ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.29 by root, Sat Aug 11 00:37:31 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most
31important global variables.
32
23=cut 33=cut
24 34
25package Coro; 35package Coro;
26 36
27use Coro::State; 37use Coro::State;
28 38
29use base Exporter; 39use base Exporter;
30 40
31$VERSION = 0.03; 41$VERSION = 0.45;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($current); 44@EXPORT_OK = qw($current);
35 45
36{ 46{
37 use subs 'async';
38
39 my @async; 47 my @async;
48 my $init;
40 49
41 # this way of handling attributes simply is NOT scalable ;() 50 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 51 sub import {
43 Coro->export_to_level(1, @_); 52 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 53 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
46 my ($package, $ref) = (shift, shift); 55 my ($package, $ref) = (shift, shift);
47 my @attrs; 56 my @attrs;
48 for (@_) { 57 for (@_) {
49 if ($_ eq "Coro") { 58 if ($_ eq "Coro") {
50 push @async, $ref; 59 push @async, $ref;
60 unless ($init++) {
61 eval q{
62 sub INIT {
63 &async(pop @async) while @async;
64 }
65 };
66 }
51 } else { 67 } else {
52 push @attrs, @_; 68 push @attrs, $_;
53 } 69 }
54 } 70 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 71 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 72 };
57 } 73 }
58 74
59 sub INIT {
60 async pop @async while @async;
61 }
62} 75}
63
64my $idle = new Coro sub {
65 &yield while 1;
66};
67 76
68=item $main 77=item $main
69 78
70This coroutine represents the main program. 79This coroutine represents the main program.
71 80
72=cut 81=cut
73 82
74$main = new Coro; 83our $main = new Coro;
75 84
76=item $current 85=item $current (or as function: current)
77 86
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 87The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 88
80=cut 89=cut
81 90
82# maybe some other module used Coro::Specific before... 91# maybe some other module used Coro::Specific before...
83if ($current) { 92if ($current) {
84 $main->{specific} = $current->{specific}; 93 $main->{specific} = $current->{specific};
85} 94}
86 95
87$current = $main; 96our $current = $main;
97
98sub current() { $current }
99
100=item $idle
101
102The coroutine to switch to when no other coroutine is running. The default
103implementation prints "FATAL: deadlock detected" and exits.
104
105=cut
106
107# should be done using priorities :(
108our $idle = new Coro sub {
109 print STDERR "FATAL: deadlock detected\n";
110 exit(51);
111};
112
113# this coroutine is necessary because a coroutine
114# cannot destroy itself.
115my @destroy;
116my $manager = new Coro sub {
117 while() {
118 delete ((pop @destroy)->{_coro_state}) while @destroy;
119 &schedule;
120 }
121};
88 122
89# we really need priorities... 123# we really need priorities...
90my @ready = (); # the ready queue. hehe, rather broken ;) 124my @ready; # the ready queue. hehe, rather broken ;)
91 125
92# static methods. not really. 126# static methods. not really.
93 127
94=head2 STATIC METHODS 128=head2 STATIC METHODS
95 129
96Static methods are actually functions that operate on the current process only. 130Static methods are actually functions that operate on the current process only.
97 131
98=over 4 132=over 4
99 133
100=item async { ... }; 134=item async { ... } [@args...]
101 135
102Create a new asynchronous process and return it's process object 136Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 137(usually unused). When the sub returns the new process is automatically
104terminated. 138terminated.
105 139
106=cut 140 # create a new coroutine that just prints its arguments
141 async {
142 print "@_\n";
143 } 1,2,3,4;
107 144
145The coderef you submit MUST NOT be a closure that refers to variables
146in an outer scope. This does NOT work. Pass arguments into it instead.
147
148=cut
149
108sub async(&) { 150sub async(&@) {
109 (new Coro $_[0])->ready; 151 my $pid = new Coro @_;
152 $manager->ready; # this ensures that the stack is cloned from the manager
153 $pid->ready;
154 $pid;
110} 155}
111 156
112=item schedule 157=item schedule
113 158
114Calls the scheduler. Please note that the current process will not be put 159Calls the scheduler. Please note that the current process will not be put
… …
118=cut 163=cut
119 164
120my $prev; 165my $prev;
121 166
122sub schedule { 167sub schedule {
168 # should be done using priorities :(
123 ($prev, $current) = ($current, shift @ready); 169 ($prev, $current) = ($current, shift @ready || $idle);
124 Coro::State::transfer($prev, $current); 170 Coro::State::transfer($prev, $current);
125} 171}
126 172
127=item yield 173=item cede
128 174
129Yield to other processes. This function puts the current process into the 175"Cede" to other processes. This function puts the current process into the
130ready queue and calls C<schedule>. 176ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority.
131 178
132=cut 179=cut
133 180
134sub yield { 181sub cede {
135 $current->ready; 182 $current->ready;
136 &schedule; 183 &schedule;
137} 184}
138 185
139=item terminate 186=item terminate
140 187
141Terminates the current process. 188Terminates the current process.
142 189
190Future versions of this function will allow result arguments.
191
143=cut 192=cut
144 193
145sub terminate { 194sub terminate {
195 $current->cancel;
146 &schedule; 196 &schedule;
197 die; # NORETURN
147} 198}
148 199
149=back 200=back
150 201
151# dynamic methods 202# dynamic methods
… …
154 205
155These are the methods you can call on process objects. 206These are the methods you can call on process objects.
156 207
157=over 4 208=over 4
158 209
159=item new Coro \&sub; 210=item new Coro \&sub [, @args...]
160 211
161Create a new process and return it. When the sub returns the process 212Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 213automatically terminates. To start the process you must first put it into
163the ready queue by calling the ready method. 214the ready queue by calling the ready method.
164 215
216The coderef you submit MUST NOT be a closure that refers to variables
217in an outer scope. This does NOT work. Pass arguments into it instead.
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
… …
180 237
181sub ready { 238sub ready {
182 push @ready, $_[0]; 239 push @ready, $_[0];
183} 240}
184 241
242=item $process->cancel
243
244Like C<terminate>, but terminates the specified process instead.
245
246=cut
247
248sub cancel {
249 push @destroy, $_[0];
250 $manager->ready;
251}
252
185=back 253=back
186 254
187=cut 255=cut
188 256
1891; 2571;
258
259=head1 BUGS/LIMITATIONS
260
261 - could be faster, especially when the core would introduce special
262 support for coroutines (like it does for threads).
263 - there is still a memleak on coroutine termination that I could not
264 identify. Could be as small as a single SV.
265 - this module is not well-tested.
266 - if variables or arguments "disappear" (become undef) or become
267 corrupted please contact the author so he cen iron out the
268 remaining bugs.
269 - this module is not thread-safe. You must only ever use this module from
270 the same thread (this requirement might be loosened in the future to
271 allow per-thread schedulers, but Coro::State does not yet allow this).
272
273=head1 SEE ALSO
274
275L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
276L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
277L<Coro::Handle>, L<Coro::Socket>.
190 278
191=head1 AUTHOR 279=head1 AUTHOR
192 280
193 Marc Lehmann <pcg@goof.com> 281 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 282 http://www.goof.com/pcg/marc/

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines