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Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.30 by root, Sat Aug 11 19:59:19 2001 UTC vs.
Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 UTC

19 cede; 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
26This module is still experimental, see the BUGS section below.
27 25
28In this module, coroutines are defined as "callchain + lexical variables 26In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own 27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most 28callchain, it's own set of lexicals and it's own set of perl's most
31important global variables. 29important global variables.
32 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
37use Coro::State; 37use Coro::State;
38 38
39use vars qw($idle $main $current);
40
39use base Exporter; 41use base Exporter;
40 42
41$VERSION = 0.45; 43$VERSION = 0.95;
42 44
43@EXPORT = qw(async cede schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
44@EXPORT_OK = qw($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}};
45 50
46{ 51{
47 my @async; 52 my @async;
48 my $init; 53 my $init;
49 54
72 }; 77 };
73 } 78 }
74 79
75} 80}
76 81
82=over 4
83
77=item $main 84=item $main
78 85
79This coroutine represents the main program. 86This coroutine represents the main program.
80 87
81=cut 88=cut
82 89
83our $main = new Coro; 90$main = new Coro;
84 91
85=item $current (or as function: current) 92=item $current (or as function: current)
86 93
87The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
88 95
91# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
92if ($current) { 99if ($current) {
93 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
94} 101}
95 102
96our $current = $main; 103$current = $main;
97 104
98sub current() { $current } 105sub current() { $current }
99 106
100=item $idle 107=item $idle
101 108
103implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
104 111
105=cut 112=cut
106 113
107# should be done using priorities :( 114# should be done using priorities :(
108our $idle = new Coro sub { 115$idle = new Coro sub {
109 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
110 exit(51); 117 exit(51);
111}; 118};
112 119
113# this coroutine is necessary because a coroutine 120# this coroutine is necessary because a coroutine
114# cannot destroy itself. 121# cannot destroy itself.
115my @destroy; 122my @destroy;
123my $manager;
116my $manager = new Coro sub { 124$manager = new Coro sub {
117 while() { 125 while () {
118 delete ((pop @destroy)->{_coro_state}) while @destroy; 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 }
119 &schedule; 137 &schedule;
120 } 138 }
121}; 139};
122 140
123# static methods. not really. 141# static methods. not really.
142
143=back
124 144
125=head2 STATIC METHODS 145=head2 STATIC METHODS
126 146
127Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
128 148
136 156
137 # create a new coroutine that just prints its arguments 157 # create a new coroutine that just prints its arguments
138 async { 158 async {
139 print "@_\n"; 159 print "@_\n";
140 } 1,2,3,4; 160 } 1,2,3,4;
141
142The coderef you submit MUST NOT be a closure that refers to variables
143in an outer scope. This does NOT work. Pass arguments into it instead.
144 161
145=cut 162=cut
146 163
147sub async(&@) { 164sub async(&@) {
148 my $pid = new Coro @_; 165 my $pid = new Coro @_;
165ready queue and calls C<schedule>, which has the effect of giving up the 182ready queue and calls C<schedule>, which has the effect of giving up the
166current "timeslice" to other coroutines of the same or higher priority. 183current "timeslice" to other coroutines of the same or higher priority.
167 184
168=cut 185=cut
169 186
170=item terminate 187=item terminate [arg...]
171 188
172Terminates the current process. 189Terminates the current process.
173 190
174Future versions of this function will allow result arguments. 191Future versions of this function will allow result arguments.
175 192
176=cut 193=cut
177 194
178sub terminate { 195sub terminate {
196 $current->{status} = [@_];
179 $current->cancel; 197 $current->cancel;
180 &schedule; 198 &schedule;
181 die; # NORETURN 199 die; # NORETURN
182} 200}
183 201
192=over 4 210=over 4
193 211
194=item new Coro \&sub [, @args...] 212=item new Coro \&sub [, @args...]
195 213
196Create 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
197automatically 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
198the ready queue by calling the ready method. 217by calling the ready method.
199
200The coderef you submit MUST NOT be a closure that refers to variables
201in an outer scope. This does NOT work. Pass arguments into it instead.
202 218
203=cut 219=cut
204 220
205sub _newcoro { 221sub _newcoro {
206 terminate &{+shift}; 222 terminate &{+shift};
213 }, $class; 229 }, $class;
214} 230}
215 231
216=item $process->ready 232=item $process->ready
217 233
218Put the current process into the ready queue. 234Put the given process into the ready queue.
219 235
220=cut 236=cut
221 237
222=item $process->cancel 238=item $process->cancel
223 239
226=cut 242=cut
227 243
228sub cancel { 244sub cancel {
229 push @destroy, $_[0]; 245 push @destroy, $_[0];
230 $manager->ready; 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;
231} 319}
232 320
233=back 321=back
234 322
235=cut 323=cut
236 324
2371; 3251;
238 326
239=head1 BUGS/LIMITATIONS 327=head1 BUGS/LIMITATIONS
240 328
241 - could be faster, especially when the core would introduce special 329 - you must make very sure that no coro is still active on global
242 support for coroutines (like it does for threads). 330 destruction. very bad things might happen otherwise (usually segfaults).
243 - there is still a memleak on coroutine termination that I could not 331
244 identify. Could be as small as a single SV.
245 - this module is not well-tested.
246 - if variables or arguments "disappear" (become undef) or become
247 corrupted please contact the author so he cen iron out the
248 remaining bugs.
249 - 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
250 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
251 allow per-thread schedulers, but Coro::State does not yet allow this). 334 to allow per-thread schedulers, but Coro::State does not yet allow
335 this).
252 336
253=head1 SEE ALSO 337=head1 SEE ALSO
254 338
255L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 339L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
256L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, 340L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
257L<Coro::Handle>, L<Coro::Socket>. 341L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
258 342
259=head1 AUTHOR 343=head1 AUTHOR
260 344
261 Marc Lehmann <pcg@goof.com> 345 Marc Lehmann <pcg@goof.com>
262 http://www.goof.com/pcg/marc/ 346 http://www.goof.com/pcg/marc/

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