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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC vs.
Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC

… …
340=head2 CHILD PROCESS WATCHERS 340=head2 CHILD PROCESS WATCHERS
341 341
342You can also watch on a child process exit and catch its exit status. 342You can also watch on a child process exit and catch its exit status.
343 343
344The child process is specified by the C<pid> argument (if set to C<0>, it 344The child process is specified by the C<pid> argument (if set to C<0>, it
345watches for any child process exit). The watcher will trigger as often 345watches for any child process exit). The watcher will triggered only when
346as status change for the child are received. This works by installing a 346the child process has finished and an exit status is available, not on
347signal handler for C<SIGCHLD>. The callback will be called with the pid 347any trace events (stopped/continued).
348and exit status (as returned by waitpid), so unlike other watcher types, 348
349you I<can> rely on child watcher callback arguments. 349The callback will be called with the pid and exit status (as returned by
350waitpid), so unlike other watcher types, you I<can> rely on child watcher
351callback arguments.
352
353This watcher type works by installing a signal handler for C<SIGCHLD>,
354and since it cannot be shared, nothing else should use SIGCHLD or reap
355random child processes (waiting for specific child processes, e.g. inside
356C<system>, is just fine).
350 357
351There is a slight catch to child watchers, however: you usually start them 358There is a slight catch to child watchers, however: you usually start them
352I<after> the child process was created, and this means the process could 359I<after> the child process was created, and this means the process could
353have exited already (and no SIGCHLD will be sent anymore). 360have exited already (and no SIGCHLD will be sent anymore).
354 361
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818=item L<AnyEvent::IGS> 825=item L<AnyEvent::IGS>
819 826
820A non-blocking interface to the Internet Go Server protocol (used by 827A non-blocking interface to the Internet Go Server protocol (used by
821L<App::IGS>). 828L<App::IGS>).
822 829
823=item L<Net::IRC3> 830=item L<AnyEvent::IRC>
824 831
825AnyEvent based IRC client module family. 832AnyEvent based IRC client module family (replacing the older Net::IRC3).
826 833
827=item L<Net::XMPP2> 834=item L<Net::XMPP2>
828 835
829AnyEvent based XMPP (Jabber protocol) module family. 836AnyEvent based XMPP (Jabber protocol) module family.
830 837
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854no warnings; 861no warnings;
855use strict qw(vars subs); 862use strict qw(vars subs);
856 863
857use Carp; 864use Carp;
858 865
859our $VERSION = 4.233; 866our $VERSION = 4.32;
860our $MODEL; 867our $MODEL;
861 868
862our $AUTOLOAD; 869our $AUTOLOAD;
863our @ISA; 870our @ISA;
864 871
… …
1021BEGIN { 1028BEGIN {
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
1030sub time { _time } 1037sub time { _time }
1031sub now { _time } 1038sub now { _time }
… …
1526watcher. 1533watcher.
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
1544The benchmark does I<not> measure scalability of the event loop very 1551The benchmark does I<not> measure scalability of the event loop very
1545well. For example, a select-based event loop (such as the pure perl one) 1552well. For example, a select-based event loop (such as the pure perl one)
… …
1747watchers, as the management overhead dominates. 1754watchers, as the management overhead dominates.
1748 1755
1749=back 1756=back
1750 1757
1751 1758
1759=head1 SIGNALS
1760
1761AnyEvent currently installs handlers for these signals:
1762
1763=over 4
1764
1765=item SIGCHLD
1766
1767A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1768emulation for event loops that do not support them natively. Also, some
1769event loops install a similar handler.
1770
1771=item SIGPIPE
1772
1773A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1774when AnyEvent gets loaded.
1775
1776The rationale for this is that AnyEvent users usually do not really depend
1777on SIGPIPE delivery (which is purely an optimisation for shell use, or
1778badly-written programs), but C<SIGPIPE> can cause spurious and rare
1779program exits as a lot of people do not expect C<SIGPIPE> when writing to
1780some random socket.
1781
1782The rationale for installing a no-op handler as opposed to ignoring it is
1783that this way, the handler will be restored to defaults on exec.
1784
1785Feel 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
1754Most event libraries are not fork-safe. The ones who are usually are 1797Most event libraries are not fork-safe. The ones who are usually are
1755because they rely on inefficient but fork-safe C<select> or C<poll> 1798because they rely on inefficient but fork-safe C<select> or C<poll>
1756calls. Only L<EV> is fully fork-aware. 1799calls. Only L<EV> is fully fork-aware.

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