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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.383 by root, Fri Sep 2 04:41:16 2011 UTC vs.
Revision 1.410 by root, Fri Mar 1 06:03:21 2013 UTC

 not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
 pure perl implementation).
 =head3 Safe/Unsafe Signals
-Perl signals can be either "safe" (synchronous to opcode handling) or
+Perl signals can be either "safe" (synchronous to opcode handling)
-"unsafe" (asynchronous) - the former might get delayed indefinitely, the
+or "unsafe" (asynchronous) - the former might delay signal delivery
-latter might corrupt your memory.
+indefinitely, the latter might corrupt your memory.
 AnyEvent signal handlers are, in addition, synchronous to the event loop,
 i.e. they will not interrupt your running perl program but will only be
 called as part of the normal event handling (just like timer, I/O etc.
 callbacks, too).
 =head3 Signal Races, Delays and Workarounds
-Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
+Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
-callbacks to signals in a generic way, which is a pity, as you cannot
+attaching callbacks to signals in a generic way, which is a pity,
-do race-free signal handling in perl, requiring C libraries for
+as you cannot do race-free signal handling in perl, requiring
-this. AnyEvent will try to do its best, which means in some cases,
+C libraries for this. AnyEvent will try to do its best, which
-signals will be delayed. The maximum time a signal might be delayed is
+means in some cases, signals will be delayed. The maximum time
-specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
+a signal might be delayed is 10 seconds by default, but can
-variable can be changed only before the first signal watcher is created,
+be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
-and should be left alone otherwise. This variable determines how often
+C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
-AnyEvent polls for signals (in case a wake-up was missed). Higher values
+section for details.
-will cause fewer spurious wake-ups, which is better for power and CPU
-saving.
 All these problems can be avoided by installing the optional
 L<Async::Interrupt> module, which works with most event loops. It will not
 work with inherently broken event loops such as L<Event> or L<Event::Lib>
-(and not with L<POE> currently, as POE does its own workaround with
+(and not with L<POE> currently). For those, you just have to suffer the
-one-second latency). For those, you just have to suffer the delays.
+delays.
 =head2 CHILD PROCESS WATCHERS
    $w = AnyEvent->child (pid => <process id>, cb => <callback>);
       };
    }
    $cv->end;
+   ...
+   my $results = $cv->recv;
 This code fragment supposedly pings a number of hosts and calls
 C<send> after results for all then have have been gathered - in any
 order. To achieve this, the code issues a call to C<begin> when it starts
 each ping request and calls C<end> when it has received some result for
 it. Since C<begin> and C<end> only maintain a counter, the order in which
 In list context, all parameters passed to C<send> will be returned,
 in scalar context only the first one will be returned.
 Note that doing a blocking wait in a callback is not supported by any
-event loop, that is, recursive invocation of a blocking C<< ->recv
+event loop, that is, recursive invocation of a blocking C<< ->recv >> is
->> is not allowed, and the C<recv> call will C<croak> if such a
+not allowed and the C<recv> call will C<croak> if such a condition is
-condition is detected. This condition can be slightly loosened by using
+detected. This requirement can be dropped by relying on L<Coro::AnyEvent>
-L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
+, which allows you to do a blocking C<< ->recv >> from any thread
-any thread that doesn't run the event loop itself.
+that doesn't run the event loop itself. L<Coro::AnyEvent> is loaded
+automatically when L<Coro> is used with L<AnyEvent>, so code does not need
+to do anything special to take advantage of that: any code that would
+normally block your program because it calls C<recv>, be executed in an
+C<async> thread instead without blocking other threads.
 Not all event models support a blocking wait - some die in that case
 (programs might want to do that to stay interactive), so I<if you are
 using this from a module, never require a blocking wait>. Instead, let the
 caller decide whether the call will block or not (for example, by coupling
 package AnyEvent;
 # basically a tuned-down version of common::sense
 sub common_sense {
-   # from common:.sense 3.4
+   # from common:.sense 3.5
+   local $^W;
    ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
    # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
    $^H |= 0x00000600;
 }
 BEGIN { AnyEvent::common_sense }
 use Carp ();
-our $VERSION = '6.02';
+our $VERSION = '7.04';
 our $MODEL;
 our @ISA;
 our @REGISTRY;
 our $VERBOSE;
-our $MAX_SIGNAL_LATENCY = 10;
 our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
+our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
 BEGIN {
    require "AnyEvent/constants.pl";
    eval "sub TAINT (){" . (${^TAINT}*1) . "}";
    @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
       if ${^TAINT};
    # $ENV{PERL_ANYEVENT_xxx} now valid
-   $VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 3;
+   $VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
    my $idx;
    $PROTOCOL{$_} = ++$idx
       for reverse split /\s*,\s*/,
              $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
    ()
 }
 sub log($$;@) {
    # only load the big bloated module when we actually are about to log something
-   if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!)
+   if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
-      require AnyEvent::Log;
+      local ($!, $@);
+      require AnyEvent::Log; # among other things, sets $VERBOSE to 9
       # AnyEvent::Log overwrites this function
       goto &log;
    }
    0 # not logged
 }
+sub _logger($;$) {
+   my ($level, $renabled) = @_;
+   $$renabled = $level <= $VERBOSE;
+   my $logger = [(caller)[0], $level, $renabled];
+   $AnyEvent::Log::LOGGER{$logger+0} = $logger;
+#   return unless defined wantarray;
+#
+#   require AnyEvent::Util;
+#   my $guard = AnyEvent::Util::guard (sub {
+#      # "clean up"
+#      delete $LOGGER{$logger+0};
+#   });
+#
+#   sub {
+#      return 0 unless $$renabled;
+#
+#      $guard if 0; # keep guard alive, but don't cause runtime overhead
+#      require AnyEvent::Log unless $AnyEvent::Log::VERSION;
+#      package AnyEvent::Log;
+#      _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
+#   }
+}
 if (length $ENV{PERL_ANYEVENT_LOG}) {
    require AnyEvent::Log; # AnyEvent::Log does the thing for us
 }
 our @models = (
-   [EV::                   => AnyEvent::Impl::EV::   , 1],
+   [EV::                   => AnyEvent::Impl::EV::],
-   [AnyEvent::Loop::       => AnyEvent::Impl::Perl:: , 1],
+   [AnyEvent::Loop::       => AnyEvent::Impl::Perl::],
    # everything below here will not (normally) be autoprobed
    # as the pure perl backend should work everywhere
    # and is usually faster
+   [Irssi::                => AnyEvent::Impl::Irssi::],    # Irssi has a bogus "Event" package, so msut be near the top
-   [Event::                => AnyEvent::Impl::Event::, 1],
+   [Event::                => AnyEvent::Impl::Event::],    # slow, stable
-   [Glib::                 => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
+   [Glib::                 => AnyEvent::Impl::Glib::],     # becomes extremely slow with many watchers
+   # everything below here should not be autoloaded
    [Event::Lib::           => AnyEvent::Impl::EventLib::], # too buggy
-   [Irssi::                => AnyEvent::Impl::Irssi::],    # Irssi has a bogus "Event" package
    [Tk::                   => AnyEvent::Impl::Tk::],       # crashes with many handles
    [Qt::                   => AnyEvent::Impl::Qt::],       # requires special main program
    [POE::Kernel::          => AnyEvent::Impl::POE::],      # lasciate ogni speranza
    [Wx::                   => AnyEvent::Impl::POE::],
    [Prima::                => AnyEvent::Impl::POE::],
 our @methods = qw(io timer time now now_update signal child idle condvar);
 sub detect() {
    return $MODEL if $MODEL; # some programs keep references to detect
+   # IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
+   # the author knows about the problems and what it does to AnyEvent as a whole
+   # (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
+   # anyway.
+   AnyEvent::log fatal => "IO::Async::Loop::AnyEvent detected - that module is broken by\n"
+                        . "design, abuses internals and breaks AnyEvent - will not continue."
+      if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
    local $!; # for good measure
    local $SIG{__DIE__}; # we use eval
    # free some memory
    *detect = sub () { $MODEL };
    if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
       my $model = $1;
       $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
       if (eval "require $model") {
-         AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
+         AnyEvent::log 7 => "Loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
          $MODEL = $model;
       } else {
-         AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
+         AnyEvent::log 4 => "Unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
       }
    }
    # check for already loaded models
    unless ($MODEL) {
       for (@REGISTRY, @models) {
          my ($package, $model) = @$_;
          if (${"$package\::VERSION"} > 0) {
             if (eval "require $model") {
-               AnyEvent::log 7 => "autodetected model '$model', using it.";
+               AnyEvent::log 7 => "Autodetected model '$model', using it.";
+               $MODEL = $model;
+               last;
+            } else {
+               AnyEvent::log 8 => "Detected event loop $package, but cannot load '$model', skipping: $@";
+            }
+         }
+      }
+      unless ($MODEL) {
+         # try to autoload a model
+         for (@REGISTRY, @models) {
+            my ($package, $model) = @$_;
+            if (
+               eval "require $package"
+               and ${"$package\::VERSION"} > 0
+               and eval "require $model"
+            ) {
+               AnyEvent::log 7 => "Autoloaded model '$model', using it.";
                $MODEL = $model;
                last;
             }
          }
-      }
-      unless ($MODEL) {
-         # try to autoload a model
-         for (@REGISTRY, @models) {
-            my ($package, $model, $autoload) = @$_;
-            if (
-               $autoload
-               and eval "require $package"
-               and ${"$package\::VERSION"} > 0
-               and eval "require $model"
-            ) {
-               AnyEvent::log 7 => "autoloaded model '$model', using it.";
-               $MODEL = $model;
-               last;
-            }
-         }
          $MODEL
-           or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
+           or AnyEvent::log fatal => "Backend autodetection failed - did you properly install AnyEvent?";
       }
    }
    # free memory only needed for probing
    undef @models;
       # probe for availability of Time::HiRes
       if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
          *time     = sub { Time::HiRes::time () };
          *AE::time = \&    Time::HiRes::time     ;
          *now      = \&time;
-         AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
+         AnyEvent::log 8 => "using Time::HiRes for sub-second timing accuracy.";
          # if (eval "use POSIX (); (POSIX::times())...
       } else {
          *time     = sub   { CORE::time };
          *AE::time = sub (){ CORE::time };
          *now      = \&time;
-         AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
+         AnyEvent::log 3 => "Using built-in time(), no sub-second resolution!";
       }
    };
    die if $@;
    &time
 sub signal {
    eval q{ # poor man's autoloading {}
       # probe for availability of Async::Interrupt
       if (_have_async_interrupt) {
-         AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
+         AnyEvent::log 8 => "Using Async::Interrupt for race-free signal handling.";
          $SIGPIPE_R = new Async::Interrupt::EventPipe;
          $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
       } else {
-         AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
+         AnyEvent::log 8 => "Using emulated perl signal handling with latency timer.";
          if (AnyEvent::WIN32) {
             require AnyEvent::Util;
             ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
 =over 4
 =item C<PERL_ANYEVENT_VERBOSE>
-By default, AnyEvent will only log messages with loglevel C<3>
+By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
-(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
+higher (see L<AnyEvent::Log>). You can set this environment variable to a
-environment variable to a numerical loglevel to make AnyEvent more (or
+numerical loglevel to make AnyEvent more (or less) talkative.
-less) talkative.
 If you want to do more than just set the global logging level
 you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
 complex specifications.
 When set to C<0> (C<off>), then no messages whatsoever will be logged with
-the default logging settings.
+everything else at defaults.
-When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
+When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
-unexpected conditions, such as not being able to load the event model
+conditions, such as not being able to load the event model specified by
-specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
+C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
-exception - this is the minimum recommended level.
+is the minimum recommended level for use during development.
-When set to C<7> or higher (info), cause AnyEvent to report which event model it
+When set to C<7> or higher (info), AnyEvent reports which event model it
 chooses.
