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Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs.
Revision 1.312 by root, Mon Feb 15 18:02:35 2010 UTC

363might affect timers and time-outs. 363might affect timers and time-outs.
364 364
365When this is the case, you can call this method, which will update the 365When this is the case, you can call this method, which will update the
366event loop's idea of "current time". 366event loop's idea of "current time".
367 367
368A typical example would be a script in a web server (e.g. C<mod_perl>) -
369when mod_perl executes the script, then the event loop will have the wrong
370idea about the "current time" (being potentially far in the past, when the
371script ran the last time). In that case you should arrange a call to C<<
372AnyEvent->now_update >> each time the web server process wakes up again
373(e.g. at the start of your script, or in a handler).
374
368Note that updating the time I<might> cause some events to be handled. 375Note that updating the time I<might> cause some events to be handled.
369 376
370=back 377=back
371 378
372=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
395correctly. 402correctly.
396 403
397Example: exit on SIGINT 404Example: exit on SIGINT
398 405
399 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
400 424
401=head3 Signal Races, Delays and Workarounds 425=head3 Signal Races, Delays and Workarounds
402 426
403Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404callbacks to signals in a generic way, which is a pity, as you cannot 428callbacks to signals in a generic way, which is a pity, as you cannot
479 503
480=head2 IDLE WATCHERS 504=head2 IDLE WATCHERS
481 505
482 $w = AnyEvent->idle (cb => <callback>); 506 $w = AnyEvent->idle (cb => <callback>);
483 507
484Sometimes there is a need to do something, but it is not so important 508Repeatedly invoke the callback after the process becomes idle, until
485to do it instantly, but only when there is nothing better to do. This 509either the watcher is destroyed or new events have been detected.
486"nothing better to do" is usually defined to be "no other events need
487attention by the event loop".
488 510
489Idle watchers ideally get invoked when the event loop has nothing 511Idle watchers are useful when there is a need to do something, but it
490better to do, just before it would block the process to wait for new 512is not so important (or wise) to do it instantly. The callback will be
491events. Instead of blocking, the idle watcher is invoked. 513invoked only when there is "nothing better to do", which is usually
514defined as "all outstanding events have been handled and no new events
515have been detected". That means that idle watchers ideally get invoked
516when the event loop has just polled for new events but none have been
517detected. Instead of blocking to wait for more events, the idle watchers
518will be invoked.
492 519
493Most event loops unfortunately do not really support idle watchers (only 520Unfortunately, most event loops do not really support idle watchers (only
494EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 521EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
495will simply call the callback "from time to time". 522will simply call the callback "from time to time".
496 523
497Example: read lines from STDIN, but only process them when the 524Example: read lines from STDIN, but only process them when the
498program is otherwise idle: 525program is otherwise idle:
592 after => 1, 619 after => 1,
593 cb => sub { $result_ready->send }, 620 cb => sub { $result_ready->send },
594 ); 621 );
595 622
596 # this "blocks" (while handling events) till the callback 623 # this "blocks" (while handling events) till the callback
597 # calls -<send 624 # calls ->send
598 $result_ready->recv; 625 $result_ready->recv;
599 626
600Example: wait for a timer, but take advantage of the fact that condition 627Example: wait for a timer, but take advantage of the fact that condition
601variables are also callable directly. 628variables are also callable directly.
602 629
666one. For example, a function that pings many hosts in parallel might want 693one. For example, a function that pings many hosts in parallel might want
667to use a condition variable for the whole process. 694to use a condition variable for the whole process.
668 695
669Every call to C<< ->begin >> will increment a counter, and every call to 696Every call to C<< ->begin >> will increment a counter, and every call to
670C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 697C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
671>>, the (last) callback passed to C<begin> will be executed. That callback 698>>, the (last) callback passed to C<begin> will be executed, passing the
672is I<supposed> to call C<< ->send >>, but that is not required. If no 699condvar as first argument. That callback is I<supposed> to call C<< ->send
673callback was set, C<send> will be called without any arguments. 700>>, but that is not required. If no group callback was set, C<send> will
701be called without any arguments.
674 702
675You can think of C<< $cv->send >> giving you an OR condition (one call 703You can think of C<< $cv->send >> giving you an OR condition (one call
676sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 704sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
677condition (all C<begin> calls must be C<end>'ed before the condvar sends). 705condition (all C<begin> calls must be C<end>'ed before the condvar sends).
678 706
705begung can potentially be zero: 733begung can potentially be zero:
706 734
707 my $cv = AnyEvent->condvar; 735 my $cv = AnyEvent->condvar;
708 736
709 my %result; 737 my %result;
710 $cv->begin (sub { $cv->send (\%result) }); 738 $cv->begin (sub { shift->send (\%result) });
711 739
712 for my $host (@list_of_hosts) { 740 for my $host (@list_of_hosts) {
713 $cv->begin; 741 $cv->begin;
714 ping_host_then_call_callback $host, sub { 742 ping_host_then_call_callback $host, sub {
715 $result{$host} = ...; 743 $result{$host} = ...;
941You should check C<$AnyEvent::MODEL> before adding to this array, though: 969You should check C<$AnyEvent::MODEL> before adding to this array, though:
942if it is defined then the event loop has already been detected, and the 970if it is defined then the event loop has already been detected, and the
943array will be ignored. 971array will be ignored.
944 972
945Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 973Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946it,as it takes care of these details. 974it, as it takes care of these details.
947 975
948This variable is mainly useful for modules that can do something useful 976This variable is mainly useful for modules that can do something useful
949when AnyEvent is used and thus want to know when it is initialised, but do 977when AnyEvent is used and thus want to know when it is initialised, but do
950not need to even load it by default. This array provides the means to hook 978not need to even load it by default. This array provides the means to hook
951into AnyEvent passively, without loading it. 979into AnyEvent passively, without loading it.
980
981Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
982together, you could put this into Coro (this is the actual code used by
983Coro to accomplish this):
984
985 if (defined $AnyEvent::MODEL) {
986 # AnyEvent already initialised, so load Coro::AnyEvent
987 require Coro::AnyEvent;
988 } else {
989 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
990 # as soon as it is
991 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
992 }
952 993
953=back 994=back
954 995
955=head1 WHAT TO DO IN A MODULE 996=head1 WHAT TO DO IN A MODULE
956 997
1105 1146
1106package AnyEvent; 1147package AnyEvent;
1107 1148
1108# basically a tuned-down version of common::sense 1149# basically a tuned-down version of common::sense
1109sub common_sense { 1150sub common_sense {
1110 # no warnings 1151 # from common:.sense 1.0
1111 ${^WARNING_BITS} ^= ${^WARNING_BITS}; 1152 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1112 # use strict vars subs 1153 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113 $^H |= 0x00000600; 1154 $^H |= 0x00000600;
1114} 1155}
1115 1156
1116BEGIN { AnyEvent::common_sense } 1157BEGIN { AnyEvent::common_sense }
1117 1158
1118use Carp (); 1159use Carp ();
1119 1160
1120our $VERSION = '5.0'; 1161our $VERSION = '5.24';
1121our $MODEL; 1162our $MODEL;
1122 1163
1123our $AUTOLOAD; 1164our $AUTOLOAD;
1124our @ISA; 1165our @ISA;
1125 1166
1126our @REGISTRY; 1167our @REGISTRY;
1127 1168
1128our $WIN32;
1129
1130our $VERBOSE; 1169our $VERBOSE;
1131 1170
1132BEGIN { 1171BEGIN {
1172 eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}";
1133 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1173 eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}";
1134 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1174 eval "sub TAINT (){" . (${^TAINT} *1) . "}";
1135 1175
1136 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1176 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137 if ${^TAINT}; 1177 if ${^TAINT};
1138 1178
1139 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1179 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1200sub AnyEvent::Util::postdetect::DESTROY { 1240sub AnyEvent::Util::postdetect::DESTROY {
1201 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1241 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1202} 1242}
1203 1243
1204sub detect() { 1244sub detect() {
1245 # free some memory
1246 *detect = sub () { $MODEL };
1247
1248 local $!; # for good measure
1249 local $SIG{__DIE__};
1250
1251 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1252 my $model = "AnyEvent::Impl::$1";
1253 if (eval "require $model") {
1254 $MODEL = $model;
1255 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1256 } else {
1257 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1258 }
1259 }
1260
1261 # check for already loaded models
1205 unless ($MODEL) { 1262 unless ($MODEL) {
1206 local $SIG{__DIE__}; 1263 for (@REGISTRY, @models) {
1207 1264 my ($package, $model) = @$_;
1208 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1265 if (${"$package\::VERSION"} > 0) {
1209 my $model = "AnyEvent::Impl::$1";
1210 if (eval "require $model") { 1266 if (eval "require $model") {
1211 $MODEL = $model; 1267 $MODEL = $model;
1212 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1268 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1213 } else { 1269 last;
1214 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; 1270 }
1215 } 1271 }
1216 } 1272 }
1217 1273
1218 # check for already loaded models
1219 unless ($MODEL) { 1274 unless ($MODEL) {
1275 # try to autoload a model
1220 for (@REGISTRY, @models) { 1276 for (@REGISTRY, @models) {
1221 my ($package, $model) = @$_; 1277 my ($package, $model, $autoload) = @$_;
1278 if (
1279 $autoload
1280 and eval "require $package"
1222 if (${"$package\::VERSION"} > 0) { 1281 and ${"$package\::VERSION"} > 0
1223 if (eval "require $model") { 1282 and eval "require $model"
1283 ) {
1224 $MODEL = $model; 1284 $MODEL = $model;
1225 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; 1285 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1226 last; 1286 last;
1227 }
1228 } 1287 }
1229 } 1288 }
1230 1289
1231 unless ($MODEL) {
1232 # try to autoload a model
1233 for (@REGISTRY, @models) {
1234 my ($package, $model, $autoload) = @$_;
1235 if (
1236 $autoload
1237 and eval "require $package"
1238 and ${"$package\::VERSION"} > 0
1239 and eval "require $model"
1240 ) {
1241 $MODEL = $model;
1242 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1243 last;
1244 }
1245 }
1246
1247 $MODEL 1290 $MODEL
1248 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1291 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1249 }
1250 } 1292 }
1251
1252 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1253
1254 unshift @ISA, $MODEL;
1255
1256 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1257
1258 (shift @post_detect)->() while @post_detect;
1259 } 1293 }
1294
1295 @models = (); # free probe data
1296
1297 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1298 unshift @ISA, $MODEL;
1299
1300 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1301
1302 (shift @post_detect)->() while @post_detect;
1260 1303
1261 $MODEL 1304 $MODEL
1262} 1305}
1263 1306
1264sub AUTOLOAD { 1307sub AUTOLOAD {
1265 (my $func = $AUTOLOAD) =~ s/.*://; 1308 (my $func = $AUTOLOAD) =~ s/.*://;
1266 1309
1267 $method{$func} 1310 $method{$func}
1268 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1311 or Carp::croak "$func: not a valid AnyEvent class method";
1269 1312
1270 detect unless $MODEL; 1313 detect;
1271 1314
1272 my $class = shift; 1315 my $class = shift;
1273 $class->$func (@_); 1316 $class->$func (@_);
1274} 1317}
1275 1318
1342 1385
1343package AnyEvent::Base; 1386package AnyEvent::Base;
1344 1387
1345# default implementations for many methods 1388# default implementations for many methods
1346 1389
1347sub _time { 1390sub _time() {
1391 eval q{ # poor man's autoloading
1348 # probe for availability of Time::HiRes 1392 # probe for availability of Time::HiRes
1349 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1393 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1350 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1394 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1351 *_time = \&Time::HiRes::time; 1395 *_time = \&Time::HiRes::time;
1352 # if (eval "use POSIX (); (POSIX::times())... 1396 # if (eval "use POSIX (); (POSIX::times())...
1353 } else { 1397 } else {
1354 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1398 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1355 *_time = sub { time }; # epic fail 1399 *_time = sub (){ time }; # epic fail
1400 }
1356 } 1401 };
1402 die if $@;
1357 1403
1358 &_time 1404 &_time
1359} 1405}
1360 1406
1361sub time { _time } 1407sub time { _time }
1372 1418
1373our $HAVE_ASYNC_INTERRUPT; 1419our $HAVE_ASYNC_INTERRUPT;
1374 1420
1375sub _have_async_interrupt() { 1421sub _have_async_interrupt() {
1376 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} 1422 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1377 && eval "use Async::Interrupt 1.0 (); 1") 1423 && eval "use Async::Interrupt 1.02 (); 1")
1378 unless defined $HAVE_ASYNC_INTERRUPT; 1424 unless defined $HAVE_ASYNC_INTERRUPT;
1379 1425
1380 $HAVE_ASYNC_INTERRUPT 1426 $HAVE_ASYNC_INTERRUPT
1381} 1427}
1382 1428
1383our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1429our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1384our (%SIG_ASY, %SIG_ASY_W); 1430our (%SIG_ASY, %SIG_ASY_W);
1385our ($SIG_COUNT, $SIG_TW); 1431our ($SIG_COUNT, $SIG_TW);
1386 1432
1387sub _signal_exec {
1388 $HAVE_ASYNC_INTERRUPT
1389 ? $SIGPIPE_R->drain
1390 : sysread $SIGPIPE_R, my $dummy, 9;
1391
1392 while (%SIG_EV) {
1393 for (keys %SIG_EV) {
1394 delete $SIG_EV{$_};
1395 $_->() for values %{ $SIG_CB{$_} || {} };
1396 }
1397 }
1398}
1399
1400# install a dummy wakeup watcher to reduce signal catching latency 1433# install a dummy wakeup watcher to reduce signal catching latency
1434# used by Impls
1401sub _sig_add() { 1435sub _sig_add() {
1402 unless ($SIG_COUNT++) { 1436 unless ($SIG_COUNT++) {
1403 # try to align timer on a full-second boundary, if possible 1437 # try to align timer on a full-second boundary, if possible
1404 my $NOW = AE::now; 1438 my $NOW = AE::now;
1405 1439
1536 # print weird messages, or just unconditionally exit 1570 # print weird messages, or just unconditionally exit
1537 # instead of getting the default action. 1571 # instead of getting the default action.
1538 undef $SIG{$signal} 1572 undef $SIG{$signal}
1539 unless keys %{ $SIG_CB{$signal} }; 1573 unless keys %{ $SIG_CB{$signal} };
1540 }; 1574 };
1575
1576 *_signal_exec = sub {
1577 $HAVE_ASYNC_INTERRUPT
1578 ? $SIGPIPE_R->drain
1579 : sysread $SIGPIPE_R, (my $dummy), 9;
1580
1581 while (%SIG_EV) {
1582 for (keys %SIG_EV) {
1583 delete $SIG_EV{$_};
1584 $_->() for values %{ $SIG_CB{$_} || {} };
1585 }
1586 }
1587 };
1541 }; 1588 };
1542 die if $@; 1589 die if $@;
1590
1543 &signal 1591 &signal
1544} 1592}
1545 1593
1546# default implementation for ->child 1594# default implementation for ->child
1547 1595
1548our %PID_CB; 1596our %PID_CB;
1549our $CHLD_W; 1597our $CHLD_W;
1550our $CHLD_DELAY_W; 1598our $CHLD_DELAY_W;
1551our $WNOHANG; 1599our $WNOHANG;
1552 1600
1601# used by many Impl's
1553sub _emit_childstatus($$) { 1602sub _emit_childstatus($$) {
1554 my (undef, $rpid, $rstatus) = @_; 1603 my (undef, $rpid, $rstatus) = @_;
1555 1604
1556 $_->($rpid, $rstatus) 1605 $_->($rpid, $rstatus)
1557 for values %{ $PID_CB{$rpid} || {} }, 1606 for values %{ $PID_CB{$rpid} || {} },
1558 values %{ $PID_CB{0} || {} }; 1607 values %{ $PID_CB{0} || {} };
1559} 1608}
1560 1609
1561sub _sigchld {
1562 my $pid;
1563
1564 AnyEvent->_emit_childstatus ($pid, $?)
1565 while ($pid = waitpid -1, $WNOHANG) > 0;
1566}
1567
1568sub child { 1610sub child {
1611 eval q{ # poor man's autoloading {}
1612 *_sigchld = sub {
1613 my $pid;
1614
1615 AnyEvent->_emit_childstatus ($pid, $?)
1616 while ($pid = waitpid -1, $WNOHANG) > 0;
1617 };
1618
1619 *child = sub {
1569 my (undef, %arg) = @_; 1620 my (undef, %arg) = @_;
1570 1621
1571 defined (my $pid = $arg{pid} + 0) 1622 defined (my $pid = $arg{pid} + 0)
1572 or Carp::croak "required option 'pid' is missing"; 1623 or Carp::croak "required option 'pid' is missing";
1573 1624
1574 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1625 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1575 1626
1576 # WNOHANG is almost cetrainly 1 everywhere 1627 # WNOHANG is almost cetrainly 1 everywhere
1577 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ 1628 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1578 ? 1 1629 ? 1
1579 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1630 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1580 1631
1581 unless ($CHLD_W) { 1632 unless ($CHLD_W) {
1582 $CHLD_W = AE::signal CHLD => \&_sigchld; 1633 $CHLD_W = AE::signal CHLD => \&_sigchld;
1583 # child could be a zombie already, so make at least one round 1634 # child could be a zombie already, so make at least one round
1584 &_sigchld; 1635 &_sigchld;
1585 } 1636 }
1586 1637
1587 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1638 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1588} 1639 };
1589 1640
1590sub AnyEvent::Base::child::DESTROY { 1641 *AnyEvent::Base::child::DESTROY = sub {
1591 my ($pid, $cb) = @{$_[0]}; 1642 my ($pid, $cb) = @{$_[0]};
1592 1643
1593 delete $PID_CB{$pid}{$cb}; 1644 delete $PID_CB{$pid}{$cb};
1594 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1645 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1595 1646
1596 undef $CHLD_W unless keys %PID_CB; 1647 undef $CHLD_W unless keys %PID_CB;
1648 };
1649 };
1650 die if $@;
1651
1652 &child
1597} 1653}
1598 1654
1599# idle emulation is done by simply using a timer, regardless 1655# idle emulation is done by simply using a timer, regardless
1600# of whether the process is idle or not, and not letting 1656# of whether the process is idle or not, and not letting
1601# the callback use more than 50% of the time. 1657# the callback use more than 50% of the time.
1602sub idle { 1658sub idle {
1659 eval q{ # poor man's autoloading {}
1660 *idle = sub {
1603 my (undef, %arg) = @_; 1661 my (undef, %arg) = @_;
1604 1662
1605 my ($cb, $w, $rcb) = $arg{cb}; 1663 my ($cb, $w, $rcb) = $arg{cb};
1606 1664
1607 $rcb = sub { 1665 $rcb = sub {
1608 if ($cb) { 1666 if ($cb) {
1609 $w = _time; 1667 $w = _time;
1610 &$cb; 1668 &$cb;
1611 $w = _time - $w; 1669 $w = _time - $w;
1612 1670
1613 # never use more then 50% of the time for the idle watcher, 1671 # never use more then 50% of the time for the idle watcher,
1614 # within some limits 1672 # within some limits
1615 $w = 0.0001 if $w < 0.0001; 1673 $w = 0.0001 if $w < 0.0001;
1616 $w = 5 if $w > 5; 1674 $w = 5 if $w > 5;
1617 1675
1618 $w = AE::timer $w, 0, $rcb; 1676 $w = AE::timer $w, 0, $rcb;
1619 } else { 1677 } else {
1620 # clean up... 1678 # clean up...
1621 undef $w; 1679 undef $w;
1622 undef $rcb; 1680 undef $rcb;
1681 }
1682 };
1683
1684 $w = AE::timer 0.05, 0, $rcb;
1685
1686 bless \\$cb, "AnyEvent::Base::idle"
1623 } 1687 };
1688
1689 *AnyEvent::Base::idle::DESTROY = sub {
1690 undef $${$_[0]};
1691 };
1624 }; 1692 };
1693 die if $@;
1625 1694
1626 $w = AE::timer 0.05, 0, $rcb; 1695 &idle
1627
1628 bless \\$cb, "AnyEvent::Base::idle"
1629}
1630
1631sub AnyEvent::Base::idle::DESTROY {
1632 undef $${$_[0]};
1633} 1696}
1634 1697
1635package AnyEvent::CondVar; 1698package AnyEvent::CondVar;
1636 1699
1637our @ISA = AnyEvent::CondVar::Base::; 1700our @ISA = AnyEvent::CondVar::Base::;
1911 warn "read: $input\n"; # output what has been read 1974 warn "read: $input\n"; # output what has been read
1912 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1975 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1913 }, 1976 },
1914 ); 1977 );
1915 1978
1916 my $time_watcher; # can only be used once
1917
1918 sub new_timer {
1919 $timer = AnyEvent->timer (after => 1, cb => sub { 1979 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1920 warn "timeout\n"; # print 'timeout' about every second 1980 warn "timeout\n"; # print 'timeout' at most every second
1921 &new_timer; # and restart the time
1922 }); 1981 });
1923 }
1924
1925 new_timer; # create first timer
1926 1982
1927 $cv->recv; # wait until user enters /^q/i 1983 $cv->recv; # wait until user enters /^q/i
1928 1984
1929=head1 REAL-WORLD EXAMPLE 1985=head1 REAL-WORLD EXAMPLE
1930 1986
2374As you can see, the AnyEvent + EV combination even beats the 2430As you can see, the AnyEvent + EV combination even beats the
2375hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2431hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2376backend easily beats IO::Lambda and POE. 2432backend easily beats IO::Lambda and POE.
2377 2433
2378And even the 100% non-blocking version written using the high-level (and 2434And even the 100% non-blocking version written using the high-level (and
2379slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2435slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2380large margin, even though it does all of DNS, tcp-connect and socket I/O 2436higher level ("unoptimised") abstractions by a large margin, even though
2381in a non-blocking way. 2437it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2382 2438
2383The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2439The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2384F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2440F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2385part of the IO::lambda distribution and were used without any changes. 2441part of the IO::Lambda distribution and were used without any changes.
2386 2442
2387 2443
2388=head1 SIGNALS 2444=head1 SIGNALS
2389 2445
2390AnyEvent currently installs handlers for these signals: 2446AnyEvent currently installs handlers for these signals:
2432it's built-in modules) are required to use it. 2488it's built-in modules) are required to use it.
2433 2489
2434That does not mean that AnyEvent won't take advantage of some additional 2490That does not mean that AnyEvent won't take advantage of some additional
2435modules if they are installed. 2491modules if they are installed.
2436 2492
2437This section epxlains which additional modules will be used, and how they 2493This section explains which additional modules will be used, and how they
2438affect AnyEvent's operetion. 2494affect AnyEvent's operation.
2439 2495
2440=over 4 2496=over 4
2441 2497
2442=item L<Async::Interrupt> 2498=item L<Async::Interrupt>
2443 2499
2448catch the signals) with some delay (default is 10 seconds, look for 2504catch the signals) with some delay (default is 10 seconds, look for
2449C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2505C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2450 2506
2451If this module is available, then it will be used to implement signal 2507If this module is available, then it will be used to implement signal
2452catching, which means that signals will not be delayed, and the event loop 2508catching, which means that signals will not be delayed, and the event loop
2453will not be interrupted regularly, which is more efficient (And good for 2509will not be interrupted regularly, which is more efficient (and good for
2454battery life on laptops). 2510battery life on laptops).
2455 2511
2456This affects not just the pure-perl event loop, but also other event loops 2512This affects not just the pure-perl event loop, but also other event loops
2457that have no signal handling on their own (e.g. Glib, Tk, Qt). 2513that have no signal handling on their own (e.g. Glib, Tk, Qt).
2458 2514
2479lot less memory), but otherwise doesn't affect guard operation much. It is 2535lot less memory), but otherwise doesn't affect guard operation much. It is
2480purely used for performance. 2536purely used for performance.
2481 2537
2482=item L<JSON> and L<JSON::XS> 2538=item L<JSON> and L<JSON::XS>
2483 2539
2484This module is required when you want to read or write JSON data via 2540One of these modules is required when you want to read or write JSON data
2485L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2541via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2486advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2542advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2487 2543
2488In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is 2544In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2489installed. 2545installed.
2490 2546
2505 2561
2506 2562
2507=head1 FORK 2563=head1 FORK
2508 2564
2509Most event libraries are not fork-safe. The ones who are usually are 2565Most event libraries are not fork-safe. The ones who are usually are
2510because they rely on inefficient but fork-safe C<select> or C<poll> 2566because they rely on inefficient but fork-safe C<select> or C<poll> calls
2511calls. Only L<EV> is fully fork-aware. 2567- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2568are usually badly thought-out hacks that are incompatible with fork in
2569one way or another. Only L<EV> is fully fork-aware and ensures that you
2570continue event-processing in both parent and child (or both, if you know
2571what you are doing).
2572
2573This means that, in general, you cannot fork and do event processing in
2574the child if the event library was initialised before the fork (which
2575usually happens when the first AnyEvent watcher is created, or the library
2576is loaded).
2512 2577
2513If you have to fork, you must either do so I<before> creating your first 2578If you have to fork, you must either do so I<before> creating your first
2514watcher OR you must not use AnyEvent at all in the child OR you must do 2579watcher OR you must not use AnyEvent at all in the child OR you must do
2515something completely out of the scope of AnyEvent. 2580something completely out of the scope of AnyEvent.
2581
2582The problem of doing event processing in the parent I<and> the child
2583is much more complicated: even for backends that I<are> fork-aware or
2584fork-safe, their behaviour is not usually what you want: fork clones all
2585watchers, that means all timers, I/O watchers etc. are active in both
2586parent and child, which is almost never what you want. USing C<exec>
2587to start worker children from some kind of manage rprocess is usually
2588preferred, because it is much easier and cleaner, at the expense of having
2589to have another binary.
2516 2590
2517 2591
2518=head1 SECURITY CONSIDERATIONS 2592=head1 SECURITY CONSIDERATIONS
2519 2593
2520AnyEvent can be forced to load any event model via 2594AnyEvent can be forced to load any event model via

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