… | |
… | |
340 | =head2 CHILD PROCESS WATCHERS |
340 | =head2 CHILD PROCESS WATCHERS |
341 | |
341 | |
342 | You can also watch on a child process exit and catch its exit status. |
342 | You can also watch on a child process exit and catch its exit status. |
343 | |
343 | |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
345 | watches for any child process exit). The watcher will trigger as often |
345 | watches for any child process exit). The watcher will triggered only when |
346 | as status change for the child are received. This works by installing a |
346 | the child process has finished and an exit status is available, not on |
347 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
347 | any trace events (stopped/continued). |
348 | and exit status (as returned by waitpid), so unlike other watcher types, |
348 | |
349 | you I<can> rely on child watcher callback arguments. |
349 | The callback will be called with the pid and exit status (as returned by |
|
|
350 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
351 | callback arguments. |
|
|
352 | |
|
|
353 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
354 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
355 | random child processes (waiting for specific child processes, e.g. inside |
|
|
356 | C<system>, is just fine). |
350 | |
357 | |
351 | There is a slight catch to child watchers, however: you usually start them |
358 | There is a slight catch to child watchers, however: you usually start them |
352 | I<after> the child process was created, and this means the process could |
359 | I<after> the child process was created, and this means the process could |
353 | have exited already (and no SIGCHLD will be sent anymore). |
360 | have exited already (and no SIGCHLD will be sent anymore). |
354 | |
361 | |
… | |
… | |
818 | =item L<AnyEvent::IGS> |
825 | =item L<AnyEvent::IGS> |
819 | |
826 | |
820 | A non-blocking interface to the Internet Go Server protocol (used by |
827 | A non-blocking interface to the Internet Go Server protocol (used by |
821 | L<App::IGS>). |
828 | L<App::IGS>). |
822 | |
829 | |
823 | =item L<Net::IRC3> |
830 | =item L<AnyEvent::IRC> |
824 | |
831 | |
825 | AnyEvent based IRC client module family. |
832 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
826 | |
833 | |
827 | =item L<Net::XMPP2> |
834 | =item L<Net::XMPP2> |
828 | |
835 | |
829 | AnyEvent based XMPP (Jabber protocol) module family. |
836 | AnyEvent based XMPP (Jabber protocol) module family. |
830 | |
837 | |
… | |
… | |
854 | no warnings; |
861 | no warnings; |
855 | use strict qw(vars subs); |
862 | use strict qw(vars subs); |
856 | |
863 | |
857 | use Carp; |
864 | use Carp; |
858 | |
865 | |
859 | our $VERSION = 4.233; |
866 | our $VERSION = 4.32; |
860 | our $MODEL; |
867 | our $MODEL; |
861 | |
868 | |
862 | our $AUTOLOAD; |
869 | our $AUTOLOAD; |
863 | our @ISA; |
870 | our @ISA; |
864 | |
871 | |
… | |
… | |
1021 | BEGIN { |
1028 | BEGIN { |
1022 | if (eval "use Time::HiRes (); time (); 1") { |
1029 | if (eval "use Time::HiRes (); time (); 1") { |
1023 | *_time = \&Time::HiRes::time; |
1030 | *_time = \&Time::HiRes::time; |
1024 | # if (eval "use POSIX (); (POSIX::times())... |
1031 | # if (eval "use POSIX (); (POSIX::times())... |
1025 | } else { |
1032 | } else { |
1026 | *_time = \&CORE::time; # epic fail |
1033 | *_time = sub { time }; # epic fail |
1027 | } |
1034 | } |
1028 | } |
1035 | } |
1029 | |
1036 | |
1030 | sub time { _time } |
1037 | sub time { _time } |
1031 | sub now { _time } |
1038 | sub now { _time } |
… | |
… | |
1526 | watcher. |
1533 | watcher. |
1527 | |
1534 | |
1528 | =head3 Results |
1535 | =head3 Results |
1529 | |
1536 | |
1530 | name watchers bytes create invoke destroy comment |
1537 | name watchers bytes create invoke destroy comment |
1531 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1538 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1532 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1539 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1533 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1540 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1534 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1541 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1535 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1542 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1536 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1543 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1537 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1544 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1538 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1545 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1539 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1546 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1540 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1547 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1541 | |
1548 | |
1542 | =head3 Discussion |
1549 | =head3 Discussion |
1543 | |
1550 | |
1544 | The benchmark does I<not> measure scalability of the event loop very |
1551 | The benchmark does I<not> measure scalability of the event loop very |
1545 | well. For example, a select-based event loop (such as the pure perl one) |
1552 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1747 | watchers, as the management overhead dominates. |
1754 | watchers, as the management overhead dominates. |
1748 | |
1755 | |
1749 | =back |
1756 | =back |
1750 | |
1757 | |
1751 | |
1758 | |
|
|
1759 | =head1 SIGNALS |
|
|
1760 | |
|
|
1761 | AnyEvent currently installs handlers for these signals: |
|
|
1762 | |
|
|
1763 | =over 4 |
|
|
1764 | |
|
|
1765 | =item SIGCHLD |
|
|
1766 | |
|
|
1767 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1768 | emulation for event loops that do not support them natively. Also, some |
|
|
1769 | event loops install a similar handler. |
|
|
1770 | |
|
|
1771 | =item SIGPIPE |
|
|
1772 | |
|
|
1773 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
1774 | when AnyEvent gets loaded. |
|
|
1775 | |
|
|
1776 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
1777 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
1778 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
1779 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
1780 | some random socket. |
|
|
1781 | |
|
|
1782 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
1783 | that this way, the handler will be restored to defaults on exec. |
|
|
1784 | |
|
|
1785 | Feel free to install your own handler, or reset it to defaults. |
|
|
1786 | |
|
|
1787 | =back |
|
|
1788 | |
|
|
1789 | =cut |
|
|
1790 | |
|
|
1791 | $SIG{PIPE} = sub { } |
|
|
1792 | unless defined $SIG{PIPE}; |
|
|
1793 | |
|
|
1794 | |
1752 | =head1 FORK |
1795 | =head1 FORK |
1753 | |
1796 | |
1754 | Most event libraries are not fork-safe. The ones who are usually are |
1797 | Most event libraries are not fork-safe. The ones who are usually are |
1755 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1798 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1756 | calls. Only L<EV> is fully fork-aware. |
1799 | calls. Only L<EV> is fully fork-aware. |