81 lines
2.1 KiB
Perl
81 lines
2.1 KiB
Perl
package StartXDummy;
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# vim:ts=4:sw=4:expandtab
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use strict;
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use warnings;
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use POSIX ();
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use Exporter 'import';
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use Time::HiRes qw(sleep);
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use v5.10;
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our @EXPORT = qw(start_xdummy);
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# reads in a whole file
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sub slurp {
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open(my $fh, '<', shift) or return '';
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local $/;
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<$fh>;
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}
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=head2 start_xdummy($parallel)
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Starts C<$parallel> (or number of cores * 2 if undef) Xdummy processes (see
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the file ./Xdummy) and returns two arrayrefs: a list of X11 display numbers to
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the Xdummy processes and a list of PIDs of the processes.
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=cut
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sub start_xdummy {
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my ($parallel) = @_;
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my @displays = ();
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my @childpids = ();
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# Yeah, I know it’s non-standard, but Perl’s POSIX module doesn’t have
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# _SC_NPROCESSORS_CONF.
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my $cpuinfo = slurp('/proc/cpuinfo');
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my $num_cores = scalar grep { /model name/ } split("\n", $cpuinfo);
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# If /proc/cpuinfo does not exist, we fall back to 2 cores.
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$num_cores ||= 2;
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$parallel ||= $num_cores * 2;
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# First get the last used display number, then increment it by one.
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# Effectively falls back to 1 if no X server is running.
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my ($displaynum) = reverse ('0', sort </tmp/.X11-unix/X*>);
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$displaynum =~ s/.*(\d)$/$1/;
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$displaynum++;
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say "Starting $parallel Xdummy instances, starting at :$displaynum...";
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for my $idx (0 .. ($parallel-1)) {
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my $pid = fork();
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die "Could not fork: $!" unless defined($pid);
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if ($pid == 0) {
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# Child, close stdout/stderr, then start Xdummy.
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POSIX::close(0);
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POSIX::close(2);
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exec './Xdummy', ":$displaynum", '-config', '/dev/null';
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exit 1;
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}
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push(@childpids, $pid);
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push(@displays, ":$displaynum");
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$displaynum++;
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}
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# Wait until the X11 sockets actually appear. Pretty ugly solution, but as
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# long as we can’t socket-activate X11…
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my $sockets_ready;
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do {
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$sockets_ready = 1;
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for (@displays) {
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my $path = "/tmp/.X11-unix/X" . substr($_, 1);
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$sockets_ready = 0 unless -S $path;
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}
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sleep 0.1;
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} until $sockets_ready;
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return \@displays, \@childpids;
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}
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1
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