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Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.75 by root, Wed Jan 25 21:43:58 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35use strict;
36no warnings "uninitialized";
37
27use Coro::State; 38use Coro::State;
28 39
29use base Exporter; 40use base Exporter::;
30 41
31$VERSION = 0.03; 42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
32 45
33@EXPORT = qw(async yield schedule); 46our $VERSION = 1.8;
34@EXPORT_OK = qw($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}
63 87
64my $idle = new Coro sub { 88=over 4
65 &yield while 1;
66};
67 89
68=item $main 90=item $main
69 91
70This coroutine represents the main program. 92This coroutine represents the main program.
71 93
72=cut 94=cut
73 95
74$main = new Coro; 96$main = new Coro;
75 97
76=item $current 98=item $current (or as function: current)
77 99
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 101
80=cut 102=cut
81 103
… …
84 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
85} 107}
86 108
87$current = $main; 109$current = $main;
88 110
89# we really need priorities... 111sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 112
113=item $idle
114
115The coroutine to switch to when no other coroutine is running. The default
116implementation prints "FATAL: deadlock detected" and exits.
117
118=cut
119
120# should be done using priorities :(
121$idle = new Coro sub {
122 print STDERR "FATAL: deadlock detected\n";
123 exit(51);
124};
125
126# this coroutine is necessary because a coroutine
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};
91 151
92# static methods. not really. 152# static methods. not really.
93 153
154=back
155
94=head2 STATIC METHODS 156=head2 STATIC METHODS
95 157
96Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
97 159
98=over 4 160=over 4
99 161
100=item async { ... }; 162=item async { ... } [@args...]
101 163
102Create a new asynchronous process and return it's process object 164Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 165(usually unused). When the sub returns the new process is automatically
104terminated. 166terminated.
105 167
106=cut 168 # create a new coroutine that just prints its arguments
169 async {
170 print "@_\n";
171 } 1,2,3,4;
107 172
173=cut
174
108sub async(&) { 175sub async(&@) {
109 (new Coro $_[0])->ready; 176 my $pid = new Coro @_;
177 $manager->ready; # this ensures that the stack is cloned from the manager
178 $pid->ready;
179 $pid;
110} 180}
111 181
112=item schedule 182=item schedule
113 183
114Calls the scheduler. Please note that the current process will not be put 184Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 185into the ready queue, so calling this function usually means you will
116never be called again. 186never be called again.
117 187
118=cut 188=cut
119 189
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 190=item cede
128 191
129Yield to other processes. This function puts the current process into the 192"Cede" to other processes. This function puts the current process into the
130ready 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.
131 195
132=cut 196=cut
133 197
134sub yield {
135 $current->ready;
136 &schedule;
137}
138
139=item terminate 198=item terminate [arg...]
140 199
141Terminates the current process. 200Terminates the current process with the given status values (see L<cancel>).
142 201
143=cut 202=cut
144 203
145sub terminate { 204sub terminate {
146 &schedule; 205 $current->cancel (@_);
147} 206}
148 207
149=back 208=back
150 209
151# dynamic methods 210# dynamic methods
… …
154 213
155These are the methods you can call on process objects. 214These are the methods you can call on process objects.
156 215
157=over 4 216=over 4
158 217
159=item new Coro \&sub; 218=item new Coro \&sub [, @args...]
160 219
161Create 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
162automatically 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
163the ready queue by calling the ready method. 223by calling the ready method.
164 224
165=cut 225=cut
226
227sub _newcoro {
228 terminate &{+shift};
229}
166 230
167sub new { 231sub new {
168 my $class = shift; 232 my $class = shift;
169 my $proc = $_[0];
170 bless { 233 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 234 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 235 }, $class;
173} 236}
174 237
175=item $process->ready 238=item $process->ready
176 239
177Put the current process into the ready queue. 240Put the given process into the ready queue.
178 241
179=cut 242=cut
180 243
181sub ready { 244=item $process->cancel (arg...)
182 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;
183} 328}
184 329
185=back 330=back
186 331
187=cut 332=cut
188 333
1891; 3341;
190 335
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
346=head1 SEE ALSO
347
348Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
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>
355
191=head1 AUTHOR 356=head1 AUTHOR
192 357
193 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
194 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
195 360
196=cut 361=cut
197 362

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