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Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC vs.
Revision 1.98 by root, Mon Dec 4 21:56:00 2006 UTC

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18 18
19 cede; 19 cede;
20 20
21=head1 DESCRIPTION 21=head1 DESCRIPTION
22 22
23This module collection manages coroutines. Coroutines are similar to 23This module collection manages coroutines. Coroutines are similar
24threads but don't run in parallel. 24to threads but don't run in parallel at the same time even on SMP
25machines. The specific flavor of coroutine use din this module also
26guarentees you that it will not switch between coroutines unless
27necessary, at easily-identified points in your program, so locking and
28parallel access are rarely an issue, making coroutine programming much
29safer than threads programming.
25 30
31(Perl, however, does not natively support real threads but instead does a
32very slow and memory-intensive emulation of processes using threads. This
33is a performance win on Windows machines, and a loss everywhere else).
34
26In this module, coroutines are defined as "callchain + lexical variables 35In this module, coroutines are defined as "callchain + lexical variables +
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own 36@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
28callchain, it's own set of lexicals and it's own set of perl's most 37its own set of lexicals and its own set of perls most important global
29important global variables. 38variables.
30 39
31=cut 40=cut
32 41
33package Coro; 42package Coro;
34 43
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41 50
42our $idle; # idle handler 51our $idle; # idle handler
43our $main; # main coroutine 52our $main; # main coroutine
44our $current; # current coroutine 53our $current; # current coroutine
45 54
46our $VERSION = '3.0'; 55our $VERSION = '3.1';
47 56
48our @EXPORT = qw(async cede schedule terminate current unblock_sub); 57our @EXPORT = qw(async cede schedule terminate current unblock_sub);
49our %EXPORT_TAGS = ( 58our %EXPORT_TAGS = (
50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
51); 60);
52our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; 61our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
53 62
54{ 63{
55 my @async; 64 my @async;
56 my $init; 65 my $init;
57 66
58 # this way of handling attributes simply is NOT scalable ;() 67 # this way of handling attributes simply is NOT scalable ;()
59 sub import { 68 sub import {
60 no strict 'refs'; 69 no strict 'refs';
61 70
62 Coro->export_to_level(1, @_); 71 Coro->export_to_level (1, @_);
63 72
64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 73 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 74 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
66 my ($package, $ref) = (shift, shift); 75 my ($package, $ref) = (shift, shift);
67 my @attrs; 76 my @attrs;
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105C<Coro::current> function instead. 114C<Coro::current> function instead.
106 115
107=cut 116=cut
108 117
109# maybe some other module used Coro::Specific before... 118# maybe some other module used Coro::Specific before...
110if ($current) {
111 $main->{specific} = $current->{specific}; 119$main->{specific} = $current->{specific}
112} 120 if $current;
113 121
114$current = $main; 122_set_current $main;
115 123
116sub current() { $current } 124sub current() { $current }
117 125
118=item $idle 126=item $idle
119 127
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129handlers), then it must be prepared to be called recursively. 137handlers), then it must be prepared to be called recursively.
130 138
131=cut 139=cut
132 140
133$idle = sub { 141$idle = sub {
134 print STDERR "FATAL: deadlock detected\n"; 142 require Carp;
135 exit (51); 143 Carp::croak ("FATAL: deadlock detected");
136}; 144};
137 145
138# this coroutine is necessary because a coroutine 146# this coroutine is necessary because a coroutine
139# cannot destroy itself. 147# cannot destroy itself.
140my @destroy; 148my @destroy;
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255 263
256Calling C<exit> in a coroutine will not work correctly, so do not do that. 264Calling C<exit> in a coroutine will not work correctly, so do not do that.
257 265
258=cut 266=cut
259 267
260sub _new_coro { 268sub _run_coro {
261 terminate &{+shift}; 269 terminate &{+shift};
262} 270}
263 271
264sub new { 272sub new {
265 my $class = shift; 273 my $class = shift;
266 274
267 $class->SUPER::new (\&_new_coro, @_) 275 $class->SUPER::new (\&_run_coro, @_)
268} 276}
269 277
270=item $success = $coroutine->ready 278=item $success = $coroutine->ready
271 279
272Put the given coroutine into the ready queue (according to it's priority) 280Put the given coroutine into the ready queue (according to it's priority)
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349 $old; 357 $old;
350} 358}
351 359
352=back 360=back
353 361
354=head2 UTILITY FUNCTIONS 362=head2 GLOBAL FUNCTIONS
355 363
356=over 4 364=over 4
365
366=item Coro::nready
367
368Returns the number of coroutines that are currently in the ready state,
369i.e. that can be swicthed to. The value C<0> means that the only runnable
370coroutine is the currently running one, so C<cede> would have no effect,
371and C<schedule> would cause a deadlock unless there is an idle handler
372that wakes up some coroutines.
357 373
358=item unblock_sub { ... } 374=item unblock_sub { ... }
359 375
360This utility function takes a BLOCK or code reference and "unblocks" it, 376This utility function takes a BLOCK or code reference and "unblocks" it,
361returning the new coderef. This means that the new coderef will return 377returning the new coderef. This means that the new coderef will return

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