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Comparing Coro/Coro.pm (file contents):
Revision 1.21 by root, Sun Jul 22 03:24:10 2001 UTC vs.
Revision 1.72 by root, Mon Dec 12 17:49:07 2005 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
26This module is still experimental, see the BUGS section below.
27 25
28In this module, coroutines are defined as "callchain + lexical variables 26In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's 27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30own set of lexicals and it's own set of perl's most important global 28callchain, it's own set of lexicals and it's own set of perl's most
31variables. 29important global variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38 30
39=cut 31=cut
40 32
41package Coro; 33package Coro;
42 34
35use strict;
36no warnings "uninitialized";
37
43use Coro::State; 38use Coro::State;
44 39
45use base Exporter; 40use base Exporter::;
46 41
42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
45
47$VERSION = 0.10; 46our $VERSION = 1.51;
48 47
49@EXPORT = qw(async yield schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
50@EXPORT_OK = qw($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}};
51 53
52{ 54{
53 my @async; 55 my @async;
56 my $init;
54 57
55 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
56 sub import { 59 sub import {
60 no strict 'refs';
61
57 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
59 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
60 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
61 my @attrs; 67 my @attrs;
62 for (@_) { 68 for (@_) {
63 if ($_ eq "Coro") { 69 if ($_ eq "Coro") {
64 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 }
65 } else { 78 } else {
66 push @attrs, $_; 79 push @attrs, $_;
67 } 80 }
68 } 81 }
69 return $old ? $old->($package, $ref, @attrs) : @attrs; 82 return $old ? $old->($package, $ref, @attrs) : @attrs;
70 }; 83 };
71 } 84 }
72 85
73 sub INIT {
74 &async(pop @async) while @async;
75 }
76} 86}
87
88=over 4
77 89
78=item $main 90=item $main
79 91
80This coroutine represents the main program. 92This coroutine represents the main program.
81 93
82=cut 94=cut
83 95
84our $main = new Coro; 96$main = new Coro;
85 97
86=item $current (or as function: current) 98=item $current (or as function: current)
87 99
88The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
89 101
92# maybe some other module used Coro::Specific before... 104# maybe some other module used Coro::Specific before...
93if ($current) { 105if ($current) {
94 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
95} 107}
96 108
97our $current = $main; 109$current = $main;
98 110
99sub current() { $current } 111sub current() { $current }
100 112
101=item $idle 113=item $idle
102 114
104implementation prints "FATAL: deadlock detected" and exits. 116implementation prints "FATAL: deadlock detected" and exits.
105 117
106=cut 118=cut
107 119
108# should be done using priorities :( 120# should be done using priorities :(
109our $idle = new Coro sub { 121$idle = new Coro sub {
110 print STDERR "FATAL: deadlock detected\n"; 122 print STDERR "FATAL: deadlock detected\n";
111 exit(51); 123 exit(51);
112}; 124};
113 125
114# we really need priorities... 126# this coroutine is necessary because a coroutine
115my @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};
116 151
117# static methods. not really. 152# static methods. not really.
153
154=back
118 155
119=head2 STATIC METHODS 156=head2 STATIC METHODS
120 157
121Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
122 159
131 # create a new coroutine that just prints its arguments 168 # create a new coroutine that just prints its arguments
132 async { 169 async {
133 print "@_\n"; 170 print "@_\n";
134 } 1,2,3,4; 171 } 1,2,3,4;
135 172
136The coderef you submit MUST NOT be a closure that refers to variables
137in an outer scope. This does NOT work. Pass arguments into it instead.
138
139=cut 173=cut
140 174
141sub async(&@) { 175sub async(&@) {
142 my $pid = new Coro @_; 176 my $pid = new Coro @_;
177 $manager->ready; # this ensures that the stack is cloned from the manager
143 $pid->ready; 178 $pid->ready;
144 $pid; 179 $pid;
145} 180}
146 181
147=item schedule 182=item schedule
150into the ready queue, so calling this function usually means you will 185into the ready queue, so calling this function usually means you will
151never be called again. 186never be called again.
152 187
153=cut 188=cut
154 189
155my $prev;
156
157sub schedule {
158 # should be done using priorities :(
159 ($prev, $current) = ($current, shift @ready || $idle);
160 Coro::State::transfer($prev, $current);
161}
162
163=item yield 190=item cede
164 191
165Yield to other processes. This function puts the current process into the 192"Cede" to other processes. This function puts the current process into the
166ready queue and calls C<schedule>. 193ready queue and calls C<schedule>, which has the effect of giving up the
194current "timeslice" to other coroutines of the same or higher priority.
167 195
168=cut 196=cut
169 197
170sub yield {
171 $current->ready;
172 &schedule;
173}
174
175=item terminate 198=item terminate [arg...]
176 199
177Terminates the current process. 200Terminates the current process with the given status values (see L<cancel>).
178
179Future versions of this function will allow result arguments.
180 201
181=cut 202=cut
182 203
183sub terminate { 204sub terminate {
184 $current->{_results} = [@_]; 205 $current->cancel (@_);
185 delete $current->{_coro_state};
186 &schedule;
187} 206}
188 207
189=back 208=back
190 209
191# dynamic methods 210# dynamic methods
197=over 4 216=over 4
198 217
199=item new Coro \&sub [, @args...] 218=item new Coro \&sub [, @args...]
200 219
201Create a new process and return it. When the sub returns the process 220Create a new process and return it. When the sub returns the process
202automatically terminates. To start the process you must first put it into 221automatically terminates as if C<terminate> with the returned values were
222called. To make the process run you must first put it into the ready queue
203the ready queue by calling the ready method. 223by calling the ready method.
204
205The coderef you submit MUST NOT be a closure that refers to variables
206in an outer scope. This does NOT work. Pass arguments into it instead.
207 224
208=cut 225=cut
209 226
210sub _newcoro { 227sub _newcoro {
211 terminate &{+shift}; 228 terminate &{+shift};
218 }, $class; 235 }, $class;
219} 236}
220 237
221=item $process->ready 238=item $process->ready
222 239
223Put the current process into the ready queue. 240Put the given process into the ready queue.
224 241
225=cut 242=cut
226 243
227sub ready { 244=item $process->cancel (arg...)
228 push @ready, $_[0]; 245
246Temrinates the given process and makes it return the given arguments as
247status (default: the empty list).
248
249=cut
250
251sub cancel {
252 my $self = shift;
253 $self->{status} = [@_];
254 push @destroy, $self;
255 $manager->ready;
256 &schedule if $current == $self;
257}
258
259=item $process->join
260
261Wait until the coroutine terminates and return any values given to the
262C<terminate> or C<cancel> functions. C<join> can be called multiple times
263from multiple processes.
264
265=cut
266
267sub join {
268 my $self = shift;
269 unless ($self->{status}) {
270 push @{$self->{join}}, $current;
271 &schedule;
272 }
273 wantarray ? @{$self->{status}} : $self->{status}[0];
274}
275
276=item $oldprio = $process->prio($newprio)
277
278Sets (or gets, if the argument is missing) the priority of the
279process. Higher priority processes get run before lower priority
280processes. Priorities are small signed integers (currently -4 .. +3),
281that you can refer to using PRIO_xxx constants (use the import tag :prio
282to get then):
283
284 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
285 3 > 1 > 0 > -1 > -3 > -4
286
287 # set priority to HIGH
288 current->prio(PRIO_HIGH);
289
290The idle coroutine ($Coro::idle) always has a lower priority than any
291existing coroutine.
292
293Changing the priority of the current process will take effect immediately,
294but changing the priority of processes in the ready queue (but not
295running) will only take effect after the next schedule (of that
296process). This is a bug that will be fixed in some future version.
297
298=cut
299
300sub prio {
301 my $old = $_[0]{prio};
302 $_[0]{prio} = $_[1] if @_ > 1;
303 $old;
304}
305
306=item $newprio = $process->nice($change)
307
308Similar to C<prio>, but subtract the given value from the priority (i.e.
309higher values mean lower priority, just as in unix).
310
311=cut
312
313sub nice {
314 $_[0]{prio} -= $_[1];
315}
316
317=item $olddesc = $process->desc($newdesc)
318
319Sets (or gets in case the argument is missing) the description for this
320process. This is just a free-form string you can associate with a process.
321
322=cut
323
324sub desc {
325 my $old = $_[0]{desc};
326 $_[0]{desc} = $_[1] if @_ > 1;
327 $old;
229} 328}
230 329
231=back 330=back
232 331
233=cut 332=cut
234 333
2351; 3341;
236 335
237=head1 BUGS/LIMITATIONS 336=head1 BUGS/LIMITATIONS
238 337
239 - could be faster, especially when the core would introduce special 338 - you must make very sure that no coro is still active on global
240 support for coroutines (like it does for threads). 339 destruction. very bad things might happen otherwise (usually segfaults).
241 - there is still a memleak on coroutine termination that I could not 340
242 identify. Could be as small as a single SV.
243 - this module is not well-tested.
244 - if variables or arguments "disappear" (become undef) or become
245 corrupted please contact the author so he cen iron out the
246 remaining bugs.
247 - this module is not thread-safe. You must only ever use this module from 341 - this module is not thread-safe. You should only ever use this module
248 the same thread (this requirement might be loosened in the future to 342 from the same thread (this requirement might be losened in the future
249 allow per-thread schedulers, but Coro::State does not yet allow this). 343 to allow per-thread schedulers, but Coro::State does not yet allow
344 this).
250 345
251=head1 SEE ALSO 346=head1 SEE ALSO
252 347
253L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 348Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
254L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 349
350Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
351
352Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
353
354Embedding: L<Coro:MakeMaker>
255 355
256=head1 AUTHOR 356=head1 AUTHOR
257 357
258 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
259 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
260 360
261=cut 361=cut
262 362

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