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

Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 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
24threads but don't run in parallel.
25
26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35use strict;
36no warnings "uninitialized";
37
27use Coro::State; 38use Coro::State;
28 39
29use base Exporter; 40use base qw(Coro::State Exporter);
30 41
31$VERSION = 0.04; 42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
32 45
33@EXPORT = qw(async yield schedule); 46our $VERSION = '2.5';
34@EXPORT_OK = qw($current); 47
48our @EXPORT = qw(async cede schedule terminate 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
99my @ready = (); # the ready queue. hehe, rather broken ;) 136# cannot destroy itself.
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};
100 160
101# static methods. not really. 161# static methods. not really.
102 162
163=back
164
103=head2 STATIC METHODS 165=head2 STATIC METHODS
104 166
105Static methods are actually functions that operate on the current process only. 167Static methods are actually functions that operate on the current process only.
106 168
107=over 4 169=over 4
108 170
109=item async { ... }; 171=item async { ... } [@args...]
110 172
111Create a new asynchronous process and return it's process object 173Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 174(usually unused). When the sub returns the new process is automatically
113terminated. 175terminated.
114 176
115=cut 177When the coroutine dies, the program will exit, just as in the main
178program.
116 179
180 # create a new coroutine that just prints its arguments
181 async {
182 print "@_\n";
183 } 1,2,3,4;
184
185=cut
186
117sub async(&) { 187sub async(&@) {
118 my $pid = new Coro $_[0]; 188 my $pid = new Coro @_;
189 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 190 $pid->ready;
120 $pid; 191 $pid;
121} 192}
122 193
123=item schedule 194=item schedule
… …
126into the ready queue, so calling this function usually means you will 197into the ready queue, so calling this function usually means you will
127never be called again. 198never be called again.
128 199
129=cut 200=cut
130 201
131my $prev;
132
133sub schedule {
134 # should be done using priorities :(
135 ($prev, $current) = ($current, shift @ready || $idle);
136 Coro::State::transfer($prev, $current);
137}
138
139=item yield 202=item cede
140 203
141Yield to other processes. This function puts the current process into the 204"Cede" to other processes. This function puts the current process into the
142ready 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.
143 207
144=cut 208=cut
145 209
146sub yield {
147 $current->ready;
148 &schedule;
149}
150
151=item terminate 210=item terminate [arg...]
152 211
153Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
154 213
155=cut 214=cut
156 215
157sub terminate { 216sub terminate {
158 &schedule; 217 $current->cancel (@_);
159} 218}
160 219
161=back 220=back
162 221
163# dynamic methods 222# dynamic methods
… …
166 225
167These are the methods you can call on process objects. 226These are the methods you can call on process objects.
168 227
169=over 4 228=over 4
170 229
171=item new Coro \&sub; 230=item new Coro \&sub [, @args...]
172 231
173Create 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
174automatically 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
175the ready queue by calling the ready method. 235by calling the ready method.
176 236
177=cut 237=cut
238
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;
243 terminate &{+shift};
244}
178 245
179sub new { 246sub new {
180 my $class = shift; 247 my $class = shift;
181 my $proc = $_[0]; 248
182 bless { 249 $class->SUPER::new (\&_new_coro, @_)
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
184 }, $class;
185} 250}
186 251
187=item $process->ready 252=item $process->ready
188 253
189Put the current process into the ready queue. 254Put the given process into the ready queue.
190 255
191=cut 256=cut
192 257
193sub ready { 258=item $process->cancel (arg...)
194 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;
195} 328}
196 329
197=back 330=back
198 331
199=cut 332=cut
200 333
2011; 3341;
202 335
336=head1 BUGS/LIMITATIONS
337
338 - you must make very sure that no coro is still active on global
339 destruction. very bad things might happen otherwise (usually segfaults).
340
341 - this module is not thread-safe. You should only ever use this module
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).
345
203=head1 SEE ALSO 346=head1 SEE ALSO
204 347
205L<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>.
206L<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>
207 355
208=head1 AUTHOR 356=head1 AUTHOR
209 357
210 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
211 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
212 360
213=cut 361=cut
214 362

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines