 246 my $class = shift;
204 bless { 247
205 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 248 $class->SUPER::new (\&_new_coro, @_)
206 }, $class;
207} 249}
208 250
209=item $process->ready 251=item $process->ready
210 252
211Put the current process into the ready queue. 253Put the given process into the ready queue.
212 254
213=cut 255=cut
214 256
215sub ready { 257=item $process->cancel (arg...)
216 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;
217} 327}
218 328
219=back 329=back
220 330
221=cut 331=cut
222 332
2231; 3331;
224 334
225=head1 BUGS/LIMITATIONS 335=head1 BUGS/LIMITATIONS
226 336
227 - could be faster, especially when the core would introduce special 337 - you must make very sure that no coro is still active on global
228 support for coroutines (like it does for threads). 338 destruction. very bad things might happen otherwise (usually segfaults).
229 - there is still a memleak on coroutine termination that I could not 339
230 identify. Could be as small as a single SV.
231 - this module is not well-tested.
232 - if variables or arguments "disappear" (become undef) or become
233 corrupted please contact the author so he cen iron out the
234 remaining bugs.
235 - this module is not thread-safe. You must only ever use this module from 340 - this module is not thread-safe. You should only ever use this module
236 the same thread (this requirement might be loosened in the future to 341 from the same thread (this requirement might be losened in the future
237 allow per-thread schedulers, but Coro::Satte does not yet allow this). 342 to allow per-thread schedulers, but Coro::State does not yet allow
343 this).
238 344
239=head1 SEE ALSO 345=head1 SEE ALSO
240 346
241L<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>.
242L<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>
243 354
244=head1 AUTHOR 355=head1 AUTHOR
245 356
246 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
247 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
248 359
249=cut 360=cut
250 361

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