From b1628d8bedb8a4145c77ed5917999379fc99a5d5 Mon Sep 17 00:00:00 2001
From: Chris Dyer <redpony@gmail.com>
Date: Wed, 15 Jan 2014 20:33:02 -0500
Subject: maybe better randomization to prevent port conflicts on big machines?

---
 training/utils/parallelize.pl | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

(limited to 'training/utils/parallelize.pl')

diff --git a/training/utils/parallelize.pl b/training/utils/parallelize.pl
index 4197e0e5..c9ab88ce 100755
--- a/training/utils/parallelize.pl
+++ b/training/utils/parallelize.pl
@@ -45,11 +45,22 @@ my $numnodes = 8;
 my $user = $ENV{"USER"};
 my $pmem = "9g";
 my $basep=50300;
-my $randp=300;
 my $tryp=50;
 my $no_which;
 my $no_cd;
 
+if (-r '/dev/urandom') {
+  open(RR,'</dev/urandom') or die "Failed to read /dev/urandom: $!";
+  my $buffer;
+  die "Failed to read 4 bytes of entropy" unless read(RR,$buffer,4) == 4;
+  close RR;
+  my ($val) = unpack 'L1', $buffer;
+  srand($val);
+} else {
+  srand();
+}
+my $randp=4000;
+
 my $DEBUG=$ENV{DEBUG};
 print STDERR "DEBUG=$DEBUG output enabled.\n" if $DEBUG;
 my $verbose = 1;
@@ -206,8 +217,7 @@ chomp $host;
 
 
 # find open port
-srand;
-my $port = 50300+int(rand($randp));
+my $port = $basep+int(rand($randp));
 my $endp=$port+$tryp;
 sub listening_port_lines {
     my $quiet=$verbose?'':'2>/dev/null';
-- 
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