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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 1.42 by root, Tue Nov 6 20:37:20 2001 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$VERSION = 0.52;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
64my $idle = new Coro sub {
65 &yield while 1;
66};
67 79
68=item $main 80=item $main
69 81
70This coroutine represents the main program. 82This coroutine represents the main program.
71 83
72=cut 84=cut
73 85
74$main = new Coro; 86our $main = new Coro;
75 87
76=item $current 88=item $current (or as function: current)
77 89
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 90The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 91
80=cut 92=cut
81 93
82# maybe some other module used Coro::Specific before... 94# maybe some other module used Coro::Specific before...
83if ($current) { 95if ($current) {
84 $main->{specific} = $current->{specific}; 96 $main->{specific} = $current->{specific};
85} 97}
86 98
87$current = $main; 99our $current = $main;
88 100
89# we really need priorities... 101sub current() { $current }
90my @ready = (); # the ready queue. hehe, rather broken ;) 102
103=item $idle
104
105The coroutine to switch to when no other coroutine is running. The default
106implementation prints "FATAL: deadlock detected" and exits.
107
108=cut
109
110# should be done using priorities :(
111our $idle = new Coro sub {
112 print STDERR "FATAL: deadlock detected\n";
113 exit(51);
114};
115
116# this coroutine is necessary because a coroutine
117# cannot destroy itself.
118my @destroy;
119my $manager;
120$manager = new Coro sub {
121 while() {
122 # by overwriting the state object with the manager we destroy it
123 # while still being able to schedule this coroutine (in case it has
124 # been readied multiple times. this is harmless since the manager
125 # can be called as many times as neccessary and will always
126 # remove itself from the runqueue
127 while (@destroy) {
128 my $coro = pop @destroy;
129 $coro->{status} ||= [];
130 $_->ready for @{delete $coro->{join} || []};
131 $coro->{_coro_state} = $manager->{_coro_state};
132 }
133 &schedule;
134 }
135};
91 136
92# static methods. not really. 137# static methods. not really.
93 138
94=head2 STATIC METHODS 139=head2 STATIC METHODS
95 140
96Static methods are actually functions that operate on the current process only. 141Static methods are actually functions that operate on the current process only.
97 142
98=over 4 143=over 4
99 144
100=item async { ... }; 145=item async { ... } [@args...]
101 146
102Create a new asynchronous process and return it's process object 147Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 148(usually unused). When the sub returns the new process is automatically
104terminated. 149terminated.
105 150
106=cut 151 # create a new coroutine that just prints its arguments
152 async {
153 print "@_\n";
154 } 1,2,3,4;
107 155
156The coderef you submit MUST NOT be a closure that refers to variables
157in an outer scope. This does NOT work. Pass arguments into it instead.
158
159=cut
160
108sub async(&) { 161sub async(&@) {
109 (new Coro $_[0])->ready; 162 my $pid = new Coro @_;
163 $manager->ready; # this ensures that the stack is cloned from the manager
164 $pid->ready;
165 $pid;
110} 166}
111 167
112=item schedule 168=item schedule
113 169
114Calls the scheduler. Please note that the current process will not be put 170Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 171into the ready queue, so calling this function usually means you will
116never be called again. 172never be called again.
117 173
118=cut 174=cut
119 175
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 176=item cede
128 177
129Yield to other processes. This function puts the current process into the 178"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 179ready queue and calls C<schedule>, which has the effect of giving up the
180current "timeslice" to other coroutines of the same or higher priority.
131 181
132=cut 182=cut
133 183
134sub yield { 184=item terminate [arg...]
185
186Terminates the current process.
187
188Future versions of this function will allow result arguments.
189
190=cut
191
192sub terminate {
193 $current->{status} = [@_];
135 $current->ready; 194 $current->cancel;
136 &schedule; 195 &schedule;
137} 196 die; # NORETURN
138
139=item terminate
140
141Terminates the current process.
