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Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 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$VERSION = 0.95;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
162=cut
163
108sub async(&) { 164sub async(&@) {
109 (new Coro $_[0])->ready; 165 my $pid = new Coro @_;
166 $manager->ready; # this ensures that the stack is cloned from the manager
167 $pid->ready;
168 $pid;
110} 169}
111 170
112=item schedule 171=item schedule
113 172
114Calls the scheduler. Please note that the current process will not be put 173Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 174into the ready queue, so calling this function usually means you will
116never be called again. 175never be called again.
117 176
118=cut 177=cut
119 178
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 179=item cede
128 180
129Yield to other processes. This function puts the current process into the 181"Cede" to other processes. This function puts the current process into the
130ready 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.
131 184
132=cut 185=cut
133 186
134sub 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} = [@_];
135 $current->ready; 197 $current->cancel;
136 &schedule; 198 &schedule;
137} 199 die; # NORETURN
138
139=item terminate
140
141Terminates the current process.
142
143=cut
144
145sub terminate {
146 &schedule;
147} 200}
148 201
149=back 202=back
150 203
151# dynamic methods 204# dynamic methods
… …
154 207
155These are the methods you can call on process objects. 208These are the methods you can call on process objects.
156 209
157=over 4 210=over 4
158 211
159=item new Coro \&sub; 212=item new Coro \&sub [, @args...]
160 213
161Create 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
162automatically 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
163the ready queue by calling the ready method. 217by calling the ready method.
164 218
165=cut 219=cut
220
221sub _newcoro {
222 terminate &{+shift};
223}
166 224
167sub new { 225sub new {
168 my $class = shift; 226 my $class = shift;
169 my $proc = $_[0];
170 bless { 227 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 228 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 229 }, $class;
173} 230}
174 231
175=item $process->ready 232=item $process->ready
176 233
177Put the current process into the ready queue. 234Put the given process into the ready queue.
178 235
179=cut 236=cut
180 237
181sub ready { 238=item $process->cancel
239
240Like C<terminate>, but terminates the specified process instead.
241
242=cut
243
244sub cancel {
182 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;
183} 319}
184 320
185=back 321=back
186 322
187=cut 323=cut
188 324
1891; 3251;
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
337=head1 SEE ALSO
338
339L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
340L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
341L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
190 342
191=head1 AUTHOR 343=head1 AUTHOR
192 344
193 Marc Lehmann <pcg@goof.com> 345 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 346 http://www.goof.com/pcg/marc/

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