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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 1.88 by root, Sun Nov 26 02:54:55 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
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
31$VERSION = 0.03; 46our $VERSION = '3.0';
32 47
33@EXPORT = qw(async yield schedule); 48our @EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
79 106
80=cut 107=cut
81 108
82# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
83if ($current) { 110if ($current) {
84 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
85} 112}
86 113
87$current = $main; 114$current = $main;
88 115
89# we really need priorities... 116sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 117
118=item $idle
119
120A callback that is called whenever the scheduler finds no ready coroutines
121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
123
124This hook is overwritten by modules such as C<Coro::Timer> and
125C<Coro::Event> to wait on an external event that hopefully wakes up some
126coroutine.
127
128=cut
129
130$idle = sub {
131 print STDERR "FATAL: deadlock detected\n";
132 exit (51);
133};
134
135# this coroutine is necessary because a coroutine
136# cannot destroy itself.
137my @destroy;
138my $manager; $manager = new Coro sub {
139 while () {
140 # by overwriting the state object with the manager we destroy it
141 # while still being able to schedule this coroutine (in case it has
142 # been readied multiple times. this is harmless since the manager
143 # can be called as many times as neccessary and will always
144 # remove itself from the runqueue
145 while (@destroy) {
146 my $coro = pop @destroy;
147 $coro->{status} ||= [];
148 $_->ready for @{delete $coro->{join} || []};
149
150 # the next line destroys the coro state, but keeps the
151 # process itself intact (we basically make it a zombie
152 # process that always runs the manager thread, so it's possible
153 # to transfer() to this process).
154 $coro->_clone_state_from ($manager);
155 }
156 &schedule;
157 }
158};
91 159
92# static methods. not really. 160# static methods. not really.
93 161
162=back
163
94=head2 STATIC METHODS 164=head2 STATIC METHODS
95 165
96Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
97 167
98=over 4 168=over 4
99 169
100=item async { ... }; 170=item async { ... } [@args...]
101 171
102Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
104terminated. 174terminated.
105 175
106=cut 176When the coroutine dies, the program will exit, just as in the main
177program.
107 178
179 # create a new coroutine that just prints its arguments
180 async {
181 print "@_\n";
182 } 1,2,3,4;
183
184=cut
185
108sub async(&) { 186sub async(&@) {
109 (new Coro $_[0])->ready; 187 my $pid = new Coro @_;
188 $pid->ready;
189 $pid
110} 190}
111 191
112=item schedule 192=item schedule
113 193
114Calls the scheduler. Please note that the current process will not be put 194Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 195into the ready queue, so calling this function usually means you will
116never be called again. 196never be called again.
117 197
118=cut 198=cut
119 199
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 200=item cede
128 201
129Yield to other processes. This function puts the current process into the 202"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 203ready queue and calls C<schedule>, which has the effect of giving up the
204current "timeslice" to other coroutines of the same or higher priority.
131 205
132=cut 206=cut
133 207
134sub yield {
135 $current->ready;
136 &schedule;
137}
138
139=item terminate 208=item terminate [arg...]
140 209
141Terminates the current process. 210Terminates the current process with the given status values (see L<cancel>).
142 211
143=cut 212=cut
144 213
145sub terminate { 214sub terminate {
146 &schedule; 215 $current->cancel (@_);
147} 216}
148 217
149=back 218=back
150 219
151# dynamic methods 220# dynamic methods
… …
154 223
155These are the methods you can call on process objects. 224These are the methods you can call on process objects.
156 225
157=over 4 226=over 4
158 227
159=item new Coro \&sub; 228=item new Coro \&sub [, @args...]
160 229
161Create a new process and return it. When the sub returns the process 230Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 231automatically terminates as if C<terminate> with the returned values were
232called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 233by calling the ready method.
164 234
165=cut 235=cut
236
237sub _new_coro {
238 terminate &{+shift};
239}
166 240
167sub new { 241sub new {
168 my $class = shift; 242 my $class = shift;
169 my $proc = $_[0]; 243
170 bless { 244 $class->SUPER::new (\&_new_coro, @_)
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
172 }, $class;
173} 245}
174 246
175=item $process->ready 247=item $process->ready
176 248
177Put the current process into the ready queue. 249Put the given process into the ready queue.
178 250
179=cut 251=cut
180 252
181sub ready { 253=item $process->cancel (arg...)
182 push @ready, $_[0]; 254
255Terminates the given process and makes it return the given arguments as
256status (default: the empty list).
257
258=cut
259
260sub cancel {
261 my $self = shift;
262 $self->{status} = [@_];
263 push @destroy, $self;
264 $manager->ready;
265 &schedule if $current == $self;
266}
267
268=item $process->join
269
270Wait until the coroutine terminates and return any values given to the
271C<terminate> or C<cancel> functions. C<join> can be called multiple times
272from multiple processes.
273
274=cut
275
276sub join {
277 my $self = shift;
278 unless ($self->{status}) {
279 push @{$self->{join}}, $current;
280 &schedule;
281 }
282 wantarray ? @{$self->{status}} : $self->{status}[0];
283}
284
285=item $oldprio = $process->prio ($newprio)
286
287Sets (or gets, if the argument is missing) the priority of the
288process. Higher priority processes get run before lower priority
289processes. Priorities are small signed integers (currently -4 .. +3),
290that you can refer to using PRIO_xxx constants (use the import tag :prio
291to get then):
292
293 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
294 3 > 1 > 0 > -1 > -3 > -4
295
296 # set priority to HIGH
297 current->prio(PRIO_HIGH);
298
299The idle coroutine ($Coro::idle) always has a lower priority than any
300existing coroutine.
301
302Changing the priority of the current process will take effect immediately,
303but changing the priority of processes in the ready queue (but not
304running) will only take effect after the next schedule (of that
305process). This is a bug that will be fixed in some future version.
306
307=item $newprio = $process->nice ($change)
308
309Similar to C<prio>, but subtract the given value from the priority (i.e.
310higher values mean lower priority, just as in unix).
311
312=item $olddesc = $process->desc ($newdesc)
313
314Sets (or gets in case the argument is missing) the description for this
315process. This is just a free-form string you can associate with a process.
316
317=cut
318
319sub desc {
320 my $old = $_[0]{desc};
321 $_[0]{desc} = $_[1] if @_ > 1;
322 $old;
183} 323}
184 324
185=back 325=back
186 326
187=cut 327=cut
188 328
1891; 3291;
190 330
331=head1 BUGS/LIMITATIONS
332
333 - you must make very sure that no coro is still active on global
334 destruction. very bad things might happen otherwise (usually segfaults).
335
336 - this module is not thread-safe. You should only ever use this module
337 from the same thread (this requirement might be losened in the future
338 to allow per-thread schedulers, but Coro::State does not yet allow
339 this).
340
341=head1 SEE ALSO
342
343Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
344
345Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
346
347Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
348
349Embedding: L<Coro:MakeMaker>
350
191=head1 AUTHOR 351=head1 AUTHOR
192 352
193 Marc Lehmann <pcg@goof.com> 353 Marc Lehmann <schmorp@schmorp.de>
194 http://www.goof.com/pcg/marc/ 354 http://home.schmorp.de/
195 355
196=cut 356=cut
197 357

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