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Comparing Coro/Coro.pm (file contents):
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC vs.
Revision 1.66 by root, Thu Mar 3 17:20:31 2005 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
27use Coro::State; 37use Coro::State;
28 38
39use vars qw($idle $main $current);
40
29use base Exporter; 41use base Exporter;
30 42
31$VERSION = 0.04; 43$VERSION = 1.11;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($current); 46%EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48);
49@EXPORT_OK = @{$EXPORT_TAGS{prio}};
35 50
36{ 51{
37 use subs 'async';
38
39 my @async; 52 my @async;
53 my $init;
40 54
41 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 56 sub import {
43 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
46 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
47 my @attrs; 61 my @attrs;
48 for (@_) { 62 for (@_) {
49 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
50 push @async, $ref; 64 push @async, $ref;
65 unless ($init++) {
66 eval q{
67 sub INIT {
68 &async(pop @async) while @async;
69 }
70 };
71 }
51 } else { 72 } else {
52 push @attrs, @_; 73 push @attrs, $_;
53 } 74 }
54 } 75 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 77 };
57 } 78 }
58 79
59 sub INIT {
60 async pop @async while @async;
61 }
62} 80}
81
82=over 4
63 83
64=item $main 84=item $main
65 85
66This coroutine represents the main program. 86This coroutine represents the main program.
67 87
68=cut 88=cut
69 89
70our $main = new Coro; 90$main = new Coro;
71 91
72=item $current 92=item $current (or as function: current)
73 93
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 95
76=cut 96=cut
77 97
78# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
79if ($current) { 99if ($current) {
80 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
81} 101}
82 102
83our $current = $main; 103$current = $main;
104
105sub current() { $current }
84 106
85=item $idle 107=item $idle
86 108
87The coroutine to switch to when no other coroutine is running. The default 109The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
89 111
90=cut 112=cut
91 113
92# should be done using priorities :( 114# should be done using priorities :(
93our $idle = new Coro sub { 115$idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 117 exit(51);
96}; 118};
97 119
98# we really need priorities... 120# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 121# cannot destroy itself.
122my @destroy;
123my $manager;
124$manager = new Coro sub {
125 while () {
126 # by overwriting the state object with the manager we destroy it
127 # while still being able to schedule this coroutine (in case it has
128 # been readied multiple times. this is harmless since the manager
129 # can be called as many times as neccessary and will always
130 # remove itself from the runqueue
131 while (@destroy) {
132 my $coro = pop @destroy;
133 $coro->{status} ||= [];
134 $_->ready for @{delete $coro->{join} || []};
135
136 # the next line destroys the _coro_state, but keeps the
137 # process itself intact (we basically make it a zombie
138 # process that always runs the manager thread, so it's possible
139 # to transfer() to this process).
140 $coro->{_coro_state} = $manager->{_coro_state};
141 }
142 &schedule;
143 }
144};
100 145
101# static methods. not really. 146# static methods. not really.
102 147
148=back
149
103=head2 STATIC METHODS 150=head2 STATIC METHODS
104 151
105Static methods are actually functions that operate on the current process only. 152Static methods are actually functions that operate on the current process only.
106 153
107=over 4 154=over 4
108 155
109=item async { ... }; 156=item async { ... } [@args...]
110 157
111Create a new asynchronous process and return it's process object 158Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 159(usually unused). When the sub returns the new process is automatically
113terminated. 160terminated.
114 161
115=cut 162 # create a new coroutine that just prints its arguments
163 async {
164 print "@_\n";
165 } 1,2,3,4;
116 166
167=cut
168
117sub async(&) { 169sub async(&@) {
118 (new Coro $_[0])->ready; 170 my $pid = new Coro @_;
171 $manager->ready; # this ensures that the stack is cloned from the manager
172 $pid->ready;
173 $pid;
119} 174}
120 175
121=item schedule 176=item schedule
122 177
123Calls the scheduler. Please note that the current process will not be put 178Calls the scheduler. Please note that the current process will not be put
124into the ready queue, so calling this function usually means you will 179into the ready queue, so calling this function usually means you will
125never be called again. 180never be called again.
126 181
127=cut 182=cut
128 183
129my $prev;
130
131sub schedule {
132 # should be done using priorities :(
133 ($prev, $current) = ($current, shift @ready || $idle);
134 Coro::State::transfer($prev, $current);
135}
136
137=item yield 184=item cede
138 185
139Yield to other processes. This function puts the current process into the 186"Cede" to other processes. This function puts the current process into the
140ready queue and calls C<schedule>. 187ready queue and calls C<schedule>, which has the effect of giving up the
188current "timeslice" to other coroutines of the same or higher priority.
141 189
142=cut 190=cut
143 191
144sub yield {
145 $current->ready;
146 &schedule;
147}
148
149=item terminate 192=item terminate [arg...]
150 193
151Terminates the current process. 194Terminates the current process with the given status values (see L<cancel>).
152 195
153=cut 196=cut
154 197
155sub terminate { 198sub terminate {
156 &schedule; 199 $current->cancel (@_);
157} 200}
158 201
159=back 202=back
160 203
161# dynamic methods 204# dynamic methods
164 207
165These are the methods you can call on process objects. 208These are the methods you can call on process objects.
166 209
167=over 4 210=over 4
168 211
169=item new Coro \&sub; 212=item new Coro \&sub [, @args...]
170 213
171Create a new process and return it. When the sub returns the process 214Create a new process and return it. When the sub returns the process
172automatically terminates. To start the process you must first put it into 215automatically terminates as if C<terminate> with the returned values were
216called. To make the process run you must first put it into the ready queue
173the ready queue by calling the ready method. 217by calling the ready method.
174 218
175=cut 219=cut
220
221sub _newcoro {
222 terminate &{+shift};
223}
176 224
177sub new { 225sub new {
178 my $class = shift; 226 my $class = shift;
179 my $proc = $_[0];
180 bless { 227 bless {
181 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 228 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
182 }, $class; 229 }, $class;
183} 230}
184 231
185=item $process->ready 232=item $process->ready
186 233
187Put the current process into the ready queue. 234Put the given process into the ready queue.
188 235
189=cut 236=cut
190 237
191sub ready { 238=item $process->cancel (arg...)
192 push @ready, $_[0]; 239
240Temrinates the given process and makes it return the given arguments as
241status (default: the empty list).
242
243=cut
244
245sub cancel {
246 my $self = shift;
247 $self->{status} = [@_];
248 push @destroy, $self;
249 $manager->ready;
250 &schedule if $current == $self;
251}
252
253=item $process->join
254
255Wait until the coroutine terminates and return any values given to the
256C<terminate> or C<cancel> functions. C<join> can be called multiple times
257from multiple processes.
258
259=cut
260
261sub join {
262 my $self = shift;
263 unless ($self->{status}) {
264 push @{$self->{join}}, $current;
265 &schedule;
266 }
267 wantarray ? @{$self->{status}} : $self->{status}[0];
268}
269
270=item $oldprio = $process->prio($newprio)
271
272Sets (or gets, if the argument is missing) the priority of the
273process. Higher priority processes get run before lower priority
274processes. Priorities are small signed integers (currently -4 .. +3),
275that you can refer to using PRIO_xxx constants (use the import tag :prio
276to get then):
277
278 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279 3 > 1 > 0 > -1 > -3 > -4
280
281 # set priority to HIGH
282 current->prio(PRIO_HIGH);
283
284The idle coroutine ($Coro::idle) always has a lower priority than any
285existing coroutine.
286
287Changing the priority of the current process will take effect immediately,
288but changing the priority of processes in the ready queue (but not
289running) will only take effect after the next schedule (of that
290process). This is a bug that will be fixed in some future version.
291
292=cut
293
294sub prio {
295 my $old = $_[0]{prio};
296 $_[0]{prio} = $_[1] if @_ > 1;
297 $old;
298}
299
300=item $newprio = $process->nice($change)
301
302Similar to C<prio>, but subtract the given value from the priority (i.e.
303higher values mean lower priority, just as in unix).
304
305=cut
306
307sub nice {
308 $_[0]{prio} -= $_[1];
309}
310
311=item $olddesc = $process->desc($newdesc)
312
313Sets (or gets in case the argument is missing) the description for this
314process. This is just a free-form string you can associate with a process.
315
316=cut
317
318sub desc {
319 my $old = $_[0]{desc};
320 $_[0]{desc} = $_[1] if @_ > 1;
321 $old;
193} 322}
194 323
195=back 324=back
196 325
197=cut 326=cut
198 327
1991; 3281;
200 329
330=head1 BUGS/LIMITATIONS
331
332 - you must make very sure that no coro is still active on global
333 destruction. very bad things might happen otherwise (usually segfaults).
334
335 - this module is not thread-safe. You should only ever use this module
336 from the same thread (this requirement might be losened in the future
337 to allow per-thread schedulers, but Coro::State does not yet allow
338 this).
339
201=head1 SEE ALSO 340=head1 SEE ALSO
202 341
203L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
204L<Coro::Signal>, L<Coro::State>. 343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::Handle>, L<Coro::RWLock>, L<Coro::Socket>.
205 345
206=head1 AUTHOR 346=head1 AUTHOR
207 347
208 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <schmorp@schmorp.de>
209 http://www.goof.com/pcg/marc/ 349 http://home.schmorp.de/
210 350
211=cut 351=cut
212 352

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