--- AnyEvent/lib/AnyEvent.pm	2009/07/08 13:46:46	1.231
+++ AnyEvent/lib/AnyEvent.pm	2009/07/16 03:48:33	1.238
@@ -742,55 +742,117 @@
 
 =back
 
-=head1 GLOBAL VARIABLES AND FUNCTIONS
+=head1 SUPPORTED EVENT LOOPS/BACKENDS
 
-=over 4
+The available backend classes are (every class has its own manpage):
 
-=item $AnyEvent::MODEL
+=over 4
 
-Contains C<undef> until the first watcher is being created. Then it
-contains the event model that is being used, which is the name of the
-Perl class implementing the model. This class is usually one of the
-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>).
+=item Backends that are autoprobed when no other event loop can be found.
 
-The known classes so far are:
+EV is the preferred backend when no other event loop seems to be in
+use. If EV is not installed, then AnyEvent will try Event, and, failing
+that, will fall back to its own pure-perl implementation, which is
+available everywhere as it comes with AnyEvent itself.
 
-   AnyEvent::Impl::EV        based on EV (an interface to libev, best choice).
-   AnyEvent::Impl::Event     based on Event, second best choice.
+   AnyEvent::Impl::EV        based on EV (interface to libev, best choice).
+   AnyEvent::Impl::Event     based on Event, very stable, few glitches.
    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.
-   AnyEvent::Impl::Qt        based on Qt, cannot be autoprobed (see its docs).
+
+=item Backends that are transparently being picked up when they are used.
+
+These will be used when they are currently loaded when the first watcher
+is created, in which case it is assumed that the application is using
+them. This means that AnyEvent will automatically pick the right backend
+when the main program loads an event module before anything starts to
+create watchers. Nothing special needs to be done by the main program.
+
+   AnyEvent::Impl::Glib      based on Glib, slow but very stable.
+   AnyEvent::Impl::Tk        based on Tk, very broken.
    AnyEvent::Impl::EventLib  based on Event::Lib, leaks memory and worse.
-   AnyEvent::Impl::POE       based on POE, not generic enough for full support.
+   AnyEvent::Impl::POE       based on POE, very slow, some limitations.
+
+=item Backends with special needs.
+
+Qt requires the Qt::Application to be instantiated first, but will
+otherwise be picked up automatically. As long as the main program
+instantiates the application before any AnyEvent watchers are created,
+everything should just work.
+
+   AnyEvent::Impl::Qt        based on Qt.
+
+Support for IO::Async can only be partial, as it is too broken and
+architecturally limited to even support the AnyEvent API. It also
+is the only event loop that needs the loop to be set explicitly, so
+it can only be used by a main program knowing about AnyEvent. See
+L<AnyEvent::Impl::Async> for the gory details.
+
+   AnyEvent::Impl::IOAsync   based on IO::Async, cannot be autoprobed.
+
+=item Event loops that are indirectly supported via other backends.
+
+Some event loops can be supported via other modules:
+
+There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
+
+B<WxWidgets> has no support for watching file handles. However, you can
+use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
+polls 20 times per second, which was considered to be too horrible to even
+consider for AnyEvent.
 
-   # warning, support for IO::Async is only partial, as it is too broken
-   # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
-   AnyEvent::Impl::IOAsync   based on IO::Async, cannot be autoprobed (see its docs).
-
-There is no support for WxWidgets, as WxWidgets has no support for
-watching file handles. However, you can use WxWidgets through the
-POE Adaptor, as POE has a Wx backend that simply polls 20 times per
-second, which was considered to be too horrible to even consider for
-AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
-it's adaptor.
+B<Prima> is not supported as nobody seems to be using it, but it has a POE
+backend, so it can be supported through POE.
 
-AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
-autodetecting them.
+AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
+load L<POE> when detecting them, in the hope that POE will pick them up,
+in which case everything will be automatic.
+
+=back
+
+=head1 GLOBAL VARIABLES AND FUNCTIONS
+
+These are not normally required to use AnyEvent, but can be useful to
+write AnyEvent extension modules.
+
+=over 4
+
+=item $AnyEvent::MODEL
+
+Contains C<undef> until the first watcher is being created, before the
+backend has been autodetected.
+
+Afterwards it contains the event model that is being used, which is the
+name of the Perl class implementing the model. This class is usually one
+of the 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> it
+will be C<urxvt::anyevent>).
 
 =item AnyEvent::detect
 
 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.
+runtime, and not e.g. while initialising of your module.
+
+If you need to do some initialisation before AnyEvent watchers are
+created, use C<post_detect>.
 
 =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).
 
+The block will be executed I<after> the actual backend has been detected
+(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
+created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
+other initialisations - see the sources of L<AnyEvent::Strict> or
+L<AnyEvent::AIO> to see how this is used.
+
+The most common usage is to create some global watchers, without forcing
+event module detection too early, for example, L<AnyEvent::AIO> creates
+and installs the global L<IO::AIO> watcher in a C<post_detect> block to
+avoid autodetecting the event module at load time.
+
 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.
@@ -802,10 +864,16 @@
 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.
+if it is defined then the event loop has already been detected, and the
+array will be ignored.
+
+Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
+it,as it takes care of these details.
 
-Best use C<AnyEvent::post_detect { BLOCK }> instead.
+This variable is mainly useful for modules that can do something useful
+when AnyEvent is used and thus want to know when it is initialised, but do
+not need to even load it by default. This array provides the means to hook
+into AnyEvent passively, without loading it.
 
 =back
 
@@ -967,7 +1035,7 @@
 
 use Carp;
 
-our $VERSION = 4.801;
+our $VERSION = 4.82;
 our $MODEL;
 
 our $AUTOLOAD;
@@ -1003,14 +1071,14 @@
    # everything below here will not be autoprobed
    # as the pureperl backend should work everywhere
    # and is usually faster
-   [Tk::                   => AnyEvent::Impl::Tk::],       # crashes with many handles
    [Glib::                 => AnyEvent::Impl::Glib::],     # becomes extremely slow with many watchers
    [Event::Lib::           => AnyEvent::Impl::EventLib::], # too buggy
+   [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::],
-   # IO::Async is just too broken - we would need workaorunds for its
+   # IO::Async is just too broken - we would need workarounds for its
    # byzantine signal and broken child handling, among others.
    # IO::Async is rather hard to detect, as it doesn't have any
    # obvious default class.
@@ -1053,9 +1121,9 @@
          my $model = "AnyEvent::Impl::$1";
          if (eval "require $model") {
             $MODEL = $model;
-            warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;
+            warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;
          } else {
-            warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;
+            warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
          }
       }
 
@@ -2034,8 +2102,8 @@
 emulation for event loops that do not support them natively. Also, some
 event loops install a similar handler.
 
-If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will
-reset it to default, to avoid losing child exit statuses.
+Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
+AnyEvent will reset it to default, to avoid losing child exit statuses.
 
 =item SIGPIPE