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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.349 by root, Mon Jul 4 21:14:42 2011 UTC vs.
Revision 1.352 by root, Thu Aug 4 09:14:01 2011 UTC

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121The interface itself is vaguely similar, but not identical to the L<Event> 121The interface itself is vaguely similar, but not identical to the L<Event>
122module. 122module.
123 123
124During the first call of any watcher-creation method, the module tries 124During the first call of any watcher-creation method, the module tries
125to detect the currently loaded event loop by probing whether one of the 125to detect the currently loaded event loop by probing whether one of the
126following modules is already loaded: L<EV>, L<AnyEvent::Impl::Perl>, 126following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
127L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one 127L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
128found is used. If none are detected, the module tries to load the first 128found is used. If none are detected, the module tries to load the first
129four modules in the order given; but note that if L<EV> is not 129four modules in the order given; but note that if L<EV> is not
130available, the pure-perl L<AnyEvent::Impl::Perl> should always work, so 130available, the pure-perl L<AnyEvent::Loop> should always work, so
131the other two are not normally tried. 131the other two are not normally tried.
132 132
133Because AnyEvent first checks for modules that are already loaded, loading 133Because AnyEvent first checks for modules that are already loaded, loading
134an event model explicitly before first using AnyEvent will likely make 134an event model explicitly before first using AnyEvent will likely make
135that model the default. For example: 135that model the default. For example:
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142The I<likely> means that, if any module loads another event model and 142The I<likely> means that, if any module loads another event model and
143starts using it, all bets are off - this case should be very rare though, 143starts using it, all bets are off - this case should be very rare though,
144as very few modules hardcode event loops without announcing this very 144as very few modules hardcode event loops without announcing this very
145loudly. 145loudly.
146 146
147The pure-perl implementation of AnyEvent is called 147The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
148C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148other event modules you can load it explicitly and enjoy the high
149explicitly and enjoy the high availability of that event loop :) 149availability of that event loop :)
150 150
151=head1 WATCHERS 151=head1 WATCHERS
152 152
153AnyEvent has the central concept of a I<watcher>, which is an object that 153AnyEvent has the central concept of a I<watcher>, which is an object that
154stores relevant data for each kind of event you are waiting for, such as 154stores relevant data for each kind of event you are waiting for, such as
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356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into 356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
357account. 357account.
358 358
359=item AnyEvent->now_update 359=item AnyEvent->now_update
360 360
361Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache 361Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
362the current time for each loop iteration (see the discussion of L<< 362time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
363AnyEvent->now >>, above). 363above).
364 364
365When a callback runs for a long time (or when the process sleeps), then 365When a callback runs for a long time (or when the process sleeps), then
366this "current" time will differ substantially from the real time, which 366this "current" time will differ substantially from the real time, which
367might affect timers and time-outs. 367might affect timers and time-outs.
368 368
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482thing in an AnyEvent program, you I<have> to create at least one 482thing in an AnyEvent program, you I<have> to create at least one
483watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
484C<AnyEvent::detect>). 484C<AnyEvent::detect>).
485 485
486As most event loops do not support waiting for child events, they will be 486As most event loops do not support waiting for child events, they will be
487emulated by AnyEvent in most cases, in which the latency and race problems 487emulated by AnyEvent in most cases, in which case the latency and race
488mentioned in the description of signal watchers apply. 488problems mentioned in the description of signal watchers apply.
489 489
490Example: fork a process and wait for it 490Example: fork a process and wait for it
491 491
492 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
493 493
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860use. If EV is not installed, then AnyEvent will fall back to its own 860use. If EV is not installed, then AnyEvent will fall back to its own
861pure-perl implementation, which is available everywhere as it comes with 861pure-perl implementation, which is available everywhere as it comes with
862AnyEvent itself. 862AnyEvent itself.
863 863
864 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
865 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
866 866
867=item Backends that are transparently being picked up when they are used. 867=item Backends that are transparently being picked up when they are used.
868 868
869These will be used if they are already loaded when the first watcher 869These will be used if they are already loaded when the first watcher
870is created, in which case it is assumed that the application is using 870is created, in which case it is assumed that the application is using
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1047modules might create watchers when they are loaded, and AnyEvent will 1047modules might create watchers when they are loaded, and AnyEvent will
1048decide on the event model to use as soon as it creates watchers, and it 1048decide on the event model to use as soon as it creates watchers, and it
1049might choose the wrong one unless you load the correct one yourself. 1049might choose the wrong one unless you load the correct one yourself.
1050 1050
1051You can chose to use a pure-perl implementation by loading the 1051You can chose to use a pure-perl implementation by loading the
1052C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1052C<AnyEvent::Loop> module, which gives you similar behaviour
1053everywhere, but letting AnyEvent chose the model is generally better. 1053everywhere, but letting AnyEvent chose the model is generally better.
1054 1054
1055=head2 MAINLOOP EMULATION 1055=head2 MAINLOOP EMULATION
1056 1056
1057Sometimes (often for short test scripts, or even standalone programs who 1057Sometimes (often for short test scripts, or even standalone programs who
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1197 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1197 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1198} 1198}
1199 1199
1200my @models = ( 1200my @models = (
1201 [EV:: => AnyEvent::Impl::EV:: , 1], 1201 [EV:: => AnyEvent::Impl::EV:: , 1],
1202 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1202 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1203 # everything below here will not (normally) be autoprobed 1203 # everything below here will not (normally) be autoprobed
1204 # as the pureperl backend should work everywhere 1204 # as the pure perl backend should work everywhere
1205 # and is usually faster 1205 # and is usually faster
1206 [Event:: => AnyEvent::Impl::Event::, 1], 1206 [Event:: => AnyEvent::Impl::Event::, 1],
1207 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1207 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1208 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1208 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1209 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1209 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
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1216 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::], 1216 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1217 [FLTK:: => AnyEvent::Impl::FLTK::], 1217 [FLTK:: => AnyEvent::Impl::FLTK::],
1218); 1218);
1219 1219
1220our %method = map +($_ => 1), 1220our %method = map +($_ => 1),
1221 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1221 qw(io timer time now now_update signal child idle condvar DESTROY);
1222 1222
1223our @post_detect; 1223our @post_detect;
1224 1224
1225sub post_detect(&) { 1225sub post_detect(&) {
1226 my ($cb) = @_; 1226 my ($cb) = @_;
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1423 1423
1424*now = \&time; 1424*now = \&time;
1425 1425
1426sub now_update { } 1426sub now_update { }
1427 1427
1428sub _poll {
1429 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1430}
1431
1428# default implementation for ->condvar 1432# default implementation for ->condvar
1433# in fact,t he default should not be overwritten
1429 1434
1430sub condvar { 1435sub condvar {
1431 eval q{ # poor man's autoloading {} 1436 eval q{ # poor man's autoloading {}
1432 *condvar = sub { 1437 *condvar = sub {
1433 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1438 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
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1640 }; 1645 };
1641 1646
1642 *child = sub { 1647 *child = sub {
1643 my (undef, %arg) = @_; 1648 my (undef, %arg) = @_;
1644 1649
1645 defined (my $pid = $arg{pid} + 0) 1650 my $pid = $arg{pid};
1646 or Carp::croak "required option 'pid' is missing"; 1651 my $cb = $arg{cb};
1647 1652
1648 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1653 $PID_CB{$pid}{$cb+0} = $cb;
1649 1654
1650 unless ($CHLD_W) { 1655 unless ($CHLD_W) {
1651 $CHLD_W = AE::signal CHLD => \&_sigchld; 1656 $CHLD_W = AE::signal CHLD => \&_sigchld;
1652 # child could be a zombie already, so make at least one round 1657 # child could be a zombie already, so make at least one round
1653 &_sigchld; 1658 &_sigchld;
1654 } 1659 }
1655 1660
1656 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1661 bless [$pid, $cb+0], "AnyEvent::Base::child"
1657 }; 1662 };
1658 1663
1659 *AnyEvent::Base::child::DESTROY = sub { 1664 *AnyEvent::Base::child::DESTROY = sub {
1660 my ($pid, $cb) = @{$_[0]}; 1665 my ($pid, $icb) = @{$_[0]};
1661 1666
1662 delete $PID_CB{$pid}{$cb}; 1667 delete $PID_CB{$pid}{$icb};
1663 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1668 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1664 1669
1665 undef $CHLD_W unless keys %PID_CB; 1670 undef $CHLD_W unless keys %PID_CB;
1666 }; 1671 };
1667 }; 1672 };
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1739 1744
1740sub _send { 1745sub _send {
1741 # nop 1746 # nop
1742} 1747}
1743 1748
1749sub _wait {
1750 AnyEvent->_poll until $_[0]{_ae_sent};
1751}
1752
1744sub send { 1753sub send {
1745 my $cv = shift; 1754 my $cv = shift;
1746 $cv->{_ae_sent} = [@_]; 1755 $cv->{_ae_sent} = [@_];
1747 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1756 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1748 $cv->_send; 1757 $cv->_send;
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1755 1764
1756sub ready { 1765sub ready {
1757 $_[0]{_ae_sent} 1766 $_[0]{_ae_sent}
1758} 1767}
1759 1768
1760sub _wait {
1761 $WAITING
1762 and !$_[0]{_ae_sent}
1763 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1764
1765 local $WAITING = 1;
1766 AnyEvent->one_event while !$_[0]{_ae_sent};
1767}
1768
1769sub recv { 1769sub recv {
1770 unless ($_[0]{_ae_sent}) {
1771 $WAITING
1772 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1773
1774 local $WAITING = 1;
1770 $_[0]->_wait; 1775 $_[0]->_wait;
1776 }
1771 1777
1772 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1778 $_[0]{_ae_croak}
1773 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1779 and Carp::croak $_[0]{_ae_croak};
1780
1781 wantarray
1782 ? @{ $_[0]{_ae_sent} }
1783 : $_[0]{_ae_sent}[0]
1774} 1784}
1775 1785
1776sub cb { 1786sub cb {
1777 my $cv = shift; 1787 my $cv = shift;
1778 1788
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1794 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 1804 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1795} 1805}
1796 1806
1797# undocumented/compatibility with pre-3.4 1807# undocumented/compatibility with pre-3.4
1798*broadcast = \&send; 1808*broadcast = \&send;
1799*wait = \&_wait; 1809*wait = \&recv;
1800 1810
1801=head1 ERROR AND EXCEPTION HANDLING 1811=head1 ERROR AND EXCEPTION HANDLING
1802 1812
1803In general, AnyEvent does not do any error handling - it relies on the 1813In general, AnyEvent does not do any error handling - it relies on the
1804caller to do that if required. The L<AnyEvent::Strict> module (see also 1814caller to do that if required. The L<AnyEvent::Strict> module (see also
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1867used as event model. If it fails to load AnyEvent will proceed with 1877used as event model. If it fails to load AnyEvent will proceed with
1868auto detection and -probing. 1878auto detection and -probing.
1869 1879
1870This functionality might change in future versions. 1880This functionality might change in future versions.
1871 1881
1872For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1882For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1873could start your program like this: 1883could start your program like this:
1874 1884
1875 PERL_ANYEVENT_MODEL=Perl perl ... 1885 PERL_ANYEVENT_MODEL=Perl perl ...
1876 1886
1877=item C<PERL_ANYEVENT_PROTOCOLS> 1887=item C<PERL_ANYEVENT_PROTOCOLS>
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2576 2586
2577=item L<Time::HiRes> 2587=item L<Time::HiRes>
2578 2588
2579This module is part of perl since release 5.008. It will be used when the 2589This module is part of perl since release 5.008. It will be used when the
2580chosen event library does not come with a timing source of its own. The 2590chosen event library does not come with a timing source of its own. The
2581pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2591pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2582try to use a monotonic clock for timing stability. 2592try to use a monotonic clock for timing stability.
2583 2593
2584=back 2594=back
2585 2595
2586 2596
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2654 2664
2655FAQ: L<AnyEvent::FAQ>. 2665FAQ: L<AnyEvent::FAQ>.
2656 2666
2657Utility functions: L<AnyEvent::Util>. 2667Utility functions: L<AnyEvent::Util>.
2658 2668
2659Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2669Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2660L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2670L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2661 2671
2662Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2672Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2663L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2673L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2664L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2674L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2665L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2675L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.

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