[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.183 by root, Wed Oct 1 07:40:39 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC

 These watchers are normal Perl objects with normal Perl lifetime. After
 creating a watcher it will immediately "watch" for events and invoke the
 callback when the event occurs (of course, only when the event model
 is in control).
+Note that B<callbacks must not permanently change global variables>
+potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
+callbacks must not C<die> >>. The former is good programming practise in
+Perl and the latter stems from the fact that exception handling differs
+widely between event loops.
 To disable the watcher you have to destroy it (e.g. by setting the
 variable you store it in to C<undef> or otherwise deleting all references
 to it).
 All watchers are created by calling a method on the C<AnyEvent> class.
 =head2 I/O WATCHERS
 You can create an I/O watcher by calling the C<< AnyEvent->io >> method
 with the following mandatory key-value pairs as arguments:
-C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
+C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch
-(AnyEvent might or might not keep a reference to this file handle). C<poll>
+for events (AnyEvent might or might not keep a reference to this file
+handle). Note that only file handles pointing to things for which
+non-blocking operation makes sense are allowed. This includes sockets,
+most character devices, pipes, fifos and so on, but not for example files
+or block devices.
-must be a string that is either C<r> or C<w>, which creates a watcher
+C<poll> must be a string that is either C<r> or C<w>, which creates a
-waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
+watcher waiting for "r"eadable or "w"ritable events, respectively.
-callback to invoke each time the file handle becomes ready.
+C<cb> is the callback to invoke each time the file handle becomes ready.
 Although the callback might get passed parameters, their value and
 presence is undefined and you cannot rely on them. Portable AnyEvent
 callbacks cannot use arguments passed to I/O watcher callbacks.
 =item L<AnyEvent::IGS>
 A non-blocking interface to the Internet Go Server protocol (used by
 L<App::IGS>).
-=item L<Net::IRC3>
+=item L<AnyEvent::IRC>
-AnyEvent based IRC client module family.
+AnyEvent based IRC client module family (replacing the older Net::IRC3).
 =item L<Net::XMPP2>
 AnyEvent based XMPP (Jabber protocol) module family.
 no warnings;
 use strict qw(vars subs);
 use Carp;
-our $VERSION = 4.3;
+our $VERSION = 4.35;
 our $MODEL;
 our $AUTOLOAD;
 our @ISA;
 # to support binding more than one watcher per filehandle (they usually
 # allow only one watcher per fd, so we dup it to get a different one).
 sub _dupfh($$$$) {
    my ($poll, $fh, $r, $w) = @_;
-   require Fcntl;
    # cygwin requires the fh mode to be matching, unix doesn't
    my ($rw, $mode) = $poll eq "r" ? ($r, "<")
                    : $poll eq "w" ? ($w, ">")
                    : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
    bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
 }
 # default implementation for ->signal
-our %SIG_CB;
+our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
+sub _signal_exec {
+   sysread $SIGPIPE_R, my $dummy, 4;
+   while (%SIG_EV) {
+      for (keys %SIG_EV) {
+         delete $SIG_EV{$_};
+         $_->() for values %{ $SIG_CB{$_} || {} };
+      }
+   }
+}
 sub signal {
    my (undef, %arg) = @_;
+   unless ($SIGPIPE_R) {
+      require Fcntl;
+      if (AnyEvent::WIN32) {
+         require AnyEvent::Util;
+         ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
+         AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
+         AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
+      } else {
+         pipe $SIGPIPE_R, $SIGPIPE_W;
+         fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
+         fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
+      }
+      $SIGPIPE_R
+         or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
+      # not strictly required, as $^F is normally 2, but let's make sure...
+      fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
+      fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
+      $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
+   }
    my $signal = uc $arg{signal}
       or Carp::croak "required option 'signal' is missing";
    $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
    $SIG{$signal} ||= sub {
-      $_->() for values %{ $SIG_CB{$signal} || {} };
+      local $!;
+      syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
+      undef $SIG_EV{$signal};
    };
    bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
 }
 used, and preference will be given to protocols mentioned earlier in the
 list.
 This variable can effectively be used for denial-of-service attacks
 against local programs (e.g. when setuid), although the impact is likely
-small, as the program has to handle connection errors already-
+small, as the program has to handle conenction and other failures anyways.
 Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
 but support both and try to use both.  C<PERL_ANYEVENT_PROTOCOLS=ipv4>
 - only support IPv4, never try to resolve or contact IPv6
 addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
 watcher.
 =head3 Results
           name watchers bytes create invoke destroy comment
-         EV/EV   400000   244   0.56   0.46    0.31 EV native interface
+         EV/EV   400000   224   0.47   0.35    0.27 EV native interface
-        EV/Any   100000   244   2.50   0.46    0.29 EV + AnyEvent watchers
+        EV/Any   100000   224   2.88   0.34    0.27 EV + AnyEvent watchers
-    CoroEV/Any   100000   244   2.49   0.44    0.29 coroutines + Coro::Signal
+    CoroEV/Any   100000   224   2.85   0.35    0.28 coroutines + Coro::Signal
-      Perl/Any   100000   513   4.92   0.87    1.12 pure perl implementation
+      Perl/Any   100000   452   4.13   0.73    0.95 pure perl implementation
-   Event/Event    16000   516  31.88  31.30    0.85 Event native interface
+   Event/Event    16000   517  32.20  31.80    0.81 Event native interface
-     Event/Any    16000   590  35.75  31.42    1.08 Event + AnyEvent watchers
+     Event/Any    16000   590  35.85  31.55    1.06 Event + AnyEvent watchers
-      Glib/Any    16000  1357  98.22  12.41   54.00 quadratic behaviour
+      Glib/Any    16000  1357 102.33  12.31   51.00 quadratic behaviour
-        Tk/Any     2000  1860  26.97  67.98   14.00 SEGV with >> 2000 watchers
+        Tk/Any     2000  1860  27.20  66.31   14.00 SEGV with >> 2000 watchers
-     POE/Event     2000  6644 108.64 736.02   14.73 via POE::Loop::Event
+     POE/Event     2000  6328 109.99 751.67   14.02 via POE::Loop::Event
-    POE/Select     2000  6343  94.13 809.12  565.96 via POE::Loop::Select
+    POE/Select     2000  6027  94.54 809.13  579.80 via POE::Loop::Select
 =head3 Discussion
 The benchmark does I<not> measure scalability of the event loop very
 well. For example, a select-based event loop (such as the pure perl one)
 watchers, as the management overhead dominates.
 =back
+=head1 SIGNALS
+AnyEvent currently installs handlers for these signals:
+=over 4
+=item SIGCHLD
+A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
+emulation for event loops that do not support them natively. Also, some
+event loops install a similar handler.
+=item SIGPIPE
+A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
+when AnyEvent gets loaded.
+The rationale for this is that AnyEvent users usually do not really depend
+on SIGPIPE delivery (which is purely an optimisation for shell use, or
+badly-written programs), but C<SIGPIPE> can cause spurious and rare
+program exits as a lot of people do not expect C<SIGPIPE> when writing to
+some random socket.
+The rationale for installing a no-op handler as opposed to ignoring it is
+that this way, the handler will be restored to defaults on exec.
+Feel free to install your own handler, or reset it to defaults.
+=back
+=cut
+$SIG{PIPE} = sub { }
+   unless defined $SIG{PIPE};
 =head1 FORK
 Most event libraries are not fork-safe. The ones who are usually are
 because they rely on inefficient but fork-safe C<select> or C<poll>
 calls. Only L<EV> is fully fork-aware.
 =head1 BUGS
 Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
 to work around. If you suffer from memleaks, first upgrade to Perl 5.10
 and check wether the leaks still show up. (Perl 5.10.0 has other annoying
-mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
+memleaks, such as leaking on C<map> and C<grep> but it is usually not as
 pronounced).
 =head1 SEE ALSO

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.183 by root, Wed Oct 1 07:40:39 2008 UTC vs. Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.183 by root, Wed Oct 1 07:40:39 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC