… | |
… | |
33 | |
33 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
35 | policy> and AnyEvent is I<small and efficient>. |
36 | |
36 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
38 | interfaces to whatever event model the main program happens to use in a |
38 | interfaces to whatever event model the main program happens to use, in a |
39 | pragmatic way. For event models and certain classes of immortals alike, |
39 | pragmatic way. For event models and certain classes of immortals alike, |
40 | the statement "there can only be one" is a bitter reality: In general, |
40 | the statement "there can only be one" is a bitter reality: In general, |
41 | only one event loop can be active at the same time in a process. AnyEvent |
41 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
42 | cannot change this, but it can hide the differences between those event |
|
|
43 | loops. |
43 | |
44 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | programming (waiting for I/O or timer events) without subscribing to a |
46 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
47 | religion, a way of living, and most importantly: without forcing your |
47 | module users into the same thing by forcing them to use the same event |
48 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
49 | model you use. |
49 | |
50 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | like joining a cult: After you joined, you are dependent on them and you |
53 | like joining a cult: After you joined, you are dependent on them and you |
53 | cannot use anything else, as it is simply incompatible to everything that |
54 | cannot use anything else, as they are simply incompatible to everything |
54 | isn't itself. What's worse, all the potential users of your module are |
55 | that isn't them. What's worse, all the potential users of your |
55 | I<also> forced to use the same event loop you use. |
56 | module are I<also> forced to use the same event loop you use. |
56 | |
57 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | your module uses one of those, every user of your module has to use it, |
61 | your module uses one of those, every user of your module has to use it, |
61 | too. But if your module uses AnyEvent, it works transparently with all |
62 | too. But if your module uses AnyEvent, it works transparently with all |
62 | event models it supports (including stuff like POE and IO::Async, as long |
63 | event models it supports (including stuff like IO::Async, as long as those |
63 | as those use one of the supported event loops. It is trivial to add new |
64 | use one of the supported event loops. It is trivial to add new event loops |
64 | event loops to AnyEvent, too, so it is future-proof). |
65 | to AnyEvent, too, so it is future-proof). |
65 | |
66 | |
66 | In addition to being free of having to use I<the one and only true event |
67 | In addition to being free of having to use I<the one and only true event |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | modules, you get an enormous amount of code and strict rules you have to |
69 | modules, you get an enormous amount of code and strict rules you have to |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
70 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
… | |
… | |
152 | =head2 I/O WATCHERS |
153 | =head2 I/O WATCHERS |
153 | |
154 | |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | with the following mandatory key-value pairs as arguments: |
156 | with the following mandatory key-value pairs as arguments: |
156 | |
157 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
158 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
159 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
159 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
160 | must be a string that is either C<r> or C<w>, which creates a watcher |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
161 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
161 | becomes ready. |
162 | callback to invoke each time the file handle becomes ready. |
162 | |
163 | |
163 | Although the callback might get passed parameters, their value and |
164 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
167 | |
… | |
… | |
170 | |
171 | |
171 | Some event loops issue spurious readyness notifications, so you should |
172 | Some event loops issue spurious readyness notifications, so you should |
172 | always use non-blocking calls when reading/writing from/to your file |
173 | always use non-blocking calls when reading/writing from/to your file |
173 | handles. |
174 | handles. |
174 | |
175 | |
175 | Example: |
|
|
176 | |
|
|
177 | # wait for readability of STDIN, then read a line and disable the watcher |
176 | Example: wait for readability of STDIN, then read a line and disable the |
|
|
177 | watcher. |
|
|
178 | |
178 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
179 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
179 | chomp (my $input = <STDIN>); |
180 | chomp (my $input = <STDIN>); |
180 | warn "read: $input\n"; |
181 | warn "read: $input\n"; |
181 | undef $w; |
182 | undef $w; |
182 | }); |
183 | }); |
… | |
… | |
192 | |
193 | |
193 | Although the callback might get passed parameters, their value and |
194 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
197 | |
197 | The timer callback will be invoked at most once: if you want a repeating |
198 | The callback will normally be invoked once only. If you specify another |
198 | timer you have to create a new watcher (this is a limitation by both Tk |
199 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | and Glib). |
200 | callback will be invoked regularly at that interval (in fractional |
|
|
201 | seconds) after the first invocation. If C<interval> is specified with a |
|
|
202 | false value, then it is treated as if it were missing. |
200 | |
203 | |
201 | Example: |
204 | The callback will be rescheduled before invoking the callback, but no |
|
|
205 | attempt is done to avoid timer drift in most backends, so the interval is |
|
|
206 | only approximate. |
202 | |
207 | |
203 | # fire an event after 7.7 seconds |
208 | Example: fire an event after 7.7 seconds. |
|
|
209 | |
204 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
210 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
205 | warn "timeout\n"; |
211 | warn "timeout\n"; |
206 | }); |
212 | }); |
207 | |
213 | |
208 | # to cancel the timer: |
214 | # to cancel the timer: |
209 | undef $w; |
215 | undef $w; |
210 | |
216 | |
211 | Example 2: |
|
|
212 | |
|
|
213 | # fire an event after 0.5 seconds, then roughly every second |
217 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
214 | my $w; |
|
|
215 | |
218 | |
216 | my $cb = sub { |
|
|
217 | # cancel the old timer while creating a new one |
|
|
218 | $w = AnyEvent->timer (after => 1, cb => $cb); |
219 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
|
|
220 | warn "timeout\n"; |
219 | }; |
221 | }; |
220 | |
|
|
221 | # start the "loop" by creating the first watcher |
|
|
222 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
|
|
223 | |
222 | |
224 | =head3 TIMING ISSUES |
223 | =head3 TIMING ISSUES |
225 | |
224 | |
226 | There are two ways to handle timers: based on real time (relative, "fire |
225 | There are two ways to handle timers: based on real time (relative, "fire |
227 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
226 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
… | |
… | |
305 | =back |
304 | =back |
306 | |
305 | |
307 | =head2 SIGNAL WATCHERS |
306 | =head2 SIGNAL WATCHERS |
308 | |
307 | |
309 | You can watch for signals using a signal watcher, C<signal> is the signal |
308 | You can watch for signals using a signal watcher, C<signal> is the signal |
310 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
309 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
311 | be invoked whenever a signal occurs. |
310 | callback to be invoked whenever a signal occurs. |
312 | |
311 | |
313 | Although the callback might get passed parameters, their value and |
312 | Although the callback might get passed parameters, their value and |
314 | presence is undefined and you cannot rely on them. Portable AnyEvent |
313 | presence is undefined and you cannot rely on them. Portable AnyEvent |
315 | callbacks cannot use arguments passed to signal watcher callbacks. |
314 | callbacks cannot use arguments passed to signal watcher callbacks. |
316 | |
315 | |
… | |
… | |
738 | =item L<AnyEvent::Util> |
737 | =item L<AnyEvent::Util> |
739 | |
738 | |
740 | Contains various utility functions that replace often-used but blocking |
739 | Contains various utility functions that replace often-used but blocking |
741 | functions such as C<inet_aton> by event-/callback-based versions. |
740 | functions such as C<inet_aton> by event-/callback-based versions. |
742 | |
741 | |
743 | =item L<AnyEvent::Handle> |
|
|
744 | |
|
|
745 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
746 | |
|
|
747 | =item L<AnyEvent::Socket> |
742 | =item L<AnyEvent::Socket> |
748 | |
743 | |
749 | Provides various utility functions for (internet protocol) sockets, |
744 | Provides various utility functions for (internet protocol) sockets, |
750 | addresses and name resolution. Also functions to create non-blocking tcp |
745 | addresses and name resolution. Also functions to create non-blocking tcp |
751 | connections or tcp servers, with IPv6 and SRV record support and more. |
746 | connections or tcp servers, with IPv6 and SRV record support and more. |
752 | |
747 | |
|
|
748 | =item L<AnyEvent::Handle> |
|
|
749 | |
|
|
750 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
751 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
752 | non-blocking SSL/TLS. |
|
|
753 | |
753 | =item L<AnyEvent::DNS> |
754 | =item L<AnyEvent::DNS> |
754 | |
755 | |
755 | Provides rich asynchronous DNS resolver capabilities. |
756 | Provides rich asynchronous DNS resolver capabilities. |
756 | |
757 | |
757 | =item L<AnyEvent::HTTP> |
758 | =item L<AnyEvent::HTTP> |
… | |
… | |
765 | |
766 | |
766 | =item L<AnyEvent::FastPing> |
767 | =item L<AnyEvent::FastPing> |
767 | |
768 | |
768 | The fastest ping in the west. |
769 | The fastest ping in the west. |
769 | |
770 | |
|
|
771 | =item L<AnyEvent::DBI> |
|
|
772 | |
|
|
773 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
774 | |
|
|
775 | =item L<AnyEvent::AIO> |
|
|
776 | |
|
|
777 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
778 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
779 | together. |
|
|
780 | |
|
|
781 | =item L<AnyEvent::BDB> |
|
|
782 | |
|
|
783 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
784 | L<BDB> and AnyEvent together. |
|
|
785 | |
|
|
786 | =item L<AnyEvent::GPSD> |
|
|
787 | |
|
|
788 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
789 | |
|
|
790 | =item L<AnyEvent::IGS> |
|
|
791 | |
|
|
792 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
793 | L<App::IGS>). |
|
|
794 | |
770 | =item L<Net::IRC3> |
795 | =item L<Net::IRC3> |
771 | |
796 | |
772 | AnyEvent based IRC client module family. |
797 | AnyEvent based IRC client module family. |
773 | |
798 | |
774 | =item L<Net::XMPP2> |
799 | =item L<Net::XMPP2> |
… | |
… | |
786 | |
811 | |
787 | =item L<Coro> |
812 | =item L<Coro> |
788 | |
813 | |
789 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
814 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
790 | |
815 | |
791 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
792 | |
|
|
793 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
794 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
795 | together. |
|
|
796 | |
|
|
797 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
798 | |
|
|
799 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
800 | IO::AIO and AnyEvent together. |
|
|
801 | |
|
|
802 | =item L<IO::Lambda> |
816 | =item L<IO::Lambda> |
803 | |
817 | |
804 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
818 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
805 | |
819 | |
806 | =back |
820 | =back |
… | |
… | |
812 | no warnings; |
826 | no warnings; |
813 | use strict; |
827 | use strict; |
814 | |
828 | |
815 | use Carp; |
829 | use Carp; |
816 | |
830 | |
817 | our $VERSION = 4.14; |
831 | our $VERSION = 4.2; |
818 | our $MODEL; |
832 | our $MODEL; |
819 | |
833 | |
820 | our $AUTOLOAD; |
834 | our $AUTOLOAD; |
821 | our @ISA; |
835 | our @ISA; |
822 | |
836 | |
… | |
… | |
925 | $MODEL |
939 | $MODEL |
926 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
940 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
927 | } |
941 | } |
928 | } |
942 | } |
929 | |
943 | |
|
|
944 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
945 | |
930 | unshift @ISA, $MODEL; |
946 | unshift @ISA, $MODEL; |
931 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
947 | |
|
|
948 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
932 | |
949 | |
933 | (shift @post_detect)->() while @post_detect; |
950 | (shift @post_detect)->() while @post_detect; |
934 | } |
951 | } |
935 | |
952 | |
936 | $MODEL |
953 | $MODEL |
… | |
… | |
944 | |
961 | |
945 | detect unless $MODEL; |
962 | detect unless $MODEL; |
946 | |
963 | |
947 | my $class = shift; |
964 | my $class = shift; |
948 | $class->$func (@_); |
965 | $class->$func (@_); |
|
|
966 | } |
|
|
967 | |
|
|
968 | # utility function to dup a filehandle. this is used by many backends |
|
|
969 | # to support binding more than one watcher per filehandle (they usually |
|
|
970 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
971 | sub _dupfh($$$$) { |
|
|
972 | my ($poll, $fh, $r, $w) = @_; |
|
|
973 | |
|
|
974 | require Fcntl; |
|
|
975 | |
|
|
976 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
977 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
978 | : $poll eq "w" ? ($w, ">") |
|
|
979 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
980 | |
|
|
981 | open my $fh2, "$mode&" . fileno $fh |
|
|
982 | or die "cannot dup() filehandle: $!"; |
|
|
983 | |
|
|
984 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
985 | |
|
|
986 | ($fh2, $rw) |
949 | } |
987 | } |
950 | |
988 | |
951 | package AnyEvent::Base; |
989 | package AnyEvent::Base; |
952 | |
990 | |
953 | # default implementation for now and time |
991 | # default implementation for now and time |
… | |
… | |
984 | sub AnyEvent::Base::Signal::DESTROY { |
1022 | sub AnyEvent::Base::Signal::DESTROY { |
985 | my ($signal, $cb) = @{$_[0]}; |
1023 | my ($signal, $cb) = @{$_[0]}; |
986 | |
1024 | |
987 | delete $SIG_CB{$signal}{$cb}; |
1025 | delete $SIG_CB{$signal}{$cb}; |
988 | |
1026 | |
989 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1027 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
990 | } |
1028 | } |
991 | |
1029 | |
992 | # default implementation for ->child |
1030 | # default implementation for ->child |
993 | |
1031 | |
994 | our %PID_CB; |
1032 | our %PID_CB; |
… | |
… | |
1163 | conditions, such as not being able to load the event model specified by |
1201 | conditions, such as not being able to load the event model specified by |
1164 | C<PERL_ANYEVENT_MODEL>. |
1202 | C<PERL_ANYEVENT_MODEL>. |
1165 | |
1203 | |
1166 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1204 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1167 | model it chooses. |
1205 | model it chooses. |
|
|
1206 | |
|
|
1207 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1208 | |
|
|
1209 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1210 | argument checking is very costly. Setting this variable to a true value |
|
|
1211 | will cause AnyEvent to thoroughly check the arguments passed to most |
|
|
1212 | method calls and croaks if it finds any problems. In other words, enables |
|
|
1213 | "strict" mode. Unlike C<use strict> it is definitely recommended ot keep |
|
|
1214 | it off in production. |
1168 | |
1215 | |
1169 | =item C<PERL_ANYEVENT_MODEL> |
1216 | =item C<PERL_ANYEVENT_MODEL> |
1170 | |
1217 | |
1171 | This can be used to specify the event model to be used by AnyEvent, before |
1218 | This can be used to specify the event model to be used by AnyEvent, before |
1172 | auto detection and -probing kicks in. It must be a string consisting |
1219 | auto detection and -probing kicks in. It must be a string consisting |
… | |
… | |
1669 | |
1716 | |
1670 | use AnyEvent; |
1717 | use AnyEvent; |
1671 | |
1718 | |
1672 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1719 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1673 | be used to probe what backend is used and gain other information (which is |
1720 | be used to probe what backend is used and gain other information (which is |
1674 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1721 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
1722 | $ENV{PERL_ANYEGENT_STRICT}. |
1675 | |
1723 | |
1676 | |
1724 | |
1677 | =head1 BUGS |
1725 | =head1 BUGS |
1678 | |
1726 | |
1679 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1727 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |