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=head1 NAME |
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|
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AnyEvent::Util - various utility functions. |
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|
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=head1 SYNOPSIS |
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|
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use AnyEvent::Util; |
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|
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=head1 DESCRIPTION |
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|
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This module implements various utility functions, mostly replacing |
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well-known functions by event-ised counterparts. |
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|
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All functions documented without C<AnyEvent::Util::> prefix are exported |
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by default. |
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|
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=over 4 |
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|
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=cut |
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|
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package AnyEvent::Util; |
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|
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no warnings; |
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use strict; |
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|
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use Carp (); |
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use Errno (); |
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use Socket (); |
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|
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use AnyEvent (); |
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|
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use base 'Exporter'; |
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|
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our @EXPORT = qw(fh_nonblocking guard fork_call portable_pipe); |
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our @EXPORT_OK = qw(AF_INET6 WSAWOULDBLOCK WSAEINPROGRESS); |
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|
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our $VERSION = '1.0'; |
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|
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BEGIN { |
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my $posix = 1 * eval { local $SIG{__DIE__}; require POSIX }; |
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eval "sub POSIX() { $posix }"; |
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} |
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|
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BEGIN { |
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# TODO remove this once not used anymore |
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*socket_inet_aton = \&Socket::inet_aton; # take a copy, in case Coro::LWP overrides it |
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} |
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|
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BEGIN { |
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my $af_inet6 = eval { local $SIG{__DIE__}; &Socket::AF_INET6 }; |
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|
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# uhoh |
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$af_inet6 ||= 10 if $^O =~ /linux/; |
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$af_inet6 ||= 23 if $^O =~ /cygwin/i; |
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$af_inet6 ||= 23 if AnyEvent::WIN32; |
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$af_inet6 ||= 24 if $^O =~ /openbsd|netbsd/; |
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$af_inet6 ||= 28 if $^O =~ /freebsd/; |
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|
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$af_inet6 && socket my $ipv6_socket, $af_inet6, &Socket::SOCK_STREAM, 0 # check if they can be created |
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or $af_inet6 = 0; |
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|
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eval "sub AF_INET6() { $af_inet6 }"; die if $@; |
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|
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delete $AnyEvent::PROTOCOL{ipv6} unless $af_inet6; |
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} |
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|
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BEGIN { |
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# broken windows perls use undocumented error codes... |
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if (AnyEvent::WIN32) { |
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eval "sub WSAWOULDBLOCK() { 10035 }"; |
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eval "sub WSAEINPROGRESS() { 10036 }"; |
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} else { |
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eval "sub WSAWOULDBLOCK() { -1e99 }"; # should never match any errno value |
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eval "sub WSAEINPROGRESS() { -1e99 }"; # should never match any errno value |
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} |
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} |
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|
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=item ($r, $w) = portable_pipe |
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|
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Calling C<pipe> in Perl is portable - except it doesn't really work on |
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sucky windows platforms (at least not with most perls - cygwin's perl |
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notably works fine). |
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|
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On that platform, you actually get two file handles you cannot use select |
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on. |
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|
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This function gives you a pipe that actually works even on the broken |
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Windows platform (by creating a pair of TCP sockets, so do not expect any |
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speed from that). |
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|
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Returns the empty list on any errors. |
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|
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=cut |
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|
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sub portable_pipe() { |
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my ($r, $w); |
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|
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if (AnyEvent::WIN32) { |
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socketpair $r, $w, &Socket::AF_UNIX, &Socket::SOCK_STREAM, 0 |
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or return; |
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} else { |
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pipe $r, $w |
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or return; |
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} |
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|
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($r, $w) |
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} |
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|
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=item fork_call $coderef, @args, $cb->(@res) |
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|
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Executes the given code reference asynchronously, by forking. Everything |
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the C<$coderef> returns will transferred to the calling process (by |
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serialising and deserialising via L<Storable>). |
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|
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If there are any errors, then the C<$cb> will be called without any |
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arguments. In that case, either C<$@> contains the exception, or C<$!> |
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contains an error number. In all other cases, C<$@> will be C<undef>ined. |
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|
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The C<$coderef> must not ever call an event-polling function or use |
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event-based programming. |
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|
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Note that forking can be expensive in large programs (RSS 200MB+). On |
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windows, it is abysmally slow, do not expect more than 5..20 forks/s on |
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that sucky platform (note this uses perl's pseudo-threads, so avoid those |
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like the plague). |
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|
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=item $AnyEvent::Util::MAX_FORKS [default: 10] |
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|
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The maximum number of child processes that C<fork_call> will fork in |
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parallel. Any additional requests will be queued until a slot becomes free |
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again. |
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|
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The environment variable C<PERL_ANYEVENT_MAX_FORKS> is used to initialise |
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this value. |
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|
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=cut |
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|
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our $MAX_FORKS = int 1 * $ENV{PERL_ANYEVENT_MAX_FORKS}; |
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$MAX_FORKS = 10 if $MAX_FORKS <= 0; |
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|
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my $forks; |
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my @fork_queue; |
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|
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sub _fork_schedule; |
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sub _fork_schedule { |
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while () { |
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return if $forks >= $MAX_FORKS; |
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|
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my $job = shift @fork_queue |
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or return; |
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|
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++$forks; |
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|
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my $coderef = shift @$job; |
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my $cb = pop @$job; |
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|
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# gimme a break... |
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my ($r, $w) = portable_pipe |
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or ($forks and last) # allow failures when we have at least one job |
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or die "fork_call: $!"; |
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|
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my $pid = fork; |
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|
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if ($pid != 0) { |
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# parent |
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close $w; |
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|
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my $buf; |
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|
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my $ww; $ww = AnyEvent->io (fh => $r, poll => 'r', cb => sub { |
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my $len = sysread $r, $buf, 65536, length $buf; |
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|
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if ($len <= 0) { |
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undef $ww; |
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close $r; |
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--$forks; |
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_fork_schedule; |
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|
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my $result = eval { Storable::thaw ($buf) }; |
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$result = [$@] unless $result; |
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$@ = shift @$result; |
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|
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$cb->(@$result); |
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|
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# clean up the pid |
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waitpid $pid, 0; |
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} |
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}); |
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|
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} elsif (defined $pid) { |
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# child |
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close $r; |
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|
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my $result = eval { |
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local $SIG{__DIE__}; |
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|
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Storable::freeze ([undef, $coderef->(@$job)]) |
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}; |
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|
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$result = Storable::freeze (["$@"]) |
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if $@; |
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|
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# windows forces us to these contortions |
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my $ofs; |
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|
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while () { |
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my $len = (length $result) - $ofs |
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or last; |
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|
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$len = syswrite $w, $result, $len < 65536 ? $len : 65536, $ofs; |
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|
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last if $len <= 0; |
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|
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$ofs += $len; |
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} |
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|
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close $w; |
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|
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if (AnyEvent::WIN32) { |
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kill 9, $$; # yeah, windows for the win |
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} else { |
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# on native windows, _exit KILLS YOUR FORKED CHILDREN! |
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POSIX::_exit (0); |
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} |
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exit 1; |
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|
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} elsif (($! != &Errno::EAGAIN && $! != &Errno::ENOMEM) || !$forks) { |
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# we ignore some errors as long as we can run at least one job |
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# maybe we should wait a few seconds and retry instead |
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die "fork_call: $!"; |
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} |
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} |
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} |
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|
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sub fork_call { |
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require Storable; |
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|
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push @fork_queue, [@_]; |
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_fork_schedule; |
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} |
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|
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# to be removed |
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sub dotted_quad($) { |
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$_[0] =~ /^(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) |
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\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) |
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\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) |
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\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?)$/x |
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} |
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|
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# just a forwarder |
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sub inet_aton { |
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require AnyEvent::Socket; |
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*inet_aton = \&AnyEvent::Socket::inet_aton; |
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goto &inet_aton |
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} |
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|
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=item fh_nonblocking $fh, $nonblocking |
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|
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Sets the blocking state of the given filehandle (true == nonblocking, |
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false == blocking). Uses fcntl on anything sensible and ioctl FIONBIO on |
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broken (i.e. windows) platforms. |
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|
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=cut |
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|
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sub fh_nonblocking($$) { |
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my ($fh, $nb) = @_; |
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|
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require Fcntl; |
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|
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if (AnyEvent::WIN32) { |
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$nb = (! ! $nb) + 0; |
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ioctl $fh, 0x8004667e, \$nb; # FIONBIO |
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} else { |
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fcntl $fh, &Fcntl::F_SETFL, $nb ? &Fcntl::O_NONBLOCK : 0; |
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} |
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} |
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|
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=item $guard = guard { CODE } |
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|
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This function creates a special object that, when called, will execute the |
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code block. |
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|
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This is often handy in continuation-passing style code to clean up some |
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resource regardless of where you break out of a process. |
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|
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You can call one method on the returned object: |
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|
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=item $guard->cancel |
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|
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This simply causes the code block not to be invoked: it "cancels" the |
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guard. |
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|
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=cut |
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|
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sub AnyEvent::Util::Guard::DESTROY { |
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${$_[0]}->(); |
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} |
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|
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sub AnyEvent::Util::Guard::cancel($) { |
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${$_[0]} = sub { }; |
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} |
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|
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sub guard(&) { |
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bless \(my $cb = shift), AnyEvent::Util::Guard:: |
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} |
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|
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1; |
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|
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=back |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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|
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=cut |
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|
