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18 | |
18 | |
19 | cede; |
19 | cede; |
20 | |
20 | |
21 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
22 | |
22 | |
23 | This module collection manages coroutines. Coroutines are similar to |
23 | This module collection manages coroutines. Coroutines are similar |
24 | threads but don't run in parallel. |
24 | to threads but don't run in parallel at the same time even on SMP |
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25 | machines. The specific flavor of coroutine use din this module also |
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26 | guarentees you that it will not switch between coroutines unless |
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27 | necessary, at easily-identified points in your program, so locking and |
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28 | parallel access are rarely an issue, making coroutine programming much |
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29 | safer than threads programming. |
25 | |
30 | |
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31 | (Perl, however, does not natively support real threads but instead does a |
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32 | very slow and memory-intensive emulation of processes using threads. This |
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33 | is a performance win on Windows machines, and a loss everywhere else). |
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34 | |
26 | In this module, coroutines are defined as "callchain + lexical variables |
35 | In 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, |
28 | callchain, it's own set of lexicals and it's own set of perl's most |
37 | its own set of lexicals and its own set of perls most important global |
29 | important global variables. |
38 | variables. |
30 | |
39 | |
31 | =cut |
40 | =cut |
32 | |
41 | |
33 | package Coro; |
42 | package Coro; |
34 | |
43 | |
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41 | |
50 | |
42 | our $idle; # idle handler |
51 | our $idle; # idle handler |
43 | our $main; # main coroutine |
52 | our $main; # main coroutine |
44 | our $current; # current coroutine |
53 | our $current; # current coroutine |
45 | |
54 | |
46 | our $VERSION = '3.01'; |
55 | our $VERSION = '3.3'; |
47 | |
56 | |
48 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
57 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
49 | our %EXPORT_TAGS = ( |
58 | our %EXPORT_TAGS = ( |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
51 | ); |
60 | ); |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
61 | our @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 | |
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144 | # been readied multiple times. this is harmless since the manager |
153 | # been readied multiple times. this is harmless since the manager |
145 | # can be called as many times as neccessary and will always |
154 | # can be called as many times as neccessary and will always |
146 | # remove itself from the runqueue |
155 | # remove itself from the runqueue |
147 | while (@destroy) { |
156 | while (@destroy) { |
148 | my $coro = pop @destroy; |
157 | my $coro = pop @destroy; |
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158 | |
149 | $coro->{status} ||= []; |
159 | $coro->{status} ||= []; |
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160 | |
150 | $_->ready for @{delete $coro->{join} || []}; |
161 | $_->ready for @{(delete $coro->{join} ) || []}; |
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162 | $_->(@{$coro->{status}}) for @{(delete $coro->{destroy_cb}) || []}; |
151 | |
163 | |
152 | # the next line destroys the coro state, but keeps the |
164 | # the next line destroys the coro state, but keeps the |
153 | # coroutine itself intact (we basically make it a zombie |
165 | # coroutine itself intact (we basically make it a zombie |
154 | # coroutine that always runs the manager thread, so it's possible |
166 | # coroutine that always runs the manager thread, so it's possible |
155 | # to transfer() to this coroutine). |
167 | # to transfer() to this coroutine). |
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306 | &schedule; |
318 | &schedule; |
307 | } |
319 | } |
308 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
320 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
309 | } |
321 | } |
310 | |
322 | |
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323 | =item $coroutine->on_destroy (\&cb) |
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324 | |
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325 | Registers a callback that is called when this coroutine gets destroyed, |
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326 | but before it is joined. The callback gets passed the terminate arguments, |
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327 | if any. |
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328 | |
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329 | =cut |
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330 | |
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331 | sub on_destroy { |
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332 | my ($self, $cb) = @_; |
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333 | |
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334 | push @{ $self->{destroy_cb} }, $cb; |
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335 | } |
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336 | |
311 | =item $oldprio = $coroutine->prio ($newprio) |
337 | =item $oldprio = $coroutine->prio ($newprio) |
312 | |
338 | |
313 | Sets (or gets, if the argument is missing) the priority of the |
339 | Sets (or gets, if the argument is missing) the priority of the |
314 | coroutine. Higher priority coroutines get run before lower priority |
340 | coroutine. Higher priority coroutines get run before lower priority |
315 | coroutines. Priorities are small signed integers (currently -4 .. +3), |
341 | coroutines. Priorities are small signed integers (currently -4 .. +3), |
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348 | $old; |
374 | $old; |
349 | } |
375 | } |
350 | |
376 | |
351 | =back |
377 | =back |
352 | |
378 | |
353 | =head2 UTILITY FUNCTIONS |
379 | =head2 GLOBAL FUNCTIONS |
354 | |
380 | |
355 | =over 4 |
381 | =over 4 |
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382 | |
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383 | =item Coro::nready |
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384 | |
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385 | Returns the number of coroutines that are currently in the ready state, |
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386 | i.e. that can be swicthed to. The value C<0> means that the only runnable |
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387 | coroutine is the currently running one, so C<cede> would have no effect, |
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388 | and C<schedule> would cause a deadlock unless there is an idle handler |
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389 | that wakes up some coroutines. |
356 | |
390 | |
357 | =item unblock_sub { ... } |
391 | =item unblock_sub { ... } |
358 | |
392 | |
359 | This utility function takes a BLOCK or code reference and "unblocks" it, |
393 | This utility function takes a BLOCK or code reference and "unblocks" it, |
360 | returning the new coderef. This means that the new coderef will return |
394 | returning the new coderef. This means that the new coderef will return |