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Comparing Coro/Coro.pm (file contents):
Revision 1.13 by root, Tue Jul 17 00:24:14 2001 UTC vs.
Revision 1.86 by root, Sat Nov 25 01:14:11 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 = 0.05; 46our $VERSION = '2.5';
32 47
33@EXPORT = qw(async yield schedule terminate); 48our @EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
99## my @ready; #d# 136# cannot destroy itself.
100our @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};
101 159
102# static methods. not really. 160# static methods. not really.
161
162=back
103 163
104=head2 STATIC METHODS 164=head2 STATIC METHODS
105 165
106Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
107 167
110=item async { ... } [@args...] 170=item async { ... } [@args...]
111 171
112Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
113(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
114terminated. 174terminated.
175
176When the coroutine dies, the program will exit, just as in the main
177program.
115 178
116 # create a new coroutine that just prints its arguments 179 # create a new coroutine that just prints its arguments
117 async { 180 async {
118 print "@_\n"; 181 print "@_\n";
119 } 1,2,3,4; 182 } 1,2,3,4;
120 183
121The coderef you submit MUST NOT be a closure that refers to variables
122in an outer scope. This does NOT work. Pass arguments into it instead.
123
124=cut 184=cut
125 185
126sub async(&@) { 186sub async(&@) {
127 my $pid = new Coro @_; 187 my $pid = new Coro @_;
128 $pid->ready; 188 $pid->ready;
129 $pid; 189 $pid
130} 190}
131 191
132=item schedule 192=item schedule
133 193
134Calls the scheduler. Please note that the current process will not be put 194Calls the scheduler. Please note that the current process will not be put
135into the ready queue, so calling this function usually means you will 195into the ready queue, so calling this function usually means you will
136never be called again. 196never be called again.
137 197
138=cut 198=cut
139 199
140my $prev;
141
142sub schedule {
143 # should be done using priorities :(
144 ($prev, $current) = ($current, shift @ready || $idle);
145 Coro::State::transfer($prev, $current);
146}
147
148=item yield 200=item cede
149 201
150Yield to other processes. This function puts the current process into the 202"Cede" to other processes. This function puts the current process into the
151ready queue and calls C<schedule>. 203ready queue and calls C<schedule>, which has the effect of giving up the
204current "timeslice" to other coroutines of the same or higher priority.
152 205
153=cut 206=cut
154 207
155sub yield {
156 $current->ready;
157 &schedule;
158}
159
160=item terminate 208=item terminate [arg...]
161 209
162Terminates the current process. 210Terminates the current process with the given status values (see L<cancel>).
163
164Future versions of this function will allow result arguments.
165 211
166=cut 212=cut
167 213
168sub terminate { 214sub terminate {
169 $current->{_results} = [@_]; 215 $current->cancel (@_);
170 &schedule;
171} 216}
172 217
173=back 218=back
174 219
175# dynamic methods 220# dynamic methods
181=over 4 226=over 4
182 227
183=item new Coro \&sub [, @args...] 228=item new Coro \&sub [, @args...]
184 229
185Create a new process and return it. When the sub returns the process 230Create a new process and return it. When the sub returns the process
186automatically terminates. To start the process you must first put it into 231automatically terminates as if C<terminate> with the returned values were
232called. To make the process run you must first put it into the ready queue
187the ready queue by calling the ready method. 233by calling the ready method.
188 234
189The coderef you submit MUST NOT be a closure that refers to variables
190in an outer scope. This does NOT work. Pass arguments into it instead.
191
192=cut 235=cut
193 236
194sub _newcoro { 237sub _new_coro {
238 $current->_clear_idle_sp; # (re-)set the idle sp on the following cede
239 _set_cede_self; # ensures that cede cede's us first
240 cede;
195 terminate &{+shift}; 241 terminate &{+shift};
196} 242}
197 243
198sub new { 244sub new {
199 my $class = shift; 245 my $class = shift;
200 bless { 246
201 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 247 $class->SUPER::new (\&_new_coro, @_)
202 }, $class;
203} 248}
204 249
205=item $process->ready 250=item $process->ready
206 251
207Put the current process into the ready queue. 252Put the given process into the ready queue.
208 253
209=cut 254=cut
210 255
211sub ready { 256=item $process->cancel (arg...)
212 push @ready, $_[0]; 257
258Terminates the given process and makes it return the given arguments as
259status (default: the empty list).
260
261=cut
262
263sub cancel {
264 my $self = shift;
265 $self->{status} = [@_];
266 push @destroy, $self;
267 $manager->ready;
268 &schedule if $current == $self;
269}
270
271=item $process->join
272
273Wait until the coroutine terminates and return any values given to the
274C<terminate> or C<cancel> functions. C<join> can be called multiple times
275from multiple processes.
276
277=cut
278
279sub join {
280 my $self = shift;
281 unless ($self->{status}) {
282 push @{$self->{join}}, $current;
283 &schedule;
284 }
285 wantarray ? @{$self->{status}} : $self->{status}[0];
286}
287
288=item $oldprio = $process->prio ($newprio)
289
290Sets (or gets, if the argument is missing) the priority of the
291process. Higher priority processes get run before lower priority
292processes. Priorities are small signed integers (currently -4 .. +3),
293that you can refer to using PRIO_xxx constants (use the import tag :prio
294to get then):
295
296 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
297 3 > 1 > 0 > -1 > -3 > -4
298
299 # set priority to HIGH
300 current->prio(PRIO_HIGH);
301
302The idle coroutine ($Coro::idle) always has a lower priority than any
303existing coroutine.
304
305Changing the priority of the current process will take effect immediately,
306but changing the priority of processes in the ready queue (but not
307running) will only take effect after the next schedule (of that
308process). This is a bug that will be fixed in some future version.
309
310=item $newprio = $process->nice ($change)
311
312Similar to C<prio>, but subtract the given value from the priority (i.e.
313higher values mean lower priority, just as in unix).
314
315=item $olddesc = $process->desc ($newdesc)
316
317Sets (or gets in case the argument is missing) the description for this
318process. This is just a free-form string you can associate with a process.
319
320=cut
321
322sub desc {
323 my $old = $_[0]{desc};
324 $_[0]{desc} = $_[1] if @_ > 1;
325 $old;
213} 326}
214 327
215=back 328=back
216 329
217=cut 330=cut
218 331
2191; 3321;
220 333
334=head1 BUGS/LIMITATIONS
335
336 - you must make very sure that no coro is still active on global
337 destruction. very bad things might happen otherwise (usually segfaults).
338
339 - this module is not thread-safe. You should only ever use this module
340 from the same thread (this requirement might be losened in the future
341 to allow per-thread schedulers, but Coro::State does not yet allow
342 this).
343
221=head1 SEE ALSO 344=head1 SEE ALSO
222 345
223L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 346Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
224L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 347
348Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
349
350Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
351
352Embedding: L<Coro:MakeMaker>
225 353
226=head1 AUTHOR 354=head1 AUTHOR
227 355
228 Marc Lehmann <pcg@goof.com> 356 Marc Lehmann <schmorp@schmorp.de>
229 http://www.goof.com/pcg/marc/ 357 http://home.schmorp.de/
230 358
231=cut 359=cut
232 360

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