--- cvsroot/EV/EV.pm 2007/11/08 17:02:10 1.32 +++ cvsroot/EV/EV.pm 2007/11/24 16:20:30 1.52 @@ -12,8 +12,8 @@ warn "is called after 2s"; }; - my $w = EV::timer 2, 1, sub { - warn "is called roughly every 2s (repeat = 1)"; + my $w = EV::timer 2, 2, sub { + warn "is called roughly every 2s (repeat = 2)"; }; undef $w; # destroy event watcher again @@ -25,7 +25,7 @@ # IO my $w = EV::io *STDIN, EV::READ, sub { - my ($w, $revents) = @_; # all callbacks get the watcher object and event mask + my ($w, $revents) = @_; # all callbacks receive the watcher and event mask warn "stdin is readable, you entered: ", ; }; @@ -35,27 +35,26 @@ warn "sigquit received\n"; }; - my $w = EV::signal 3, sub { - warn "sigquit received (this is GNU/Linux, right?)\n"; - }; - # CHILD/PID STATUS CHANGES my $w = EV::child 666, sub { my ($w, $revents) = @_; - # my $pid = $w->rpid; my $status = $w->rstatus; }; # MAINLOOP - EV::loop; # loop until EV::loop_done is called + EV::loop; # loop until EV::unloop is called or all watchers stop EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block =head1 DESCRIPTION This module provides an interface to libev -(L). +(L). While the documentation +below is comprehensive, one might also consult the documentation of libev +itself (L) for more subtle details on +watcher semantics or some discussion on the available backends, or how to +force a specific backend with C. =cut @@ -64,12 +63,12 @@ use strict; BEGIN { - our $VERSION = '0.6'; + our $VERSION = '1.3'; use XSLoader; XSLoader::load "EV", $VERSION; } -@EV::Io::ISA = +@EV::IO::ISA = @EV::Timer::ISA = @EV::Periodic::ISA = @EV::Signal::ISA = @@ -100,7 +99,7 @@ is the time that (relative) timers are based on, and refering to it is usually faster then calling EV::time. -=item $method = EV::ev_method +=item $method = EV::method Returns an integer describing the backend used by libev (EV::METHOD_SELECT or EV::METHOD_EPOLL). @@ -108,7 +107,7 @@ =item EV::loop [$flags] Begin checking for events and calling callbacks. It returns when a -callback calls EV::loop_done. +callback calls EV::unloop. The $flags argument can be one of the following: @@ -116,14 +115,37 @@ EV::LOOP_ONESHOT block at most once (wait, but do not loop) EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) -=item EV::loop_done [$how] +=item EV::unloop [$how] -When called with no arguments or an argument of 1, makes the innermost -call to EV::loop return. +When called with no arguments or an argument of EV::UNLOOP_ONE, makes the +innermost call to EV::loop return. -When called with an agrument of 2, all calls to EV::loop will return as +When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as fast as possible. +=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) + +This function rolls together an I/O and a timer watcher for a single +one-shot event without the need for managing a watcher object. + +If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> +must be a bitset containing either C, C or C, indicating the type of I/O event you want to wait for. If +you do not want to wait for some I/O event, specify C for +C<$fh_or_undef> and C<0> for C<$events>). + +If timeout is C or negative, then there will be no +timeout. Otherwise a EV::timer with this value will be started. + +When an error occurs or either the timeout or I/O watcher triggers, then +the callback will be called with the received event set (in general +you can expect it to be a combination of C, C, +C and C). + +EV::once doesn't return anything: the watchers stay active till either +of them triggers, then they will be stopped and freed, and the callback +invoked. + =back =head2 WATCHER @@ -217,12 +239,42 @@ -2). If the priority is outside this range it will automatically be normalised to the nearest valid priority. -The default priority of any newly-created weatcher is 0. +The default priority of any newly-created watcher is 0. + +Note that the priority semantics have not yet been fleshed out and are +subject to almost certain change. =item $w->trigger ($revents) Call the callback *now* with the given event mask. +=item $previous_state = $w->keepalive ($bool) + +Normally, C will return when there are no active watchers +(which is a "deadlock" because no progress can be made anymore). This is +convinient because it allows you to start your watchers (and your jobs), +call C once and when it returns you know that all your jobs are +finished (or they forgot to register some watchers for their task :). + +Sometimes, however, this gets in your way, for example when you the module +that calls C (usually the main program) is not the same module +as a long-living watcher (for example a DNS client module written by +somebody else even). Then you might want any outstanding requests to be +handled, but you would not want to keep C from returning just +because you happen to have this long-running UDP port watcher. + +In this case you can clear the keepalive status, which means that even +though your watcher is active, it won't keep C from returning. + +The initial value for keepalive is true (enabled), and you cna change it +any time. + +Example: Register an IO watcher for some UDP socket but do not keep the +event loop from running just because of that watcher. + + my $udp_socket = ... + my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; + $udp_watcher->keepalive (0); =item $w = EV::io $fileno_or_fh, $eventmask, $callback @@ -265,11 +317,12 @@ callback returns. This means that the callback would be called roughly after C<$after> -seconds, and then every C<$repeat> seconds. "Roughly" because the time of -callback processing is not taken into account, so the timer will slowly -drift. If that isn't acceptable, look at EV::periodic. +seconds, and then every C<$repeat> seconds. The timer does his best not +to drift, but it will not invoke the timer more often then once per event +loop iteration, and might drift in other cases. If that isn't acceptable, +look at EV::periodic, which can provide long-term stable timers. -The timer is based on a monotonic clock, that is if somebody is sitting +The timer is based on a monotonic clock, that is, if somebody is sitting in front of the machine while the timer is running and changes the system clock, the timer will nevertheless run (roughly) the same time. @@ -284,12 +337,12 @@ Similar to the C method, but has special semantics for repeating timers: +If the timer is active and non-repeating, it will be stopped. + If the timer is active and repeating, reset the timeout to occur C<$repeat> seconds after now. -If the timer is active and non-repeating, it will be stopped. - -If the timer is in active and repeating, start it. +If the timer is inactive and repeating, start it using the repeat value. Otherwise do nothing. @@ -343,10 +396,10 @@ =item * manual reschedule mode ($reschedule_cb = coderef) -In this mode $interval and $at are both being ignored. Instead, each time -the periodic watcher gets scheduled, the first callback ($reschedule_cb) -will be called with the watcher as first, and the current time as second -argument. +In this mode $interval and $at are both being ignored. Instead, each +time the periodic watcher gets scheduled, the reschedule callback +($reschedule_cb) will be called with the watcher as first, and the current +time as second argument. I. If you need to stop it, return 1e30 and stop it @@ -499,28 +552,30 @@ or return; # make the dispatcher handle any outstanding stuff + ... not shown # create an IO watcher for each and every socket @snmp_watcher = ( (map { EV::io $_, EV::READ, sub { } } keys %{ $dispatcher->{_descriptors} }), - ); - # if there are any timeouts, also create a timer - push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } - if $event->[Net::SNMP::Dispatcher::_ACTIVE]; + EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] + ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), + 0, sub { }, + ); }; -The callbacks are irrelevant, the only purpose of those watchers is -to wake up the process as soon as one of those events occurs (socket -readable, or timer timed out). The corresponding EV::check watcher will then -clean up: +The callbacks are irrelevant (and are not even being called), the +only purpose of those watchers is to wake up the process as soon as +one of those events occurs (socket readable, or timer timed out). The +corresponding EV::check watcher will then clean up: our $snmp_check = EV::check sub { # destroy all watchers @snmp_watcher = (); # make the dispatcher handle any new stuff + ... not shown }; The callbacks of the created watchers will not be called as the watchers @@ -533,8 +588,26 @@ =head1 THREADS -Threads are not supported by this in any way. Perl pseudo-threads is evil -stuff and must die. +Threads are not supported by this module in any way. Perl pseudo-threads +is evil stuff and must die. As soon as Perl gains real threads I will work +on thread support for it. + +=head1 FORK + +Most of the "improved" event delivering mechanisms of modern operating +systems have quite a few problems with fork(2) (to put it bluntly: it is +not supported and usually destructive). Libev makes it possible to work +around this by having a function that recreates the kernel state after +fork in the child. + +On non-win32 platforms, this module requires the pthread_atfork +functionality to do this automatically for you. This function is quite +buggy on most BSDs, though, so YMMV. The overhead for this is quite +negligible, because everything the function currently does is set a flag +that is checked only when the event loop gets used the next time, so when +you do fork but not use EV, the overhead is minimal. + +On win32, there is no notion of fork so all this doesn't apply, of course. =cut @@ -545,13 +618,11 @@ default_loop or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; -push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"]; - 1; =head1 SEE ALSO - L, L. + L. =head1 AUTHOR