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Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.21 by root, Sun Jul 22 03:24:10 2001 UTC

… …
18 18
19 yield; 19 yield;
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+ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's
30own set of lexicals and it's own set of perl's most important global
31variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38
23=cut 39=cut
24 40
25package Coro; 41package Coro;
26 42
27use Coro::State; 43use Coro::State;
28 44
29use base Exporter; 45use base Exporter;
30 46
31$VERSION = 0.03; 47$VERSION = 0.10;
32 48
33@EXPORT = qw(async yield schedule); 49@EXPORT = qw(async yield schedule terminate current);
34@EXPORT_OK = qw($current); 50@EXPORT_OK = qw($current);
35 51
36{ 52{
37 use subs 'async';
38
39 my @async; 53 my @async;
40 54
41 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 56 sub import {
43 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
… …
47 my @attrs; 61 my @attrs;
48 for (@_) { 62 for (@_) {
49 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
50 push @async, $ref; 64 push @async, $ref;
51 } else { 65 } else {
52 push @attrs, @_; 66 push @attrs, $_;
53 } 67 }
54 } 68 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 69 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 70 };
57 } 71 }
58 72
59 sub INIT { 73 sub INIT {
60 async pop @async while @async; 74 &async(pop @async) while @async;
61 } 75 }
62} 76}
63 77
64my $idle = new Coro sub {
65 &yield while 1;
66};
67
68=item $main 78=item $main
69 79
70This coroutine represents the main program. 80This coroutine represents the main program.
71 81
72=cut 82=cut
73 83
74$main = new Coro; 84our $main = new Coro;
75 85
76=item $current 86=item $current (or as function: current)
77 87
78The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 88The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79 89
80=cut 90=cut
81 91
82# maybe some other module used Coro::Specific before... 92# maybe some other module used Coro::Specific before...
83if ($current) { 93if ($current) {
84 $main->{specific} = $current->{specific}; 94 $main->{specific} = $current->{specific};
85} 95}
86 96
87$current = $main; 97our $current = $main;
98
99sub current() { $current }
100
101=item $idle
102
103The coroutine to switch to when no other coroutine is running. The default
104implementation prints "FATAL: deadlock detected" and exits.
105
106=cut
107
108# should be done using priorities :(
109our $idle = new Coro sub {
110 print STDERR "FATAL: deadlock detected\n";
111 exit(51);
112};
88 113
89# we really need priorities... 114# we really need priorities...
90my @ready = (); # the ready queue. hehe, rather broken ;) 115my @ready; # the ready queue. hehe, rather broken ;)
91 116
92# static methods. not really. 117# static methods. not really.
93 118
94=head2 STATIC METHODS 119=head2 STATIC METHODS
95 120
96Static methods are actually functions that operate on the current process only. 121Static methods are actually functions that operate on the current process only.
97 122
98=over 4 123=over 4
99 124
100=item async { ... }; 125=item async { ... } [@args...]
101 126
102Create a new asynchronous process and return it's process object 127Create a new asynchronous process and return it's process object
103(usually unused). When the sub returns the new process is automatically 128(usually unused). When the sub returns the new process is automatically
104terminated. 129terminated.
105 130
106=cut 131 # create a new coroutine that just prints its arguments
132 async {
133 print "@_\n";
134 } 1,2,3,4;
107 135
136The coderef you submit MUST NOT be a closure that refers to variables
137in an outer scope. This does NOT work. Pass arguments into it instead.
138
139=cut
140
108sub async(&) { 141sub async(&@) {
109 (new Coro $_[0])->ready; 142 my $pid = new Coro @_;
143 $pid->ready;
144 $pid;
110} 145}
111 146
112=item schedule 147=item schedule
113 148
114Calls the scheduler. Please note that the current process will not be put 149Calls the scheduler. Please note that the current process will not be put
… …
118=cut 153=cut
119 154
120my $prev; 155my $prev;
121 156
122sub schedule { 157sub schedule {
158 # should be done using priorities :(
123 ($prev, $current) = ($current, shift @ready); 159 ($prev, $current) = ($current, shift @ready || $idle);
124 Coro::State::transfer($prev, $current); 160 Coro::State::transfer($prev, $current);
125} 161}
126 162
127=item yield 163=item yield
128 164
… …
138 174
139=item terminate 175=item terminate
140 176
141Terminates the current process. 177Terminates the current process.
142 178
179Future versions of this function will allow result arguments.
180
143=cut 181=cut
144 182
145sub terminate { 183sub terminate {
184 $current->{_results} = [@_];
185 delete $current->{_coro_state};
146 &schedule; 186 &schedule;
147} 187}
148 188
149=back 189=back
150 190
… …
154 194
155These are the methods you can call on process objects. 195These are the methods you can call on process objects.
156 196
157=over 4 197=over 4
158 198
159=item new Coro \&sub; 199=item new Coro \&sub [, @args...]
160 200
161Create a new process and return it. When the sub returns the process 201Create a new process and return it. When the sub returns the process
162automatically terminates. To start the process you must first put it into 202automatically terminates. To start the process you must first put it into
163the ready queue by calling the ready method. 203the ready queue by calling the ready method.
164 204
205The coderef you submit MUST NOT be a closure that refers to variables
206in an outer scope. This does NOT work. Pass arguments into it instead.
207
165=cut 208=cut
209
210sub _newcoro {
211 terminate &{+shift};
212}
166 213
167sub new { 214sub new {
168 my $class = shift; 215 my $class = shift;
169 my $proc = $_[0];
170 bless { 216 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 217 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
172 }, $class; 218 }, $class;
173} 219}
174 220
175=item $process->ready 221=item $process->ready
176 222
… …
186 232
187=cut 233=cut
188 234
1891; 2351;
190 236
237=head1 BUGS/LIMITATIONS
238
239 - could be faster, especially when the core would introduce special
240 support for coroutines (like it does for threads).
241 - there is still a memleak on coroutine termination that I could not
242 identify. Could be as small as a single SV.
243 - this module is not well-tested.
244 - if variables or arguments "disappear" (become undef) or become
245 corrupted please contact the author so he cen iron out the
246 remaining bugs.
247 - this module is not thread-safe. You must only ever use this module from
248 the same thread (this requirement might be loosened in the future to
249 allow per-thread schedulers, but Coro::State does not yet allow this).
250
251=head1 SEE ALSO
252
253L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
254L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
255
191=head1 AUTHOR 256=head1 AUTHOR
192 257
193 Marc Lehmann <pcg@goof.com> 258 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/ 259 http://www.goof.com/pcg/marc/
195 260

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