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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 1.53 by root, Tue May 27 01:15:26 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35no warnings qw(uninitialized);
36
27use Coro::State; 37use Coro::State;
28 38
29use base Exporter; 39use base Exporter;
30 40
31$VERSION = 0.03; 41$VERSION = 0.7;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($current); 44%EXPORT_TAGS = (
45 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46);
47@EXPORT_OK = @{$EXPORT_TAGS{prio}};
35 48
36{ 49{
37 use subs 'async';
38
39 my @async; 50 my @async;
51 my $init;
40 52
41 # this way of handling attributes simply is NOT scalable ;() 53 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 54 sub import {
43 Coro->export_to_level(1, @_); 55 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
46 my ($package, $ref) = (shift, shift); 58 my ($package, $ref) = (shift, shift);
47 my @attrs; 59 my @attrs;
48 for (@_) { 60 for (@_) {
49 if ($_ eq "Coro") { 61 if ($_ eq "Coro") {
50 push @async, $ref; 62 push @async, $ref;
63 unless ($init++) {
64 eval q{
65 sub INIT {
66 &async(pop @async) while @async;
67 }
68 };
69 }
51 } else { 70 } else {
52 push @attrs, @_; 71 push @attrs, $_;
53 } 72 }
54 } 73 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 74 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 75 };
57 } 76 }
58 77
59 sub INIT {
60 async pop @async while @async;
61 }
62} 78}
63 79
64my $idle = new Coro sub { 80=over 4
65 &yield while 1;
66};
67 81
68=item $main 82=item $main
69 83
70This coroutine represents the main program. 84This coroutine represents the main program.
71 85
72=cut 86=cut
73 87
74$main = new Coro; 88our $main = new Coro;
75 89
76=item $current 90=item $current (or as function: current)
77 91
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 92The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 93
80=cut 94=cut
81 95
82# maybe some other module used Coro::Specific before... 96# maybe some other module used Coro::Specific before...
83if ($current) { 97if ($current) {
84 $main->{specific} = $current->{specific}; 98 $main->{specific} = $current->{specific};
85} 99}
86 100
87$current = $main; 101our $current = $main;
88 102
89# we really need priorities... 103sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 104
105=item $idle
106
107The coroutine to switch to when no other coroutine is running. The default
108implementation prints "FATAL: deadlock detected" and exits.
109
110=cut
111
112# should be done using priorities :(
113our $idle = new Coro sub {
114 print STDERR "FATAL: deadlock detected\n";
115 exit(51);
116};
117
118# this coroutine is necessary because a coroutine
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};
91 138
92# static methods. not really. 139# static methods. not really.
93 140
141=back
142
94=head2 STATIC METHODS 143=head2 STATIC METHODS
95 144
96Static methods are actually functions that operate on the current process only. 145Static methods are actually functions that operate on the current process only.
97 146
98=over 4 147=over 4
99 148
100=item async { ... }; 149=item async { ... } [@args...]
101 150
102Create a new asynchronous process and return it's process object 151Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 152(usually unused). When the sub returns the new process is automatically
104terminated. 153terminated.
105 154
106=cut 155 # create a new coroutine that just prints its arguments
156 async {
157 print "@_\n";
158 } 1,2,3,4;
107 159
160The coderef you submit MUST NOT be a closure that refers to variables
161in an outer scope. This does NOT work. Pass arguments into it instead.
162
163=cut
164
108sub async(&) { 165sub async(&@) {
109 (new Coro $_[0])->ready; 166 my $pid = new Coro @_;
167 $manager->ready; # this ensures that the stack is cloned from the manager
168 $pid->ready;
169 $pid;
110} 170}
111 171
112=item schedule 172=item schedule
113 173
114Calls the scheduler. Please note that the current process will not be put 174Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 175into the ready queue, so calling this function usually means you will
116never be called again. 176never be called again.
117 177
118=cut 178=cut
119 179
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 180=item cede
128 181
129Yield to other processes. This function puts the current process into the 182"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 183ready queue and calls C<schedule>, which has the effect of giving up the
184current "timeslice" to other coroutines of the same or higher priority.
131 185
132=cut 186=cut
133 187
134sub yield { 188=item terminate [arg...]
189
190Terminates the current process.
191
192Future versions of this function will allow result arguments.
193
194=cut
195
196sub terminate {
197 $current->{status} = [@_];
135 $current->ready; 198 $current->cancel;
136 &schedule; 199 &schedule;
137} 200 die; # NORETURN
138
139=item terminate
140
141Terminates the current process.
142
143=cut
144
145sub terminate {
146 &schedule;
147} 201}
148 202
149=back 203=back
150 204
151# dynamic methods 205# dynamic methods
… …
154 208
155These are the methods you can call on process objects. 209These are the methods you can call on process objects.
156 210
157=over 4 211=over 4
158 212
159=item new Coro \&sub; 213=item new Coro \&sub [, @args...]
160 214
161Create a new process and return it. When the sub returns the process 215Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 216automatically terminates as if C<terminate> with the returned values were
217called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 218by calling the ready method.
164 219
165=cut 220=cut
221
222sub _newcoro {
223 terminate &{+shift};
224}
166 225
167sub new { 226sub new {
168 my $class = shift; 227 my $class = shift;
169 my $proc = $_[0];
170 bless { 228 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 229 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 230 }, $class;
173} 231}
174 232
175=item $process->ready 233=item $process->ready
176 234
177Put the current process into the ready queue. 235Put the given process into the ready queue.
178 236
179=cut 237=cut
180 238
181sub ready { 239=item $process->cancel
240
241Like C<terminate>, but terminates the specified process instead.
242
243=cut
244
245sub cancel {
182 push @ready, $_[0]; 246 push @destroy, $_[0];
247 $manager->ready;
248 &schedule if $current == $_[0];
249}
250
251=item $process->join
252
253Wait until the coroutine terminates and return any values given to the
254C<terminate> function. C<join> can be called multiple times from multiple
255processes.
256
257=cut
258
259sub join {
260 my $self = shift;
261 unless ($self->{status}) {
262 push @{$self->{join}}, $current;
263 &schedule;
264 }
265 wantarray ? @{$self->{status}} : $self->{status}[0];
266}
267
268=item $oldprio = $process->prio($newprio)
269
270Sets (or gets, if the argument is missing) the priority of the
271process. Higher priority processes get run before lower priority
272processes. Priorities are small signed integers (currently -4 .. +3),
273that you can refer to using PRIO_xxx constants (use the import tag :prio
274to 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];
307}
308
309=item $olddesc = $process->desc($newdesc)
310
311Sets (or gets in case the argument is missing) the description for this
312process. This is just a free-form string you can associate with a process.
313
314=cut
315
316sub desc {
317 my $old = $_[0]{desc};
318 $_[0]{desc} = $_[1] if @_ > 1;
319 $old;
183} 320}
184 321
185=back 322=back
186 323
187=cut 324=cut
188 325
1891; 3261;
327
328=head1 BUGS/LIMITATIONS
329
330 - you must make very sure that no coro is still active on global
331 destruction. very bad things might happen otherwise (usually segfaults).
332
333 - this module is not thread-safe. You should only ever use this module
334 from the same thread (this requirement might be losened in the future
335 to allow per-thread schedulers, but Coro::State does not yet allow
336 this).
337
338=head1 SEE ALSO
339
340L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
341L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
342L<Coro::Handle>, L<Coro::Socket>.
190 343
191=head1 AUTHOR 344=head1 AUTHOR
192 345
193 Marc Lehmann <pcg@goof.com> 346 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 347 http://www.goof.com/pcg/marc/

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