142
143=cut
144
145sub terminate {
146 &schedule;
147} 197}
148 198
149=back 199=back
150 200
151# dynamic methods 201# dynamic methods
… …
154 204
155These are the methods you can call on process objects. 205These are the methods you can call on process objects.
156 206
157=over 4 207=over 4
158 208
159=item new Coro \&sub; 209=item new Coro \&sub [, @args...]
160 210
161Create a new process and return it. When the sub returns the process 211Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 212automatically terminates as if C<terminate> with the returned values were
213called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 214by calling the ready method.
164 215
165=cut 216=cut
217
218sub _newcoro {
219 terminate &{+shift};
220}
166 221
167sub new { 222sub new {
168 my $class = shift; 223 my $class = shift;
169 my $proc = $_[0];
170 bless { 224 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 225 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 226 }, $class;
173} 227}
174 228
175=item $process->ready 229=item $process->ready
176 230
177Put the current process into the ready queue. 231Put the given process into the ready queue.
178 232
179=cut 233=cut
180 234
181sub ready { 235=item $process->cancel
236
237Like C<terminate>, but terminates the specified process instead.
238
239=cut
240
241sub cancel {
182 push @ready, $_[0]; 242 push @destroy, $_[0];
243 $manager->ready;
244 &schedule if $current == $_[0];
245}
246
247=item $process->join
248
249Wait until the coroutine terminates and return any values given to the
250C<terminate> function. C<join> can be called multiple times from multiple
251processes.
252
253=cut
254
255sub join {
256 my $self = shift;
257 unless ($self->{status}) {
258 push @{$self->{join}}, $current;
259 &schedule;
260 }
261 wantarray ? @{$self->{status}} : $self->{status}[0];
262}
263
264=item $oldprio = $process->prio($newprio)
265
266Sets (or gets, if the argument is missing) the priority of the
267process. Higher priority processes get run before lower priority
268processes. Priorities are smalled signed integer (currently -4 .. +3),
269that you can refer to using PRIO_xxx constants (use the import tag :prio
270to get then):
271
272 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
273 3 > 1 > 0 > -1 > -3 > -4
274
275 # set priority to HIGH
276 current->prio(PRIO_HIGH);
277
278The idle coroutine ($Coro::idle) always has a lower priority than any
279existing coroutine.
280
281Changing the priority of the current process will take effect immediately,
282but changing the priority of processes in the ready queue (but not
283running) will only take effect after the next schedule (of that
284process). This is a bug that will be fixed in some future version.
285
286=cut
287
288sub prio {
289 my $old = $_[0]{prio};
290 $_[0]{prio} = $_[1] if @_ > 1;
291 $old;
292}
293
294=item $newprio = $process->nice($change)
295
296Similar to C<prio>, but subtract the given value from the priority (i.e.
297higher values mean lower priority, just as in unix).
298
299=cut
300
301sub nice {
302 $_[0]{prio} -= $_[1];
303}
304
305=item $olddesc = $process->desc($newdesc)
306
307Sets (or gets in case the argument is missing) the description for this
308process. This is just a free-form string you can associate with a process.
309
310=cut
311
312sub desc {
313 my $old = $_[0]{desc};
314 $_[0]{desc} = $_[1] if @_ > 1;
315 $old;
183} 316}
184 317
185=back 318=back
186 319
187=cut 320=cut
188 321
1891; 3221;
323
324=head1 BUGS/LIMITATIONS
325
326 - you must make very sure that no coro is still active on global destruction.
327 very bad things might happen otherwise (usually segfaults).
328 - this module is not thread-safe. You should only ever use this module from
329 the same thread (this requirement might be loosened in the future to
330 allow per-thread schedulers, but Coro::State does not yet allow this).
331
332=head1 SEE ALSO
333
334L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
335L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
336L<Coro::Handle>, L<Coro::Socket>.
190 337
191=head1 AUTHOR 338=head1 AUTHOR
192 339
193 Marc Lehmann <pcg@goof.com> 340 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 341 http://www.goof.com/pcg/marc/

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