ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.56 by pcg, Sat Nov 15 03:53:10 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 = 0.03; 43$VERSION = "0.9";
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}
63 81
64my $idle = new Coro sub { 82=over 4
65 &yield while 1;
66};
67 83
68=item $main 84=item $main
69 85
70This coroutine represents the main program. 86This coroutine represents the main program.
71 87
72=cut 88=cut
73 89
74$main = new Coro; 90$main = new Coro;
75 91
76=item $current 92=item $current (or as function: current)
77 93
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 95
80=cut 96=cut
81 97
… …
84 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
85} 101}
86 102
87$current = $main; 103$current = $main;
88 104
89# we really need priorities... 105sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 106
107=item $idle
108
109The coroutine to switch to when no other coroutine is running. The default
110implementation prints "FATAL: deadlock detected" and exits.
111
112=cut
113
114# should be done using priorities :(
115$idle = new Coro sub {
116 print STDERR "FATAL: deadlock detected\n";
117 exit(51);
118};
119
120# this coroutine is necessary because a coroutine
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};
91 140
92# static methods. not really. 141# static methods. not really.
93 142
143=back
144
94=head2 STATIC METHODS 145=head2 STATIC METHODS
95 146
96Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
97 148
98=over 4 149=over 4
99 150
100=item async { ... }; 151=item async { ... } [@args...]
101 152
102Create a new asynchronous process and return it's process object 153Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 154(usually unused). When the sub returns the new process is automatically
104terminated. 155terminated.
105 156
106=cut 157 # create a new coroutine that just prints its arguments
158 async {
159 print "@_\n";
160 } 1,2,3,4;
107 161
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
108sub async(&) { 167sub async(&@) {
109 (new Coro $_[0])->ready; 168 my $pid = new Coro @_;
169 $manager->ready; # this ensures that the stack is cloned from the manager
170 $pid->ready;
171 $pid;
110} 172}
111 173
112=item schedule 174=item schedule
113 175
114Calls the scheduler. Please note that the current process will not be put 176Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 177into the ready queue, so calling this function usually means you will
116never be called again. 178never be called again.
117 179
118=cut 180=cut
119 181
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 182=item cede
128 183
129Yield to other processes. This function puts the current process into the 184"Cede" to other processes. This function puts the current process into the
130ready 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.
131 187
132=cut 188=cut
133 189
134sub 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} = [@_];
135 $current->ready; 200 $current->cancel;
136 &schedule; 201 &schedule;
137} 202 die; # NORETURN
138
139=item terminate
140
141Terminates the current process.
142
143=cut
144
145sub terminate {
146 &schedule;
147} 203}
148 204
149=back 205=back
150 206
151# dynamic methods 207# dynamic methods
… …
154 210
155These are the methods you can call on process objects. 211These are the methods you can call on process objects.
156 212
157=over 4 213=over 4
158 214
159=item new Coro \&sub; 215=item new Coro \&sub [, @args...]
160 216
161Create 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
162automatically 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
163the ready queue by calling the ready method. 220by calling the ready method.
164 221
165=cut 222=cut
223
224sub _newcoro {
225 terminate &{+shift};
226}
166 227
167sub new { 228sub new {
168 my $class = shift; 229 my $class = shift;
169 my $proc = $_[0];
170 bless { 230 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 231 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 232 }, $class;
173} 233}
174 234
175=item $process->ready 235=item $process->ready
176 236
177Put the current process into the ready queue. 237Put the given process into the ready queue.
178 238
179=cut 239=cut
180 240
181sub ready { 241=item $process->cancel
242
243Like C<terminate>, but terminates the specified process instead.
244
245=cut
246
247sub cancel {
182 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;
183} 322}
184 323
185=back 324=back
186 325
187=cut 326=cut
188 327
1891; 3281;
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
340=head1 SEE ALSO
341
342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
190 345
191=head1 AUTHOR 346=head1 AUTHOR
192 347
193 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 349 http://www.goof.com/pcg/marc/

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines