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 $cores;
  28 # Don't use given/when here - it's not compatible with old perl versions
  29 if ($^O eq 'darwin') {
  30     chomp($cores = `sysctl -n hw.ncpu`);
  31     $cores = 1 if ($?);
  32 }
  33 elsif ($^O eq 'solaris') {
  34     $cores = scalar grep /on-line/i, `psrinfo`;
  35     $cores = 1 if ($?);
  36 }
  37 else {
  38     if (open CPUINFO, "</proc/cpuinfo") {
  39         $cores = scalar grep /^processor/i, <CPUINFO>;
  40         close CPUINFO;
  41     }
  42     else {
  43         $cores = 1;
  44     }
  45 }
  46
  47 # fork children
  48 my @pids;
  49 my $slice = int((scalar @files + $cores) / $cores);
  50
  51 # reset $cores to 0 so we can count the number of actually used cores
  52 $cores=0;
  53
  54 for (my $i=0;$i<scalar @files;$i += $slice)
  55 {
  56     my $pid = fork;
  57     if ($pid)
  58     {
  59         # mother
  60         $pids[$cores++] = $pid;
  61     }
  62     else
  63     {
  64         # get my slice of the files
  65         my @list = @files[$i .. $i + $slice - 1];
  66
  67         # run command
  68         system("$command @list > $tempfile.$$");
  69
  70         exit;
  71     }
  72 }
  73
  74 for my $i (0 .. $cores - 1)
  75 {
  76     # wait for child to complete
  77     waitpid $pids[$i], 0;
  78
  79     # read & print result
  80     if (open F, "<$tempfile.$pids[$i]")
  81     {
  82         print <F>;
  83         close F;
  84         unlink "$tempfile.$pids[$i]";
  85     }
  86 }