tools/multigcc.pl

   1 #!/usr/bin/perl
   2 use List::Util 'shuffle'; # standard from Perl 5.8 and later
   3
   4 my $tempfile = "multigcc.out";
   5 my @params;
   6 my @files;
   7 my $list = \@params;
   8
   9 # parse command line arguments
  10 for my $a (@ARGV) {
  11     if ($a eq "--") {
  12         $list = \@files;
  13         next;
  14     }
  15
  16     push @{$list}, $a;
  17 }
  18
  19 exit if (not @files);
  20
  21 my $command = join " ", @params;
  22
  23 # shuffle the file list to spread the load as evenly as we can
  24 @files = shuffle(@files);
  25
  26 # count number of cores
  27 my $cores = 1;
  28 if (open CPUINFO, "</proc/cpuinfo") {
  29     $cores = scalar grep /^processor/i, <CPUINFO>;
  30     close CPUINFO;
  31 }
  32
  33 # don't run empty children
  34 if (scalar @files <= $cores)
  35 {
  36     $cores = 1;
  37 }
  38
  39 # fork children
  40 my @pids;
  41 my $slice = int((scalar @files + $cores) / $cores);
  42 for my $i (0 .. $cores-1)
  43 {
  44     my $pid = fork;
  45     if ($pid)
  46     {
  47         # mother
  48         $pids[$i] = $pid;
  49     }
  50     else
  51     {
  52         # get my slice of the files
  53         my @list = @files[$i * $slice .. $i * $slice + $slice - 1];
  54
  55         # run command
  56         system("$command @list > $tempfile.$$");
  57
  58         exit;
  59     }
  60 }
  61
  62 for my $i (0 .. $cores - 1)
  63 {
  64     # wait for child to complete
  65     waitpid $pids[$i], 0;
  66
  67     # read & print result
  68     if (open F, "<$tempfile.$pids[$i]")
  69     {
  70         print <F>;
  71         close F;
  72         unlink "$tempfile.$pids[$i]";
  73     }
  74 }