… | |
… | |
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"). |
… | |
… | |
736 | }; |
736 | }; |
737 | } |
737 | } |
738 | |
738 | |
739 | $cv->end; |
739 | $cv->end; |
740 | |
740 | |
|
|
741 | ... |
|
|
742 | |
|
|
743 | my $results = $cv->recv; |
|
|
744 | |
741 | This code fragment supposedly pings a number of hosts and calls |
745 | This code fragment supposedly pings a number of hosts and calls |
742 | "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 |
743 | 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 |
744 | 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 |
745 | 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 |
… | |
… | |
774 | In list context, all parameters passed to "send" will be returned, |
778 | In list context, all parameters passed to "send" will be returned, |
775 | in scalar context only the first one will be returned. |
779 | in scalar context only the first one will be returned. |
776 | |
780 | |
777 | 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 |
778 | any event loop, that is, recursive invocation of a blocking "->recv" |
782 | any event loop, that is, recursive invocation of a blocking "->recv" |
779 | 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 |
780 | is detected. This condition can be slightly loosened by using |
784 | is detected. This requirement can be dropped by relying on |
781 | 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 |
782 | thread that doesn't run the event loop itself. |
786 | thread that doesn't run the event loop itself. Coro::AnyEvent is |
|
|
787 | loaded automatically when Coro is used with AnyEvent, so code does |
|
|
788 | not need to do anything special to take advantage of that: any code |
|
|
789 | that would normally block your program because it calls "recv", be |
|
|
790 | executed in an "async" thread instead without blocking other |
|
|
791 | threads. |
783 | |
792 | |
784 | 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 |
785 | (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 |
786 | using this from a module, never require a blocking wait*. Instead, |
795 | using this from a module, never require a blocking wait*. Instead, |
787 | 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 |
… | |
… | |
1082 | modules come as part of AnyEvent, the others are available via CPAN (see |
1091 | modules come as part of AnyEvent, the others are available via CPAN (see |
1083 | <http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for a longer |
1092 | <http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for a longer |
1084 | non-exhaustive list), and the list is heavily biased towards modules of |
1093 | non-exhaustive list), and the list is heavily biased towards modules of |
1085 | the AnyEvent author himself :) |
1094 | the AnyEvent author himself :) |
1086 | |
1095 | |
1087 | AnyEvent::Util |
1096 | AnyEvent::Util (part of the AnyEvent distribution) |
1088 | Contains various utility functions that replace often-used blocking |
1097 | Contains various utility functions that replace often-used blocking |
1089 | functions such as "inet_aton" with event/callback-based versions. |
1098 | functions such as "inet_aton" with event/callback-based versions. |
1090 | |
1099 | |
1091 | AnyEvent::Socket |
1100 | AnyEvent::Socket (part of the AnyEvent distribution) |
1092 | Provides various utility functions for (internet protocol) sockets, |
1101 | Provides various utility functions for (internet protocol) sockets, |
1093 | addresses and name resolution. Also functions to create non-blocking |
1102 | addresses and name resolution. Also functions to create non-blocking |
1094 | 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 |
1095 | more. |
1104 | more. |
1096 | |
1105 | |
1097 | AnyEvent::Handle |
1106 | AnyEvent::Handle (part of the AnyEvent distribution) |
1098 | Provide read and write buffers, manages watchers for reads and |
1107 | Provide read and write buffers, manages watchers for reads and |
1099 | 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 |
1100 | transparent and non-blocking SSL/TLS (via AnyEvent::TLS). |
1109 | transparent and non-blocking SSL/TLS (via AnyEvent::TLS). |
1101 | |
1110 | |
1102 | AnyEvent::DNS |
1111 | AnyEvent::DNS (part of the AnyEvent distribution) |
1103 | Provides rich asynchronous DNS resolver capabilities. |
1112 | Provides rich asynchronous DNS resolver capabilities. |
1104 | |
1113 | |
1105 | AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD, |
1114 | AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD, |
1106 | AnyEvent::IGS, AnyEvent::FCP |
1115 | AnyEvent::IGS, AnyEvent::FCP |
1107 | Implement event-based interfaces to the protocols of the same name |
1116 | Implement event-based interfaces to the protocols of the same name |
1108 | (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 |
1109 | Freenet Client Protocol). |
1118 | Freenet Client Protocol). |
1110 | |
1119 | |
1111 | AnyEvent::AIO |
1120 | AnyEvent::AIO (part of the AnyEvent distribution) |
1112 | 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 |
1113 | the toolbox of every event programmer. AnyEvent::AIO transparently |
1122 | the toolbox of every event programmer. AnyEvent::AIO transparently |
1114 | fuses IO::AIO and AnyEvent together, giving AnyEvent access to |
1123 | fuses IO::AIO and AnyEvent together, giving AnyEvent access to |
1115 | event-based file I/O, and much more. |
1124 | event-based file I/O, and much more. |
1116 | |
1125 | |
… | |
… | |
2001 | 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 |
2002 | 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 |
2003 | its own. The pure-perl event loop (AnyEvent::Loop) will additionally |
2012 | its own. The pure-perl event loop (AnyEvent::Loop) will additionally |
2004 | 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. |
2005 | |
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 | |
2006 | FORK |
2024 | FORK |
2007 | 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 |
2008 | 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 |
2009 | - 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 |
2010 | epoll are usually badly thought-out hacks that are incompatible with |
2028 | epoll are usually badly thought-out hacks that are incompatible with |