ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.20 by root, Sat Jul 21 18:21:45 2001 UTC vs.
Revision 1.78 by root, Wed Nov 1 01:21:21 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
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 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35use strict;
36no warnings "uninitialized";
37
37use Coro::State; 38use Coro::State;
38 39
39use base Exporter; 40use base Exporter::;
40 41
42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
45
41$VERSION = 0.10; 46our $VERSION = '2.1';
42 47
43@EXPORT = qw(async yield schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
44@EXPORT_OK = qw($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}};
45 53
46{ 54{
47 my @async; 55 my @async;
56 my $init;
48 57
49 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
50 sub import { 59 sub import {
60 no strict 'refs';
61
51 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
52 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
53 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
54 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
55 my @attrs; 67 my @attrs;
56 for (@_) { 68 for (@_) {
57 if ($_ eq "Coro") { 69 if ($_ eq "Coro") {
58 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 }
59 } else { 78 } else {
60 push @attrs, $_; 79 push @attrs, $_;
61 } 80 }
62 } 81 }
63 return $old ? $old->($package, $ref, @attrs) : @attrs; 82 return $old ? $old->($package, $ref, @attrs) : @attrs;
64 }; 83 };
65 } 84 }
66 85
67 sub INIT {
68 &async(pop @async) while @async;
69 }
70} 86}
87
88=over 4
71 89
72=item $main 90=item $main
73 91
74This coroutine represents the main program. 92This coroutine represents the main program.
75 93
76=cut 94=cut
77 95
78our $main = new Coro; 96$main = new Coro;
79 97
80=item $current (or as function: current) 98=item $current (or as function: current)
81 99
82The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
83 101
86# maybe some other module used Coro::Specific before... 104# maybe some other module used Coro::Specific before...
87if ($current) { 105if ($current) {
88 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
89} 107}
90 108
91our $current = $main; 109$current = $main;
92 110
93sub current() { $current } 111sub current() { $current }
94 112
95=item $idle 113=item $idle
96 114
98implementation prints "FATAL: deadlock detected" and exits. 116implementation prints "FATAL: deadlock detected" and exits.
99 117
100=cut 118=cut
101 119
102# should be done using priorities :( 120# should be done using priorities :(
103our $idle = new Coro sub { 121$idle = new Coro sub {
104 print STDERR "FATAL: deadlock detected\n"; 122 print STDERR "FATAL: deadlock detected\n";
105 exit(51); 123 exit(51);
106}; 124};
107 125
108# we really need priorities... 126# this coroutine is necessary because a coroutine
109my @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};
110 151
111# static methods. not really. 152# static methods. not really.
153
154=back
112 155
113=head2 STATIC METHODS 156=head2 STATIC METHODS
114 157
115Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
116 159
125 # create a new coroutine that just prints its arguments 168 # create a new coroutine that just prints its arguments
126 async { 169 async {
127 print "@_\n"; 170 print "@_\n";
128 } 1,2,3,4; 171 } 1,2,3,4;
129 172
130The coderef you submit MUST NOT be a closure that refers to variables
131in an outer scope. This does NOT work. Pass arguments into it instead.
132
133=cut 173=cut
134 174
135sub async(&@) { 175sub async(&@) {
136 my $pid = new Coro @_; 176 my $pid = new Coro @_;
177 $manager->ready; # this ensures that the stack is cloned from the manager
137 $pid->ready; 178 $pid->ready;
138 $pid; 179 $pid;
139} 180}
140 181
141=item schedule 182=item schedule
144into the ready queue, so calling this function usually means you will 185into the ready queue, so calling this function usually means you will
145never be called again. 186never be called again.
146 187
147=cut 188=cut
148 189
149my $prev;
150
151sub schedule {
152 # should be done using priorities :(
153 ($prev, $current) = ($current, shift @ready || $idle);
154 Coro::State::transfer($prev, $current);
155}
156
157=item yield 190=item cede
158 191
159Yield to other processes. This function puts the current process into the 192"Cede" to other processes. This function puts the current process into the
160ready 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.
161 195
162=cut 196=cut
163 197
164sub yield {
165 $current->ready;
166 &schedule;
167}
168
169=item terminate 198=item terminate [arg...]
170 199
171Terminates the current process. 200Terminates the current process with the given status values (see L<cancel>).
172
173Future versions of this function will allow result arguments.
174 201
175=cut 202=cut
176 203
177sub terminate { 204sub terminate {
178 $current->{_results} = [@_]; 205 $current->cancel (@_);
179 &schedule;
180} 206}
181 207
182=back 208=back
183 209
184# dynamic methods 210# dynamic methods
190=over 4 216=over 4
191 217
192=item new Coro \&sub [, @args...] 218=item new Coro \&sub [, @args...]
193 219
194Create 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
195automatically 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
196the ready queue by calling the ready method. 223by calling the ready method.
197
198The coderef you submit MUST NOT be a closure that refers to variables
199in an outer scope. This does NOT work. Pass arguments into it instead.
200 224
201=cut 225=cut
202 226
203sub _newcoro { 227sub _newcoro {
204 terminate &{+shift}; 228 terminate &{+shift};
211 }, $class; 235 }, $class;
212} 236}
213 237
214=item $process->ready 238=item $process->ready
215 239
216Put the current process into the ready queue. 240Put the given process into the ready queue.
217 241
218=cut 242=cut
219 243
220sub ready { 244=item $process->cancel (arg...)
221 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;
222} 328}
223 329
224=back 330=back
225 331
226=cut 332=cut
227 333
2281; 3341;
229 335
230=head1 BUGS/LIMITATIONS 336=head1 BUGS/LIMITATIONS
231 337
232 - could be faster, especially when the core would introduce special 338 - you must make very sure that no coro is still active on global
233 support for coroutines (like it does for threads). 339 destruction. very bad things might happen otherwise (usually segfaults).
234 - there is still a memleak on coroutine termination that I could not 340
235 identify. Could be as small as a single SV.
236 - this module is not well-tested.
237 - if variables or arguments "disappear" (become undef) or become
238 corrupted please contact the author so he cen iron out the
239 remaining bugs.
240 - 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
241 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
242 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).
243 345
244=head1 SEE ALSO 346=head1 SEE ALSO
245 347
246L<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>.
247L<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>
248 355
249=head1 AUTHOR 356=head1 AUTHOR
250 357
251 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
252 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
253 360
254=cut 361=cut
255 362

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines