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 my $command = join " ", @params;
  20
  21 # shuffle the file list to spread the load as evenly as we can
  22 @files = shuffle(@files);
  23
  24 # count number of cores
  25 my $cores = 1;
  26 if (open CPUINFO, "</proc/cpuinfo") {
  27     $cores = scalar grep /^processor/i, <CPUINFO>;
  28     close CPUINFO;
  29 }
  30
  31 # don't run empty children
  32 if (scalar @files < $cores)
  33 {
  34     $cores = 1;
  35 }
  36
  37 # fork children
  38 my @pids;
  39 my $slice = int((scalar @files + $cores) / $cores);
  40 for my $i (0 .. $cores-1)
  41 {
  42     my $pid = fork;
  43     if ($pid)
  44     {
  45         # mother
  46         $pids[$i] = $pid;
  47     }
  48     else
  49     {
  50         # get my slice of the files
  51         my @list = @files[$i * $slice .. $i * $slice + $slice - 1];
  52
  53         # run command
  54         system("$command @list > $tempfile.$$");
  55
  56         exit;
  57     }
  58 }
  59
  60 for my $i (0 .. $cores - 1)
  61 {
  62     # wait for child to complete
  63     waitpid $pids[$i], 0;
  64
  65     # read & print result
  66     if (open F, "<$tempfile.$pids[$i]")
  67     {
  68         print <F>;
  69         close F;
  70         unlink "$tempfile.$pids[$i]";
  71     }
  72 }