[ViewVC] Diff of: cvs/EV/EV.pm

Comparing EV/EV.pm (file contents):
Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC vs.
Revision 1.118 by root, Tue Jul 14 20:31:21 2009 UTC

 EV - perl interface to libev, a high performance full-featured event loop
 =head1 SYNOPSIS
-  use EV;
+   use EV;
+   # TIMERS
+   my $w = EV::timer 2, 0, sub {
+      warn "is called after 2s";
+   };
+   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, 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 receive the watcher and event mask
+      warn "stdin is readable, you entered: ", <STDIN>;
+   };
+   # SIGNALS
+   my $w = EV::signal 'QUIT', sub {
+      warn "sigquit received\n";
+   };
+   # CHILD/PID STATUS CHANGES
-  # TIMERS
+   my $w = EV::child 666, 0, sub {
+      my ($w, $revents) = @_;
+      my $status = $w->rstatus;
+   };
-  my $w = EV::timer 2, 0, sub {
-     warn "is called after 2s";
-  };
-  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, 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 receive the watcher and event mask
-     warn "stdin is readable, you entered: ", <STDIN>;
-  };
-  # SIGNALS
-  my $w = EV::signal 'QUIT', sub {
-     warn "sigquit received\n";
-  };
-  # CHILD/PID STATUS CHANGES
-  my $w = EV::child 666, sub {
-     my ($w, $revents) = @_;
-     my $status = $w->rstatus;
-  };
-  # STAT CHANGES
+   # STAT CHANGES
-  my $w = EV::stat "/etc/passwd", 10, sub {
+   my $w = EV::stat "/etc/passwd", 10, sub {
-     my ($w, $revents) = @_;
+      my ($w, $revents) = @_;
-     warn $w->path, " has changed somehow.\n";
+      warn $w->path, " has changed somehow.\n";
-  };
+   };
-  # MAINLOOP
+   # MAINLOOP
-  EV::loop;           # loop until EV::unloop is called or all watchers stop
+   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_ONESHOT;  # block until at least one event could be handled
-  EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
+   EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
 =head1 DESCRIPTION
 This module provides an interface to libev
 (L<http://software.schmorp.de/pkg/libev.html>). While the documentation
-below is comprehensive, one might also consult the documentation of libev
+below is comprehensive, one might also consult the documentation of
-itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
+libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
-watcher semantics or some discussion on the available backends, or how to
+F<perldoc EV::libev>) for more subtle details on watcher semantics or some
-force a specific backend with C<LIBEV_FLAGS>, or just about in any case
+discussion on the available backends, or how to force a specific backend
-because it has much more detailed information.
+with C<LIBEV_FLAGS>, or just about in any case because it has much more
+detailed information.
+This module is very fast and scalable. It is actually so fast that you
+can use it through the L<AnyEvent> module, stay portable to other event
+loops (if you don't rely on any watcher types not available through it)
+and still be faster than with any other event loop currently supported in
+Perl.
+=head2 MODULE EXPORTS
+This module does not export any symbols.
 =cut
 package EV;
-use strict;
+use common::sense;
 BEGIN {
-   our $VERSION = '2.0';
+   our $VERSION = '3.7';
    use XSLoader;
    XSLoader::load "EV", $VERSION;
 }
 @EV::IO::ISA       =
 @EV::Idle::ISA     =
 @EV::Prepare::ISA  =
 @EV::Check::ISA    =
 @EV::Embed::ISA    =
 @EV::Fork::ISA     =
+@EV::Async::ISA    =
    "EV::Watcher";
 @EV::Loop::Default::ISA = "EV::Loop";
 =head1 EVENT LOOPS
 selecting a working backend (which for example rules out kqueue on most
 BSDs). Modules should, unless they have "special needs" always use the
 default loop as this is fastest (perl-wise), best supported by other
 modules (e.g. AnyEvent or Coro) and most portable event loop.
-For specific programs you cna create additional event loops dynamically.
+For specific programs you can create additional event loops dynamically.
-=over 4
+If you want to take advantage of kqueue (which often works properly for
+sockets only) even though the default loop doesn't enable it, you can
+I<embed> a kqueue loop into the default loop: running the default loop
+will then also service the kqueue loop to some extent. See the example in
+the section about embed watchers for an example on how to achieve that.
+=over 4
-=item $loop = new EV::loop [$flags]
+=item $loop = new EV::Loop [$flags]
-Create a new event loop as per the specified flags. Please refer to the
+Create a new event loop as per the specified flags. Please refer to
-C<ev_loop_new ()> function description in the libev documentation
+the C<ev_loop_new ()> function description in the libev documentation
-(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
+(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
-for more info.
+or locally-installed as F<EV::libev> manpage) for more info.
 The loop will automatically be destroyed when it is no longer referenced
 by any watcher and the loop object goes out of scope.
-Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
+If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
-is protected by this module.
+is recommended, as only the default event loop is protected by this
+module. If you I<are> embedding this loop in the default loop, this is not
+necessary, as C<EV::embed> automatically does the right thing on fork.
 =item $loop->loop_fork
 Must be called after a fork in the child, before entering or continuing
 the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
-this fucntion automatically, at some performance loss (refer to the libev
+this function automatically, at some performance loss (refer to the libev
 documentation).
+=item $loop->loop_verify
+Calls C<ev_verify> to make internal consistency checks (for debugging
+libev) and abort the program if any data structures were found to be
+corrupted.
+=item $loop = EV::default_loop [$flags]
+Return the default loop (which is a singleton object). Since this module
+already creates the default loop with default flags, specifying flags here
+will not have any effect unless you destroy the default loop first, which
+isn't supported. So in short: don't do it, and if you break it, you get to
+keep the pieces.
 =back
 =head1 BASIC INTERFACE
 throws an exception (with $@ containing the error). The default prints an
 informative message and continues.
 If this callback throws an exception it will be silently ignored.
+=item $flags = EV::supported_backends
+=item $flags = EV::recommended_backends
+=item $flags = EV::embeddable_backends
+Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
+instance of EV, the set of recommended backends (supposed to be good) for
+this platform and the set of embeddable backends (see EMBED WATCHERS).
+=item EV::sleep $seconds
+Block the process for the given number of (fractional) seconds.
 =item $time = EV::time
 Returns the current time in (fractional) seconds since the epoch.
 =item $time = EV::now
 =item $time = $loop->now
 Returns the time the last event loop iteration has been started. This
-is the time that (relative) timers are based on, and refering to it is
+is the time that (relative) timers are based on, and referring to it is
 usually faster then calling EV::time.
+=item EV::now_update
+=item $loop->now_update
+Establishes the current time by querying the kernel, updating the time
+returned by C<EV::now> in the progress. This is a costly operation and
+is usually done automatically within C<EV::loop>.
+This function is rarely useful, but when some event callback runs for a
+very long time without entering the event loop, updating libev's idea of
+the current time is a good idea.
+=item EV::suspend
+=item $loop->suspend
+=item EV::resume
+=item $loop->resume
+These two functions suspend and resume a loop, for use when the loop is
+not used for a while and timeouts should not be processed.
+A typical use case would be an interactive program such as a game:  When
+the user presses C<^Z> to suspend the game and resumes it an hour later it
+would be best to handle timeouts as if no time had actually passed while
+the program was suspended. This can be achieved by calling C<suspend>
+in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
+C<resume> directly afterwards to resume timer processing.
+Effectively, all C<timer> watchers will be delayed by the time spend
+between C<suspend> and C<resume>, and all C<periodic> watchers
+will be rescheduled (that is, they will lose any events that would have
+occured while suspended).
+After calling C<suspend> you B<must not> call I<any> function on the given
+loop other than C<resume>, and you B<must not> call C<resume>
+without a previous call to C<suspend>.
+Calling C<suspend>/C<resume> has the side effect of updating the event
+loop time (see C<now_update>).
 =item $backend = EV::backend
 =item $backend = $loop->backend
-Returns an integer describing the backend used by libev (EV::METHOD_SELECT
+Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
-or EV::METHOD_EPOLL).
+or EV::BACKEND_EPOLL).
 =item EV::loop [$flags]
 =item $loop->loop ([$flags])
 =item $count = EV::loop_count
 =item $count = $loop->loop_count
 Return the number of times the event loop has polled for new
-events. Sometiems useful as a generation counter.
+events. Sometimes useful as a generation counter.
 =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
 =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
 If timeout is C<undef> 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<EV:ERROR>, C<EV::READ>,
+you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
 C<EV::WRITE> and C<EV::TIMEOUT>).
 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.
 =item EV::feed_signal_event ($signal)
 Feed a signal event into EV. EV will react to this call as if the signal
 specified by C<$signal> had occured.
+=item EV::set_io_collect_interval $time
+=item $loop->set_io_collect_interval ($time)
+=item EV::set_timeout_collect_interval $time
+=item $loop->set_timeout_collect_interval ($time)
+These advanced functions set the minimum block interval when polling for I/O events and the minimum
+wait interval for timer events. See the libev documentation at
+L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
+(locally installed as F<EV::libev>) for a more detailed discussion.
 =back
 =head1 WATCHER OBJECTS
 A watcher is an object that gets created to record your interest in some
 event. For instance, if you want to wait for STDIN to become readable, you
 would create an EV::io watcher for that:
-  my $watcher = EV::io *STDIN, EV::READ, sub {
+   my $watcher = EV::io *STDIN, EV::READ, sub {
-     my ($watcher, $revents) = @_;
+      my ($watcher, $revents) = @_;
-     warn "yeah, STDIN should not be readable without blocking!\n"
+      warn "yeah, STDIN should now be readable without blocking!\n"
-  };
+   };
 All watchers can be active (waiting for events) or inactive (paused). Only
 active watchers will have their callbacks invoked. All callbacks will be
 called with at least two arguments: the watcher and a bitmask of received
 events.
 Each watcher type has its associated bit in revents, so you can use the
 same callback for multiple watchers. The event mask is named after the
-type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
+type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
 (which can set both EV::READ and EV::WRITE bits), and EV::timer (which
 uses EV::TIMEOUT).
 In the rare case where one wants to create a watcher but not start it at
 Feed some events on this watcher into EV. EV will react to this call as if
 the watcher had received the given C<$revents> mask.
 =item $revents = $w->clear_pending
-If the watcher is pending, this function returns clears its pending status
+If the watcher is pending, this function clears its pending status and
-and returns its C<$revents> bitset (as if its callback was invoked). If the
+returns its C<$revents> bitset (as if its callback was invoked). If the
 watcher isn't pending it does nothing and returns C<0>.
 =item $previous_state = $w->keepalive ($bool)
 Normally, C<EV::loop> 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<EV::loop> 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
+Sometimes, however, this gets in your way, for example when the module
 that calls C<EV::loop> (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<EV::loop> 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<EV::loop> from returning.
-The initial value for keepalive is true (enabled), and you cna change it
+The initial value for keepalive is true (enabled), and you can change it
 any time.
 Example: Register an I/O 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 { ... };
-   $1000udp_watcher->keepalive (0);
+   $udp_watcher->keepalive (0);
 =item $loop = $w->loop
 Return the loop that this watcher is attached to.
 This time simply fires at the wallclock time C<$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.
-=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)
+=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
 In this mode the watcher will always be scheduled to time out at the
 next C<$at + N * $interval> time (for some integer N) and then repeat,
 regardless of any time jumps.
 time the periodic watcher gets scheduled, the reschedule callback
 ($reschedule_cb) will be called with the watcher as first, and the current
 time as second argument.
 I<This callback MUST NOT stop or destroy this or any other periodic
-watcher, ever>. If you need to stop it, return 1e30 and stop it
+watcher, ever, and MUST NOT call any event loop functions or methods>. If
-afterwards.
+you need to stop it, return 1e30 and stop it afterwards. You may create
+and start a C<EV::prepare> watcher for this task.
 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
+(that is, the lowest time value larger than or equal to to the second
-will usually be called just before the callback will be triggered, but
+argument). It will usually be called just before the callback will be
-might be called at other times, too.
+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
 =head3 CHILD WATCHERS - watch out for process status changes
 =over 4
-=item $w = EV::child $pid, $callback
+=item $w = EV::child $pid, $trace, $callback
-=item $w = EV::child_ns $pid, $callback
+=item $w = EV::child_ns $pid, $trace, $callback
-=item $w = $loop->child ($pid, $callback)
+=item $w = $loop->child ($pid, $trace, $callback)
-=item $w = $loop->child_ns ($pid, $callback)
+=item $w = $loop->child_ns ($pid, $trace, $callback)
-Call the callback when a status change for pid C<$pid> (or any pid if
+Call the callback when a status change for pid C<$pid> (or any pid
-C<$pid> is 0) has been received. More precisely: when the process receives
+if C<$pid> is 0) has been received (a status change happens when the
+process terminates or is killed, or, when trace is true, additionally when
+it is stopped or continued). More precisely: when the process receives
 a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
 changed/zombie children and call the callback.
