… | |
… | |
392 | |
392 | |
393 | There is a slight catch to child watchers, however: you usually start them |
393 | There is a slight catch to child watchers, however: you usually start them |
394 | I<after> the child process was created, and this means the process could |
394 | I<after> the child process was created, and this means the process could |
395 | have exited already (and no SIGCHLD will be sent anymore). |
395 | have exited already (and no SIGCHLD will be sent anymore). |
396 | |
396 | |
397 | Not all event models handle this correctly (POE doesn't), but even for |
397 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
398 | see their AnyEvent::Impl manpages for details), but even for event models |
398 | event models that I<do> handle this correctly, they usually need to be |
399 | that I<do> handle this correctly, they usually need to be loaded before |
399 | loaded before the process exits (i.e. before you fork in the first place). |
400 | the process exits (i.e. before you fork in the first place). AnyEvent's |
|
|
401 | pure perl event loop handles all cases correctly regardless of when you |
|
|
402 | start the watcher. |
400 | |
403 | |
401 | This means you cannot create a child watcher as the very first thing in an |
404 | This means you cannot create a child watcher as the very first |
402 | AnyEvent program, you I<have> to create at least one watcher before you |
405 | thing in an AnyEvent program, you I<have> to create at least one |
403 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
406 | watcher before you C<fork> the child (alternatively, you can call |
|
|
407 | C<AnyEvent::detect>). |
404 | |
408 | |
405 | Example: fork a process and wait for it |
409 | Example: fork a process and wait for it |
406 | |
410 | |
407 | my $done = AnyEvent->condvar; |
411 | my $done = AnyEvent->condvar; |
408 | |
412 | |
… | |
… | |
595 | |
599 | |
596 | =item $cv->begin ([group callback]) |
600 | =item $cv->begin ([group callback]) |
597 | |
601 | |
598 | =item $cv->end |
602 | =item $cv->end |
599 | |
603 | |
600 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
601 | |
|
|
602 | These two methods can be used to combine many transactions/events into |
604 | These two methods can be used to combine many transactions/events into |
603 | one. For example, a function that pings many hosts in parallel might want |
605 | one. For example, a function that pings many hosts in parallel might want |
604 | to use a condition variable for the whole process. |
606 | to use a condition variable for the whole process. |
605 | |
607 | |
606 | Every call to C<< ->begin >> will increment a counter, and every call to |
608 | Every call to C<< ->begin >> will increment a counter, and every call to |
607 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
609 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
608 | >>, the (last) callback passed to C<begin> will be executed. That callback |
610 | >>, the (last) callback passed to C<begin> will be executed. That callback |
609 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
611 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
610 | callback was set, C<send> will be called without any arguments. |
612 | callback was set, C<send> will be called without any arguments. |
611 | |
613 | |
612 | Let's clarify this with the ping example: |
614 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
615 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
616 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
617 | |
|
|
618 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
619 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
620 | close before activating a condvar: |
|
|
621 | |
|
|
622 | my $cv = AnyEvent->condvar; |
|
|
623 | |
|
|
624 | $cv->begin; # first watcher |
|
|
625 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
626 | defined sysread $fh1, my $buf, 4096 |
|
|
627 | or $cv->end; |
|
|
628 | }); |
|
|
629 | |
|
|
630 | $cv->begin; # second watcher |
|
|
631 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
632 | defined sysread $fh2, my $buf, 4096 |
|
|
633 | or $cv->end; |
|
|
634 | }); |
|
|
635 | |
|
|
636 | $cv->recv; |
|
|
637 | |
|
|
638 | This works because for every event source (EOF on file handle), there is |
|
|
639 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
640 | sending. |
|
|
641 | |
|
|
642 | The ping example mentioned above is slightly more complicated, as the |
|
|
643 | there are results to be passwd back, and the number of tasks that are |
|
|
644 | begung can potentially be zero: |
613 | |
645 | |
614 | my $cv = AnyEvent->condvar; |
646 | my $cv = AnyEvent->condvar; |
615 | |
647 | |
616 | my %result; |
648 | my %result; |
617 | $cv->begin (sub { $cv->send (\%result) }); |
649 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
637 | loop, which serves two important purposes: first, it sets the callback |
669 | loop, which serves two important purposes: first, it sets the callback |
638 | to be called once the counter reaches C<0>, and second, it ensures that |
670 | to be called once the counter reaches C<0>, and second, it ensures that |
639 | C<send> is called even when C<no> hosts are being pinged (the loop |
671 | C<send> is called even when C<no> hosts are being pinged (the loop |
640 | doesn't execute once). |
672 | doesn't execute once). |
641 | |
673 | |
642 | This is the general pattern when you "fan out" into multiple subrequests: |
674 | This is the general pattern when you "fan out" into multiple (but |
643 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
675 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
644 | is called at least once, and then, for each subrequest you start, call |
676 | the callback and ensure C<end> is called at least once, and then, for each |
645 | C<begin> and for each subrequest you finish, call C<end>. |
677 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
678 | call C<end>. |
646 | |
679 | |
647 | =back |
680 | =back |
648 | |
681 | |
649 | =head3 METHODS FOR CONSUMERS |
682 | =head3 METHODS FOR CONSUMERS |
650 | |
683 | |
… | |
… | |
730 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
763 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
731 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
764 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
732 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
765 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
733 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
766 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
734 | |
767 | |
|
|
768 | # warning, support for IO::Async is only partial, as it is too broken |
|
|
769 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
|
|
770 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
|
|
771 | |
735 | There is no support for WxWidgets, as WxWidgets has no support for |
772 | There is no support for WxWidgets, as WxWidgets has no support for |
736 | watching file handles. However, you can use WxWidgets through the |
773 | watching file handles. However, you can use WxWidgets through the |
737 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
774 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
738 | second, which was considered to be too horrible to even consider for |
775 | second, which was considered to be too horrible to even consider for |
739 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
776 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
… | |
… | |
931 | no warnings; |
968 | no warnings; |
932 | use strict qw(vars subs); |
969 | use strict qw(vars subs); |
933 | |
970 | |
934 | use Carp; |
971 | use Carp; |
935 | |
972 | |
936 | our $VERSION = 4.411; |
973 | our $VERSION = 4.45; |
937 | our $MODEL; |
974 | our $MODEL; |
938 | |
975 | |
939 | our $AUTOLOAD; |
976 | our $AUTOLOAD; |
940 | our @ISA; |
977 | our @ISA; |
941 | |
978 | |
… | |
… | |
974 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1011 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
975 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1012 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
976 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1013 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
977 | [Wx:: => AnyEvent::Impl::POE::], |
1014 | [Wx:: => AnyEvent::Impl::POE::], |
978 | [Prima:: => AnyEvent::Impl::POE::], |
1015 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1016 | # IO::Async is just too broken - we would need workaorunds for its |
|
|
1017 | # byzantine signal and broken child handling, among others. |
|
|
1018 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1019 | # obvious default class. |
|
|
1020 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1021 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1022 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
979 | ); |
1023 | ); |
980 | |
1024 | |
981 | our %method = map +($_ => 1), |
1025 | our %method = map +($_ => 1), |
982 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
1026 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
983 | |
1027 | |
… | |
… | |
1075 | } |
1119 | } |
1076 | |
1120 | |
1077 | # utility function to dup a filehandle. this is used by many backends |
1121 | # utility function to dup a filehandle. this is used by many backends |
1078 | # to support binding more than one watcher per filehandle (they usually |
1122 | # to support binding more than one watcher per filehandle (they usually |
1079 | # allow only one watcher per fd, so we dup it to get a different one). |
1123 | # allow only one watcher per fd, so we dup it to get a different one). |
1080 | sub _dupfh($$$$) { |
1124 | sub _dupfh($$;$$) { |
1081 | my ($poll, $fh, $r, $w) = @_; |
1125 | my ($poll, $fh, $r, $w) = @_; |
1082 | |
1126 | |
1083 | # cygwin requires the fh mode to be matching, unix doesn't |
1127 | # cygwin requires the fh mode to be matching, unix doesn't |
1084 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1128 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1085 | : $poll eq "w" ? ($w, ">") |
1129 | : $poll eq "w" ? ($w, ">") |
… | |
… | |
1366 | =item C<PERL_ANYEVENT_STRICT> |
1410 | =item C<PERL_ANYEVENT_STRICT> |
1367 | |
1411 | |
1368 | AnyEvent does not do much argument checking by default, as thorough |
1412 | AnyEvent does not do much argument checking by default, as thorough |
1369 | argument checking is very costly. Setting this variable to a true value |
1413 | argument checking is very costly. Setting this variable to a true value |
1370 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
1414 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
1371 | check the arguments passed to most method calls. If it finds any problems |
1415 | check the arguments passed to most method calls. If it finds any problems, |
1372 | it will croak. |
1416 | it will croak. |
1373 | |
1417 | |
1374 | In other words, enables "strict" mode. |
1418 | In other words, enables "strict" mode. |
1375 | |
1419 | |
1376 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
1420 | Unlike C<use strict>, it is definitely recommended to keep it off in |
1377 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
1421 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
1378 | developing programs can be very useful, however. |
1422 | developing programs can be very useful, however. |
1379 | |
1423 | |
1380 | =item C<PERL_ANYEVENT_MODEL> |
1424 | =item C<PERL_ANYEVENT_MODEL> |
1381 | |
1425 | |
… | |
… | |
1680 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1724 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1681 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1725 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1682 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1726 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1683 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1727 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1684 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1728 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1729 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1730 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1685 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1731 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1686 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1732 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1687 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1733 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1688 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1734 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1689 | |
1735 | |
… | |
… | |
1718 | performance becomes really bad with lots of file descriptors (and few of |
1764 | performance becomes really bad with lots of file descriptors (and few of |
1719 | them active), of course, but this was not subject of this benchmark. |
1765 | them active), of course, but this was not subject of this benchmark. |
1720 | |
1766 | |
1721 | The C<Event> module has a relatively high setup and callback invocation |
1767 | The C<Event> module has a relatively high setup and callback invocation |
1722 | cost, but overall scores in on the third place. |
1768 | cost, but overall scores in on the third place. |
|
|
1769 | |
|
|
1770 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1771 | when using its pure perl backend. |
1723 | |
1772 | |
1724 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1773 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1725 | faster callback invocation and overall ends up in the same class as |
1774 | faster callback invocation and overall ends up in the same class as |
1726 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1775 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1727 | watchers increases the processing time by more than a factor of four, |
1776 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1805 | it to another server. This includes deleting the old timeout and creating |
1854 | it to another server. This includes deleting the old timeout and creating |
1806 | a new one that moves the timeout into the future. |
1855 | a new one that moves the timeout into the future. |
1807 | |
1856 | |
1808 | =head3 Results |
1857 | =head3 Results |
1809 | |
1858 | |
1810 | name sockets create request |
1859 | name sockets create request |
1811 | EV 20000 69.01 11.16 |
1860 | EV 20000 69.01 11.16 |
1812 | Perl 20000 73.32 35.87 |
1861 | Perl 20000 73.32 35.87 |
|
|
1862 | IOAsync 20000 157.00 98.14 epoll |
|
|
1863 | IOAsync 20000 159.31 616.06 poll |
1813 | Event 20000 212.62 257.32 |
1864 | Event 20000 212.62 257.32 |
1814 | Glib 20000 651.16 1896.30 |
1865 | Glib 20000 651.16 1896.30 |
1815 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1866 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1816 | |
1867 | |
1817 | =head3 Discussion |
1868 | =head3 Discussion |
1818 | |
1869 | |
1819 | This benchmark I<does> measure scalability and overall performance of the |
1870 | This benchmark I<does> measure scalability and overall performance of the |
1820 | particular event loop. |
1871 | particular event loop. |
… | |
… | |
1822 | EV is again fastest. Since it is using epoll on my system, the setup time |
1873 | EV is again fastest. Since it is using epoll on my system, the setup time |
1823 | is relatively high, though. |
1874 | is relatively high, though. |
1824 | |
1875 | |
1825 | Perl surprisingly comes second. It is much faster than the C-based event |
1876 | Perl surprisingly comes second. It is much faster than the C-based event |
1826 | loops Event and Glib. |
1877 | loops Event and Glib. |
|
|
1878 | |
|
|
1879 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1880 | good compared to Glib when using its pure perl backend. |
1827 | |
1881 | |
1828 | Event suffers from high setup time as well (look at its code and you will |
1882 | Event suffers from high setup time as well (look at its code and you will |
1829 | understand why). Callback invocation also has a high overhead compared to |
1883 | understand why). Callback invocation also has a high overhead compared to |
1830 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1884 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1831 | uses select or poll in basically all documented configurations. |
1885 | uses select or poll in basically all documented configurations. |
… | |
… | |
1894 | =item * C-based event loops perform very well with small number of |
1948 | =item * C-based event loops perform very well with small number of |
1895 | watchers, as the management overhead dominates. |
1949 | watchers, as the management overhead dominates. |
1896 | |
1950 | |
1897 | =back |
1951 | =back |
1898 | |
1952 | |
|
|
1953 | =head2 THE IO::Lambda BENCHMARK |
|
|
1954 | |
|
|
1955 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1956 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1957 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
1958 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
1959 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
1960 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
1961 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
1962 | |
|
|
1963 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
1964 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
1965 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
1966 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
1967 | benchmark nevertheless. |
|
|
1968 | |
|
|
1969 | name runtime |
|
|
1970 | Lambda/select 0.330 sec |
|
|
1971 | + optimized 0.122 sec |
|
|
1972 | Lambda/AnyEvent 0.327 sec |
|
|
1973 | + optimized 0.138 sec |
|
|
1974 | Raw sockets/select 0.077 sec |
|
|
1975 | POE/select, components 0.662 sec |
|
|
1976 | POE/select, raw sockets 0.226 sec |
|
|
1977 | POE/select, optimized 0.404 sec |
|
|
1978 | |
|
|
1979 | AnyEvent/select/nb 0.085 sec |
|
|
1980 | AnyEvent/EV/nb 0.068 sec |
|
|
1981 | +state machine 0.134 sec |
|
|
1982 | |
|
|
1983 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
1984 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
1985 | defeating the purpose of an event-based solution. All of the newly |
|
|
1986 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
1987 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
1988 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
1989 | generally require a lot more bookkeeping and event handling than blocking |
|
|
1990 | connects (which involve a single syscall only). |
|
|
1991 | |
|
|
1992 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
1993 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
1994 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
1995 | non-blocking, further placing it at a disadvantage. |
|
|
1996 | |
|
|
1997 | As you can see, the AnyEvent + EV combination even beats the |
|
|
1998 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
1999 | backend easily beats IO::Lambda and POE. |
|
|
2000 | |
|
|
2001 | And even the 100% non-blocking version written using the high-level (and |
|
|
2002 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2003 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2004 | in a non-blocking way. |
|
|
2005 | |
|
|
2006 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2007 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2008 | part of the IO::lambda distribution and were used without any changes. |
|
|
2009 | |
1899 | |
2010 | |
1900 | =head1 SIGNALS |
2011 | =head1 SIGNALS |
1901 | |
2012 | |
1902 | AnyEvent currently installs handlers for these signals: |
2013 | AnyEvent currently installs handlers for these signals: |
1903 | |
2014 | |
… | |
… | |
1906 | =item SIGCHLD |
2017 | =item SIGCHLD |
1907 | |
2018 | |
1908 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
2019 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
1909 | emulation for event loops that do not support them natively. Also, some |
2020 | emulation for event loops that do not support them natively. Also, some |
1910 | event loops install a similar handler. |
2021 | event loops install a similar handler. |
|
|
2022 | |
|
|
2023 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2024 | reset it to default, to avoid losing child exit statuses. |
1911 | |
2025 | |
1912 | =item SIGPIPE |
2026 | =item SIGPIPE |
1913 | |
2027 | |
1914 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
2028 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
1915 | when AnyEvent gets loaded. |
2029 | when AnyEvent gets loaded. |
… | |
… | |
1927 | |
2041 | |
1928 | =back |
2042 | =back |
1929 | |
2043 | |
1930 | =cut |
2044 | =cut |
1931 | |
2045 | |
|
|
2046 | undef $SIG{CHLD} |
|
|
2047 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2048 | |
1932 | $SIG{PIPE} = sub { } |
2049 | $SIG{PIPE} = sub { } |
1933 | unless defined $SIG{PIPE}; |
2050 | unless defined $SIG{PIPE}; |
1934 | |
|
|
1935 | |
2051 | |
1936 | =head1 FORK |
2052 | =head1 FORK |
1937 | |
2053 | |
1938 | Most event libraries are not fork-safe. The ones who are usually are |
2054 | Most event libraries are not fork-safe. The ones who are usually are |
1939 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2055 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1962 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2078 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1963 | be used to probe what backend is used and gain other information (which is |
2079 | be used to probe what backend is used and gain other information (which is |
1964 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
2080 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
1965 | $ENV{PERL_ANYEVENT_STRICT}. |
2081 | $ENV{PERL_ANYEVENT_STRICT}. |
1966 | |
2082 | |
|
|
2083 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2084 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2085 | enabled. |
|
|
2086 | |
1967 | |
2087 | |
1968 | =head1 BUGS |
2088 | =head1 BUGS |
1969 | |
2089 | |
1970 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2090 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1971 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
2091 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |