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Comparing Coro/Coro.pm (file contents):
Revision 1.17 by root, Thu Jul 19 02:45:09 2001 UTC vs.
Revision 1.80 by root, Mon Nov 6 19:56:26 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35use strict;
36no warnings "uninitialized";
37
32use Coro::State; 38use Coro::State;
33 39
34use base Exporter; 40use base Exporter::;
35 41
36$VERSION = 0.08; 42our $idle; # idle coroutine
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 is C<$main> (of course).
80 101
81=cut 102=cut
82 103
83# maybe some other module used Coro::Specific before... 104# maybe some other module used Coro::Specific before...
84if ($current) { 105if ($current) {
85 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
86} 107}
87 108
88our $current = $main; 109$current = $main;
110
111sub current() { $current }
89 112
90=item $idle 113=item $idle
91 114
92The coroutine to switch to when no other coroutine is running. The default 115The coroutine to switch to when no other coroutine is running. The default
93implementation prints "FATAL: deadlock detected" and exits. 116implementation prints "FATAL: deadlock detected" and exits.
94 117
95=cut 118=cut
96 119
97# should be done using priorities :( 120# should be done using priorities :(
98our $idle = new Coro sub { 121$idle = new Coro sub {
99 print STDERR "FATAL: deadlock detected\n"; 122 print STDERR "FATAL: deadlock detected\n";
100 exit(51); 123 exit(51);
101}; 124};
102 125
103# we really need priorities... 126# this coroutine is necessary because a coroutine
104my @ready; # the ready queue. hehe, rather broken ;) 127# cannot destroy itself.
128my @destroy;
129my $manager;
130$manager = new Coro sub {
131 while () {
132 # by overwriting the state object with the manager we destroy it
133 # while still being able to schedule this coroutine (in case it has
134 # been readied multiple times. this is harmless since the manager
135 # can be called as many times as neccessary and will always
136 # remove itself from the runqueue
137 while (@destroy) {
138 my $coro = pop @destroy;
139 $coro->{status} ||= [];
140 $_->ready for @{delete $coro->{join} || []};
141
142 # the next line destroys the _coro_state, but keeps the
143 # process itself intact (we basically make it a zombie
144 # process that always runs the manager thread, so it's possible
145 # to transfer() to this process).
146 $coro->{_coro_state} = $manager->{_coro_state};
147 }
148 &schedule;
149 }
150};
105 151
106# static methods. not really. 152# static methods. not really.
153
154=back
107 155
108=head2 STATIC METHODS 156=head2 STATIC METHODS
109 157
110Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
111 159
… …
114=item async { ... } [@args...] 162=item async { ... } [@args...]
115 163
116Create a new asynchronous process and return it's process object 164Create a new asynchronous process and return it's process object
117(usually unused). When the sub returns the new process is automatically 165(usually unused). When the sub returns the new process is automatically
118terminated. 166terminated.
167
168When the coroutine dies, the program will exit, just as in the main
169program.
119 170
120 # create a new coroutine that just prints its arguments 171 # create a new coroutine that just prints its arguments
121 async { 172 async {
122 print "@_\n"; 173 print "@_\n";
123 } 1,2,3,4; 174 } 1,2,3,4;
124 175
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 176=cut
129 177
130sub async(&@) { 178sub async(&@) {
131 my $pid = new Coro @_; 179 my $pid = new Coro @_;
180 $manager->ready; # this ensures that the stack is cloned from the manager
132 $pid->ready; 181 $pid->ready;
133 $pid; 182 $pid;
134} 183}
135 184
136=item schedule 185=item schedule
… …
139into the ready queue, so calling this function usually means you will 188into the ready queue, so calling this function usually means you will
140never be called again. 189never be called again.
141 190
142=cut 191=cut
143 192
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 193=item cede
153 194
154Yield to other processes. This function puts the current process into the 195"Cede" to other processes. This function puts the current process into the
155ready queue and calls C<schedule>. 196ready queue and calls C<schedule>, which has the effect of giving up the
197current "timeslice" to other coroutines of the same or higher priority.
156 198
157=cut 199=cut
158 200
159sub yield {
160 $current->ready;
161 &schedule;
162}
163
164=item terminate 201=item terminate [arg...]
165 202
166Terminates the current process. 203Terminates the current process with the given status values (see L<cancel>).
167
168Future versions of this function will allow result arguments.
169 204
170=cut 205=cut
171 206
172sub terminate { 207sub terminate {
173 $current->{_results} = [@_]; 208 $current->cancel (@_);
174 &schedule;
175} 209}
176 210
177=back 211=back
178 212
179# dynamic methods 213# dynamic methods
… …
185=over 4 219=over 4
186 220
187=item new Coro \&sub [, @args...] 221=item new Coro \&sub [, @args...]
188 222
189Create a new process and return it. When the sub returns the process 223Create a new process and return it. When the sub returns the process
190automatically terminates. To start the process you must first put it into 224automatically terminates as if C<terminate> with the returned values were
225called. To make the process run you must first put it into the ready queue
191the ready queue by calling the ready method. 226by calling the ready method.
192
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.
195 227
196=cut 228=cut
197 229
198sub _newcoro { 230sub _newcoro {
199 terminate &{+shift}; 231 terminate &{+shift};
… …
206 }, $class; 238 }, $class;
207} 239}
208 240
209=item $process->ready 241=item $process->ready
210 242
211Put the current process into the ready queue. 243Put the given process into the ready queue.
212 244
213=cut 245=cut
214 246
215sub ready { 247=item $process->cancel (arg...)
216 push @ready, $_[0]; 248
249Terminates the given process and makes it return the given arguments as
250status (default: the empty list).
251
252=cut
253
254sub cancel {
255 my $self = shift;
256 $self->{status} = [@_];
257 push @destroy, $self;
258 $manager->ready;
259 &schedule if $current == $self;
260}
261
262=item $process->join
263
264Wait until the coroutine terminates and return any values given to the
265C<terminate> or C<cancel> functions. C<join> can be called multiple times
266from multiple processes.
267
268=cut
269
270sub join {
271 my $self = shift;
272 unless ($self->{status}) {
273 push @{$self->{join}}, $current;
274 &schedule;
275 }
276 wantarray ? @{$self->{status}} : $self->{status}[0];
277}
278
279=item $oldprio = $process->prio($newprio)
280
281Sets (or gets, if the argument is missing) the priority of the
282process. Higher priority processes get run before lower priority
283processes. Priorities are small signed integers (currently -4 .. +3),
284that you can refer to using PRIO_xxx constants (use the import tag :prio
285to get then):
286
287 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
288 3 > 1 > 0 > -1 > -3 > -4
289
290 # set priority to HIGH
291 current->prio(PRIO_HIGH);
292
293The idle coroutine ($Coro::idle) always has a lower priority than any
294existing coroutine.
295
296Changing the priority of the current process will take effect immediately,
297but changing the priority of processes in the ready queue (but not
298running) will only take effect after the next schedule (of that
299process). This is a bug that will be fixed in some future version.
300
301=cut
302
303sub prio {
304 my $old = $_[0]{prio};
305 $_[0]{prio} = $_[1] if @_ > 1;
306 $old;
307}
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=cut
315
316sub nice {
317 $_[0]{prio} -= $_[1];
318}
319
320=item $olddesc = $process->desc($newdesc)
321
322Sets (or gets in case the argument is missing) the description for this
323process. This is just a free-form string you can associate with a process.
324
325=cut
326
327sub desc {
328 my $old = $_[0]{desc};
329 $_[0]{desc} = $_[1] if @_ > 1;
330 $old;
217} 331}
218 332
219=back 333=back
220 334
221=cut 335=cut
222 336
2231; 3371;
224 338
225=head1 BUGS/LIMITATIONS 339=head1 BUGS/LIMITATIONS
226 340
227 - could be faster, especially when the core would introduce special 341 - you must make very sure that no coro is still active on global
228 support for coroutines (like it does for threads). 342 destruction. very bad things might happen otherwise (usually segfaults).
229 - there is still a memleak on coroutine termination that I could not 343
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 344 - 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 345 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). 346 to allow per-thread schedulers, but Coro::State does not yet allow
347 this).
238 348
239=head1 SEE ALSO 349=head1 SEE ALSO
240 350
241L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 351Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
242L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 352
353Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
354
355Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
356
357Embedding: L<Coro:MakeMaker>
243 358
244=head1 AUTHOR 359=head1 AUTHOR
245 360
246 Marc Lehmann <pcg@goof.com> 361 Marc Lehmann <schmorp@schmorp.de>
247 http://www.goof.com/pcg/marc/ 362 http://home.schmorp.de/
248 363
249=cut 364=cut
250 365

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