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

Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC vs.
Revision 1.40 by root, Sun Oct 28 17:00:05 2001 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
26This module is still experimental, see the BUGS section below.
27
28In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most
31important global variables.
32
23=cut 33=cut
24 34
25package Coro; 35package Coro;
26 36
37no warnings qw(uninitialized);
38
27use Coro::State; 39use Coro::State;
28 40
29use base Exporter; 41use base Exporter;
30 42
31$VERSION = 0.04; 43$VERSION = 0.51;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
64=item $main 82=item $main
65 83
66This coroutine represents the main program. 84This coroutine represents the main program.
67 85
68=cut 86=cut
69 87
70our $main = new Coro; 88our $main = new Coro;
71 89
72=item $current 90=item $current (or as function: current)
73 91
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 92The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 93
76=cut 94=cut
77 95
… …
79if ($current) { 97if ($current) {
80 $main->{specific} = $current->{specific}; 98 $main->{specific} = $current->{specific};
81} 99}
82 100
83our $current = $main; 101our $current = $main;
102
103sub current() { $current }
84 104
85=item $idle 105=item $idle
86 106
87The coroutine to switch to when no other coroutine is running. The default 107The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 108implementation prints "FATAL: deadlock detected" and exits.
… …
93our $idle = new Coro sub { 113our $idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 114 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 115 exit(51);
96}; 116};
97 117
98# we really need priorities... 118# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 119# cannot destroy itself.
120my @destroy;
121my $manager;
122$manager = new Coro sub {
123 while() {
124 # by overwriting the state object with the manager we destroy it
125 # while still being able to schedule this coroutine (in case it has
126 # been readied multiple times. this is harmless since the manager
127 # can be called as many times as neccessary and will always
128 # remove itself from the runqueue
129 while (@destroy) {
130 my $coro = pop @destroy;
131 $coro->{status} ||= [];
132 $_->ready for @{delete $coro->{join} || []};
133 $coro->{_coro_state} = $manager->{_coro_state};
134 }
135 &schedule;
136 }
137};
100 138
101# static methods. not really. 139# static methods. not really.
102 140
103=head2 STATIC METHODS 141=head2 STATIC METHODS
104 142
105Static methods are actually functions that operate on the current process only. 143Static methods are actually functions that operate on the current process only.
106 144
107=over 4 145=over 4
108 146
109=item async { ... }; 147=item async { ... } [@args...]
110 148
111Create a new asynchronous process and return it's process object 149Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 150(usually unused). When the sub returns the new process is automatically
113terminated. 151terminated.
114 152
115=cut 153 # create a new coroutine that just prints its arguments
154 async {
155 print "@_\n";
156 } 1,2,3,4;
116 157
158The coderef you submit MUST NOT be a closure that refers to variables
159in an outer scope. This does NOT work. Pass arguments into it instead.
160
161=cut
162
117sub async(&) { 163sub async(&@) {
118 my $pid = new Coro $_[0]; 164 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 166 $pid->ready;
120 $pid; 167 $pid;
121} 168}
122 169
123=item schedule 170=item schedule
… …
126into the ready queue, so calling this function usually means you will 173into the ready queue, so calling this function usually means you will
127never be called again. 174never be called again.
128 175
129=cut 176=cut
130 177
131my $prev;
132
133sub schedule {
134 # should be done using priorities :(
135 ($prev, $current) = ($current, shift @ready || $idle);
136 Coro::State::transfer($prev, $current);
137}
138
139=item yield 178=item cede
140 179
141Yield to other processes. This function puts the current process into the 180"Cede" to other processes. This function puts the current process into the
142ready queue and calls C<schedule>. 181ready queue and calls C<schedule>, which has the effect of giving up the
182current "timeslice" to other coroutines of the same or higher priority.
143 183
144=cut 184=cut
145 185
146sub yield { 186=item terminate [arg...]
187
188Terminates the current process.
189
190Future versions of this function will allow result arguments.
191
192=cut
193
194sub terminate {
195 $current->{status} = [@_];
147 $current->ready; 196 $current->cancel;
148 &schedule; 197 &schedule;
149} 198 die; # NORETURN
150
151=item terminate
152
153Terminates the current process.
154
155=cut
156
157sub terminate {
158 &schedule;
159} 199}
160 200
161=back 201=back
162 202
163# dynamic methods 203# dynamic methods
… …
166 206
167These are the methods you can call on process objects. 207These are the methods you can call on process objects.
168 208
169=over 4 209=over 4
170 210
171=item new Coro \&sub; 211=item new Coro \&sub [, @args...]
172 212
173Create a new process and return it. When the sub returns the process 213Create a new process and return it. When the sub returns the process
174automatically terminates. To start the process you must first put it into 214automatically terminates as if C<terminate> with the returned values were
175the ready queue by calling the ready method. 215called. To start the process you must first put it into the ready queue by
216calling the ready method.
176 217
218The coderef you submit MUST NOT be a closure that refers to variables
219in an outer scope. This does NOT work. Pass arguments into it instead.
220
177=cut 221=cut
222
223sub _newcoro {
224 terminate &{+shift};
225}
178 226
179sub new { 227sub new {
180 my $class = shift; 228 my $class = shift;
181 my $proc = $_[0];
182 bless { 229 bless {
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 230 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
184 }, $class; 231 }, $class;
185} 232}
186 233
187=item $process->ready 234=item $process->ready
188 235
189Put the current process into the ready queue. 236Put the given process into the ready queue.
190 237
191=cut 238=cut
192 239
193sub ready { 240=item $process->cancel
241
242Like C<terminate>, but terminates the specified process instead.
243
244=cut
245
246sub cancel {
194 push @ready, $_[0]; 247 push @destroy, $_[0];
248 $manager->ready;
249 &schedule if $current == $_[0];
250}
251
252=item $process->join
253
254Wait until the coroutine terminates and return any values given to the
255C<terminate> function. C<join> can be called multiple times from multiple
256processes.
257
258=cut
259
260sub join {
261 my $self = shift;
262 unless ($self->{status}) {
263 push @{$self->{join}}, $current;
264 &schedule;
265 }
266 wantarray ? @{$self->{status}} : $self->{status}[0];
267}
268
269=item $oldprio = $process->prio($newprio)
270
271Sets the priority of the process. Higher priority processes get run before
272lower priority processes. Priorities are smalled signed integer (currently
273-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
274tag :prio to get then):
275
276 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
277 3 > 1 > 0 > -1 > -3 > -4
278
279 # set priority to HIGH
280 current->prio(PRIO_HIGH);
281
282The idle coroutine ($Coro::idle) always has a lower priority than any
283existing coroutine.
284
285Changing the priority of the current process will take effect immediately,
286but changing the priority of processes in the ready queue (but not
287running) will only take effect after the next schedule (of that
288process). This is a bug that will be fixed in some future version.
289
290=cut
291
292sub prio {
293 my $old = $_[0]{prio};
294 $_[0]{prio} = $_[1] if @_ > 1;
295 $old;
296}
297
298=item $newprio = $process->nice($change)
299
300Similar to C<prio>, but subtract the given value from the priority (i.e.
301higher values mean lower priority, just as in unix).
302
303=cut
304
305sub nice {
306 $_[0]{prio} -= $_[1];
195} 307}
196 308
197=back 309=back
198 310
199=cut 311=cut
200 312
2011; 3131;
202 314
315=head1 BUGS/LIMITATIONS
316
317 - you must make very sure that no coro is still active on global destruction.
318 very bad things might happen otherwise (usually segfaults).
319 - this module is not thread-safe. You must only ever use this module from
320 the same thread (this requirement might be loosened in the future to
321 allow per-thread schedulers, but Coro::State does not yet allow this).
322
203=head1 SEE ALSO 323=head1 SEE ALSO
204 324
205L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 325L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
206L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 326L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
327L<Coro::Handle>, L<Coro::Socket>.
207 328
208=head1 AUTHOR 329=head1 AUTHOR
209 330
210 Marc Lehmann <pcg@goof.com> 331 Marc Lehmann <pcg@goof.com>
211 http://www.goof.com/pcg/marc/ 332 http://www.goof.com/pcg/marc/

Diff Legend

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