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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 1.84 by root, Sat Nov 25 00:40:26 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 qw(Coro::State Exporter);
35 41
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
36$VERSION = 0.05; 46our $VERSION = '2.5';
37 47
38@EXPORT = qw(async yield schedule terminate); 48our @EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($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 $manager;
139$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};
106 160
107# static methods. not really. 161# static methods. not really.
162
163=back
108 164
109=head2 STATIC METHODS 165=head2 STATIC METHODS
110 166
111Static methods are actually functions that operate on the current process only. 167Static methods are actually functions that operate on the current process only.
112 168
… …
115=item async { ... } [@args...] 171=item async { ... } [@args...]
116 172
117Create a new asynchronous process and return it's process object 173Create a new asynchronous process and return it's process object
118(usually unused). When the sub returns the new process is automatically 174(usually unused). When the sub returns the new process is automatically
119terminated. 175terminated.
176
177When the coroutine dies, the program will exit, just as in the main
178program.
120 179
121 # create a new coroutine that just prints its arguments 180 # create a new coroutine that just prints its arguments
122 async { 181 async {
123 print "@_\n"; 182 print "@_\n";
124 } 1,2,3,4; 183 } 1,2,3,4;
125 184
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 185=cut
130 186
131sub async(&@) { 187sub async(&@) {
132 my $pid = new Coro @_; 188 my $pid = new Coro @_;
189 $manager->ready; # this ensures that the stack is cloned from the manager
133 $pid->ready; 190 $pid->ready;
134 $pid; 191 $pid;
135} 192}
136 193
137=item schedule 194=item schedule
… …
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
195in an outer scope. This does NOT work. Pass arguments into it instead.
196
197=cut 237=cut
198 238
199sub _newcoro { 239sub _new_coro {
240# $current->_clear_idle_sp; # set the idle sp on the following cede
241 _set_cede_self; # ensures that cede cede's us first
242 cede;
200 terminate &{+shift}; 243 terminate &{+shift};
201} 244}
202 245
203sub new { 246sub new {
204 my $class = shift; 247 my $class = shift;
205 bless { 248
206 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 249 $class->SUPER::new (\&_new_coro, @_)
207 }, $class;
208} 250}
209 251
210=item $process->ready 252=item $process->ready
211 253
212Put the current process into the ready queue. 254Put the given process into the ready queue.
213 255
214=cut 256=cut
215 257
216sub ready { 258=item $process->cancel (arg...)
217 push @ready, $_[0]; 259
260Terminates the given process and makes it return the given arguments as
261status (default: the empty list).
262
263=cut
264
265sub cancel {
266 my $self = shift;
267 $self->{status} = [@_];
268 push @destroy, $self;
269 $manager->ready;
270 &schedule if $current == $self;
271}
272
273=item $process->join
274
275Wait until the coroutine terminates and return any values given to the
276C<terminate> or C<cancel> functions. C<join> can be called multiple times
277from multiple processes.
278
279=cut
280
281sub join {
282 my $self = shift;
283 unless ($self->{status}) {
284 push @{$self->{join}}, $current;
285 &schedule;
286 }
287 wantarray ? @{$self->{status}} : $self->{status}[0];
288}
289
290=item $oldprio = $process->prio ($newprio)
291
292Sets (or gets, if the argument is missing) the priority of the
293process. Higher priority processes get run before lower priority
294processes. Priorities are small signed integers (currently -4 .. +3),
295that you can refer to using PRIO_xxx constants (use the import tag :prio
296to get then):
297
298 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
299 3 > 1 > 0 > -1 > -3 > -4
300
301 # set priority to HIGH
302 current->prio(PRIO_HIGH);
303
304The idle coroutine ($Coro::idle) always has a lower priority than any
305existing coroutine.
306
307Changing the priority of the current process will take effect immediately,
308but changing the priority of processes in the ready queue (but not
309running) will only take effect after the next schedule (of that
310process). This is a bug that will be fixed in some future version.
311
312=item $newprio = $process->nice ($change)
313
314Similar to C<prio>, but subtract the given value from the priority (i.e.
315higher values mean lower priority, just as in unix).
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;
218} 328}
219 329
220=back 330=back
221 331
222=cut 332=cut
223 333
2241; 3341;
225 335
226=head1 BUGS 336=head1 BUGS/LIMITATIONS
227 337
228 - could be faster, especially when the core would introduce special 338 - you must make very sure that no coro is still active on global
229 support for coroutines (like it does for threads). 339 destruction. very bad things might happen otherwise (usually segfaults).
230 - there is still a memleak on coroutine termination that I could not 340
231 identify. Could be as small as a single SV. 341 - this module is not thread-safe. You should only ever use this module
232 - this module is not well-tested. 342 from the same thread (this requirement might be losened in the future
343 to allow per-thread schedulers, but Coro::State does not yet allow
344 this).
233 345
234=head1 SEE ALSO 346=head1 SEE ALSO
235 347
236L<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>.
237L<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>
238 355
239=head1 AUTHOR 356=head1 AUTHOR
240 357
241 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
242 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
243 360
244=cut 361=cut
245 362

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