| 1 | =head1 NAME |
1 | =head1 NAME |
| 2 | |
2 | |
| 3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - events independent of event loop implementation |
| 4 | |
4 | |
| 5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
| 6 | event loops. |
6 | event loops. |
| 7 | |
7 | |
| 8 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
| … | |
… | |
| 40 | =head1 INTRODUCTION/TUTORIAL |
40 | =head1 INTRODUCTION/TUTORIAL |
| 41 | |
41 | |
| 42 | This manpage is mainly a reference manual. If you are interested |
42 | This manpage is mainly a reference manual. If you are interested |
| 43 | in a tutorial or some gentle introduction, have a look at the |
43 | in a tutorial or some gentle introduction, have a look at the |
| 44 | L<AnyEvent::Intro> manpage. |
44 | L<AnyEvent::Intro> manpage. |
|
|
45 | |
|
|
46 | =head1 SUPPORT |
|
|
47 | |
|
|
48 | There is a mailinglist for discussing all things AnyEvent, and an IRC |
|
|
49 | channel, too. |
|
|
50 | |
|
|
51 | See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software |
|
|
52 | Respository>, at L<http://anyevent.schmorp.de>, for more info. |
| 45 | |
53 | |
| 46 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
54 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
| 47 | |
55 | |
| 48 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
56 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
| 49 | nowadays. So what is different about AnyEvent? |
57 | nowadays. So what is different about AnyEvent? |
| … | |
… | |
| 368 | |
376 | |
| 369 | This watcher might use C<%SIG> (depending on the event loop used), |
377 | This watcher might use C<%SIG> (depending on the event loop used), |
| 370 | so programs overwriting those signals directly will likely not work |
378 | so programs overwriting those signals directly will likely not work |
| 371 | correctly. |
379 | correctly. |
| 372 | |
380 | |
|
|
381 | Example: exit on SIGINT |
|
|
382 | |
|
|
383 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
|
384 | |
|
|
385 | =head3 Signal Races, Delays and Workarounds |
|
|
386 | |
| 373 | Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not |
387 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
| 374 | support attaching callbacks to signals, which is a pity, as you cannot do |
388 | callbacks to signals in a generic way, which is a pity, as you cannot do |
| 375 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
389 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
| 376 | in some cases, signals will be delayed. The maximum time a signal might |
390 | in some cases, signals will be delayed. The maximum time a signal might |
| 377 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
391 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
| 378 | seconds). This variable can be changed only before the first signal |
392 | seconds). This variable can be changed only before the first signal |
| 379 | watcher is created, and should be left alone otherwise. Higher values |
393 | watcher is created, and should be left alone otherwise. Higher values |
| 380 | will cause fewer spurious wake-ups, which is better for power and CPU |
394 | will cause fewer spurious wake-ups, which is better for power and CPU |
| 381 | saving. All these problems can be avoided by installing the optional |
395 | saving. All these problems can be avoided by installing the optional |
| 382 | L<Async::Interrupt> module. |
396 | L<Async::Interrupt> module. This will not work with inherently broken |
| 383 | |
397 | event loops such as L<Event> or L<Event::Lib> (and not with L<POE> |
| 384 | Example: exit on SIGINT |
398 | currently, as POE does it's own workaround with one-second latency). With |
| 385 | |
399 | those, you just have to suffer the delays. |
| 386 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
|
| 387 | |
400 | |
| 388 | =head2 CHILD PROCESS WATCHERS |
401 | =head2 CHILD PROCESS WATCHERS |
| 389 | |
402 | |
| 390 | You can also watch on a child process exit and catch its exit status. |
403 | You can also watch on a child process exit and catch its exit status. |
| 391 | |
404 | |
| … | |
… | |
| 504 | Condition variables are similar to callbacks, except that you can |
517 | Condition variables are similar to callbacks, except that you can |
| 505 | optionally wait for them. They can also be called merge points - points |
518 | optionally wait for them. They can also be called merge points - points |
| 506 | in time where multiple outstanding events have been processed. And yet |
519 | in time where multiple outstanding events have been processed. And yet |
| 507 | another way to call them is transactions - each condition variable can be |
520 | another way to call them is transactions - each condition variable can be |
| 508 | used to represent a transaction, which finishes at some point and delivers |
521 | used to represent a transaction, which finishes at some point and delivers |
| 509 | a result. |
522 | a result. And yet some people know them as "futures" - a promise to |
|
|
523 | compute/deliver something that you can wait for. |
| 510 | |
524 | |
| 511 | Condition variables are very useful to signal that something has finished, |
525 | Condition variables are very useful to signal that something has finished, |
| 512 | for example, if you write a module that does asynchronous http requests, |
526 | for example, if you write a module that does asynchronous http requests, |
| 513 | then a condition variable would be the ideal candidate to signal the |
527 | then a condition variable would be the ideal candidate to signal the |
| 514 | availability of results. The user can either act when the callback is |
528 | availability of results. The user can either act when the callback is |
| … | |
… | |
| 1041 | |
1055 | |
| 1042 | =cut |
1056 | =cut |
| 1043 | |
1057 | |
| 1044 | package AnyEvent; |
1058 | package AnyEvent; |
| 1045 | |
1059 | |
|
|
1060 | # basically a tuned-down version of common::sense |
|
|
1061 | sub common_sense { |
| 1046 | no warnings; |
1062 | # no warnings |
|
|
1063 | ${^WARNING_BITS} ^= ${^WARNING_BITS}; |
| 1047 | use strict qw(vars subs); |
1064 | # use strict vars subs |
|
|
1065 | $^H |= 0x00000600; |
|
|
1066 | } |
|
|
1067 | |
|
|
1068 | BEGIN { AnyEvent::common_sense } |
| 1048 | |
1069 | |
| 1049 | use Carp (); |
1070 | use Carp (); |
| 1050 | |
1071 | |
| 1051 | our $VERSION = 4.83; |
1072 | our $VERSION = 4.86; |
| 1052 | our $MODEL; |
1073 | our $MODEL; |
| 1053 | |
1074 | |
| 1054 | our $AUTOLOAD; |
1075 | our $AUTOLOAD; |
| 1055 | our @ISA; |
1076 | our @ISA; |
| 1056 | |
1077 | |
| … | |
… | |
| 1130 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1151 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
| 1131 | } |
1152 | } |
| 1132 | |
1153 | |
| 1133 | sub detect() { |
1154 | sub detect() { |
| 1134 | unless ($MODEL) { |
1155 | unless ($MODEL) { |
| 1135 | no strict 'refs'; |
|
|
| 1136 | local $SIG{__DIE__}; |
1156 | local $SIG{__DIE__}; |
| 1137 | |
1157 | |
| 1138 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1158 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
| 1139 | my $model = "AnyEvent::Impl::$1"; |
1159 | my $model = "AnyEvent::Impl::$1"; |
| 1140 | if (eval "require $model") { |
1160 | if (eval "require $model") { |
| … | |
… | |
| 1264 | $_->() for values %{ $SIG_CB{$_} || {} }; |
1284 | $_->() for values %{ $SIG_CB{$_} || {} }; |
| 1265 | } |
1285 | } |
| 1266 | } |
1286 | } |
| 1267 | } |
1287 | } |
| 1268 | |
1288 | |
|
|
1289 | # install a dumym wakeupw atcher to reduce signal catching latency |
|
|
1290 | sub _sig_add() { |
|
|
1291 | unless ($SIG_COUNT++) { |
|
|
1292 | # try to align timer on a full-second boundary, if possible |
|
|
1293 | my $NOW = AnyEvent->now; |
|
|
1294 | |
|
|
1295 | $SIG_TW = AnyEvent->timer ( |
|
|
1296 | after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1297 | interval => $MAX_SIGNAL_LATENCY, |
|
|
1298 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
1299 | ); |
|
|
1300 | } |
|
|
1301 | } |
|
|
1302 | |
|
|
1303 | sub _sig_del { |
|
|
1304 | undef $SIG_TW |
|
|
1305 | unless --$SIG_COUNT; |
|
|
1306 | } |
|
|
1307 | |
| 1269 | sub _signal { |
1308 | sub _signal { |
| 1270 | my (undef, %arg) = @_; |
1309 | my (undef, %arg) = @_; |
| 1271 | |
1310 | |
| 1272 | my $signal = uc $arg{signal} |
1311 | my $signal = uc $arg{signal} |
| 1273 | or Carp::croak "required option 'signal' is missing"; |
1312 | or Carp::croak "required option 'signal' is missing"; |
| … | |
… | |
| 1297 | undef $SIG_EV{$signal}; |
1336 | undef $SIG_EV{$signal}; |
| 1298 | }; |
1337 | }; |
| 1299 | |
1338 | |
| 1300 | # can't do signal processing without introducing races in pure perl, |
1339 | # can't do signal processing without introducing races in pure perl, |
| 1301 | # so limit the signal latency. |
1340 | # so limit the signal latency. |
| 1302 | ++$SIG_COUNT; |
1341 | _sig_add; |
| 1303 | $SIG_TW ||= AnyEvent->timer ( |
|
|
| 1304 | after => $MAX_SIGNAL_LATENCY, |
|
|
| 1305 | interval => $MAX_SIGNAL_LATENCY, |
|
|
| 1306 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
| 1307 | ); |
|
|
| 1308 | } |
1342 | } |
| 1309 | |
1343 | |
| 1310 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
1344 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
| 1311 | } |
1345 | } |
| 1312 | |
1346 | |
| … | |
… | |
| 1351 | } |
1385 | } |
| 1352 | |
1386 | |
| 1353 | sub AnyEvent::Base::signal::DESTROY { |
1387 | sub AnyEvent::Base::signal::DESTROY { |
| 1354 | my ($signal, $cb) = @{$_[0]}; |
1388 | my ($signal, $cb) = @{$_[0]}; |
| 1355 | |
1389 | |
| 1356 | undef $SIG_TW |
1390 | _sig_del; |
| 1357 | unless --$SIG_COUNT; |
|
|
| 1358 | |
1391 | |
| 1359 | delete $SIG_CB{$signal}{$cb}; |
1392 | delete $SIG_CB{$signal}{$cb}; |
| 1360 | |
1393 | |
|
|
1394 | $HAVE_ASYNC_INTERRUPT |
|
|
1395 | ? delete $SIG_ASY{$signal} |
| 1361 | # delete doesn't work with older perls - they then |
1396 | : # delete doesn't work with older perls - they then |
| 1362 | # print weird messages, or just unconditionally exit |
1397 | # print weird messages, or just unconditionally exit |
| 1363 | # instead of getting the default action. |
1398 | # instead of getting the default action. |
| 1364 | undef $SIG{$signal} |
1399 | undef $SIG{$signal} |
| 1365 | unless keys %{ $SIG_CB{$signal} }; |
1400 | unless keys %{ $SIG_CB{$signal} }; |
| 1366 | } |
1401 | } |
| 1367 | |
1402 | |
| 1368 | # default implementation for ->child |
1403 | # default implementation for ->child |
| 1369 | |
1404 | |
| … | |
… | |
| 1386 | defined (my $pid = $arg{pid} + 0) |
1421 | defined (my $pid = $arg{pid} + 0) |
| 1387 | or Carp::croak "required option 'pid' is missing"; |
1422 | or Carp::croak "required option 'pid' is missing"; |
| 1388 | |
1423 | |
| 1389 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1424 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
| 1390 | |
1425 | |
|
|
1426 | # WNOHANG is almost cetrainly 1 everywhere |
|
|
1427 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
|
|
1428 | ? 1 |
| 1391 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1429 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
| 1392 | |
1430 | |
| 1393 | unless ($CHLD_W) { |
1431 | unless ($CHLD_W) { |
| 1394 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1432 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
| 1395 | # child could be a zombie already, so make at least one round |
1433 | # child could be a zombie already, so make at least one round |
| 1396 | &_sigchld; |
1434 | &_sigchld; |
| … | |
… | |
| 1448 | |
1486 | |
| 1449 | our @ISA = AnyEvent::CondVar::Base::; |
1487 | our @ISA = AnyEvent::CondVar::Base::; |
| 1450 | |
1488 | |
| 1451 | package AnyEvent::CondVar::Base; |
1489 | package AnyEvent::CondVar::Base; |
| 1452 | |
1490 | |
| 1453 | use overload |
1491 | #use overload |
| 1454 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1492 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
| 1455 | fallback => 1; |
1493 | # fallback => 1; |
|
|
1494 | |
|
|
1495 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1496 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1497 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1498 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1499 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
| 1456 | |
1500 | |
| 1457 | our $WAITING; |
1501 | our $WAITING; |
| 1458 | |
1502 | |
| 1459 | sub _send { |
1503 | sub _send { |
| 1460 | # nop |
1504 | # nop |
| … | |
… | |
| 1551 | C<PERL_ANYEVENT_MODEL>. |
1595 | C<PERL_ANYEVENT_MODEL>. |
| 1552 | |
1596 | |
| 1553 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1597 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
| 1554 | model it chooses. |
1598 | model it chooses. |
| 1555 | |
1599 | |
|
|
1600 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1601 | which optional modules it loads and how it implements certain features. |
|
|
1602 | |
| 1556 | =item C<PERL_ANYEVENT_STRICT> |
1603 | =item C<PERL_ANYEVENT_STRICT> |
| 1557 | |
1604 | |
| 1558 | AnyEvent does not do much argument checking by default, as thorough |
1605 | AnyEvent does not do much argument checking by default, as thorough |
| 1559 | argument checking is very costly. Setting this variable to a true value |
1606 | argument checking is very costly. Setting this variable to a true value |
| 1560 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
1607 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
| 1561 | check the arguments passed to most method calls. If it finds any problems, |
1608 | check the arguments passed to most method calls. If it finds any problems, |
| 1562 | it will croak. |
1609 | it will croak. |
| 1563 | |
1610 | |
| 1564 | In other words, enables "strict" mode. |
1611 | In other words, enables "strict" mode. |
| 1565 | |
1612 | |
| 1566 | Unlike C<use strict>, it is definitely recommended to keep it off in |
1613 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
| 1567 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
1614 | >>, it is definitely recommended to keep it off in production. Keeping |
| 1568 | developing programs can be very useful, however. |
1615 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1616 | can be very useful, however. |
| 1569 | |
1617 | |
| 1570 | =item C<PERL_ANYEVENT_MODEL> |
1618 | =item C<PERL_ANYEVENT_MODEL> |
| 1571 | |
1619 | |
| 1572 | This can be used to specify the event model to be used by AnyEvent, before |
1620 | This can be used to specify the event model to be used by AnyEvent, before |
| 1573 | auto detection and -probing kicks in. It must be a string consisting |
1621 | auto detection and -probing kicks in. It must be a string consisting |
| … | |
… | |
| 1635 | |
1683 | |
| 1636 | When neither C<ca_file> nor C<ca_path> was specified during |
1684 | When neither C<ca_file> nor C<ca_path> was specified during |
| 1637 | L<AnyEvent::TLS> context creation, and either of these environment |
1685 | L<AnyEvent::TLS> context creation, and either of these environment |
| 1638 | variables exist, they will be used to specify CA certificate locations |
1686 | variables exist, they will be used to specify CA certificate locations |
| 1639 | instead of a system-dependent default. |
1687 | instead of a system-dependent default. |
|
|
1688 | |
|
|
1689 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1690 | |
|
|
1691 | When these are set to C<1>, then the respective modules are not |
|
|
1692 | loaded. Mostly good for testing AnyEvent itself. |
| 1640 | |
1693 | |
| 1641 | =back |
1694 | =back |
| 1642 | |
1695 | |
| 1643 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1696 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
| 1644 | |
1697 | |
| … | |
… | |
| 2231 | |
2284 | |
| 2232 | This slightly arcane module is used to implement fast signal handling: To |
2285 | This slightly arcane module is used to implement fast signal handling: To |
| 2233 | my knowledge, there is no way to do completely race-free and quick |
2286 | my knowledge, there is no way to do completely race-free and quick |
| 2234 | signal handling in pure perl. To ensure that signals still get |
2287 | signal handling in pure perl. To ensure that signals still get |
| 2235 | delivered, AnyEvent will start an interval timer to wake up perl (and |
2288 | delivered, AnyEvent will start an interval timer to wake up perl (and |
| 2236 | catch the signals) with soemd elay (default is 10 seconds, look for |
2289 | catch the signals) with some delay (default is 10 seconds, look for |
| 2237 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
2290 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
| 2238 | |
2291 | |
| 2239 | If this module is available, then it will be used to implement signal |
2292 | If this module is available, then it will be used to implement signal |
| 2240 | catching, which means that signals will not be delayed, and the event loop |
2293 | catching, which means that signals will not be delayed, and the event loop |
| 2241 | will not be interrupted regularly, which is more efficient (And good for |
2294 | will not be interrupted regularly, which is more efficient (And good for |
| 2242 | battery life on laptops). |
2295 | battery life on laptops). |
| 2243 | |
2296 | |
| 2244 | This affects not just the pure-perl event loop, but also other event loops |
2297 | This affects not just the pure-perl event loop, but also other event loops |
| 2245 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
2298 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2299 | |
|
|
2300 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2301 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2302 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2303 | does nothing for those backends. |
| 2246 | |
2304 | |
| 2247 | =item L<EV> |
2305 | =item L<EV> |
| 2248 | |
2306 | |
| 2249 | This module isn't really "optional", as it is simply one of the backend |
2307 | This module isn't really "optional", as it is simply one of the backend |
| 2250 | event loops that AnyEvent can use. However, it is simply the best event |
2308 | event loops that AnyEvent can use. However, it is simply the best event |
| … | |
… | |
| 2264 | |
2322 | |
| 2265 | =item L<JSON> and L<JSON::XS> |
2323 | =item L<JSON> and L<JSON::XS> |
| 2266 | |
2324 | |
| 2267 | This module is required when you want to read or write JSON data via |
2325 | This module is required when you want to read or write JSON data via |
| 2268 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
2326 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
| 2269 | advantage of the ulta-high-speed L<JSON::XS> module when it is installed. |
2327 | advantage of the ultra-high-speed L<JSON::XS> module when it is installed. |
| 2270 | |
2328 | |
| 2271 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
2329 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
| 2272 | installed. |
2330 | installed. |
| 2273 | |
2331 | |
| 2274 | =item L<Net::SSLeay> |
2332 | =item L<Net::SSLeay> |
