Fix issue http://code.google.com/p/v8/issues/detail?id=58:...

src/platform-macos.cc

Index: src/platform-macos.cc
===================================================================
--- src/platform-macos.cc	(revision 244)
+++ src/platform-macos.cc	(working copy)
@@ -73,7 +73,12 @@
 
 void OS::Setup() {
   // Seed the random number generator.
-  srandom(static_cast<unsigned int>(TimeCurrentMillis()));
+  // Convert the current time to a 64-bit integer first, before converting it
+  // to an unsigned. Going directly will cause an overflow and the seed to be
+  // set to all ones. The seed will be identical for different instances that
+  // call this setup code within the same millisecond.
+  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
+  srandom(static_cast<unsigned int>(seed));
 }