--- cvsroot/EV/EV.pm 2007/11/01 17:20:25 1.21 +++ cvsroot/EV/EV.pm 2007/11/17 01:41:33 1.42 @@ -12,20 +12,20 @@ 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 - my $w = EV::periodic 0, 60, sub { + my $w = EV::periodic 0, 60, 0, sub { warn "is called every minute, on the minute, exactly"; }; # 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: ", ; }; @@ -35,18 +35,15 @@ 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, $status) = @_; + my ($w, $revents) = @_; + 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 @@ -62,7 +59,7 @@ use strict; BEGIN { - our $VERSION = '0.1'; + our $VERSION = '1.0'; use XSLoader; XSLoader::load "EV", $VERSION; } @@ -98,7 +95,7 @@ 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 $method = EV::method Returns an integer describing the backend used by libev (EV::METHOD_SELECT or EV::METHOD_EPOLL). @@ -106,7 +103,7 @@ =item EV::loop [$flags] Begin checking for events and calling callbacks. It returns when a -callback calls EV::loop_done. +callback calls EV::unloop. The $flags argument can be one of the following: @@ -114,12 +111,12 @@ EV::LOOP_ONESHOT block at most once (wait, but do not loop) EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) -=item EV::loop_done [$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. =back @@ -152,9 +149,13 @@ its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. Please note that a watcher will automatically be stopped when the watcher -object is returned, so you I to keep the watcher objects returned by +object is destroyed, so you I to keep the watcher objects returned by the constructors. +Also, all methods changing some aspect of a watcher (->set, ->priority, +->fh and so on) automatically stop and start it again if it is active, +which means pending events get lost. + =head2 WATCHER TYPES Now lets move to the existing watcher types and asociated methods. @@ -182,12 +183,36 @@ Returns true if the watcher is active, false otherwise. +=item $current_data = $w->data + +=item $old_data = $w->data ($new_data) + +Queries a freely usable data scalar on the watcher and optionally changes +it. This is a way to associate custom data with a watcher: + + my $w = EV::timer 60, 0, sub { + warn $_[0]->data; + }; + $w->data ("print me!"); + =item $current_cb = $w->cb =item $old_cb = $w->cb ($new_cb) -Queries the callback on the watcher and optionally changes it. You cna do -this at any time. +Queries the callback on the watcher and optionally changes it. You can do +this at any time without the watcher restarting. + +=item $current_priority = $w->priority + +=item $old_priority = $w->priority ($new_priority) + +Queries the priority on the watcher and optionally changes it. Pending +watchers with higher priority will be invoked first. The valid range of +priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default +-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. =item $w->trigger ($revents) @@ -235,11 +260,12 @@ 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<$repeat> seconds. The timer does his best not +to drift, but it will not invoke the timer more often then once per event +loop iteration, and might drift in other cases. If that isn't acceptable, +look at EV::periodic, which can provide long-term stable timers. -The timer is based on a monotonic clock, that is if somebody is sitting +The timer is based on a monotonic clock, that is, if somebody is sitting in front of the machine while the timer is running and changes the system clock, the timer will nevertheless run (roughly) the same time. @@ -254,12 +280,12 @@ Similar to the C method, but has special semantics for repeating timers: +If the timer is active and non-repeating, it will be stopped. + If the timer is active and repeating, reset the timeout to occur C<$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. @@ -269,40 +295,93 @@ on the timeout. -=item $w = EV::periodic $at, $interval, $callback +=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback + +=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback + +Similar to EV::timer, but is not based on relative timeouts but on +absolute times. Apart from creating "simple" timers that trigger "at" the +specified time, it can also be used for non-drifting absolute timers and +more complex, cron-like, setups that are not adversely affected by time +jumps (i.e. when the system clock is changed by explicit date -s or other +means such as ntpd). It is also the most complex watcher type in EV. -=item $w = EV::periodic_ns $at, $interval, $callback +It has three distinct "modes": + +=over 4 -Similar to EV::timer, but the time is given as an absolute point in time -(C<$at>), plus an optional C<$interval>. +=item * absolute timer ($interval = $reschedule_cb = 0) -If the C<$interval> is zero, then the callback will be called at the time -C<$at> if that is in the future, or as soon as possible if it is in the -past. It will not automatically repeat. +This time simply fires at the wallclock time C<$at> and doesn't repeat. It +will not adjust when a time jump occurs, that is, if it is to be run +at January 1st 2011 then it will run when the system time reaches or +surpasses this time. -If the C<$interval> is nonzero, then the watcher will always be scheduled -to time out at the next C<$at + N * $interval> time. +=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) -This can be used to schedule a callback to run at very regular intervals, -as long as the processing time is less then the interval (otherwise -obviously events will be skipped). +In this mode the watcher will always be scheduled to time out at the +next C<$at + N * $interval> time (for some integer N) and then repeat, +regardless of any time jumps. + +This can be used to create timers that do not drift with respect to system +time: + + my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; + +That doesn't mean there will always be 3600 seconds in between triggers, +but only that the the clalback will be called when the system time shows a +full hour (UTC). Another way to think about it (for the mathematically inclined) is that -EV::periodic will try to run the callback at the next possible time where -C<$time = $at (mod $interval)>, regardless of any time jumps. +EV::periodic will try to run the callback in this mode at the next +possible time where C<$time = $at (mod $interval)>, regardless of any time +jumps. + +=item * manual reschedule mode ($reschedule_cb = coderef) + +In this mode $interval and $at are both being ignored. Instead, each +time the periodic watcher gets scheduled, the reschedule callback +($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 +afterwards. + +It must return the next time to trigger, based on the passed time value +(that is, the lowest time value larger than to the second argument). It +will usually be called just before the callback will be triggered, but +might be called at other times, too. + +This can be used to create very complex timers, such as a timer that +triggers on each midnight, local time (actually 24 hours after the last +midnight, to keep the example simple. If you know a way to do it correctly +in about the same space (without requiring elaborate modules), drop me a +note :): + + my $daily = EV::periodic 0, 0, sub { + my ($w, $now) = @_; + + use Time::Local (); + my (undef, undef, undef, $d, $m, $y) = localtime $now; + 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y + }, sub { + print "it's midnight or likely shortly after, now\n"; + }; -This periodic timer is based on "wallclock time", that is, if the clock -changes (C, C etc.), then the timer will nevertheless run at -the specified time. This means it will never drift (it might jitter, but -it will not drift). +=back The C variant doesn't start (activate) the newly created watcher. -=item $w->set ($at, $interval) +=item $w->set ($at, $interval, $reschedule_cb) Reconfigures the watcher, see the constructor above for details. Can be at any time. +=item $w->again + +Simply stops and starts the watcher again. + =item $w = EV::signal $signal, $callback @@ -325,6 +404,13 @@ Reconfigures the watcher, see the constructor above for details. Can be at any time. +=item $current_signum = $w->signal + +=item $old_signum = $w->signal ($new_signal) + +Returns the previously set signal (always as a number not name) and +optionally set a new one. + =item $w = EV::child $pid, $callback @@ -335,9 +421,8 @@ receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all changed/zombie children and call the callback. -Unlike all other callbacks, this callback will be called with an -additional third argument which is the exit status. See the C -function for details. +You can access both status and pid by using the C and C +methods on the watcher object. You can have as many pid watchers per pid as you want. @@ -348,6 +433,22 @@ Reconfigures the watcher, see the constructor above for details. Can be at any time. +=item $current_pid = $w->pid + +=item $old_pid = $w->pid ($new_pid) + +Returns the previously set process id and optionally set a new one. + +=item $exit_status = $w->rstatus + +Return the exit/wait status (as returned by waitpid, see the waitpid entry +in perlfunc). + +=item $pid = $w->rpid + +Return the pid of the awaited child (useful when you have installed a +watcher for all pids). + =item $w = EV::idle $callback @@ -437,15 +538,14 @@ warn "EV: error in callback (ignoring): $@"; }; -init; - -push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"]; +default_loop + or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; 1; =head1 SEE ALSO - L, L. + L. =head1 AUTHOR