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Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC vs.
Revision 1.57 by pcg, Sun Nov 30 22:49:25 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 = 0.04; 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}
81
82=over 4
63 83
64=item $main 84=item $main
65 85
66This coroutine represents the main program. 86This coroutine represents the main program.
67 87
68=cut 88=cut
69 89
70our $main = new Coro; 90$main = new Coro;
71 91
72=item $current 92=item $current (or as function: current)
73 93
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 95
76=cut 96=cut
77 97
78# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
79if ($current) { 99if ($current) {
80 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
81} 101}
82 102
83our $current = $main; 103$current = $main;
104
105sub current() { $current }
84 106
85=item $idle 107=item $idle
86 108
87The coroutine to switch to when no other coroutine is running. The default 109The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
89 111
90=cut 112=cut
91 113
92# should be done using priorities :( 114# should be done using priorities :(
93our $idle = new Coro sub { 115$idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 117 exit(51);
96}; 118};
97 119
98# we really need priorities... 120# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 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};
100 140
101# static methods. not really. 141# static methods. not really.
102 142
143=back
144
103=head2 STATIC METHODS 145=head2 STATIC METHODS
104 146
105Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
106 148
107=over 4 149=over 4
108 150
109=item async { ... }; 151=item async { ... } [@args...]
110 152
111Create a new asynchronous process and return it's process object 153Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 154(usually unused). When the sub returns the new process is automatically
113terminated. 155terminated.
114 156
115=cut 157 # create a new coroutine that just prints its arguments
158 async {
159 print "@_\n";
160 } 1,2,3,4;
116 161
162=cut
163
117sub async(&) { 164sub async(&@) {
118 my $pid = new Coro $_[0]; 165 my $pid = new Coro @_;
166 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 167 $pid->ready;
120 $pid; 168 $pid;
121} 169}
122 170
123=item schedule 171=item schedule
… …
126into the ready queue, so calling this function usually means you will 174into the ready queue, so calling this function usually means you will
127never be called again. 175never be called again.
128 176
129=cut 177=cut
130 178
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 179=item cede
140 180
141Yield to other processes. This function puts the current process into the 181"Cede" to other processes. This function puts the current process into the
142ready queue and calls C<schedule>. 182ready queue and calls C<schedule>, which has the effect of giving up the
183current "timeslice" to other coroutines of the same or higher priority.
143 184
144=cut 185=cut
145 186
146sub yield { 187=item terminate [arg...]
188
189Terminates the current process.
190
191Future versions of this function will allow result arguments.
192
193=cut
194
195sub terminate {
196 $current->{status} = [@_];
147 $current->ready; 197 $current->cancel;
148 &schedule; 198 &schedule;
149} 199 die; # NORETURN
150
151=item terminate
152
153Terminates the current process.
154
155=cut
156
157sub terminate {
158 &schedule;
159} 200}
160 201
161=back 202=back
162 203
163# dynamic methods 204# dynamic methods
… …
166 207
167These are the methods you can call on process objects. 208These are the methods you can call on process objects.
168 209
169=over 4 210=over 4
170 211
171=item new Coro \&sub; 212=item new Coro \&sub [, @args...]
172 213
173Create a new process and return it. When the sub returns the process 214Create a new process and return it. When the sub returns the process
174automatically terminates. To start the process you must first put it into 215automatically terminates as if C<terminate> with the returned values were
216called. To make the process run you must first put it into the ready queue
175the ready queue by calling the ready method. 217by calling the ready method.
176 218
177=cut 219=cut
220
221sub _newcoro {
222 terminate &{+shift};
223}
178 224
179sub new { 225sub new {
180 my $class = shift; 226 my $class = shift;
181 my $proc = $_[0];
182 bless { 227 bless {
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 228 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
184 }, $class; 229 }, $class;
185} 230}
186 231
187=item $process->ready 232=item $process->ready
188 233
189Put the current process into the ready queue. 234Put the given process into the ready queue.
190 235
191=cut 236=cut
192 237
193sub ready { 238=item $process->cancel
239
240Like C<terminate>, but terminates the specified process instead.
241
242=cut
243
244sub cancel {
194 push @ready, $_[0]; 245 push @destroy, $_[0];
246 $manager->ready;
247 &schedule if $current == $_[0];
248}
249
250=item $process->join
251
252Wait until the coroutine terminates and return any values given to the
253C<terminate> function. C<join> can be called multiple times from multiple
254processes.
255
256=cut
257
258sub join {
259 my $self = shift;
260 unless ($self->{status}) {
261 push @{$self->{join}}, $current;
262 &schedule;
263 }
264 wantarray ? @{$self->{status}} : $self->{status}[0];
265}
266
267=item $oldprio = $process->prio($newprio)
268
269Sets (or gets, if the argument is missing) the priority of the
270process. Higher priority processes get run before lower priority
271processes. Priorities are small signed integers (currently -4 .. +3),
272that you can refer to using PRIO_xxx constants (use the import tag :prio
273to get then):
274
275 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
276 3 > 1 > 0 > -1 > -3 > -4
277
278 # set priority to HIGH
279 current->prio(PRIO_HIGH);
280
281The idle coroutine ($Coro::idle) always has a lower priority than any
282existing coroutine.
283
284Changing the priority of the current process will take effect immediately,
285but changing the priority of processes in the ready queue (but not
286running) will only take effect after the next schedule (of that
287process). This is a bug that will be fixed in some future version.
288
289=cut
290
291sub prio {
292 my $old = $_[0]{prio};
293 $_[0]{prio} = $_[1] if @_ > 1;
294 $old;
295}
296
297=item $newprio = $process->nice($change)
298
299Similar to C<prio>, but subtract the given value from the priority (i.e.
300higher values mean lower priority, just as in unix).
301
302=cut
303
304sub nice {
305 $_[0]{prio} -= $_[1];
306}
307
308=item $olddesc = $process->desc($newdesc)
309
310Sets (or gets in case the argument is missing) the description for this
311process. This is just a free-form string you can associate with a process.
312
313=cut
314
315sub desc {
316 my $old = $_[0]{desc};
317 $_[0]{desc} = $_[1] if @_ > 1;
318 $old;
195} 319}
196 320
197=back 321=back
198 322
199=cut 323=cut
200 324
2011; 3251;
202 326
327=head1 BUGS/LIMITATIONS
328
329 - you must make very sure that no coro is still active on global
330 destruction. very bad things might happen otherwise (usually segfaults).
331
332 - this module is not thread-safe. You should only ever use this module
333 from the same thread (this requirement might be losened in the future
334 to allow per-thread schedulers, but Coro::State does not yet allow
335 this).
336
203=head1 SEE ALSO 337=head1 SEE ALSO
204 338
205L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 339L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
206L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 340L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
341L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
207 342
208=head1 AUTHOR 343=head1 AUTHOR
209 344
210 Marc Lehmann <pcg@goof.com> 345 Marc Lehmann <pcg@goof.com>
211 http://www.goof.com/pcg/marc/ 346 http://www.goof.com/pcg/marc/

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