1 | NAME |
1 | NAME |
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, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, |
5 | Qt and POE are various supported event loops/environments. |
5 | Qt, FLTK and POE are various supported event loops/environments. |
6 | |
6 | |
7 | SYNOPSIS |
7 | SYNOPSIS |
8 | use AnyEvent; |
8 | use AnyEvent; |
9 | |
9 | |
10 | # if you prefer function calls, look at the AE manpage for |
10 | # if you prefer function calls, look at the AE manpage for |
… | |
… | |
262 | |
262 | |
263 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
263 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
264 | |
264 | |
265 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
265 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
266 | warn "timeout\n"; |
266 | warn "timeout\n"; |
267 | }; |
267 | }); |
268 | |
268 | |
269 | TIMING ISSUES |
269 | TIMING ISSUES |
270 | There are two ways to handle timers: based on real time (relative, "fire |
270 | There are two ways to handle timers: based on real time (relative, "fire |
271 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
271 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
272 | o'clock"). |
272 | o'clock"). |
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403 | will not restart syscalls (that includes Async::Interrupt and AnyEvent's |
403 | will not restart syscalls (that includes Async::Interrupt and AnyEvent's |
404 | pure perl implementation). |
404 | pure perl implementation). |
405 | |
405 | |
406 | Safe/Unsafe Signals |
406 | Safe/Unsafe Signals |
407 | Perl signals can be either "safe" (synchronous to opcode handling) or |
407 | Perl signals can be either "safe" (synchronous to opcode handling) or |
408 | "unsafe" (asynchronous) - the former might get delayed indefinitely, the |
408 | "unsafe" (asynchronous) - the former might delay signal delivery |
409 | latter might corrupt your memory. |
409 | indefinitely, the latter might corrupt your memory. |
410 | |
410 | |
411 | AnyEvent signal handlers are, in addition, synchronous to the event |
411 | AnyEvent signal handlers are, in addition, synchronous to the event |
412 | loop, i.e. they will not interrupt your running perl program but will |
412 | loop, i.e. they will not interrupt your running perl program but will |
413 | only be called as part of the normal event handling (just like timer, |
413 | only be called as part of the normal event handling (just like timer, |
414 | I/O etc. callbacks, too). |
414 | I/O etc. callbacks, too). |
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416 | Signal Races, Delays and Workarounds |
416 | Signal Races, Delays and Workarounds |
417 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
417 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
418 | callbacks to signals in a generic way, which is a pity, as you cannot do |
418 | callbacks to signals in a generic way, which is a pity, as you cannot do |
419 | race-free signal handling in perl, requiring C libraries for this. |
419 | race-free signal handling in perl, requiring C libraries for this. |
420 | AnyEvent will try to do its best, which means in some cases, signals |
420 | AnyEvent will try to do its best, which means in some cases, signals |
421 | will be delayed. The maximum time a signal might be delayed is specified |
421 | will be delayed. The maximum time a signal might be delayed is 10 |
422 | in $AnyEvent::MAX_SIGNAL_LATENCY (default: 10 seconds). This variable |
422 | seconds by default, but can be overriden via |
423 | can be changed only before the first signal watcher is created, and |
423 | $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} or $AnyEvent::MAX_SIGNAL_LATENCY |
424 | should be left alone otherwise. This variable determines how often |
424 | - see the "ENVIRONMENT VARIABLES" section for details. |
425 | AnyEvent polls for signals (in case a wake-up was missed). Higher values |
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426 | will cause fewer spurious wake-ups, which is better for power and CPU |
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427 | saving. |
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428 | |
425 | |
429 | All these problems can be avoided by installing the optional |
426 | All these problems can be avoided by installing the optional |
430 | Async::Interrupt module, which works with most event loops. It will not |
427 | Async::Interrupt module, which works with most event loops. It will not |
431 | work with inherently broken event loops such as Event or Event::Lib (and |
428 | work with inherently broken event loops such as Event or Event::Lib (and |
432 | not with POE currently, as POE does its own workaround with one-second |
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433 | latency). For those, you just have to suffer the delays. |
429 | not with POE currently). For those, you just have to suffer the delays. |
434 | |
430 | |
435 | CHILD PROCESS WATCHERS |
431 | CHILD PROCESS WATCHERS |
436 | $w = AnyEvent->child (pid => <process id>, cb => <callback>); |
432 | $w = AnyEvent->child (pid => <process id>, cb => <callback>); |
437 | |
433 | |
438 | You can also watch for a child process exit and catch its exit status. |
434 | You can also watch for a child process exit and catch its exit status. |
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… | |
740 | }; |
736 | }; |
741 | } |
737 | } |
742 | |
738 | |
743 | $cv->end; |
739 | $cv->end; |
744 | |
740 | |
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741 | ... |
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742 | |
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743 | my $results = $cv->recv; |
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744 | |
745 | This code fragment supposedly pings a number of hosts and calls |
745 | This code fragment supposedly pings a number of hosts and calls |
746 | "send" after results for all then have have been gathered - in any |
746 | "send" after results for all then have have been gathered - in any |
747 | order. To achieve this, the code issues a call to "begin" when it |
747 | order. To achieve this, the code issues a call to "begin" when it |
748 | starts each ping request and calls "end" when it has received some |
748 | starts each ping request and calls "end" when it has received some |
749 | result for it. Since "begin" and "end" only maintain a counter, the |
749 | result for it. Since "begin" and "end" only maintain a counter, the |
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778 | In list context, all parameters passed to "send" will be returned, |
778 | In list context, all parameters passed to "send" will be returned, |
779 | in scalar context only the first one will be returned. |
779 | in scalar context only the first one will be returned. |
780 | |
780 | |
781 | Note that doing a blocking wait in a callback is not supported by |
781 | Note that doing a blocking wait in a callback is not supported by |
782 | any event loop, that is, recursive invocation of a blocking "->recv" |
782 | any event loop, that is, recursive invocation of a blocking "->recv" |
783 | is not allowed, and the "recv" call will "croak" if such a condition |
783 | is not allowed and the "recv" call will "croak" if such a condition |
784 | is detected. This condition can be slightly loosened by using |
784 | is detected. This requirement can be dropped by relying on |
785 | Coro::AnyEvent, which allows you to do a blocking "->recv" from any |
785 | Coro::AnyEvent , which allows you to do a blocking "->recv" from any |
786 | thread that doesn't run the event loop itself. |
786 | thread that doesn't run the event loop itself. Coro::AnyEvent is |
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787 | loaded automatically when Coro is used with AnyEvent, so code does |
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788 | not need to do anything special to take advantage of that: any code |
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789 | that would normally block your program because it calls "recv", be |
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790 | executed in an "async" thread instead without blocking other |
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791 | threads. |
787 | |
792 | |
788 | Not all event models support a blocking wait - some die in that case |
793 | Not all event models support a blocking wait - some die in that case |
789 | (programs might want to do that to stay interactive), so *if you are |
794 | (programs might want to do that to stay interactive), so *if you are |
790 | using this from a module, never require a blocking wait*. Instead, |
795 | using this from a module, never require a blocking wait*. Instead, |
791 | let the caller decide whether the call will block or not (for |
796 | let the caller decide whether the call will block or not (for |
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839 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
844 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
840 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
845 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
841 | AnyEvent::Impl::Irssi used when running within irssi. |
846 | AnyEvent::Impl::Irssi used when running within irssi. |
842 | AnyEvent::Impl::IOAsync based on IO::Async. |
847 | AnyEvent::Impl::IOAsync based on IO::Async. |
843 | AnyEvent::Impl::Cocoa based on Cocoa::EventLoop. |
848 | AnyEvent::Impl::Cocoa based on Cocoa::EventLoop. |
844 | AnyEvent::Impl::FLTK2 based on FLTK (fltk 2 binding). |
849 | AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding). |
845 | |
850 | |
846 | Backends with special needs. |
851 | Backends with special needs. |
847 | Qt requires the Qt::Application to be instantiated first, but will |
852 | Qt requires the Qt::Application to be instantiated first, but will |
848 | otherwise be picked up automatically. As long as the main program |
853 | otherwise be picked up automatically. As long as the main program |
849 | instantiates the application before any AnyEvent watchers are |
854 | instantiates the application before any AnyEvent watchers are |
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1002 | It should use "postpone": |
1007 | It should use "postpone": |
1003 | |
1008 | |
1004 | AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later |
1009 | AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later |
1005 | if $some_error_condition; |
1010 | if $some_error_condition; |
1006 | |
1011 | |
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1012 | AnyEvent::log $level, $msg[, @args] |
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1013 | Log the given $msg at the given $level. |
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1014 | |
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1015 | If AnyEvent::Log is not loaded then this function makes a simple |
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1016 | test to see whether the message will be logged. If the test succeeds |
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1017 | it will load AnyEvent::Log and call "AnyEvent::Log::log" - |
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1018 | consequently, look at the AnyEvent::Log documentation for details. |
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1019 | |
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1020 | If the test fails it will simply return. Right now this happens when |
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1021 | a numerical loglevel is used and it is larger than the level |
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1022 | specified via $ENV{PERL_ANYEVENT_VERBOSE}. |
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1023 | |
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1024 | If you want to sprinkle loads of logging calls around your code, |
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1025 | consider creating a logger callback with the "AnyEvent::Log::logger" |
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1026 | function, which can reduce typing, codesize and can reduce the |
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1027 | logging overhead enourmously. |
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1028 | |
1007 | WHAT TO DO IN A MODULE |
1029 | WHAT TO DO IN A MODULE |
1008 | As a module author, you should "use AnyEvent" and call AnyEvent methods |
1030 | As a module author, you should "use AnyEvent" and call AnyEvent methods |
1009 | freely, but you should not load a specific event module or rely on it. |
1031 | freely, but you should not load a specific event module or rely on it. |
1010 | |
1032 | |
1011 | Be careful when you create watchers in the module body - AnyEvent will |
1033 | Be careful when you create watchers in the module body - AnyEvent will |
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… | |
1064 | |
1086 | |
1065 | OTHER MODULES |
1087 | OTHER MODULES |
1066 | The following is a non-exhaustive list of additional modules that use |
1088 | The following is a non-exhaustive list of additional modules that use |
1067 | AnyEvent as a client and can therefore be mixed easily with other |
1089 | AnyEvent as a client and can therefore be mixed easily with other |
1068 | AnyEvent modules and other event loops in the same program. Some of the |
1090 | AnyEvent modules and other event loops in the same program. Some of the |
1069 | modules come as part of AnyEvent, the others are available via CPAN. |
1091 | modules come as part of AnyEvent, the others are available via CPAN (see |
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1092 | <http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for a longer |
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1093 | non-exhaustive list), and the list is heavily biased towards modules of |
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1094 | the AnyEvent author himself :) |
1070 | |
1095 | |
1071 | AnyEvent::Util |
1096 | AnyEvent::Util (part of the AnyEvent distribution) |
1072 | Contains various utility functions that replace often-used blocking |
1097 | Contains various utility functions that replace often-used blocking |
1073 | functions such as "inet_aton" with event/callback-based versions. |
1098 | functions such as "inet_aton" with event/callback-based versions. |
1074 | |
1099 | |
1075 | AnyEvent::Socket |
1100 | AnyEvent::Socket (part of the AnyEvent distribution) |
1076 | Provides various utility functions for (internet protocol) sockets, |
1101 | Provides various utility functions for (internet protocol) sockets, |
1077 | addresses and name resolution. Also functions to create non-blocking |
1102 | addresses and name resolution. Also functions to create non-blocking |
1078 | tcp connections or tcp servers, with IPv6 and SRV record support and |
1103 | tcp connections or tcp servers, with IPv6 and SRV record support and |
1079 | more. |
1104 | more. |
1080 | |
1105 | |
1081 | AnyEvent::Handle |
1106 | AnyEvent::Handle (part of the AnyEvent distribution) |
1082 | Provide read and write buffers, manages watchers for reads and |
1107 | Provide read and write buffers, manages watchers for reads and |
1083 | writes, supports raw and formatted I/O, I/O queued and fully |
1108 | writes, supports raw and formatted I/O, I/O queued and fully |
1084 | transparent and non-blocking SSL/TLS (via AnyEvent::TLS). |
1109 | transparent and non-blocking SSL/TLS (via AnyEvent::TLS). |
1085 | |
1110 | |
1086 | AnyEvent::DNS |
1111 | AnyEvent::DNS (part of the AnyEvent distribution) |
1087 | Provides rich asynchronous DNS resolver capabilities. |
1112 | Provides rich asynchronous DNS resolver capabilities. |
1088 | |
1113 | |
1089 | AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD, |
1114 | AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD, |
1090 | AnyEvent::IGS, AnyEvent::FCP |
1115 | AnyEvent::IGS, AnyEvent::FCP |
1091 | Implement event-based interfaces to the protocols of the same name |
1116 | Implement event-based interfaces to the protocols of the same name |
1092 | (for the curious, IGS is the International Go Server and FCP is the |
1117 | (for the curious, IGS is the International Go Server and FCP is the |
1093 | Freenet Client Protocol). |
1118 | Freenet Client Protocol). |
1094 | |
1119 | |
1095 | AnyEvent::Handle::UDP |
1120 | AnyEvent::AIO (part of the AnyEvent distribution) |
1096 | Here be danger! |
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1097 | |
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1098 | As Pauli would put it, "Not only is it not right, it's not even |
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1099 | wrong!" - there are so many things wrong with AnyEvent::Handle::UDP, |
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1100 | most notably its use of a stream-based API with a protocol that |
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1101 | isn't streamable, that the only way to improve it is to delete it. |
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1102 | |
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1103 | It features data corruption (but typically only under load) and |
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1104 | general confusion. On top, the author is not only clueless about UDP |
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1105 | but also fact-resistant - some gems of his understanding: "connect |
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1106 | doesn't work with UDP", "UDP packets are not IP packets", "UDP only |
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1107 | has datagrams, not packets", "I don't need to implement proper error |
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1108 | checking as UDP doesn't support error checking" and so on - he |
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1109 | doesn't even understand what's wrong with his module when it is |
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1110 | explained to him. |
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1111 | |
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1112 | AnyEvent::DBI |
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1113 | Executes DBI requests asynchronously in a proxy process for you, |
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1114 | notifying you in an event-based way when the operation is finished. |
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1115 | |
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1116 | AnyEvent::AIO |
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1117 | Truly asynchronous (as opposed to non-blocking) I/O, should be in |
1121 | Truly asynchronous (as opposed to non-blocking) I/O, should be in |
1118 | the toolbox of every event programmer. AnyEvent::AIO transparently |
1122 | the toolbox of every event programmer. AnyEvent::AIO transparently |
1119 | fuses IO::AIO and AnyEvent together, giving AnyEvent access to |
1123 | fuses IO::AIO and AnyEvent together, giving AnyEvent access to |
1120 | event-based file I/O, and much more. |
1124 | event-based file I/O, and much more. |
1121 | |
1125 | |
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1126 | AnyEvent::Filesys::Notify |
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1127 | AnyEvent is good for non-blocking stuff, but it can't detect file or |
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1128 | path changes (e.g. "watch this directory for new files", "watch this |
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1129 | file for changes"). The AnyEvent::Filesys::Notify module promises to |
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1130 | do just that in a portbale fashion, supporting inotify on GNU/Linux |
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1131 | and some weird, without doubt broken, stuff on OS X to monitor |
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1132 | files. It can fall back to blocking scans at regular intervals |
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1133 | transparently on other platforms, so it's about as portable as it |
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1134 | gets. |
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1135 | |
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1136 | (I haven't used it myself, but I haven't heard anybody complaining |
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1137 | about it yet). |
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1138 | |
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1139 | AnyEvent::DBI |
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1140 | Executes DBI requests asynchronously in a proxy process for you, |
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1141 | notifying you in an event-based way when the operation is finished. |
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1142 | |
1122 | AnyEvent::HTTPD |
1143 | AnyEvent::HTTPD |
1123 | A simple embedded webserver. |
1144 | A simple embedded webserver. |
1124 | |
1145 | |
1125 | AnyEvent::FastPing |
1146 | AnyEvent::FastPing |
1126 | The fastest ping in the west. |
1147 | The fastest ping in the west. |
1127 | |
1148 | |
1128 | Coro |
1149 | Coro |
1129 | Has special support for AnyEvent via Coro::AnyEvent. |
1150 | Has special support for AnyEvent via Coro::AnyEvent, which allows |
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1151 | you to simply invert the flow control - don't call us, we will call |
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1152 | you: |
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1153 | |
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1154 | async { |
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1155 | Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it |
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1156 | print "5 seconds later!\n"; |
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1157 | |
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1158 | Coro::AnyEvent::readable *STDIN; # uses an I/O watcher |
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1159 | my $line = <STDIN>; # works for ttys |
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1160 | |
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1161 | AnyEvent::HTTP::http_get "url", Coro::rouse_cb; |
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1162 | my ($body, $hdr) = Coro::rouse_wait; |
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1163 | }; |
1130 | |
1164 | |
1131 | SIMPLIFIED AE API |
1165 | SIMPLIFIED AE API |
1132 | Starting with version 5.0, AnyEvent officially supports a second, much |
1166 | Starting with version 5.0, AnyEvent officially supports a second, much |
1133 | simpler, API that is designed to reduce the calling, typing and memory |
1167 | simpler, API that is designed to reduce the calling, typing and memory |
1134 | overhead by using function call syntax and a fixed number of parameters. |
1168 | overhead by using function call syntax and a fixed number of parameters. |
… | |
… | |
1150 | The pure perl event loop simply re-throws the exception (usually within |
1184 | The pure perl event loop simply re-throws the exception (usually within |
1151 | "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()", |
1185 | "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()", |
1152 | Glib uses "install_exception_handler" and so on. |
1186 | Glib uses "install_exception_handler" and so on. |
1153 | |
1187 | |
1154 | ENVIRONMENT VARIABLES |
1188 | ENVIRONMENT VARIABLES |
1155 | The following environment variables are used by this module or its |
1189 | AnyEvent supports a number of environment variables that tune the |
1156 | submodules. |
1190 | runtime behaviour. They are usually evaluated when AnyEvent is loaded, |
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1191 | initialised, or a submodule that uses them is loaded. Many of them also |
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1192 | cause AnyEvent to load additional modules - for example, |
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1193 | "PERL_ANYEVENT_DEBUG_WRAP" causes the AnyEvent::Debug module to be |
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1194 | loaded. |
1157 | |
1195 | |
1158 | Note that AnyEvent will remove *all* environment variables starting with |
1196 | All the environment variables documented here start with |
1159 | "PERL_ANYEVENT_" from %ENV when it is loaded while taint mode is |
1197 | "PERL_ANYEVENT_", which is what AnyEvent considers its own namespace. |
1160 | enabled. |
1198 | Other modules are encouraged (but by no means required) to use |
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1199 | "PERL_ANYEVENT_SUBMODULE" if they have registered the |
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1200 | AnyEvent::Submodule namespace on CPAN, for any submodule. For example, |
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1201 | AnyEvent::HTTP could be expected to use "PERL_ANYEVENT_HTTP_PROXY" (it |
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1202 | should not access env variables starting with "AE_", see below). |
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1203 | |
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1204 | All variables can also be set via the "AE_" prefix, that is, instead of |
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1205 | setting "PERL_ANYEVENT_VERBOSE" you can also set "AE_VERBOSE". In case |
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1206 | there is a clash btween anyevent and another program that uses |
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1207 | "AE_something" you can set the corresponding "PERL_ANYEVENT_something" |
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1208 | variable to the empty string, as those variables take precedence. |
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1209 | |
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1210 | When AnyEvent is first loaded, it copies all "AE_xxx" env variables to |
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1211 | their "PERL_ANYEVENT_xxx" counterpart unless that variable already |
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1212 | exists. If taint mode is on, then AnyEvent will remove *all* environment |
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1213 | variables starting with "PERL_ANYEVENT_" from %ENV (or replace them with |
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1214 | "undef" or the empty string, if the corresaponding "AE_" variable is |
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1215 | set). |
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1216 | |
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1217 | The exact algorithm is currently: |
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1218 | |
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1219 | 1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV |
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1220 | 2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists |
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1221 | 3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef. |
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1222 | |
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1223 | This ensures that child processes will not see the "AE_" variables. |
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1224 | |
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1225 | The following environment variables are currently known to AnyEvent: |
1161 | |
1226 | |
1162 | "PERL_ANYEVENT_VERBOSE" |
1227 | "PERL_ANYEVENT_VERBOSE" |
1163 | By default, AnyEvent will be completely silent except in fatal |
1228 | By default, AnyEvent will log messages with loglevel 4 ("error") or |
1164 | conditions. You can set this environment variable to make AnyEvent |
1229 | higher (see AnyEvent::Log). You can set this environment variable to |
1165 | more talkative. |
1230 | a numerical loglevel to make AnyEvent more (or less) talkative. |
1166 | |
1231 | |
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1232 | If you want to do more than just set the global logging level you |
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1233 | should have a look at "PERL_ANYEVENT_LOG", which allows much more |
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1234 | complex specifications. |
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1235 | |
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1236 | When set to 0 ("off"), then no messages whatsoever will be logged |
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1237 | with everything else at defaults. |
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1238 | |
1167 | When set to 1 or higher, causes AnyEvent to warn about unexpected |
1239 | When set to 5 or higher ("warn"), AnyEvent warns about unexpected |
1168 | conditions, such as not being able to load the event model specified |
1240 | conditions, such as not being able to load the event model specified |
1169 | by "PERL_ANYEVENT_MODEL". |
1241 | by "PERL_ANYEVENT_MODEL", or a guard callback throwing an exception |
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1242 | - this is the minimum recommended level for use during development. |
1170 | |
1243 | |
1171 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
1244 | When set to 7 or higher (info), AnyEvent reports which event model |
1172 | event model it chooses. |
1245 | it chooses. |
1173 | |
1246 | |
1174 | When set to 8 or higher, then AnyEvent will report extra information |
1247 | When set to 8 or higher (debug), then AnyEvent will report extra |
1175 | on which optional modules it loads and how it implements certain |
1248 | information on which optional modules it loads and how it implements |
1176 | features. |
1249 | certain features. |
|
|
1250 | |
|
|
1251 | "PERL_ANYEVENT_LOG" |
|
|
1252 | Accepts rather complex logging specifications. For example, you |
|
|
1253 | could log all "debug" messages of some module to stderr, warnings |
|
|
1254 | and above to stderr, and errors and above to syslog, with: |
|
|
1255 | |
|
|
1256 | PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog |
|
|
1257 | |
|
|
1258 | For the rather extensive details, see AnyEvent::Log. |
|
|
1259 | |
|
|
1260 | This variable is evaluated when AnyEvent (or AnyEvent::Log) is |
|
|
1261 | loaded, so will take effect even before AnyEvent has initialised |
|
|
1262 | itself. |
|
|
1263 | |
|
|
1264 | Note that specifying this environment variable causes the |
|
|
1265 | AnyEvent::Log module to be loaded, while "PERL_ANYEVENT_VERBOSE" |
|
|
1266 | does not, so only using the latter saves a few hundred kB of memory |
|
|
1267 | unless a module explicitly needs the extra features of |
|
|
1268 | AnyEvent::Log. |
1177 | |
1269 | |
1178 | "PERL_ANYEVENT_STRICT" |
1270 | "PERL_ANYEVENT_STRICT" |
1179 | AnyEvent does not do much argument checking by default, as thorough |
1271 | AnyEvent does not do much argument checking by default, as thorough |
1180 | argument checking is very costly. Setting this variable to a true |
1272 | argument checking is very costly. Setting this variable to a true |
1181 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
1273 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
… | |
… | |
1188 | is definitely recommended to keep it off in production. Keeping |
1280 | is definitely recommended to keep it off in production. Keeping |
1189 | "PERL_ANYEVENT_STRICT=1" in your environment while developing |
1281 | "PERL_ANYEVENT_STRICT=1" in your environment while developing |
1190 | programs can be very useful, however. |
1282 | programs can be very useful, however. |
1191 | |
1283 | |
1192 | "PERL_ANYEVENT_DEBUG_SHELL" |
1284 | "PERL_ANYEVENT_DEBUG_SHELL" |
1193 | If this env variable is set, then its contents will be interpreted |
1285 | If this env variable is nonempty, then its contents will be |
1194 | by "AnyEvent::Socket::parse_hostport" (after replacing every |
1286 | interpreted by "AnyEvent::Socket::parse_hostport" and |
1195 | occurance of $$ by the process pid) and an "AnyEvent::Debug::shell" |
1287 | "AnyEvent::Debug::shell" (after replacing every occurance of $$ by |
1196 | is bound on that port. The shell object is saved in |
1288 | the process pid). The shell object is saved in |
1197 | $AnyEvent::Debug::SHELL. |
1289 | $AnyEvent::Debug::SHELL. |
1198 | |
1290 | |
1199 | This takes place when the first watcher is created. |
1291 | This happens when the first watcher is created. |
1200 | |
1292 | |
1201 | For example, to bind a debug shell on a unix domain socket in |
1293 | For example, to bind a debug shell on a unix domain socket in |
1202 | /tmp/debug<pid>.sock, you could use this: |
1294 | /tmp/debug<pid>.sock, you could use this: |
1203 | |
1295 | |
1204 | PERL_ANYEVENT_DEBUG_SHELL=unix/:/tmp/debug\$\$.sock perlprog |
1296 | PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog |
|
|
1297 | # connect with e.g.: socat readline /tmp/debug123.sock |
1205 | |
1298 | |
|
|
1299 | Or to bind to tcp port 4545 on localhost: |
|
|
1300 | |
|
|
1301 | PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog |
|
|
1302 | # connect with e.g.: telnet localhost 4545 |
|
|
1303 | |
1206 | Note that creating sockets in /tmp is very unsafe on multiuser |
1304 | Note that creating sockets in /tmp or on localhost is very unsafe on |
1207 | systems. |
1305 | multiuser systems. |
1208 | |
1306 | |
1209 | "PERL_ANYEVENT_DEBUG_WRAP" |
1307 | "PERL_ANYEVENT_DEBUG_WRAP" |
1210 | Can be set to 0, 1 or 2 and enables wrapping of all watchers for |
1308 | Can be set to 0, 1 or 2 and enables wrapping of all watchers for |
1211 | debugging purposes. See "AnyEvent::Debug::wrap" for details. |
1309 | debugging purposes. See "AnyEvent::Debug::wrap" for details. |
1212 | |
1310 | |
… | |
… | |
1227 | |
1325 | |
1228 | For example, to force the pure perl model (AnyEvent::Loop::Perl) you |
1326 | For example, to force the pure perl model (AnyEvent::Loop::Perl) you |
1229 | could start your program like this: |
1327 | could start your program like this: |
1230 | |
1328 | |
1231 | PERL_ANYEVENT_MODEL=Perl perl ... |
1329 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1330 | |
|
|
1331 | "PERL_ANYEVENT_IO_MODEL" |
|
|
1332 | The current file I/O model - see AnyEvent::IO for more info. |
|
|
1333 | |
|
|
1334 | At the moment, only "Perl" (small, pure-perl, synchronous) and |
|
|
1335 | "IOAIO" (truly asynchronous) are supported. The default is "IOAIO" |
|
|
1336 | if AnyEvent::AIO can be loaded, otherwise it is "Perl". |
1232 | |
1337 | |
1233 | "PERL_ANYEVENT_PROTOCOLS" |
1338 | "PERL_ANYEVENT_PROTOCOLS" |
1234 | Used by both AnyEvent::DNS and AnyEvent::Socket to determine |
1339 | Used by both AnyEvent::DNS and AnyEvent::Socket to determine |
1235 | preferences for IPv4 or IPv6. The default is unspecified (and might |
1340 | preferences for IPv4 or IPv6. The default is unspecified (and might |
1236 | change, or be the result of auto probing). |
1341 | change, or be the result of auto probing). |
… | |
… | |
1250 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
1355 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
1251 | resolve or contact IPv6 addresses. |
1356 | resolve or contact IPv6 addresses. |
1252 | "PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4" support either IPv4 or IPv6, but |
1357 | "PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4" support either IPv4 or IPv6, but |
1253 | prefer IPv6 over IPv4. |
1358 | prefer IPv6 over IPv4. |
1254 | |
1359 | |
|
|
1360 | "PERL_ANYEVENT_HOSTS" |
|
|
1361 | This variable, if specified, overrides the /etc/hosts file used by |
|
|
1362 | AnyEvent::Socket"::resolve_sockaddr", i.e. hosts aliases will be |
|
|
1363 | read from that file instead. |
|
|
1364 | |
1255 | "PERL_ANYEVENT_EDNS0" |
1365 | "PERL_ANYEVENT_EDNS0" |
1256 | Used by AnyEvent::DNS to decide whether to use the EDNS0 extension |
1366 | Used by AnyEvent::DNS to decide whether to use the EDNS0 extension |
1257 | for DNS. This extension is generally useful to reduce DNS traffic, |
1367 | for DNS. This extension is generally useful to reduce DNS traffic, |
1258 | but some (broken) firewalls drop such DNS packets, which is why it |
1368 | especially when DNSSEC is involved, but some (broken) firewalls drop |
1259 | is off by default. |
1369 | such DNS packets, which is why it is off by default. |
1260 | |
1370 | |
1261 | Setting this variable to 1 will cause AnyEvent::DNS to announce |
1371 | Setting this variable to 1 will cause AnyEvent::DNS to announce |
1262 | EDNS0 in its DNS requests. |
1372 | EDNS0 in its DNS requests. |
1263 | |
1373 | |
1264 | "PERL_ANYEVENT_MAX_FORKS" |
1374 | "PERL_ANYEVENT_MAX_FORKS" |
… | |
… | |
1268 | "PERL_ANYEVENT_MAX_OUTSTANDING_DNS" |
1378 | "PERL_ANYEVENT_MAX_OUTSTANDING_DNS" |
1269 | The default value for the "max_outstanding" parameter for the |
1379 | The default value for the "max_outstanding" parameter for the |
1270 | default DNS resolver - this is the maximum number of parallel DNS |
1380 | default DNS resolver - this is the maximum number of parallel DNS |
1271 | requests that are sent to the DNS server. |
1381 | requests that are sent to the DNS server. |
1272 | |
1382 | |
|
|
1383 | "PERL_ANYEVENT_MAX_SIGNAL_LATENCY" |
|
|
1384 | Perl has inherently racy signal handling (you can basically choose |
|
|
1385 | between losing signals and memory corruption) - pure perl event |
|
|
1386 | loops (including "AnyEvent::Loop", when "Async::Interrupt" isn't |
|
|
1387 | available) therefore have to poll regularly to avoid losing signals. |
|
|
1388 | |
|
|
1389 | Some event loops are racy, but don't poll regularly, and some event |
|
|
1390 | loops are written in C but are still racy. For those event loops, |
|
|
1391 | AnyEvent installs a timer that regularly wakes up the event loop. |
|
|
1392 | |
|
|
1393 | By default, the interval for this timer is 10 seconds, but you can |
|
|
1394 | override this delay with this environment variable (or by setting |
|
|
1395 | the $AnyEvent::MAX_SIGNAL_LATENCY variable before creating signal |
|
|
1396 | watchers). |
|
|
1397 | |
|
|
1398 | Lower values increase CPU (and energy) usage, higher values can |
|
|
1399 | introduce long delays when reaping children or waiting for signals. |
|
|
1400 | |
|
|
1401 | The AnyEvent::Async module, if available, will be used to avoid this |
|
|
1402 | polling (with most event loops). |
|
|
1403 | |
1273 | "PERL_ANYEVENT_RESOLV_CONF" |
1404 | "PERL_ANYEVENT_RESOLV_CONF" |
1274 | The file to use instead of /etc/resolv.conf (or OS-specific |
1405 | The absolute path to a resolv.conf-style file to use instead of |
1275 | configuration) in the default resolver. When set to the empty |
1406 | /etc/resolv.conf (or the OS-specific configuration) in the default |
1276 | string, no default config will be used. |
1407 | resolver, or the empty string to select the default configuration. |
1277 | |
1408 | |
1278 | "PERL_ANYEVENT_CA_FILE", "PERL_ANYEVENT_CA_PATH". |
1409 | "PERL_ANYEVENT_CA_FILE", "PERL_ANYEVENT_CA_PATH". |
1279 | When neither "ca_file" nor "ca_path" was specified during |
1410 | When neither "ca_file" nor "ca_path" was specified during |
1280 | AnyEvent::TLS context creation, and either of these environment |
1411 | AnyEvent::TLS context creation, and either of these environment |
1281 | variables exist, they will be used to specify CA certificate |
1412 | variables are nonempty, they will be used to specify CA certificate |
1282 | locations instead of a system-dependent default. |
1413 | locations instead of a system-dependent default. |
1283 | |
1414 | |
1284 | "PERL_ANYEVENT_AVOID_GUARD" and "PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT" |
1415 | "PERL_ANYEVENT_AVOID_GUARD" and "PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT" |
1285 | When these are set to 1, then the respective modules are not loaded. |
1416 | When these are set to 1, then the respective modules are not loaded. |
1286 | Mostly good for testing AnyEvent itself. |
1417 | Mostly good for testing AnyEvent itself. |
… | |
… | |
1606 | when used without AnyEvent), but most event loops have acceptable |
1737 | when used without AnyEvent), but most event loops have acceptable |
1607 | performance with or without AnyEvent. |
1738 | performance with or without AnyEvent. |
1608 | |
1739 | |
1609 | * The overhead AnyEvent adds is usually much smaller than the overhead |
1740 | * The overhead AnyEvent adds is usually much smaller than the overhead |
1610 | of the actual event loop, only with extremely fast event loops such |
1741 | of the actual event loop, only with extremely fast event loops such |
1611 | as EV adds AnyEvent significant overhead. |
1742 | as EV does AnyEvent add significant overhead. |
1612 | |
1743 | |
1613 | * You should avoid POE like the plague if you want performance or |
1744 | * You should avoid POE like the plague if you want performance or |
1614 | reasonable memory usage. |
1745 | reasonable memory usage. |
1615 | |
1746 | |
1616 | BENCHMARKING THE LARGE SERVER CASE |
1747 | BENCHMARKING THE LARGE SERVER CASE |
… | |
… | |
1879 | This module is part of perl since release 5.008. It will be used |
2010 | This module is part of perl since release 5.008. It will be used |
1880 | when the chosen event library does not come with a timing source of |
2011 | when the chosen event library does not come with a timing source of |
1881 | its own. The pure-perl event loop (AnyEvent::Loop) will additionally |
2012 | its own. The pure-perl event loop (AnyEvent::Loop) will additionally |
1882 | load it to try to use a monotonic clock for timing stability. |
2013 | load it to try to use a monotonic clock for timing stability. |
1883 | |
2014 | |
|
|
2015 | AnyEvent::AIO (and IO::AIO) |
|
|
2016 | The default implementation of AnyEvent::IO is to do I/O |
|
|
2017 | synchronously, stopping programs while they access the disk, which |
|
|
2018 | is fine for a lot of programs. |
|
|
2019 | |
|
|
2020 | Installing AnyEvent::AIO (and its IO::AIO dependency) makes it |
|
|
2021 | switch to a true asynchronous implementation, so event processing |
|
|
2022 | can continue even while waiting for disk I/O. |
|
|
2023 | |
1884 | FORK |
2024 | FORK |
1885 | Most event libraries are not fork-safe. The ones who are usually are |
2025 | Most event libraries are not fork-safe. The ones who are usually are |
1886 | because they rely on inefficient but fork-safe "select" or "poll" calls |
2026 | because they rely on inefficient but fork-safe "select" or "poll" calls |
1887 | - higher performance APIs such as BSD's kqueue or the dreaded Linux |
2027 | - higher performance APIs such as BSD's kqueue or the dreaded Linux |
1888 | epoll are usually badly thought-out hacks that are incompatible with |
2028 | epoll are usually badly thought-out hacks that are incompatible with |
… | |
… | |
1942 | SEE ALSO |
2082 | SEE ALSO |
1943 | Tutorial/Introduction: AnyEvent::Intro. |
2083 | Tutorial/Introduction: AnyEvent::Intro. |
1944 | |
2084 | |
1945 | FAQ: AnyEvent::FAQ. |
2085 | FAQ: AnyEvent::FAQ. |
1946 | |
2086 | |
1947 | Utility functions: AnyEvent::Util. |
2087 | Utility functions: AnyEvent::Util (misc. grab-bag), AnyEvent::Log |
|
|
2088 | (simply logging). |
1948 | |
2089 | |
|
|
2090 | Development/Debugging: AnyEvent::Strict (stricter checking), |
|
|
2091 | AnyEvent::Debug (interactive shell, watcher tracing). |
|
|
2092 | |
1949 | Event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event, |
2093 | Supported event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event, |
1950 | Glib::Event, Glib, Tk, Event::Lib, Qt, POE. |
2094 | Glib::Event, Glib, Tk, Event::Lib, Qt, POE, FLTK. |
1951 | |
2095 | |
1952 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
2096 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
1953 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
2097 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
1954 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE, |
2098 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE, |
1955 | AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi. |
2099 | AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi, AnyEvent::Impl::FLTK. |
1956 | |
2100 | |
1957 | Non-blocking file handles, sockets, TCP clients and servers: |
2101 | Non-blocking handles, pipes, stream sockets, TCP clients and servers: |
1958 | AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS. |
2102 | AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS. |
|
|
2103 | |
|
|
2104 | Asynchronous File I/O: AnyEvent::IO. |
1959 | |
2105 | |
1960 | Asynchronous DNS: AnyEvent::DNS. |
2106 | Asynchronous DNS: AnyEvent::DNS. |
1961 | |
2107 | |
1962 | Thread support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event. |
2108 | Thread support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event. |
1963 | |
2109 | |
1964 | Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::IRC, |
2110 | Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::IRC, |
1965 | AnyEvent::HTTP. |
2111 | AnyEvent::HTTP. |
1966 | |
2112 | |
1967 | AUTHOR |
2113 | AUTHOR |
1968 | Marc Lehmann <schmorp@schmorp.de> |
2114 | Marc Lehmann <schmorp@schmorp.de> |
1969 | http://home.schmorp.de/ |
2115 | http://anyevent.schmorp.de |
1970 | |
2116 | |