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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.123 by root, Fri May 23 20:41:25 2008 UTC

 =head1 NAME
 AnyEvent - provide framework for multiple event loops
-EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
+EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
 =head1 SYNOPSIS
    use AnyEvent;
    my $w = AnyEvent->timer (after => $seconds, cb => sub {
       ...
    });
    my $w = AnyEvent->condvar; # stores whether a condition was flagged
+   $w->send; # wake up current and all future recv's
-   $w->wait; # enters "main loop" till $condvar gets ->broadcast
+   $w->recv; # enters "main loop" till $condvar gets ->send
-   $w->broadcast; # wake up current and all future wait's
 =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
 Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
 nowadays. So what is different about AnyEvent?
 The interface itself is vaguely similar, but not identical to the L<Event>
 module.
 During the first call of any watcher-creation method, the module tries
 to detect the currently loaded event loop by probing whether one of the
-following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,
+following modules is already loaded: L<EV>,
 L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,
 L<POE>. The first one found is used. If none are found, the module tries
 to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl
 adaptor should always succeed) in the order given. The first one that can
 be successfully loaded will be used. If, after this, still none could be
 Example: fork a process and wait for it
   my $done = AnyEvent->condvar;
-  AnyEvent::detect; # force event module to be initialised
   my $pid = fork or exit 5;
   my $w = AnyEvent->child (
      pid => $pid,
      cb  => sub {
         my ($pid, $status) = @_;
         warn "pid $pid exited with status $status";
-        $done->broadcast;
+        $done->send;
      },
   );
   # do something else, then wait for process exit
-  $done->wait;
+  $done->recv;
 =head2 CONDITION VARIABLES
 If you are familiar with some event loops you will know that all of them
 require you to run some blocking "loop", "run" or similar function that
 >> method, usually without arguments. The only argument pair allowed is
 C<cb>, which specifies a callback to be called when the condition variable
 becomes true.
 After creation, the conditon variable is "false" until it becomes "true"
-by calling the C<broadcast> method.
+by calling the C<send> method.
 Condition variables are similar to callbacks, except that you can
 optionally wait for them. They can also be called merge points - points
 in time where multiple outstandign events have been processed. And yet
 another way to call them is transations - each condition variable can be
 Condition variables are very useful to signal that something has finished,
 for example, if you write a module that does asynchronous http requests,
 then a condition variable would be the ideal candidate to signal the
 availability of results. The user can either act when the callback is
-called or can synchronously C<< ->wait >> for the results.
+called or can synchronously C<< ->recv >> for the results.
 You can also use them to simulate traditional event loops - for example,
 you can block your main program until an event occurs - for example, you
-could C<< ->wait >> in your main program until the user clicks the Quit
+could C<< ->recv >> in your main program until the user clicks the Quit
-button of your app, which would C<< ->broadcast >> the "quit" event.
+button of your app, which would C<< ->send >> the "quit" event.
 Note that condition variables recurse into the event loop - if you have
-two pieces of code that call C<< ->wait >> in a round-robbin fashion, you
+two pieces of code that call C<< ->recv >> in a round-robbin fashion, you
 lose. Therefore, condition variables are good to export to your caller, but
 you should avoid making a blocking wait yourself, at least in callbacks,
 as this asks for trouble.
 Condition variables are represented by hash refs in perl, and the keys
 easy (it is often useful to build your own transaction class on top of
 AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
 it's C<new> method in your own C<new> method.
 There are two "sides" to a condition variable - the "producer side" which
-eventually calls C<< -> broadcast >>, and the "consumer side", which waits
+eventually calls C<< -> send >>, and the "consumer side", which waits
-for the broadcast to occur.
+for the send to occur.
 Example:
    # wait till the result is ready
    my $result_ready = AnyEvent->condvar;
    # do something such as adding a timer
-   # or socket watcher the calls $result_ready->broadcast
+   # or socket watcher the calls $result_ready->send
    # when the "result" is ready.
    # in this case, we simply use a timer:
    my $w = AnyEvent->timer (
       after => 1,
-      cb    => sub { $result_ready->broadcast },
+      cb    => sub { $result_ready->send },
    );
    # this "blocks" (while handling events) till the callback
-   # calls broadcast
+   # calls send
-   $result_ready->wait;
+   $result_ready->recv;
 =head3 METHODS FOR PRODUCERS
 These methods should only be used by the producing side, i.e. the
-code/module that eventually broadcasts the signal. Note that it is also
+code/module that eventually sends the signal. Note that it is also
 the producer side which creates the condvar in most cases, but it isn't
 uncommon for the consumer to create it as well.
 =over 4
-=item $cv->broadcast (...)
+=item $cv->send (...)
-Flag the condition as ready - a running C<< ->wait >> and all further
+Flag the condition as ready - a running C<< ->recv >> and all further
-calls to C<wait> will (eventually) return after this method has been
+calls to C<recv> will (eventually) return after this method has been
-called. If nobody is waiting the broadcast will be remembered.
+called. If nobody is waiting the send will be remembered.
 If a callback has been set on the condition variable, it is called
-immediately from within broadcast.
+immediately from within send.
-Any arguments passed to the C<broadcast> call will be returned by all
+Any arguments passed to the C<send> call will be returned by all
-future C<< ->wait >> calls.
+future C<< ->recv >> calls.
 =item $cv->croak ($error)
-Similar to broadcast, but causes all call's wait C<< ->wait >> to invoke
+Similar to send, but causes all call's to C<< ->recv >> to invoke
 C<Carp::croak> with the given error message/object/scalar.
 This can be used to signal any errors to the condition variable
 user/consumer.
 =item $cv->begin ([group callback])
 =item $cv->end
+These two methods are EXPERIMENTAL and MIGHT CHANGE.
 These two methods can be used to combine many transactions/events into
 one. For example, a function that pings many hosts in parallel might want
 to use a condition variable for the whole process.
 Every call to C<< ->begin >> will increment a counter, and every call to
 C<< ->end >> will decrement it.  If the counter reaches C<0> in C<< ->end
 >>, the (last) callback passed to C<begin> will be executed. That callback
-is I<supposed> to call C<< ->broadcast >>, but that is not required. If no
+is I<supposed> to call C<< ->send >>, but that is not required. If no
-callback was set, C<broadcast> will be called without any arguments.
+callback was set, C<send> will be called without any arguments.
 Let's clarify this with the ping example:
    my $cv = AnyEvent->condvar;
    my %result;
-   $cv->begin (sub { $cv->broadcast (\%result) });
+   $cv->begin (sub { $cv->send (\%result) });
    for my $host (@list_of_hosts) {
       $cv->begin;
       ping_host_then_call_callback $host, sub {
          $result{$host} = ...;
    }
    $cv->end;
 This code fragment supposedly pings a number of hosts and calls
-C<broadcast> after results for all then have have been gathered - in any
+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
 results arrive is not relevant.
 There is an additional bracketing call to C<begin> and C<end> outside the
 loop, which serves two important purposes: first, it sets the callback
 to be called once the counter reaches C<0>, and second, it ensures that
-broadcast is called even when C<no> hosts are being pinged (the loop
+C<send> is called even when C<no> hosts are being pinged (the loop
 doesn't execute once).
 This is the general pattern when you "fan out" into multiple subrequests:
 use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
 is called at least once, and then, for each subrequest you start, call
 =head3 METHODS FOR CONSUMERS
 These methods should only be used by the consuming side, i.e. the
 code awaits the condition.
-=item $cv->wait
+=over 4
+=item $cv->recv
-Wait (blocking if necessary) until the C<< ->broadcast >> or C<< ->croak
+Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
 >> methods have been called on c<$cv>, while servicing other watchers
 normally.
 You can only wait once on a condition - additional calls are valid but
 will return immediately.
 If an error condition has been set by calling C<< ->croak >>, then this
 function will call C<croak>.
-In list context, all parameters passed to C<broadcast> will be returned,
+In list context, all parameters passed to C<send> will be returned,
 in scalar context only the first one will be returned.
 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>, but let the
 caller decide whether the call will block or not (for example, by coupling
 condition variables with some kind of request results and supporting
 callbacks so the caller knows that getting the result will not block,
 while still suppporting blocking waits if the caller so desires).
-Another reason I<never> to C<< ->wait >> in a module is that you cannot
+Another reason I<never> to C<< ->recv >> in a module is that you cannot
-sensibly have two C<< ->wait >>'s in parallel, as that would require
+sensibly have two C<< ->recv >>'s in parallel, as that would require
 multiple interpreters or coroutines/threads, none of which C<AnyEvent>
-can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and
+can supply.
-L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
-from different coroutines, however).
+The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
+fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
+versions and also integrates coroutines into AnyEvent, making blocking
+C<< ->recv >> calls perfectly safe as long as they are done from another
+coroutine (one that doesn't run the event loop).
-You can ensure that C<< -wait >> never blocks by setting a callback and
+You can ensure that C<< -recv >> never blocks by setting a callback and
-only calling C<< ->wait >> from within that callback (or at a later
+only calling C<< ->recv >> from within that callback (or at a later
 time). This will work even when the event loop does not support blocking
 waits otherwise.
+=item $bool = $cv->ready
+Returns true when the condition is "true", i.e. whether C<send> or
+C<croak> have been called.
+=item $cb = $cv->cb ([new callback])
+This is a mutator function that returns the callback set and optionally
+replaces it before doing so.
+The callback will be called when the condition becomes "true", i.e. when
+C<send> or C<croak> are called. Calling C<recv> inside the callback
+or at any later time is guaranteed not to block.
 =back
 =head1 GLOBAL VARIABLES AND FUNCTIONS
 C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
 AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
 The known classes so far are:
-   AnyEvent::Impl::CoroEV    based on Coro::EV, best choice.
-   AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
    AnyEvent::Impl::EV        based on EV (an interface to libev, best choice).
    AnyEvent::Impl::Event     based on Event, second best choice.
    AnyEvent::Impl::Perl      pure-perl implementation, fast and portable.
    AnyEvent::Impl::Glib      based on Glib, third-best choice.
    AnyEvent::Impl::Tk        based on Tk, very bad choice.
 Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
 if necessary. You should only call this function right before you would
 have created an AnyEvent watcher anyway, that is, as late as possible at
 runtime.
+=item $guard = AnyEvent::post_detect { BLOCK }
+Arranges for the code block to be executed as soon as the event model is
+autodetected (or immediately if this has already happened).
+If called in scalar or list context, then it creates and returns an object
+that automatically removes the callback again when it is destroyed. See
+L<Coro::BDB> for a case where this is useful.
+=item @AnyEvent::post_detect
+If there are any code references in this array (you can C<push> to it
+before or after loading AnyEvent), then they will called directly after
+the event loop has been chosen.
+You should check C<$AnyEvent::MODEL> before adding to this array, though:
+if it contains a true value then the event loop has already been detected,
+and the array will be ignored.
+Best use C<AnyEvent::post_detect { BLOCK }> instead.
 =back
 =head1 WHAT TO DO IN A MODULE
 As a module author, you should C<use AnyEvent> and call AnyEvent methods
 Be careful when you create watchers in the module body - AnyEvent will
 decide which event module to use as soon as the first method is called, so
 by calling AnyEvent in your module body you force the user of your module
 to load the event module first.
-Never call C<< ->wait >> on a condition variable unless you I<know> that
+Never call C<< ->recv >> on a condition variable unless you I<know> that
-the C<< ->broadcast >> method has been called on it already. This is
+the C<< ->send >> method has been called on it already. This is
 because it will stall the whole program, and the whole point of using
 events is to stay interactive.
-It is fine, however, to call C<< ->wait >> when the user of your module
+It is fine, however, to call C<< ->recv >> when the user of your module
 requests it (i.e. if you create a http request object ad have a method
-called C<results> that returns the results, it should call C<< ->wait >>
+called C<results> that returns the results, it should call C<< ->recv >>
 freely, as the user of your module knows what she is doing. always).
 =head1 WHAT TO DO IN THE MAIN PROGRAM
 There will always be a single main program - the only place that should
 =item L<AnyEvent::Handle>
 Provide read and write buffers and manages watchers for reads and writes.
-=item L<AnyEvent::Socket>
-Provides a means to do non-blocking connects, accepts etc.
 =item L<AnyEvent::HTTPD>
 Provides a simple web application server framework.
 =item L<AnyEvent::DNS>
 High level API for event-based execution flow control.
 =item L<Coro>
-Has special support for AnyEvent.
+Has special support for AnyEvent via L<Coro::AnyEvent>.
+=item L<AnyEvent::AIO>, L<IO::AIO>
+Truly asynchronous I/O, should be in the toolbox of every event
+programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
+together.
+=item L<AnyEvent::BDB>, L<BDB>
+Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
+IO::AIO and AnyEvent together.
 =item L<IO::Lambda>
 The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
-=item L<IO::AIO>
-Truly asynchronous I/O, should be in the toolbox of every event
-programmer. Can be trivially made to use AnyEvent.
-=item L<BDB>
-Truly asynchronous Berkeley DB access. Can be trivially made to use
-AnyEvent.
 =back
 =cut
 no warnings;
 use strict;
 use Carp;
-our $VERSION = '3.3';
+our $VERSION = '3.6';
 our $MODEL;
 our $AUTOLOAD;
 our @ISA;
 our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
 our @REGISTRY;
 my @models = (
-   [Coro::EV::             => AnyEvent::Impl::CoroEV::],
-   [Coro::Event::          => AnyEvent::Impl::CoroEvent::],
    [EV::                   => AnyEvent::Impl::EV::],
    [Event::                => AnyEvent::Impl::Event::],
    [Tk::                   => AnyEvent::Impl::Tk::],
    [Wx::                   => AnyEvent::Impl::POE::],
    [Prima::                => AnyEvent::Impl::POE::],
    [Event::Lib::           => AnyEvent::Impl::EventLib::], # too buggy
    [Qt::                   => AnyEvent::Impl::Qt::],       # requires special main program
    [POE::Kernel::          => AnyEvent::Impl::POE::],      # lasciate ogni speranza
 );
-our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);
+our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
+our @post_detect;
+sub post_detect(&) {
+   my ($cb) = @_;
+   if ($MODEL) {
+      $cb->();
+      1
+   } else {
+      push @post_detect, $cb;
+      defined wantarray
+         ? bless \$cb, "AnyEvent::Util::PostDetect"
+         : ()
+   }
+}
+sub AnyEvent::Util::PostDetect::DESTROY {
+   @post_detect = grep $_ != ${$_[0]}, @post_detect;
+}
 sub detect() {
    unless ($MODEL) {
       no strict 'refs';
                   last;
                }
             }
             $MODEL
-              or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib.";
+              or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
          }
       }
       unshift @ISA, $MODEL;
       push @{"$MODEL\::ISA"}, "AnyEvent::Base";
+      (shift @post_detect)->() while @post_detect;
    }
    $MODEL
 }
    $class->$func (@_);
 }
 package AnyEvent::Base;
-# default implementation for ->condvar, ->wait, ->broadcast
+# default implementation for ->condvar
 sub condvar {
-   bless \my $flag, "AnyEvent::Base::CondVar"
+   bless {}, AnyEvent::CondVar::
-}
-sub AnyEvent::Base::CondVar::broadcast {
-   ${$_[0]}++;
-}
-sub AnyEvent::Base::CondVar::wait {
-   AnyEvent->one_event while !${$_[0]};
 }
 # default implementation for ->signal
 our %SIG_CB;
    delete $PID_CB{$pid}{$cb};
    delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
    undef $CHLD_W unless keys %PID_CB;
 }
+package AnyEvent::CondVar;
+our @ISA = AnyEvent::CondVar::Base::;
+package AnyEvent::CondVar::Base;
+sub _send {
+   # nop
+}
+sub send {
+   my $cv = shift;
+   $cv->{_ae_sent} = [@_];
+   (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
+   $cv->_send;
+}
+sub croak {
+   $_[0]{_ae_croak} = $_[1];
+   $_[0]->send;
+}
+sub ready {
+   $_[0]{_ae_sent}
+}
+sub _wait {
+   AnyEvent->one_event while !$_[0]{_ae_sent};
+}
+sub recv {
+   $_[0]->_wait;
+   Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
+   wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
+}
+sub cb {
+   $_[0]{_ae_cb} = $_[1] if @_ > 1;
+   $_[0]{_ae_cb}
+}
+sub begin {
+   ++$_[0]{_ae_counter};
+   $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
+}
+sub end {
+   return if --$_[0]{_ae_counter};
+   &{ $_[0]{_ae_end_cb} } if $_[0]{_ae_end_cb};
+}
+# undocumented/compatibility with pre-3.4
+*broadcast = \&send;
+*wait      = \&_wait;
 =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
 This is an advanced topic that you do not normally need to use AnyEvent in
 a module. This section is only of use to event loop authors who want to
       poll => 'r',
       cb   => sub {
          warn "io event <$_[0]>\n";   # will always output <r>
          chomp (my $input = <STDIN>); # read a line
          warn "read: $input\n";       # output what has been read
-         $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i
+         $cv->send if $input =~ /^q/i; # quit program if /^q/i
       },
    );
    my $time_watcher; # can only be used once
       });
    }
    new_timer; # create first timer
-   $cv->wait; # wait until user enters /^q/i
+   $cv->recv; # wait until user enters /^q/i
 =head1 REAL-WORLD EXAMPLE
 Consider the L<Net::FCP> module. It features (among others) the following
 API calls, which are to freenet what HTTP GET requests are to http:
    sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
    if (end-of-file or data complete) {
      $txn->{result} = $txn->{buf};
-     $txn->{finished}->broadcast;
+     $txn->{finished}->send;
      $txb->{cb}->($txn) of $txn->{cb}; # also call callback
    }
 The C<result> method, finally, just waits for the finished signal (if the
 request was already finished, it doesn't wait, of course, and returns the
 data:
-   $txn->{finished}->wait;
+   $txn->{finished}->recv;
    return $txn->{result};
 The actual code goes further and collects all errors (C<die>s, exceptions)
 that occured during request processing. The C<result> method detects
 whether an exception as thrown (it is stored inside the $txn object)
    my $quit = AnyEvent->condvar;
    $fcp->txn_client_get ($url)->cb (sub {
       ...
-      $quit->broadcast;
+      $quit->send;
    });
-   $quit->wait;
+   $quit->recv;
 =head1 BENCHMARKS
 To give you an idea of the performance and overheads that AnyEvent adds
 all watchers, to avoid adding memory overhead. That means closure creation
 and memory usage is not included in the figures.
 I<invoke> is the time, in microseconds, used to invoke a simple
 callback. The callback simply counts down a Perl variable and after it was
-invoked "watcher" times, it would C<< ->broadcast >> a condvar once to
+invoked "watcher" times, it would C<< ->send >> a condvar once to
 signal the end of this phase.
 I<destroy> is the time, in microseconds, that it takes to destroy a single
 watcher.
   BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
   use AnyEvent;
+Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
+be used to probe what backend is used and gain other information (which is
+probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
 =head1 SEE ALSO
-Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,
+Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
-L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,
-L<Event::Lib>, L<Qt>, L<POE>.
+L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
-Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,
+Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
-L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,
+L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
-L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,
+L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
-L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.
+L<AnyEvent::Impl::POE>.
+Asynchronous DNS: L<AnyEvent::DNS>.
+Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
 Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.
 =head1 AUTHOR

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs. Revision 1.123 by root, Fri May 23 20:41:25 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.123 by root, Fri May 23 20:41:25 2008 UTC