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Comparing AnyEvent/README (file contents):
Revision 1.72 by root, Tue Dec 17 16:43:15 2013 UTC vs.
Revision 1.78 by root, Sat Jul 1 15:48:51 2017 UTC

1NAME 1NAME
2 AnyEvent - the DBI of event loop programming 2 AnyEvent - the DBI of event loop programming
3 3
4 EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, 4 EV, Event, Glib, Tk, UV, Perl, Event::Lib, Irssi, rxvt-unicode,
5 Qt, FLTK and POE are various supported event loops/environments. 5 IO::Async, Qt, FLTK and POE are various supported event
6 loops/environments.
6 7
7SYNOPSIS 8SYNOPSIS
8 use AnyEvent; 9 use AnyEvent;
9 10
10 # if you prefer function calls, look at the AE manpage for 11 # if you prefer function calls, look at the AE manpage for
811 $bool = $cv->ready 812 $bool = $cv->ready
812 Returns true when the condition is "true", i.e. whether "send" or 813 Returns true when the condition is "true", i.e. whether "send" or
813 "croak" have been called. 814 "croak" have been called.
814 815
815 $cb = $cv->cb ($cb->($cv)) 816 $cb = $cv->cb ($cb->($cv))
816 This is a mutator function that returns the callback set and 817 This is a mutator function that returns the callback set (or "undef"
817 optionally replaces it before doing so. 818 if not) and optionally replaces it before doing so.
818 819
819 The callback will be called when the condition becomes "true", i.e. 820 The callback will be called when the condition becomes "true", i.e.
820 when "send" or "croak" are called, with the only argument being the 821 when "send" or "croak" are called, with the only argument being the
821 condition variable itself. If the condition is already true, the 822 condition variable itself. If the condition is already true, the
822 callback is called immediately when it is set. Calling "recv" inside 823 callback is called immediately when it is set. Calling "recv" inside
823 the callback or at any later time is guaranteed not to block. 824 the callback or at any later time is guaranteed not to block.
825
826 Additionally, when the callback is invoked, it is also removed from
827 the condvar (reset to "undef"), so the condvar does not keep a
828 reference to the callback after invocation.
824 829
825SUPPORTED EVENT LOOPS/BACKENDS 830SUPPORTED EVENT LOOPS/BACKENDS
826 The available backend classes are (every class has its own manpage): 831 The available backend classes are (every class has its own manpage):
827 832
828 Backends that are autoprobed when no other event loop can be found. 833 Backends that are autoprobed when no other event loop can be found.
843 by the main program. 848 by the main program.
844 849
845 AnyEvent::Impl::Event based on Event, very stable, few glitches. 850 AnyEvent::Impl::Event based on Event, very stable, few glitches.
846 AnyEvent::Impl::Glib based on Glib, slow but very stable. 851 AnyEvent::Impl::Glib based on Glib, slow but very stable.
847 AnyEvent::Impl::Tk based on Tk, very broken. 852 AnyEvent::Impl::Tk based on Tk, very broken.
853 AnyEvent::Impl::UV based on UV, innovated square wheels.
848 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 854 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
849 AnyEvent::Impl::POE based on POE, very slow, some limitations. 855 AnyEvent::Impl::POE based on POE, very slow, some limitations.
850 AnyEvent::Impl::Irssi used when running within irssi. 856 AnyEvent::Impl::Irssi used when running within irssi.
851 AnyEvent::Impl::IOAsync based on IO::Async. 857 AnyEvent::Impl::IOAsync based on IO::Async.
852 AnyEvent::Impl::Cocoa based on Cocoa::EventLoop. 858 AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
908 $guard = AnyEvent::post_detect { BLOCK } 914 $guard = AnyEvent::post_detect { BLOCK }
909 Arranges for the code block to be executed as soon as the event 915 Arranges for the code block to be executed as soon as the event
910 model is autodetected (or immediately if that has already happened). 916 model is autodetected (or immediately if that has already happened).
911 917
912 The block will be executed *after* the actual backend has been 918 The block will be executed *after* the actual backend has been
913 detected ($AnyEvent::MODEL is set), but *before* any watchers have 919 detected ($AnyEvent::MODEL is set), so it is possible to do some
914 been created, so it is possible to e.g. patch @AnyEvent::ISA or do 920 initialisation only when AnyEvent is actually initialised - see the
915 other initialisations - see the sources of AnyEvent::Strict or
916 AnyEvent::AIO to see how this is used. 921 sources of AnyEvent::AIO to see how this is used.
917 922
918 The most common usage is to create some global watchers, without 923 The most common usage is to create some global watchers, without
919 forcing event module detection too early, for example, AnyEvent::AIO 924 forcing event module detection too early. For example, AnyEvent::AIO
920 creates and installs the global IO::AIO watcher in a "post_detect" 925 creates and installs the global IO::AIO watcher in a "post_detect"
921 block to avoid autodetecting the event module at load time. 926 block to avoid autodetecting the event module at load time.
922 927
923 If called in scalar or list context, then it creates and returns an 928 If called in scalar or list context, then it creates and returns an
924 object that automatically removes the callback again when it is 929 object that automatically removes the callback again when it is
940 # able to just C<undef $WATCHER> if the watcher causes them grief. 945 # able to just C<undef $WATCHER> if the watcher causes them grief.
941 946
942 $WATCHER ||= $guard; 947 $WATCHER ||= $guard;
943 948
944 @AnyEvent::post_detect 949 @AnyEvent::post_detect
945 If there are any code references in this array (you can "push" to it 950 This is a lower level interface then "AnyEvent::post_detect" (the
946 before or after loading AnyEvent), then they will be called directly 951 function). This variable is mainly useful for modules that can do
952 something useful when AnyEvent is used and thus want to know when it
953 is initialised, but do not need to even load it by default. This
954 array provides the means to hook into AnyEvent passively, without
955 loading it.
956
957 Here is how it works: If there are any code references in this array
958 (you can "push" to it before or after loading AnyEvent), then they
947 after the event loop has been chosen. 959 will be called directly after the event loop has been chosen.
948 960
949 You should check $AnyEvent::MODEL before adding to this array, 961 You should check $AnyEvent::MODEL before adding to this array,
950 though: if it is defined then the event loop has already been 962 though: if it is defined then the event loop has already been
951 detected, and the array will be ignored. 963 detected, and the array will be ignored.
952 964
953 Best use "AnyEvent::post_detect { BLOCK }" when your application 965 Best use "AnyEvent::post_detect { BLOCK }" when your application
954 allows it, as it takes care of these details. 966 allows it, as it takes care of these details.
955
956 This variable is mainly useful for modules that can do something
957 useful when AnyEvent is used and thus want to know when it is
958 initialised, but do not need to even load it by default. This array
959 provides the means to hook into AnyEvent passively, without loading
960 it.
961 967
962 Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used 968 Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
963 together, you could put this into Coro (this is the actual code used 969 together, you could put this into Coro (this is the actual code used
964 by Coro to accomplish this): 970 by Coro to accomplish this):
965 971
984 To understand the usefulness of this function, consider a function 990 To understand the usefulness of this function, consider a function
985 that asynchronously does something for you and returns some 991 that asynchronously does something for you and returns some
986 transaction object or guard to let you cancel the operation. For 992 transaction object or guard to let you cancel the operation. For
987 example, "AnyEvent::Socket::tcp_connect": 993 example, "AnyEvent::Socket::tcp_connect":
988 994
989 # start a conenction attempt unless one is active 995 # start a connection attempt unless one is active
990 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub { 996 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
991 delete $self->{connect_guard}; 997 delete $self->{connect_guard};
992 ... 998 ...
993 }; 999 };
994 1000
1028 If you want to sprinkle loads of logging calls around your code, 1034 If you want to sprinkle loads of logging calls around your code,
1029 consider creating a logger callback with the "AnyEvent::Log::logger" 1035 consider creating a logger callback with the "AnyEvent::Log::logger"
1030 function, which can reduce typing, codesize and can reduce the 1036 function, which can reduce typing, codesize and can reduce the
1031 logging overhead enourmously. 1037 logging overhead enourmously.
1032 1038
1039 AnyEvent::fh_block $filehandle
1040 AnyEvent::fh_unblock $filehandle
1041 Sets blocking or non-blocking behaviour for the given filehandle.
1042
1033WHAT TO DO IN A MODULE 1043WHAT TO DO IN A MODULE
1034 As a module author, you should "use AnyEvent" and call AnyEvent methods 1044 As a module author, you should "use AnyEvent" and call AnyEvent methods
1035 freely, but you should not load a specific event module or rely on it. 1045 freely, but you should not load a specific event module or rely on it.
1036 1046
1037 Be careful when you create watchers in the module body - AnyEvent will 1047 Be careful when you create watchers in the module body - AnyEvent will
1358 mentioned will be used, and preference will be given to protocols 1368 mentioned will be used, and preference will be given to protocols
1359 mentioned earlier in the list. 1369 mentioned earlier in the list.
1360 1370
1361 This variable can effectively be used for denial-of-service attacks 1371 This variable can effectively be used for denial-of-service attacks
1362 against local programs (e.g. when setuid), although the impact is 1372 against local programs (e.g. when setuid), although the impact is
1363 likely small, as the program has to handle conenction and other 1373 likely small, as the program has to handle connection and other
1364 failures anyways. 1374 failures anyways.
1365 1375
1366 Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over 1376 Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over
1367 IPv6, but support both and try to use both. 1377 IPv6, but support both and try to use both.
1368 "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to 1378 "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to
1602 my $txn = shift; 1612 my $txn = shift;
1603 my $data = $txn->result; 1613 my $data = $txn->result;
1604 ... 1614 ...
1605 }); 1615 });
1606 1616
1607 EV::loop; 1617 EV::run;
1608 1618
1609 3b. The module user could use AnyEvent, too: 1619 3b. The module user could use AnyEvent, too:
1610 1620
1611 use AnyEvent; 1621 use AnyEvent;
1612 1622
2119 2129
2120 Development/Debugging: AnyEvent::Strict (stricter checking), 2130 Development/Debugging: AnyEvent::Strict (stricter checking),
2121 AnyEvent::Debug (interactive shell, watcher tracing). 2131 AnyEvent::Debug (interactive shell, watcher tracing).
2122 2132
2123 Supported event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event, 2133 Supported event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event,
2124 Glib::Event, Glib, Tk, Event::Lib, Qt, POE, FLTK. 2134 Glib::Event, Glib, Tk, Event::Lib, Qt, POE, FLTK, Cocoa::EventLoop, UV.
2125 2135
2126 Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, 2136 Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event,
2127 AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, 2137 AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl,
2128 AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE, 2138 AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE,
2129 AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi, AnyEvent::Impl::FLTK. 2139 AnyEvent::Impl::IOAsync, AnyEvent::Impl::Irssi, AnyEvent::Impl::FLTK,
2140 AnyEvent::Impl::Cocoa, AnyEvent::Impl::UV.
2130 2141
2131 Non-blocking handles, pipes, stream sockets, TCP clients and servers: 2142 Non-blocking handles, pipes, stream sockets, TCP clients and servers:
2132 AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS. 2143 AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS.
2133 2144
2134 Asynchronous File I/O: AnyEvent::IO. 2145 Asynchronous File I/O: AnyEvent::IO.

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