 It is valid (and fully supported) to install a child watcher after a child
 has exited but before the event loop has started its next iteration (for
 You can have as many pid watchers per pid as you want, they will all be
 called.
 The C<child_ns> variant doesn't start (activate) the newly created watcher.
-=item $w->set ($pid)
+=item $w->set ($pid, $trace)
 Reconfigures the watcher, see the constructor above for details. Can be called 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
       # make the dispatcher handle any new stuff
       ... not shown
    };
 The callbacks of the created watchers will not be called as the watchers
-are destroyed before this cna happen (remember EV::check gets called
+are destroyed before this can happen (remember EV::check gets called
 first).
 The C<check_ns> variant doesn't start (activate) the newly created watcher.
 =back
 Call the callback before the event loop is resumed in the child process
 after a fork.
 The C<fork_ns> variant doesn't start (activate) the newly created watcher.
+=back
+=head3 EMBED WATCHERS - when one backend isn't enough...
+This is a rather advanced watcher type that lets you embed one event loop
+into another (currently only IO events are supported in the embedded
+loop, other types of watchers might be handled in a delayed or incorrect
+fashion and must not be used).
+See the libev documentation at
+L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
+(locally installed as F<EV::libev>) for more details.
+In short, this watcher is most useful on BSD systems without working
+kqueue to still be able to handle a large number of sockets:
+   my $socket_loop;
+   # check wether we use SELECT or POLL _and_ KQUEUE is supported
+   if (
+     (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
+     && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
+   ) {
+     # use kqueue for sockets
+     $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
+   }
+   # use the default loop otherwise
+   $socket_loop ||= EV::default_loop;
+=over 4
+=item $w = EV::embed $otherloop[, $callback]
+=item $w = EV::embed_ns $otherloop[, $callback]
+=item $w = $loop->embed ($otherloop[, $callback])
+=item $w = $loop->embed_ns ($otherloop[, $callback])
+Call the callback when the embedded event loop (C<$otherloop>) has any
+I/O activity. The C<$callback> is optional: if it is missing, then the
+embedded event loop will be managed automatically (which is recommended),
+otherwise you have to invoke C<sweep> yourself.
+The C<embed_ns> variant doesn't start (activate) the newly created watcher.
+=back
+=head3 ASYNC WATCHERS - how to wake up another event loop
+Async watchers are provided by EV, but have little use in perl directly,
+as perl neither supports threads running in parallel nor direct access to
+signal handlers or other contexts where they could be of value.
+It is, however, possible to use them from the XS level.
+Please see the libev documentation for further details.
+=over 4
+=item $w = EV::async $callback
+=item $w = EV::async_ns $callback
+=item $w->send
+=item $bool = $w->async_pending
 =back
 =head1 PERL SIGNALS
    my $async_check = EV::check sub { };
 This ensures that perl gets into control for a short time to handle any
 pending signals, and also ensures (slightly) slower overall operation.
-=head1 THREADS
+=head1 ITHREADS
-Threads are not supported by this module in any way. Perl pseudo-threads
+Ithreads 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
+is evil stuff and must die. Real threads as provided by Coro are fully
-on thread support for it.
+supported (and enhanced support is available via L<Coro::EV>).
 =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
 =head1 SEE ALSO
 L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
 event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
-coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
+coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
+event-loop agnostic and portable event driven programming.
 =head1 AUTHOR
- Marc Lehmann <schmorp@schmorp.de>
+   Marc Lehmann <schmorp@schmorp.de>
- http://home.schmorp.de/
+   http://home.schmorp.de/
 =cut

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Comparing EV/EV.pm (file contents): Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC vs. Revision 1.118 by root, Tue Jul 14 20:31:21 2009 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC vs.
Revision 1.118 by root, Tue Jul 14 20:31:21 2009 UTC