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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 1.41 by root, Tue Nov 6 20:34:09 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
26This module is still experimental, see the BUGS section below.
27
28In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most
31important global variables.
32
23=cut 33=cut
24 34
25package Coro; 35package Coro;
26 36
37no warnings qw(uninitialized);
38
27use Coro::State; 39use Coro::State;
28 40
29use base Exporter; 41use base Exporter;
30 42
31$VERSION = 0.03; 43$VERSION = 0.52;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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
64my $idle = new Coro sub {
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
94=head2 STATIC METHODS 141=head2 STATIC METHODS
95 142
96Static methods are actually functions that operate on the current process only. 143Static methods are actually functions that operate on the current process only.
97 144
98=over 4 145=over 4
99 146
100=item async { ... }; 147=item async { ... } [@args...]
101 148
102Create a new asynchronous process and return it's process object 149Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 150(usually unused). When the sub returns the new process is automatically
104terminated. 151terminated.
105 152
106=cut 153 # create a new coroutine that just prints its arguments
154 async {
155 print "@_\n";
156 } 1,2,3,4;
107 157
158The coderef you submit MUST NOT be a closure that refers to variables
159in an outer scope. This does NOT work. Pass arguments into it instead.
160
161=cut
162
108sub async(&) { 163sub async(&@) {
109 (new Coro $_[0])->ready; 164 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
166 $pid->ready;
167 $pid;
110} 168}
111 169
112=item schedule 170=item schedule
113 171
114Calls the scheduler. Please note that the current process will not be put 172Calls the scheduler. Please note that the current process will not be put
115into the ready queue, so calling this function usually means you will 173into the ready queue, so calling this function usually means you will
116never be called again. 174never be called again.
117 175
118=cut 176=cut
119 177
120my $prev;
121
122sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125}
126
127=item yield 178=item cede
128 179
129Yield to other processes. This function puts the current process into the 180"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 181ready queue and calls C<schedule>, which has the effect of giving up the
182current "timeslice" to other coroutines of the same or higher priority.
131 183
132=cut 184=cut
133 185
134sub yield { 186=item terminate [arg...]
187
188Terminates the current process.
189
190Future versions of this function will allow result arguments.
191
192=cut
193
194sub terminate {
195 $current->{status} = [@_];
135 $current->ready; 196 $current->cancel;
136 &schedule; 197 &schedule;
137} 198 die; # NORETURN
138
139=item terminate
140
141Terminates the current process.
142
143=cut
144
145sub terminate {
146 &schedule;
147} 199}
148 200
149=back 201=back
150 202
151# dynamic methods 203# dynamic methods
… …
154 206
155These are the methods you can call on process objects. 207These are the methods you can call on process objects.
156 208
157=over 4 209=over 4
158 210
159=item new Coro \&sub; 211=item new Coro \&sub [, @args...]
160 212
161Create a new process and return it. When the sub returns the process 213Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 214automatically terminates as if C<terminate> with the returned values were
215called. To make the process run you must first put it into the ready queue
163the ready queue by calling the ready method. 216by calling the ready method.
164 217
165=cut 218=cut
219
220sub _newcoro {
221 terminate &{+shift};
222}
166 223
167sub new { 224sub new {
168 my $class = shift; 225 my $class = shift;
169 my $proc = $_[0];
170 bless { 226 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 227 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 228 }, $class;
173} 229}
174 230
175=item $process->ready 231=item $process->ready
176 232
177Put the current process into the ready queue. 233Put the given process into the ready queue.
178 234
179=cut 235=cut
180 236
181sub ready { 237=item $process->cancel
238
239Like C<terminate>, but terminates the specified process instead.
240
241=cut
242
243sub cancel {
182 push @ready, $_[0]; 244 push @destroy, $_[0];
245 $manager->ready;
246 &schedule if $current == $_[0];
247}
248
249=item $process->join
250
251Wait until the coroutine terminates and return any values given to the
252C<terminate> function. C<join> can be called multiple times from multiple
253processes.
254
255=cut
256
257sub join {
258 my $self = shift;
259 unless ($self->{status}) {
260 push @{$self->{join}}, $current;
261 &schedule;
262 }
263 wantarray ? @{$self->{status}} : $self->{status}[0];
264}
265
266=item $oldprio = $process->prio($newprio)
267
268Sets (or gets, if the argument is missing) the priority of the
269process. Higher priority processes get run before lower priority
270processes. Priorities are smalled signed integer (currently -4 .. +3),
271that you can refer to using PRIO_xxx constants (use the import tag :prio
272to get then):
273
274 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
275 3 > 1 > 0 > -1 > -3 > -4
276
277 # set priority to HIGH
278 current->prio(PRIO_HIGH);
279
280The idle coroutine ($Coro::idle) always has a lower priority than any
281existing coroutine.
282
283Changing the priority of the current process will take effect immediately,
284but changing the priority of processes in the ready queue (but not
285running) will only take effect after the next schedule (of that
286process). This is a bug that will be fixed in some future version.
287
288=cut
289
290sub prio {
291 my $old = $_[0]{prio};
292 $_[0]{prio} = $_[1] if @_ > 1;
293 $old;
294}
295
296=item $newprio = $process->nice($change)
297
298Similar to C<prio>, but subtract the given value from the priority (i.e.
299higher values mean lower priority, just as in unix).
300
301=cut
302
303sub nice {
304 $_[0]{prio} -= $_[1];
305}
306
307=item $olddesc = $process->desc($newdesc)
308
309Sets (or gets in case the argument is missing) the description for this
310process. This is just a free-form string you can associate with a process.
311
312=cut
313
314sub desc {
315 my $old = $_[0]{desc};
316 $_[0]{desc} = $_[1] if @_ > 1;
317 $old;
183} 318}
184 319
185=back 320=back
186 321
187=cut 322=cut
188 323
1891; 3241;
325
326=head1 BUGS/LIMITATIONS
327
328 - you must make very sure that no coro is still active on global destruction.
329 very bad things might happen otherwise (usually segfaults).
330 - this module is not thread-safe. You must only ever use this module from
331 the same thread (this requirement might be loosened in the future to
332 allow per-thread schedulers, but Coro::State does not yet allow this).
333
334=head1 SEE ALSO
335
336L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
337L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
338L<Coro::Handle>, L<Coro::Socket>.
190 339
191=head1 AUTHOR 340=head1 AUTHOR
192 341
193 Marc Lehmann <pcg@goof.com> 342 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 343 http://www.goof.com/pcg/marc/

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