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Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.19 by root, Sat Jul 21 03:44:06 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 23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel. 24threads but don't run in parallel.
25 25
26This module is still experimental, see the BUGS section below. 26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
32use Coro::State; 37use Coro::State;
33 38
39use vars qw($idle $main $current);
40
34use base Exporter; 41use base Exporter;
35 42
36$VERSION = 0.09; 43$VERSION = "0.9";
37 44
38@EXPORT = qw(async yield schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($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}};
40 50
41{ 51{
42 use subs 'async';
43
44 my @async; 52 my @async;
53 my $init;
45 54
46 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 56 sub import {
48 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
51 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
52 my @attrs; 61 my @attrs;
53 for (@_) { 62 for (@_) {
54 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
55 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 }
56 } else { 72 } else {
57 push @attrs, $_; 73 push @attrs, $_;
58 } 74 }
59 } 75 }
60 return $old ? $old->($package, $ref, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 77 };
62 } 78 }
63 79
64 sub INIT {
65 async pop @async while @async;
66 }
67} 80}
81
82=over 4
68 83
69=item $main 84=item $main
70 85
71This coroutine represents the main program. 86This coroutine represents the main program.
72 87
73=cut 88=cut
74 89
75our $main = new Coro; 90$main = new Coro;
76 91
77=item $current (or as function: current) 92=item $current (or as function: current)
78 93
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
80 95
83# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
84if ($current) { 99if ($current) {
85 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
86} 101}
87 102
88our $current = $main; 103$current = $main;
89 104
90sub current() { $current } 105sub current() { $current }
91 106
92=item $idle 107=item $idle
93 108
95implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
96 111
97=cut 112=cut
98 113
99# should be done using priorities :( 114# should be done using priorities :(
100our $idle = new Coro sub { 115$idle = new Coro sub {
101 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
102 exit(51); 117 exit(51);
103}; 118};
104 119
105# we really need priorities... 120# this coroutine is necessary because a coroutine
106my @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};
107 140
108# static methods. not really. 141# static methods. not really.
142
143=back
109 144
110=head2 STATIC METHODS 145=head2 STATIC METHODS
111 146
112Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
113 148
122 # create a new coroutine that just prints its arguments 157 # create a new coroutine that just prints its arguments
123 async { 158 async {
124 print "@_\n"; 159 print "@_\n";
125 } 1,2,3,4; 160 } 1,2,3,4;
126 161
127The coderef you submit MUST NOT be a closure that refers to variables
128in an outer scope. This does NOT work. Pass arguments into it instead.
129
130=cut 162=cut
131 163
132sub async(&@) { 164sub async(&@) {
133 my $pid = new Coro @_; 165 my $pid = new Coro @_;
166 $manager->ready; # this ensures that the stack is cloned from the manager
134 $pid->ready; 167 $pid->ready;
135 $pid; 168 $pid;
136} 169}
137 170
138=item schedule 171=item schedule
141into the ready queue, so calling this function usually means you will 174into the ready queue, so calling this function usually means you will
142never be called again. 175never be called again.
143 176
144=cut 177=cut
145 178
146my $prev;
147
148sub schedule {
149 # should be done using priorities :(
150 ($prev, $current) = ($current, shift @ready || $idle);
151 Coro::State::transfer($prev, $current);
152}
153
154=item yield 179=item cede
155 180
156Yield to other processes. This function puts the current process into the 181"Cede" to other processes. This function puts the current process into the
157ready 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.
158 184
159=cut 185=cut
160 186
161sub 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} = [@_];
162 $current->ready; 197 $current->cancel;
163 &schedule; 198 &schedule;
164} 199 die; # NORETURN
165
166=item terminate
167
168Terminates the current process.
169
170Future versions of this function will allow result arguments.
171
172=cut
173
174sub terminate {
175 $current->{_results} = [@_];
176 &schedule;
177} 200}
178 201
179=back 202=back
180 203
181# dynamic methods 204# dynamic methods
187=over 4 210=over 4
188 211
189=item new Coro \&sub [, @args...] 212=item new Coro \&sub [, @args...]
190 213
191Create 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
192automatically 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
193the ready queue by calling the ready method. 217by calling the ready method.
194
195The coderef you submit MUST NOT be a closure that refers to variables
196in an outer scope. This does NOT work. Pass arguments into it instead.
197 218
198=cut 219=cut
199 220
200sub _newcoro { 221sub _newcoro {
201 terminate &{+shift}; 222 terminate &{+shift};
208 }, $class; 229 }, $class;
209} 230}
210 231
211=item $process->ready 232=item $process->ready
212 233
213Put the current process into the ready queue. 234Put the given process into the ready queue.
214 235
215=cut 236=cut
216 237
217sub ready { 238=item $process->cancel
239
240Like C<terminate>, but terminates the specified process instead.
241
242=cut
243
244sub cancel {
218 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;
219} 319}
220 320
221=back 321=back
222 322
223=cut 323=cut
224 324
2251; 3251;
226 326
227=head1 BUGS/LIMITATIONS 327=head1 BUGS/LIMITATIONS
228 328
229 - could be faster, especially when the core would introduce special 329 - you must make very sure that no coro is still active on global
230 support for coroutines (like it does for threads). 330 destruction. very bad things might happen otherwise (usually segfaults).
231 - there is still a memleak on coroutine termination that I could not 331
232 identify. Could be as small as a single SV.
233 - this module is not well-tested.
234 - if variables or arguments "disappear" (become undef) or become
235 corrupted please contact the author so he cen iron out the
236 remaining bugs.
237 - this module is not thread-safe. You must only ever use this module from 332 - this module is not thread-safe. You should only ever use this module
238 the same thread (this requirement might be loosened in the future to 333 from the same thread (this requirement might be losened in the future
239 allow per-thread schedulers, but Coro::Satte does not yet allow this). 334 to allow per-thread schedulers, but Coro::State does not yet allow
335 this).
240 336
241=head1 SEE ALSO 337=head1 SEE ALSO
242 338
243L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 339L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
244L<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>.
245 342
246=head1 AUTHOR 343=head1 AUTHOR
247 344
248 Marc Lehmann <pcg@goof.com> 345 Marc Lehmann <pcg@goof.com>
249 http://www.goof.com/pcg/marc/ 346 http://www.goof.com/pcg/marc/

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