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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 1.80 by root, Mon Nov 6 19:56:26 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35use strict;
36no warnings "uninitialized";
37
27use Coro::State; 38use Coro::State;
28 39
29use base Exporter; 40use base Exporter::;
30 41
31$VERSION = 0.03; 42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
32 45
33@EXPORT = qw(async yield schedule); 46our $VERSION = '2.5';
34@EXPORT_OK = qw($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}
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 168When the coroutine dies, the program will exit, just as in the main
169program.
107 170
171 # create a new coroutine that just prints its arguments
172 async {
173 print "@_\n";
174 } 1,2,3,4;
175
176=cut
177
108sub async(&) { 178sub async(&@) {
109 (new Coro $_[0])->ready; 179 my $pid = new Coro @_;
180 $manager->ready; # this ensures that the stack is cloned from the manager
181 $pid->ready;
182 $pid;
110} 183}
111 184
112=item schedule 185=item schedule
113 186
114Calls the scheduler. Please note that the current process will not be put 187Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 188into the ready queue, so calling this function usually means you will
116never be called again. 189never be called again.
117 190
118=cut 191=cut
119 192
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 193=item cede
128 194
129Yield to other processes. This function puts the current process into the 195"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 196ready queue and calls C<schedule>, which has the effect of giving up the
197current "timeslice" to other coroutines of the same or higher priority.
131 198
132=cut 199=cut
133 200
134sub yield {
135 $current->ready;
136 &schedule;
137}
138
139=item terminate 201=item terminate [arg...]
140 202
141Terminates the current process. 203Terminates the current process with the given status values (see L<cancel>).
142 204
143=cut 205=cut
144 206
145sub terminate { 207sub terminate {
146 &schedule; 208 $current->cancel (@_);
147} 209}
148 210
149=back 211=back
150 212
151# dynamic methods 213# dynamic methods
… …
154 216
155These are the methods you can call on process objects. 217These are the methods you can call on process objects.
156 218
157=over 4 219=over 4
158 220
159=item new Coro \&sub; 221=item new Coro \&sub [, @args...]
160 222
161Create a new process and return it. When the sub returns the process 223Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 224automatically terminates as if C<terminate> with the returned values were
225called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 226by calling the ready method.
164 227
165=cut 228=cut
229
230sub _newcoro {
231 terminate &{+shift};
232}
166 233
167sub new { 234sub new {
168 my $class = shift; 235 my $class = shift;
169 my $proc = $_[0];
170 bless { 236 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 237 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 238 }, $class;
173} 239}
174 240
175=item $process->ready 241=item $process->ready
176 242
177Put the current process into the ready queue. 243Put the given process into the ready queue.
178 244
179=cut 245=cut
180 246
181sub ready { 247=item $process->cancel (arg...)
182 push @ready, $_[0]; 248
249Terminates the given process and makes it return the given arguments as
250status (default: the empty list).
251
252=cut
253
254sub cancel {
255 my $self = shift;
256 $self->{status} = [@_];
257 push @destroy, $self;
258 $manager->ready;
259 &schedule if $current == $self;
260}
261
262=item $process->join
263
264Wait until the coroutine terminates and return any values given to the
265C<terminate> or C<cancel> functions. C<join> can be called multiple times
266from multiple processes.
267
268=cut
269
270sub join {
271 my $self = shift;
272 unless ($self->{status}) {
273 push @{$self->{join}}, $current;
274 &schedule;
275 }
276 wantarray ? @{$self->{status}} : $self->{status}[0];
277}
278
279=item $oldprio = $process->prio($newprio)
280
281Sets (or gets, if the argument is missing) the priority of the
282process. Higher priority processes get run before lower priority
283processes. Priorities are small signed integers (currently -4 .. +3),
284that you can refer to using PRIO_xxx constants (use the import tag :prio
285to get then):
286
287 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
288 3 > 1 > 0 > -1 > -3 > -4
289
290 # set priority to HIGH
291 current->prio(PRIO_HIGH);
292
293The idle coroutine ($Coro::idle) always has a lower priority than any
294existing coroutine.
295
296Changing the priority of the current process will take effect immediately,
297but changing the priority of processes in the ready queue (but not
298running) will only take effect after the next schedule (of that
299process). This is a bug that will be fixed in some future version.
300
301=cut
302
303sub prio {
304 my $old = $_[0]{prio};
305 $_[0]{prio} = $_[1] if @_ > 1;
306 $old;
307}
308
309=item $newprio = $process->nice($change)
310
311Similar to C<prio>, but subtract the given value from the priority (i.e.
312higher values mean lower priority, just as in unix).
313
314=cut
315
316sub nice {
317 $_[0]{prio} -= $_[1];
318}
319
320=item $olddesc = $process->desc($newdesc)
321
322Sets (or gets in case the argument is missing) the description for this
323process. This is just a free-form string you can associate with a process.
324
325=cut
326
327sub desc {
328 my $old = $_[0]{desc};
329 $_[0]{desc} = $_[1] if @_ > 1;
330 $old;
183} 331}
184 332
185=back 333=back
186 334
187=cut 335=cut
188 336
1891; 3371;
190 338
339=head1 BUGS/LIMITATIONS
340
341 - you must make very sure that no coro is still active on global
342 destruction. very bad things might happen otherwise (usually segfaults).
343
344 - this module is not thread-safe. You should only ever use this module
345 from the same thread (this requirement might be losened in the future
346 to allow per-thread schedulers, but Coro::State does not yet allow
347 this).
348
349=head1 SEE ALSO
350
351Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
352
353Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
354
355Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
356
357Embedding: L<Coro:MakeMaker>
358
191=head1 AUTHOR 359=head1 AUTHOR
192 360
193 Marc Lehmann <pcg@goof.com> 361 Marc Lehmann <schmorp@schmorp.de>
194 http://www.goof.com/pcg/marc/ 362 http://home.schmorp.de/
195 363
196=cut 364=cut
197 365

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