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Comparing Coro/Coro.pm (file contents):
Revision 1.12 by root, Sun Jul 15 15:58:16 2001 UTC vs.
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 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 = 0.05; 43$VERSION = 0.8;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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 $coro->{_coro_state} = $manager->{_coro_state};
136 }
137 &schedule;
138 }
139};
100 140
101# static methods. not really. 141# static methods. not really.
102 142
143=back
144
103=head2 STATIC METHODS 145=head2 STATIC METHODS
104 146
105Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
106 148
107=over 4 149=over 4
108 150
109=item async { ... }; 151=item async { ... } [@args...]
110 152
111Create a new asynchronous process and return it's process object 153Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 154(usually unused). When the sub returns the new process is automatically
113terminated. 155terminated.
114 156
115=cut 157 # create a new coroutine that just prints its arguments
158 async {
159 print "@_\n";
160 } 1,2,3,4;
116 161
162The coderef you submit MUST NOT be a closure that refers to variables
163in an outer scope. This does NOT work. Pass arguments into it instead.
164
165=cut
166
117sub async(&) { 167sub async(&@) {
118 my $pid = new Coro $_[0]; 168 my $pid = new Coro @_;
169 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 170 $pid->ready;
120 $pid; 171 $pid;
121} 172}
122 173
123=item schedule 174=item schedule
… …
126into the ready queue, so calling this function usually means you will 177into the ready queue, so calling this function usually means you will
127never be called again. 178never be called again.
128 179
129=cut 180=cut
130 181
131my $prev;
132
133sub schedule {
134 local @_;
135 # should be done using priorities :(
136 ($prev, $current) = ($current, shift @ready || $idle);
137 Coro::State::transfer($prev, $current);
138}
139
140=item yield 182=item cede
141 183
142Yield to other processes. This function puts the current process into the 184"Cede" to other processes. This function puts the current process into the
143ready queue and calls C<schedule>. 185ready queue and calls C<schedule>, which has the effect of giving up the
186current "timeslice" to other coroutines of the same or higher priority.
144 187
145=cut 188=cut
146 189
147sub yield { 190=item terminate [arg...]
191
192Terminates the current process.
193
194Future versions of this function will allow result arguments.
195
196=cut
197
198sub terminate {
199 $current->{status} = [@_];
148 $current->ready; 200 $current->cancel;
149 &schedule; 201 &schedule;
150} 202 die; # NORETURN
151
152=item terminate
153
154Terminates the current process.
155
156=cut
157
158sub terminate {
159 &schedule;
160} 203}
161 204
162=back 205=back
163 206
164# dynamic methods 207# dynamic methods
… …
167 210
168These are the methods you can call on process objects. 211These are the methods you can call on process objects.
169 212
170=over 4 213=over 4
171 214
172=item new Coro \&sub; 215=item new Coro \&sub [, @args...]
173 216
174Create a new process and return it. When the sub returns the process 217Create a new process and return it. When the sub returns the process
175automatically terminates. To start the process you must first put it into 218automatically terminates as if C<terminate> with the returned values were
219called. To make the process run you must first put it into the ready queue
176the ready queue by calling the ready method. 220by calling the ready method.
177 221
178=cut 222=cut
223
224sub _newcoro {
225 terminate &{+shift};
226}
179 227
180sub new { 228sub new {
181 my $class = shift; 229 my $class = shift;
182 my $proc = $_[0];
183 bless { 230 bless {
184 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 231 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
185 }, $class; 232 }, $class;
186} 233}
187 234
188=item $process->ready 235=item $process->ready
189 236
190Put the current process into the ready queue. 237Put the given process into the ready queue.
191 238
192=cut 239=cut
193 240
194sub ready { 241=item $process->cancel
242
243Like C<terminate>, but terminates the specified process instead.
244
245=cut
246
247sub cancel {
195 push @ready, $_[0]; 248 push @destroy, $_[0];
249 $manager->ready;
250 &schedule if $current == $_[0];
251}
252
253=item $process->join
254
255Wait until the coroutine terminates and return any values given to the
256C<terminate> function. C<join> can be called multiple times from multiple
257processes.
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;
196} 322}
197 323
198=back 324=back
199 325
200=cut 326=cut
201 327
2021; 3281;
203 329
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
204=head1 SEE ALSO 340=head1 SEE ALSO
205 341
206L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
207L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
208 345
209=head1 AUTHOR 346=head1 AUTHOR
210 347
211 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <pcg@goof.com>
212 http://www.goof.com/pcg/marc/ 349 http://www.goof.com/pcg/marc/

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