tools/multigcc.pl

   1 #!/usr/bin/perl
   2 use feature "switch";
   3 use List::Util 'shuffle'; # standard from Perl 5.8 and later
   4
   5 my $tempfile = "multigcc.out";
   6 my @params;
   7 my @files;
   8 my $list = \@params;
   9
  10 # parse command line arguments
  11 for my $a (@ARGV) {
  12     if ($a eq "--") {
  13         $list = \@files;
  14         next;
  15     }
  16
  17     push @{$list}, $a;
  18 }
  19
  20 exit if (not @files);
  21
  22 my $command = join " ", @params;
  23
  24 # shuffle the file list to spread the load as evenly as we can
  25 @files = shuffle(@files);
  26
  27 # count number of cores
  28 my $cores;
  29 given ($^O) {
  30     when ("darwin") {
  31         chomp($cores = `sysctl -n hw.ncpu`);
  32         $cores = 1 if ($?);
  33     }
  34     when ("solaris") {
  35         $cores = scalar grep /on-line/i, `psrinfo`;
  36         $cores = 1 if ($?);
  37     }
  38     default {
  39         if (open CPUINFO, "</proc/cpuinfo") {
  40             $cores = scalar grep /^processor/i, <CPUINFO>;
  41             close CPUINFO;
  42         }
  43         else {
  44             $cores = 1;
  45         }
  46     }
  47 }
  48
  49 # fork children
  50 my @pids;
  51 my $slice = int((scalar @files + $cores) / $cores);
  52
  53 # reset $cores to 0 so we can count the number of actually used cores
  54 $cores=0;
  55
  56 for (my $i=0;$i<scalar @files;$i += $slice)
  57 {
  58     my $pid = fork;
  59     if ($pid)
  60     {
  61         # mother
  62         $pids[$cores++] = $pid;
  63     }
  64     else
  65     {
  66         # get my slice of the files
  67         my @list = @files[$i .. $i + $slice - 1];
  68
  69         # run command
  70         system("$command @list > $tempfile.$$");
  71
  72         exit;
  73     }
  74 }
  75
  76 for my $i (0 .. $cores - 1)
  77 {
  78     # wait for child to complete
  79     waitpid $pids[$i], 0;
  80
  81     # read & print result
  82     if (open F, "<$tempfile.$pids[$i]")
  83     {
  84         print <F>;
  85         close F;
  86         unlink "$tempfile.$pids[$i]";
  87     }
  88 }