-When set to C<8> or higher (debug), then AnyEvent will report extra information on
+When set to C<8> or higher (debug), then AnyEvent will report extra
-which optional modules it loads and how it implements certain features.
+information on which optional modules it loads and how it implements
+certain features.
 =item C<PERL_ANYEVENT_LOG>
 Accepts rather complex logging specifications. For example, you could log
 all C<debug> messages of some module to stderr, warnings and above to
 This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
 so will take effect even before AnyEvent has initialised itself.
 Note that specifying this environment variable causes the L<AnyEvent::Log>
 module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
-using the latter saves a few hundred kB of memory until the first message
+using the latter saves a few hundred kB of memory unless a module
-is being logged.
+explicitly needs the extra features of AnyEvent::Log.
 =item C<PERL_ANYEVENT_STRICT>
 AnyEvent does not do much argument checking by default, as thorough
 argument checking is very costly. Setting this variable to a true value
 For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
 could start your program like this:
    PERL_ANYEVENT_MODEL=Perl perl ...
+=item C<PERL_ANYEVENT_IO_MODEL>
+The current file I/O model - see L<AnyEvent::IO> for more info.
+At the moment, only C<Perl> (small, pure-perl, synchronous) and
+C<IOAIO> (truly asynchronous) are supported. The default is C<IOAIO> if
+L<AnyEvent::AIO> can be loaded, otherwise it is C<Perl>.
 =item C<PERL_ANYEVENT_PROTOCOLS>
 Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
 for IPv4 or IPv6. The default is unspecified (and might change, or be the result
 of auto probing).
 =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
 The default value for the C<max_outstanding> parameter for the default DNS
 resolver - this is the maximum number of parallel DNS requests that are
 sent to the DNS server.
+=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
+Perl has inherently racy signal handling (you can basically choose between
+losing signals and memory corruption) - pure perl event loops (including
+C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
+have to poll regularly to avoid losing signals.
+Some event loops are racy, but don't poll regularly, and some event loops
+are written in C but are still racy. For those event loops, AnyEvent
+installs a timer that regularly wakes up the event loop.
+By default, the interval for this timer is C<10> seconds, but you can
+override this delay with this environment variable (or by setting
+the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
+watchers).
+Lower values increase CPU (and energy) usage, higher values can introduce
+long delays when reaping children or waiting for signals.
+The L<AnyEvent::Async> module, if available, will be used to avoid this
+polling (with most event loops).
 =item C<PERL_ANYEVENT_RESOLV_CONF>
 The absolute path to a F<resolv.conf>-style file to use instead of
 F</etc/resolv.conf> (or the OS-specific configuration) in the default
 This module is part of perl since release 5.008. It will be used when the
 chosen event library does not come with a timing source of its own. The
 pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
 try to use a monotonic clock for timing stability.
+=item L<AnyEvent::AIO> (and L<IO::AIO>)
+The default implementation of L<AnyEvent::IO> is to do I/O synchronously,
+stopping programs while they access the disk, which is fine for a lot of
+programs.
+Installing AnyEvent::AIO (and its IO::AIO dependency) makes it switch to
+a true asynchronous implementation, so event processing can continue even
+while waiting for disk I/O.
 =back
 =head1 FORK
 L<AnyEvent::Impl::FLTK>.
 Non-blocking handles, pipes, stream sockets, TCP clients and
 servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
+Asynchronous File I/O: L<AnyEvent::IO>.
 Asynchronous DNS: L<AnyEvent::DNS>.
 Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
 Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
 =head1 AUTHOR
    Marc Lehmann <schmorp@schmorp.de>
-   http://home.schmorp.de/
+   http://anyevent.schmorp.de
 =cut
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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.383 by root, Fri Sep 2 04:41:16 2011 UTC vs. Revision 1.410 by root, Fri Mar 1 06:03:21 2013 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.383 by root, Fri Sep 2 04:41:16 2011 UTC vs.
Revision 1.410 by root, Fri Mar 1 06:03:21 2013 UTC