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Revision 1.172 by root, Thu Jul 17 15:21:02 2008 UTC

1=head1 => NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - provide framework for multiple event loops
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops 5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
6 6
18 18
19 my $w = AnyEvent->condvar; # stores whether a condition was flagged 19 my $w = AnyEvent->condvar; # stores whether a condition was flagged
20 $w->send; # wake up current and all future recv's 20 $w->send; # wake up current and all future recv's
21 $w->recv; # enters "main loop" till $condvar gets ->send 21 $w->recv; # enters "main loop" till $condvar gets ->send
22 22
23=head1 INTRODUCTION/TUTORIAL
24
25This manpage is mainly a reference manual. If you are interested
26in a tutorial or some gentle introduction, have a look at the
27L<AnyEvent::Intro> manpage.
28
23=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 29=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24 30
25Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 31Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26nowadays. So what is different about AnyEvent? 32nowadays. So what is different about AnyEvent?
27 33
28Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of 34Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29policy> and AnyEvent is I<small and efficient>. 35policy> and AnyEvent is I<small and efficient>.
30 36
31First and foremost, I<AnyEvent is not an event model> itself, it only 37First and foremost, I<AnyEvent is not an event model> itself, it only
32interfaces to whatever event model the main program happens to use in a 38interfaces to whatever event model the main program happens to use, in a
33pragmatic way. For event models and certain classes of immortals alike, 39pragmatic way. For event models and certain classes of immortals alike,
34the statement "there can only be one" is a bitter reality: In general, 40the statement "there can only be one" is a bitter reality: In general,
35only one event loop can be active at the same time in a process. AnyEvent 41only one event loop can be active at the same time in a process. AnyEvent
36helps hiding the differences between those event loops. 42cannot change this, but it can hide the differences between those event
43loops.
37 44
38The goal of AnyEvent is to offer module authors the ability to do event 45The goal of AnyEvent is to offer module authors the ability to do event
39programming (waiting for I/O or timer events) without subscribing to a 46programming (waiting for I/O or timer events) without subscribing to a
40religion, a way of living, and most importantly: without forcing your 47religion, a way of living, and most importantly: without forcing your
41module users into the same thing by forcing them to use the same event 48module users into the same thing by forcing them to use the same event
42model you use. 49model you use.
43 50
44For modules like POE or IO::Async (which is a total misnomer as it is 51For modules like POE or IO::Async (which is a total misnomer as it is
45actually doing all I/O I<synchronously>...), using them in your module is 52actually doing all I/O I<synchronously>...), using them in your module is
46like joining a cult: After you joined, you are dependent on them and you 53like joining a cult: After you joined, you are dependent on them and you
47cannot use anything else, as it is simply incompatible to everything that 54cannot use anything else, as they are simply incompatible to everything
48isn't itself. What's worse, all the potential users of your module are 55that isn't them. What's worse, all the potential users of your
49I<also> forced to use the same event loop you use. 56module are I<also> forced to use the same event loop you use.
50 57
51AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 58AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52fine. AnyEvent + Tk works fine etc. etc. but none of these work together 59fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if 60with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54your module uses one of those, every user of your module has to use it, 61your module uses one of those, every user of your module has to use it,
55too. But if your module uses AnyEvent, it works transparently with all 62too. But if your module uses AnyEvent, it works transparently with all
56event models it supports (including stuff like POE and IO::Async, as long 63event models it supports (including stuff like IO::Async, as long as those
57as those use one of the supported event loops. It is trivial to add new 64use one of the supported event loops. It is trivial to add new event loops
58event loops to AnyEvent, too, so it is future-proof). 65to AnyEvent, too, so it is future-proof).
59 66
60In addition to being free of having to use I<the one and only true event 67In addition to being free of having to use I<the one and only true event
61model>, AnyEvent also is free of bloat and policy: with POE or similar 68model>, AnyEvent also is free of bloat and policy: with POE or similar
62modules, you get an enormous amount of code and strict rules you have to 69modules, you get an enormous amount of code and strict rules you have to
63follow. AnyEvent, on the other hand, is lean and up to the point, by only 70follow. AnyEvent, on the other hand, is lean and up to the point, by only
132Many watchers either are used with "recursion" (repeating timers for 139Many watchers either are used with "recursion" (repeating timers for
133example), or need to refer to their watcher object in other ways. 140example), or need to refer to their watcher object in other ways.
134 141
135An any way to achieve that is this pattern: 142An any way to achieve that is this pattern:
136 143
137 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 144 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138 # you can use $w here, for example to undef it 145 # you can use $w here, for example to undef it
139 undef $w; 146 undef $w;
140 }); 147 });
141 148
142Note that C<my $w; $w => combination. This is necessary because in Perl, 149Note that C<my $w; $w => combination. This is necessary because in Perl,
143my variables are only visible after the statement in which they are 150my variables are only visible after the statement in which they are
144declared. 151declared.
145 152
146=head2 I/O WATCHERS 153=head2 I/O WATCHERS
147 154
148You can create an I/O watcher by calling the C<< AnyEvent->io >> method 155You can create an I/O watcher by calling the C<< AnyEvent->io >> method
149with the following mandatory key-value pairs as arguments: 156with the following mandatory key-value pairs as arguments:
150 157
151C<fh> the Perl I<file handle> (I<not> file descriptor) to watch 158C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
152for 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>
153which creates a watcher waiting for "r"eadable or "w"ritable events, 160must be a string that is either C<r> or C<w>, which creates a watcher
154respectively. C<cb> is the callback to invoke each time the file handle 161waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
155becomes ready. 162callback to invoke each time the file handle becomes ready.
156 163
157Although the callback might get passed parameters, their value and 164Although the callback might get passed parameters, their value and
158presence is undefined and you cannot rely on them. Portable AnyEvent 165presence is undefined and you cannot rely on them. Portable AnyEvent
159callbacks cannot use arguments passed to I/O watcher callbacks. 166callbacks cannot use arguments passed to I/O watcher callbacks.
160 167
164 171
165Some event loops issue spurious readyness notifications, so you should 172Some event loops issue spurious readyness notifications, so you should
166always use non-blocking calls when reading/writing from/to your file 173always use non-blocking calls when reading/writing from/to your file
167handles. 174handles.
168 175
169Example:
170
171 # wait for readability of STDIN, then read a line and disable the watcher 176Example: wait for readability of STDIN, then read a line and disable the
177watcher.
178
172 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { 179 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173 chomp (my $input = <STDIN>); 180 chomp (my $input = <STDIN>);
174 warn "read: $input\n"; 181 warn "read: $input\n";
175 undef $w; 182 undef $w;
176 }); 183 });
186 193
187Although the callback might get passed parameters, their value and 194Although the callback might get passed parameters, their value and
188presence is undefined and you cannot rely on them. Portable AnyEvent 195presence is undefined and you cannot rely on them. Portable AnyEvent
189callbacks cannot use arguments passed to time watcher callbacks. 196callbacks cannot use arguments passed to time watcher callbacks.
190 197
191The timer callback will be invoked at most once: if you want a repeating 198The callback will normally be invoked once only. If you specify another
192timer you have to create a new watcher (this is a limitation by both Tk 199parameter, C<interval>, as a strictly positive number (> 0), then the
193and Glib). 200callback will be invoked regularly at that interval (in fractional
201seconds) after the first invocation. If C<interval> is specified with a
202false value, then it is treated as if it were missing.
194 203
195Example: 204The callback will be rescheduled before invoking the callback, but no
205attempt is done to avoid timer drift in most backends, so the interval is
206only approximate.
196 207
197 # fire an event after 7.7 seconds 208Example: fire an event after 7.7 seconds.
209
198 my $w = AnyEvent->timer (after => 7.7, cb => sub { 210 my $w = AnyEvent->timer (after => 7.7, cb => sub {
199 warn "timeout\n"; 211 warn "timeout\n";
200 }); 212 });
201 213
202 # to cancel the timer: 214 # to cancel the timer:
203 undef $w; 215 undef $w;
204 216
205Example 2:
206
207 # fire an event after 0.5 seconds, then roughly every second 217Example 2: fire an event after 0.5 seconds, then roughly every second.
208 my $w;
209 218
210 my $cb = sub {
211 # cancel the old timer while creating a new one
212 $w = AnyEvent->timer (after => 1, cb => $cb); 219 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
220 warn "timeout\n";
213 }; 221 };
214
215 # start the "loop" by creating the first watcher
216 $w = AnyEvent->timer (after => 0.5, cb => $cb);
217 222
218=head3 TIMING ISSUES 223=head3 TIMING ISSUES
219 224
220There are two ways to handle timers: based on real time (relative, "fire 225There are two ways to handle timers: based on real time (relative, "fire
221in 10 seconds") and based on wallclock time (absolute, "fire at 12 226in 10 seconds") and based on wallclock time (absolute, "fire at 12
243 248
244This returns the "current wallclock time" as a fractional number of 249This returns the "current wallclock time" as a fractional number of
245seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> 250seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
246return, and the result is guaranteed to be compatible with those). 251return, and the result is guaranteed to be compatible with those).
247 252
248It progresses independently of any event loop processing. 253It progresses independently of any event loop processing, i.e. each call
249 254will check the system clock, which usually gets updated frequently.
250In almost all cases (in all cases if you don't care), this is the function
251to call when you want to know the current time.
252 255
253=item AnyEvent->now 256=item AnyEvent->now
254 257
255This also returns the "current wallclock time", but unlike C<time>, above, 258This also returns the "current wallclock time", but unlike C<time>, above,
256this value might change only once per event loop iteration, depending on 259this value might change only once per event loop iteration, depending on
257the event loop (most return the same time as C<time>, above). This is the 260the event loop (most return the same time as C<time>, above). This is the
258time that AnyEvent timers get scheduled against. 261time that AnyEvent's timers get scheduled against.
262
263I<In almost all cases (in all cases if you don't care), this is the
264function to call when you want to know the current time.>
265
266This function is also often faster then C<< AnyEvent->time >>, and
267thus the preferred method if you want some timestamp (for example,
268L<AnyEvent::Handle> uses this to update it's activity timeouts).
269
270The rest of this section is only of relevance if you try to be very exact
271with your timing, you can skip it without bad conscience.
259 272
260For a practical example of when these times differ, consider L<Event::Lib> 273For a practical example of when these times differ, consider L<Event::Lib>
261and L<EV> and the following set-up: 274and L<EV> and the following set-up:
262 275
263The event loop is running and has just invoked one of your callback at 276The event loop is running and has just invoked one of your callback at
268 281
269With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will 282With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
270both return C<501>, because that is the current time, and the timer will 283both return C<501>, because that is the current time, and the timer will
271be scheduled to fire at time=504 (C<501> + C<3>). 284be scheduled to fire at time=504 (C<501> + C<3>).
272 285
273With L<EV>m C<< AnyEvent->time >> returns C<501> (as that is the current 286With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
274time), but C<< AnyEvent->now >> returns C<500>, as that is the time the 287time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
275last event processing phase started. With L<EV>, your timer gets scheduled 288last event processing phase started. With L<EV>, your timer gets scheduled
276to run at time=503 (C<500> + C<3>). 289to run at time=503 (C<500> + C<3>).
277 290
278In one sense, L<Event::Lib> is more exact, as it uses the current time 291In one sense, L<Event::Lib> is more exact, as it uses the current time
279regardless of any delays introduced by event processing. However, most 292regardless of any delays introduced by event processing. However, most
280callbacks do not expect large delays in processing, so this causes a 293callbacks do not expect large delays in processing, so this causes a
281higher drift (and a lot more syscalls to get the current time). 294higher drift (and a lot more system calls to get the current time).
282 295
283In another sense, L<EV> is more exact, as your timer will be scheduled at 296In another sense, L<EV> is more exact, as your timer will be scheduled at
284the same time, regardless of how long event processing actually took. 297the same time, regardless of how long event processing actually took.
285 298
286In either case, if you care (and in most cases, you don't), then you 299In either case, if you care (and in most cases, you don't), then you
291=back 304=back
292 305
293=head2 SIGNAL WATCHERS 306=head2 SIGNAL WATCHERS
294 307
295You can watch for signals using a signal watcher, C<signal> is the signal 308You can watch for signals using a signal watcher, C<signal> is the signal
296I<name> without any C<SIG> prefix, C<cb> is the Perl callback to 309I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
297be invoked whenever a signal occurs. 310callback to be invoked whenever a signal occurs.
298 311
299Although the callback might get passed parameters, their value and 312Although the callback might get passed parameters, their value and
300presence is undefined and you cannot rely on them. Portable AnyEvent 313presence is undefined and you cannot rely on them. Portable AnyEvent
301callbacks cannot use arguments passed to signal watcher callbacks. 314callbacks cannot use arguments passed to signal watcher callbacks.
302 315
338AnyEvent program, you I<have> to create at least one watcher before you 351AnyEvent program, you I<have> to create at least one watcher before you
339C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 352C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
340 353
341Example: fork a process and wait for it 354Example: fork a process and wait for it
342 355
343 my $done = AnyEvent->condvar; 356 my $done = AnyEvent->condvar;
344 357
345 my $pid = fork or exit 5; 358 my $pid = fork or exit 5;
346 359
347 my $w = AnyEvent->child ( 360 my $w = AnyEvent->child (
348 pid => $pid, 361 pid => $pid,
349 cb => sub { 362 cb => sub {
350 my ($pid, $status) = @_; 363 my ($pid, $status) = @_;
351 warn "pid $pid exited with status $status"; 364 warn "pid $pid exited with status $status";
352 $done->send; 365 $done->send;
353 }, 366 },
354 ); 367 );
355 368
356 # do something else, then wait for process exit 369 # do something else, then wait for process exit
357 $done->recv; 370 $done->recv;
358 371
359=head2 CONDITION VARIABLES 372=head2 CONDITION VARIABLES
360 373
361If you are familiar with some event loops you will know that all of them 374If you are familiar with some event loops you will know that all of them
362require you to run some blocking "loop", "run" or similar function that 375require you to run some blocking "loop", "run" or similar function that
583 596
584This is a mutator function that returns the callback set and optionally 597This is a mutator function that returns the callback set and optionally
585replaces it before doing so. 598replaces it before doing so.
586 599
587The callback will be called when the condition becomes "true", i.e. when 600The callback will be called when the condition becomes "true", i.e. when
588C<send> or C<croak> are called. Calling C<recv> inside the callback 601C<send> or C<croak> are called, with the only argument being the condition
589or at any later time is guaranteed not to block. 602variable itself. Calling C<recv> inside the callback or at any later time
603is guaranteed not to block.
590 604
591=back 605=back
592 606
593=head1 GLOBAL VARIABLES AND FUNCTIONS 607=head1 GLOBAL VARIABLES AND FUNCTIONS
594 608
723=item L<AnyEvent::Util> 737=item L<AnyEvent::Util>
724 738
725Contains various utility functions that replace often-used but blocking 739Contains various utility functions that replace often-used but blocking
726functions such as C<inet_aton> by event-/callback-based versions. 740functions such as C<inet_aton> by event-/callback-based versions.
727 741
728=item L<AnyEvent::Handle>
729
730Provide read and write buffers and manages watchers for reads and writes.
731
732=item L<AnyEvent::Socket> 742=item L<AnyEvent::Socket>
733 743
734Provides various utility functions for (internet protocol) sockets, 744Provides various utility functions for (internet protocol) sockets,
735addresses and name resolution. Also functions to create non-blocking tcp 745addresses and name resolution. Also functions to create non-blocking tcp
736connections or tcp servers, with IPv6 and SRV record support and more. 746connections or tcp servers, with IPv6 and SRV record support and more.
737 747
748=item L<AnyEvent::Handle>
749
750Provide read and write buffers, manages watchers for reads and writes,
751supports raw and formatted I/O, I/O queued and fully transparent and
752non-blocking SSL/TLS.
753
738=item L<AnyEvent::DNS> 754=item L<AnyEvent::DNS>
739 755
740Provides rich asynchronous DNS resolver capabilities. 756Provides rich asynchronous DNS resolver capabilities.
741 757
758=item L<AnyEvent::HTTP>
759
760A simple-to-use HTTP library that is capable of making a lot of concurrent
761HTTP requests.
762
742=item L<AnyEvent::HTTPD> 763=item L<AnyEvent::HTTPD>
743 764
744Provides a simple web application server framework. 765Provides a simple web application server framework.
745 766
746=item L<AnyEvent::FastPing> 767=item L<AnyEvent::FastPing>
747 768
748The fastest ping in the west. 769The fastest ping in the west.
770
771=item L<AnyEvent::DBI>
772
773Executes L<DBI> requests asynchronously in a proxy process.
774
775=item L<AnyEvent::AIO>
776
777Truly asynchronous I/O, should be in the toolbox of every event
778programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
779together.
780
781=item L<AnyEvent::BDB>
782
783Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
784L<BDB> and AnyEvent together.
785
786=item L<AnyEvent::GPSD>
787
788A non-blocking interface to gpsd, a daemon delivering GPS information.
789
790=item L<AnyEvent::IGS>
791
792A non-blocking interface to the Internet Go Server protocol (used by
793L<App::IGS>).
749 794
750=item L<Net::IRC3> 795=item L<Net::IRC3>
751 796
752AnyEvent based IRC client module family. 797AnyEvent based IRC client module family.
753 798
766 811
767=item L<Coro> 812=item L<Coro>
768 813
769Has special support for AnyEvent via L<Coro::AnyEvent>. 814Has special support for AnyEvent via L<Coro::AnyEvent>.
770 815
771=item L<AnyEvent::AIO>, L<IO::AIO>
772
773Truly asynchronous I/O, should be in the toolbox of every event
774programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
775together.
776
777=item L<AnyEvent::BDB>, L<BDB>
778
779Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
780IO::AIO and AnyEvent together.
781
782=item L<IO::Lambda> 816=item L<IO::Lambda>
783 817
784The lambda approach to I/O - don't ask, look there. Can use AnyEvent. 818The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
785 819
786=back 820=back
792no warnings; 826no warnings;
793use strict; 827use strict;
794 828
795use Carp; 829use Carp;
796 830
797our $VERSION = '4.05'; 831our $VERSION = 4.22;
798our $MODEL; 832our $MODEL;
799 833
800our $AUTOLOAD; 834our $AUTOLOAD;
801our @ISA; 835our @ISA;
802 836
905 $MODEL 939 $MODEL
906 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; 940 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
907 } 941 }
908 } 942 }
909 943
944 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
945
910 unshift @ISA, $MODEL; 946 unshift @ISA, $MODEL;
911 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 947
948 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
912 949
913 (shift @post_detect)->() while @post_detect; 950 (shift @post_detect)->() while @post_detect;
914 } 951 }
915 952
916 $MODEL 953 $MODEL
924 961
925 detect unless $MODEL; 962 detect unless $MODEL;
926 963
927 my $class = shift; 964 my $class = shift;
928 $class->$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).
971sub _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, $rw)
929} 987}
930 988
931package AnyEvent::Base; 989package AnyEvent::Base;
932 990
933# default implementation for now and time 991# default implementation for now and time
964sub AnyEvent::Base::Signal::DESTROY { 1022sub AnyEvent::Base::Signal::DESTROY {
965 my ($signal, $cb) = @{$_[0]}; 1023 my ($signal, $cb) = @{$_[0]};
966 1024
967 delete $SIG_CB{$signal}{$cb}; 1025 delete $SIG_CB{$signal}{$cb};
968 1026
969 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1027 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
970} 1028}
971 1029
972# default implementation for ->child 1030# default implementation for ->child
973 1031
974our %PID_CB; 1032our %PID_CB;
1144C<PERL_ANYEVENT_MODEL>. 1202C<PERL_ANYEVENT_MODEL>.
1145 1203
1146When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1204When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1147model it chooses. 1205model it chooses.
1148 1206
1207=item C<PERL_ANYEVENT_STRICT>
1208
1209AnyEvent does not do much argument checking by default, as thorough
1210argument checking is very costly. Setting this variable to a true value
1211will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1212check the arguments passed to most method calls. If it finds any problems
1213it will croak.
1214
1215In other words, enables "strict" mode.
1216
1217Unlike C<use strict> it is definitely recommended ot keep it off in
1218production.
1219
1149=item C<PERL_ANYEVENT_MODEL> 1220=item C<PERL_ANYEVENT_MODEL>
1150 1221
1151This can be used to specify the event model to be used by AnyEvent, before 1222This can be used to specify the event model to be used by AnyEvent, before
1152auto detection and -probing kicks in. It must be a string consisting 1223auto detection and -probing kicks in. It must be a string consisting
1153entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1224entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1158This functionality might change in future versions. 1229This functionality might change in future versions.
1159 1230
1160For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1231For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1161could start your program like this: 1232could start your program like this:
1162 1233
1163 PERL_ANYEVENT_MODEL=Perl perl ... 1234 PERL_ANYEVENT_MODEL=Perl perl ...
1164 1235
1165=item C<PERL_ANYEVENT_PROTOCOLS> 1236=item C<PERL_ANYEVENT_PROTOCOLS>
1166 1237
1167Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1238Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1168for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1239for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1643specified in the variable. 1714specified in the variable.
1644 1715
1645You can make AnyEvent completely ignore this variable by deleting it 1716You can make AnyEvent completely ignore this variable by deleting it
1646before the first watcher gets created, e.g. with a C<BEGIN> block: 1717before the first watcher gets created, e.g. with a C<BEGIN> block:
1647 1718
1648 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1719 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1649 1720
1650 use AnyEvent; 1721 use AnyEvent;
1651 1722
1652Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1723Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1653be used to probe what backend is used and gain other information (which is 1724be used to probe what backend is used and gain other information (which is
1654probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1725probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1726$ENV{PERL_ANYEGENT_STRICT}.
1727
1728
1729=head1 BUGS
1730
1731Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1732to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1733and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1734mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1735pronounced).
1655 1736
1656 1737
1657=head1 SEE ALSO 1738=head1 SEE ALSO
1658 1739
1659Utility functions: L<AnyEvent::Util>. 1740Utility functions: L<AnyEvent::Util>.
1676Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1757Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1677 1758
1678 1759
1679=head1 AUTHOR 1760=head1 AUTHOR
1680 1761
1681 Marc Lehmann <schmorp@schmorp.de> 1762 Marc Lehmann <schmorp@schmorp.de>
1682 http://home.schmorp.de/ 1763 http://home.schmorp.de/
1683 1764
1684=cut 1765=cut
1685 1766
16861 17671
1687 1768

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