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package AnyEvent::Fork::Serve; |
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|
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our $OWNER; # pid of process "owning" us |
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|
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# commands understood: |
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# e_val perlcode string... |
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# f_ork |
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# h_andle + fd |
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# a_rgs string... |
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# r_un func |
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|
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# the goal here is to keep this simple, small and efficient |
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sub serve { |
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local $^W = 0; # avoid spurious warnings |
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|
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undef &me; # free a tiny bit of memory |
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|
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my $master = shift; |
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|
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my @arg; |
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|
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my ($cmd, $fd); |
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|
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my $error = sub { |
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warn "[$0] ERROR: $_[0]\n"; |
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last; |
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}; |
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|
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local *run_args = sub () { # AnyEvent::Fork::Serve::run_args |
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my (@ret, @arg) = @arg; # copy and clear @arg |
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@ret |
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}; |
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|
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while () { |
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# we manually reap child processes before we sleep, as local $SIG... |
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# will destroy existing child handlers instead of restoring them. |
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1 while 0 < waitpid -1, 1; # WNOHANG is portably 1. prove me wrong. |
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|
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# we must not ever read "too much" data, as we might accidentally read |
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# an IO::FDPass::send request. |
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|
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my $len; |
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sysread $master, $len, 5 - length $len, length $len or last |
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while 5 > length $len; |
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($cmd, $len) = unpack "a L", $len; |
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|
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my $buf; |
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sysread $master, $buf, $len - length $buf, length $buf or last |
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while $len > length $buf; |
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|
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if ($cmd eq "h") { |
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require IO::FDPass; |
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$fd = IO::FDPass::recv (fileno $master); |
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$fd >= 0 or $error->("AnyEvent::Fork::Serve: fd_recv() failed: $!"); |
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open my $fh, "+<&=$fd" or $error->("AnyEvent::Fork::Serve: open (fd_recv) failed: $!"); |
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push @arg, $fh; |
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|
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} elsif ($cmd eq "a") { |
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push @arg, unpack "(w/a*)*", $buf; |
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|
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} elsif ($cmd eq "f") { |
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my $pid = fork; |
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|
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if ($pid eq 0) { |
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$0 = "$OWNER AnyEvent::Fork"; |
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$master = pop @arg; |
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|
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} else { |
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pop @arg; |
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|
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$pid |
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or $error->("AnyEvent::Fork::Serve: fork() failed: $!"); |
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} |
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|
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} elsif ($cmd eq "e") { |
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($cmd, @_) = unpack "(w/a*)*", $buf; |
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|
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# $cmd is allowed to access @_ and nothing else |
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package main; |
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eval $cmd; |
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$error->("$@") if $@; |
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|
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} elsif ($cmd eq "r") { |
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# we could free &serve etc., but this might just unshare |
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# memory that could be shared otherwise. |
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@_ = ($master, @arg); |
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$0 = "$OWNER $buf"; |
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package main; |
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goto &$buf; |
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|
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} else { |
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$error->("AnyEvent::Fork::Serve received unknown request '$cmd' - stream corrupted?"); |
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} |
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} |
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|
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shutdown $master, 1; |
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exit; # work around broken win32 perls |
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} |
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|
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# the entry point for new_exec |
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sub me { |
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#$^F = 2; # should always be the case |
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|
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open my $fh, "+<&=$ARGV[0]" |
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or die "AnyEvent::Fork::Serve::me unable to open communication socket: $!\n"; |
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|
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$OWNER = $ARGV[1]; |
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|
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$0 = "$OWNER AnyEvent::Fork/exec"; |
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|
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@ARGV = (); |
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@_ = $fh; |
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goto &serve; |
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} |
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|
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1 |
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