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Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC vs.
Revision 1.85 by root, Sat Nov 25 00:56:35 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 @_;
119 $pid->ready; 189 $pid->ready;
120 $pid; 190 $pid
121} 191}
122 192
123=item schedule 193=item schedule
124 194
125Calls the scheduler. Please note that the current process will not be put 195Calls the scheduler. Please note that the current process will not be put
126into the ready queue, so calling this function usually means you will 196into the ready queue, so calling this function usually means you will
127never be called again. 197never be called again.
128 198
129=cut 199=cut
130 200
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 201=item cede
140 202
141Yield to other processes. This function puts the current process into the 203"Cede" to other processes. This function puts the current process into the
142ready queue and calls C<schedule>. 204ready queue and calls C<schedule>, which has the effect of giving up the
205current "timeslice" to other coroutines of the same or higher priority.
143 206
144=cut 207=cut
145 208
146sub yield {
147 $current->ready;
148 &schedule;
149}
150
151=item terminate 209=item terminate [arg...]
152 210
153Terminates the current process. 211Terminates the current process with the given status values (see L<cancel>).
154 212
155=cut 213=cut
156 214
157sub terminate { 215sub terminate {
158 &schedule; 216 $current->cancel (@_);
159} 217}
160 218
161=back 219=back
162 220
163# dynamic methods 221# dynamic methods
… …
166 224
167These are the methods you can call on process objects. 225These are the methods you can call on process objects.
168 226
169=over 4 227=over 4
170 228
171=item new Coro \&sub; 229=item new Coro \&sub [, @args...]
172 230
173Create a new process and return it. When the sub returns the process 231Create a new process and return it. When the sub returns the process
174automatically terminates. To start the process you must first put it into 232automatically terminates as if C<terminate> with the returned values were
233called. To make the process run you must first put it into the ready queue
175the ready queue by calling the ready method. 234by calling the ready method.
176 235
177=cut 236=cut
237
238sub _new_coro {
239 $current->_clear_idle_sp; # set the idle sp on the following cede
240 _set_cede_self; # ensures that cede cede's us first
241 cede;
242 terminate &{+shift};
243}
178 244
179sub new { 245sub new {
180 my $class = shift; 246 my $class = shift;
181 my $proc = $_[0]; 247
182 bless { 248 $class->SUPER::new (\&_new_coro, @_)
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
184 }, $class;
185} 249}
186 250
187=item $process->ready 251=item $process->ready
188 252
189Put the current process into the ready queue. 253Put the given process into the ready queue.
190 254
191=cut 255=cut
192 256
193sub ready { 257=item $process->cancel (arg...)
194 push @ready, $_[0]; 258
259Terminates the given process and makes it return the given arguments as
260status (default: the empty list).
261
262=cut
263
264sub cancel {
265 my $self = shift;
266 $self->{status} = [@_];
267 push @destroy, $self;
268 $manager->ready;
269 &schedule if $current == $self;
270}
271
272=item $process->join
273
274Wait until the coroutine terminates and return any values given to the
275C<terminate> or C<cancel> functions. C<join> can be called multiple times
276from multiple processes.
277
278=cut
279
280sub join {
281 my $self = shift;
282 unless ($self->{status}) {
283 push @{$self->{join}}, $current;
284 &schedule;
285 }
286 wantarray ? @{$self->{status}} : $self->{status}[0];
287}
288
289=item $oldprio = $process->prio ($newprio)
290
291Sets (or gets, if the argument is missing) the priority of the
292process. Higher priority processes get run before lower priority
293processes. Priorities are small signed integers (currently -4 .. +3),
294that you can refer to using PRIO_xxx constants (use the import tag :prio
295to get then):
296
297 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
298 3 > 1 > 0 > -1 > -3 > -4
299
300 # set priority to HIGH
301 current->prio(PRIO_HIGH);
302
303The idle coroutine ($Coro::idle) always has a lower priority than any
304existing coroutine.
305
306Changing the priority of the current process will take effect immediately,
307but changing the priority of processes in the ready queue (but not
308running) will only take effect after the next schedule (of that
309process). This is a bug that will be fixed in some future version.
310
311=item $newprio = $process->nice ($change)
312
313Similar to C<prio>, but subtract the given value from the priority (i.e.
314higher values mean lower priority, just as in unix).
315
316=item $olddesc = $process->desc ($newdesc)
317
318Sets (or gets in case the argument is missing) the description for this
319process. This is just a free-form string you can associate with a process.
320
321=cut
322
323sub desc {
324 my $old = $_[0]{desc};
325 $_[0]{desc} = $_[1] if @_ > 1;
326 $old;
195} 327}
196 328
197=back 329=back
198 330
199=cut 331=cut
200 332
2011; 3331;
202 334
335=head1 BUGS/LIMITATIONS
336
337 - you must make very sure that no coro is still active on global
338 destruction. very bad things might happen otherwise (usually segfaults).
339
340 - this module is not thread-safe. You should only ever use this module
341 from the same thread (this requirement might be losened in the future
342 to allow per-thread schedulers, but Coro::State does not yet allow
343 this).
344
203=head1 SEE ALSO 345=head1 SEE ALSO
204 346
205L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 347Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
206L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 348
349Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
350
351Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
352
353Embedding: L<Coro:MakeMaker>
207 354
208=head1 AUTHOR 355=head1 AUTHOR
209 356
210 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
211 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
212 359
213=cut 360=cut
214 361

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