1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
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6 | event loops. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
… | |
… | |
930 | no warnings; |
931 | no warnings; |
931 | use strict qw(vars subs); |
932 | use strict qw(vars subs); |
932 | |
933 | |
933 | use Carp; |
934 | use Carp; |
934 | |
935 | |
935 | our $VERSION = 4.41; |
936 | our $VERSION = 4.412; |
936 | our $MODEL; |
937 | our $MODEL; |
937 | |
938 | |
938 | our $AUTOLOAD; |
939 | our $AUTOLOAD; |
939 | our @ISA; |
940 | our @ISA; |
940 | |
941 | |
941 | our @REGISTRY; |
942 | our @REGISTRY; |
942 | |
943 | |
943 | our $WIN32; |
944 | our $WIN32; |
944 | |
945 | |
945 | BEGIN { |
946 | BEGIN { |
946 | my $win32 = ! ! ($^O =~ /mswin32/i); |
947 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
947 | eval "sub WIN32(){ $win32 }"; |
948 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
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949 | |
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950 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
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951 | if ${^TAINT}; |
948 | } |
952 | } |
949 | |
953 | |
950 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
954 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
951 | |
955 | |
952 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
956 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
1141 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
1145 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
1142 | } else { |
1146 | } else { |
1143 | pipe $SIGPIPE_R, $SIGPIPE_W; |
1147 | pipe $SIGPIPE_R, $SIGPIPE_W; |
1144 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
1148 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
1145 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
1149 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
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1150 | |
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1151 | # not strictly required, as $^F is normally 2, but let's make sure... |
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1152 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
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1153 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
1146 | } |
1154 | } |
1147 | |
1155 | |
1148 | $SIGPIPE_R |
1156 | $SIGPIPE_R |
1149 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
1157 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
1150 | |
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1151 | # not strictly required, as $^F is normally 2, but let's make sure... |
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1152 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
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1153 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
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1154 | |
1158 | |
1155 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
1159 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
1156 | } |
1160 | } |
1157 | |
1161 | |
1158 | my $signal = uc $arg{signal} |
1162 | my $signal = uc $arg{signal} |
… | |
… | |
1171 | sub AnyEvent::Base::signal::DESTROY { |
1175 | sub AnyEvent::Base::signal::DESTROY { |
1172 | my ($signal, $cb) = @{$_[0]}; |
1176 | my ($signal, $cb) = @{$_[0]}; |
1173 | |
1177 | |
1174 | delete $SIG_CB{$signal}{$cb}; |
1178 | delete $SIG_CB{$signal}{$cb}; |
1175 | |
1179 | |
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1180 | # delete doesn't work with older perls - they then |
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1181 | # print weird messages, or just unconditionally exit |
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1182 | # instead of getting the default action. |
1176 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1183 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1177 | } |
1184 | } |
1178 | |
1185 | |
1179 | # default implementation for ->child |
1186 | # default implementation for ->child |
1180 | |
1187 | |
1181 | our %PID_CB; |
1188 | our %PID_CB; |
1182 | our $CHLD_W; |
1189 | our $CHLD_W; |
1183 | our $CHLD_DELAY_W; |
1190 | our $CHLD_DELAY_W; |
1184 | our $PID_IDLE; |
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1185 | our $WNOHANG; |
1191 | our $WNOHANG; |
1186 | |
1192 | |
1187 | sub _child_wait { |
1193 | sub _sigchld { |
1188 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1194 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1189 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1195 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1190 | (values %{ $PID_CB{0} || {} }); |
1196 | (values %{ $PID_CB{0} || {} }); |
1191 | } |
1197 | } |
1192 | |
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1193 | undef $PID_IDLE; |
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1194 | } |
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1195 | |
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1196 | sub _sigchld { |
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1197 | # make sure we deliver these changes "synchronous" with the event loop. |
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1198 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
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1199 | undef $CHLD_DELAY_W; |
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1200 | &_child_wait; |
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1201 | }); |
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1202 | } |
1198 | } |
1203 | |
1199 | |
1204 | sub child { |
1200 | sub child { |
1205 | my (undef, %arg) = @_; |
1201 | my (undef, %arg) = @_; |
1206 | |
1202 | |
1207 | defined (my $pid = $arg{pid} + 0) |
1203 | defined (my $pid = $arg{pid} + 0) |
1208 | or Carp::croak "required option 'pid' is missing"; |
1204 | or Carp::croak "required option 'pid' is missing"; |
1209 | |
1205 | |
1210 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1206 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1211 | |
1207 | |
1212 | unless ($WNOHANG) { |
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1213 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1208 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1214 | } |
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1215 | |
1209 | |
1216 | unless ($CHLD_W) { |
1210 | unless ($CHLD_W) { |
1217 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1211 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1218 | # child could be a zombie already, so make at least one round |
1212 | # child could be a zombie already, so make at least one round |
1219 | &_sigchld; |
1213 | &_sigchld; |
… | |
… | |
1230 | |
1224 | |
1231 | undef $CHLD_W unless keys %PID_CB; |
1225 | undef $CHLD_W unless keys %PID_CB; |
1232 | } |
1226 | } |
1233 | |
1227 | |
1234 | # idle emulation is done by simply using a timer, regardless |
1228 | # idle emulation is done by simply using a timer, regardless |
1235 | # of whether the proces sis idle or not, and not letting |
1229 | # of whether the process is idle or not, and not letting |
1236 | # the callback use more than 50% of the time. |
1230 | # the callback use more than 50% of the time. |
1237 | sub idle { |
1231 | sub idle { |
1238 | my (undef, %arg) = @_; |
1232 | my (undef, %arg) = @_; |
1239 | |
1233 | |
1240 | my ($cb, $w, $rcb) = $arg{cb}; |
1234 | my ($cb, $w, $rcb) = $arg{cb}; |
… | |
… | |
1346 | so on. |
1340 | so on. |
1347 | |
1341 | |
1348 | =head1 ENVIRONMENT VARIABLES |
1342 | =head1 ENVIRONMENT VARIABLES |
1349 | |
1343 | |
1350 | The following environment variables are used by this module or its |
1344 | The following environment variables are used by this module or its |
1351 | submodules: |
1345 | submodules. |
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1346 | |
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1347 | Note that AnyEvent will remove I<all> environment variables starting with |
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1348 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
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1349 | enabled. |
1352 | |
1350 | |
1353 | =over 4 |
1351 | =over 4 |
1354 | |
1352 | |
1355 | =item C<PERL_ANYEVENT_VERBOSE> |
1353 | =item C<PERL_ANYEVENT_VERBOSE> |
1356 | |
1354 | |
… | |
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1896 | =item * C-based event loops perform very well with small number of |
1894 | =item * C-based event loops perform very well with small number of |
1897 | watchers, as the management overhead dominates. |
1895 | watchers, as the management overhead dominates. |
1898 | |
1896 | |
1899 | =back |
1897 | =back |
1900 | |
1898 | |
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1899 | =head2 THE IO::Lambda BENCHMARK |
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1900 | |
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1901 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
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1902 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
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1903 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
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1904 | shouldn't come as a surprise to anybody). As such, the benchmark is |
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1905 | fine, and shows that the AnyEvent backend from IO::Lambda isn't very |
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1906 | optimal. But how would AnyEvent compare when used without the extra |
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1907 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
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1908 | |
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1909 | The benchmark itself creates an echo-server, and then, for 500 times, |
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1910 | connects to the echo server, sends a line, waits for the reply, and then |
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1911 | creates the next connection. This is a rather bad benchmark, as it doesn't |
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1912 | test the efficiency of the framework, but it is a benchmark nevertheless. |
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1913 | |
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1914 | name runtime |
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1915 | Lambda/select 0.330 sec |
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1916 | + optimized 0.122 sec |
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1917 | Lambda/AnyEvent 0.327 sec |
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1918 | + optimized 0.138 sec |
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1919 | Raw sockets/select 0.077 sec |
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1920 | POE/select, components 0.662 sec |
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1921 | POE/select, raw sockets 0.226 sec |
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1922 | POE/select, optimized 0.404 sec |
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1923 | |
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1924 | AnyEvent/select/nb 0.085 sec |
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1925 | AnyEvent/EV/nb 0.068 sec |
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1926 | +state machine 0.134 sec |
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1927 | |
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1928 | The benchmark is also a bit unfair (my fault) - the IO::Lambda |
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1929 | benchmarks actually make blocking connects and use 100% blocking I/O, |
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1930 | defeating the purpose of an event-based solution. All of the newly |
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1931 | written AnyEvent benchmarks use 100% non-blocking connects (using |
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1932 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
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1933 | resolver), so AnyEvent is at a disadvantage here as non-blocking connects |
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1934 | generally require a lot more bookkeeping and event handling than blocking |
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1935 | connects (which involve a single syscall only). |
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1936 | |
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1937 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
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1938 | offers similar expressive power as POE and IO::Lambda (using conventional |
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1939 | Perl syntax), which means both the echo server and the client are 100% |
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1940 | non-blocking w.r.t. I/O, further placing it at a disadvantage. |
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1941 | |
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1942 | As you can see, AnyEvent + EV even beats the hand-optimised "raw sockets |
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1943 | benchmark", while AnyEvent + its pure perl backend easily beats |
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1944 | IO::Lambda and POE. |
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1945 | |
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1946 | And even the 100% non-blocking version written using the high-level (and |
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1947 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda, |
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1948 | even thought it does all of DNS, tcp-connect and socket I/O in a |
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1949 | non-blocking way. |
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1950 | |
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1951 | The two AnyEvent benchmarks can be found as F<eg/ae0.pl> and F<eg/ae2.pl> |
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1952 | in the AnyEvent distribution, the remaining benchmarks are part of the |
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1953 | IO::lambda distribution and were used without any changes. |
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1954 | |
1901 | |
1955 | |
1902 | =head1 SIGNALS |
1956 | =head1 SIGNALS |
1903 | |
1957 | |
1904 | AnyEvent currently installs handlers for these signals: |
1958 | AnyEvent currently installs handlers for these signals: |
1905 | |
1959 | |
… | |
… | |
1962 | use AnyEvent; |
2016 | use AnyEvent; |
1963 | |
2017 | |
1964 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2018 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1965 | be used to probe what backend is used and gain other information (which is |
2019 | be used to probe what backend is used and gain other information (which is |
1966 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
2020 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
1967 | $ENV{PERL_ANYEGENT_STRICT}. |
2021 | $ENV{PERL_ANYEVENT_STRICT}. |
1968 | |
2022 | |
1969 | |
2023 | |
1970 | =head1 BUGS |
2024 | =head1 BUGS |
1971 | |
2025 | |
1972 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2026 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |