- Do not rely on time to seed the default PRNG.

runtime/lib/math.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <ctype.h>  // isspace.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/exceptions.h"
@@ skipping 160 matching lines @@
 
   if (seed == 0) {
     seed = 0x5a17;
   }
   array.SetUint32(0, static_cast<uint32_t>(seed));
   array.SetUint32(array.ElementSizeInBytes(),
       static_cast<uint32_t>(seed >> 32));
   return Object::null();
 }
 
+
+DEFINE_NATIVE_ENTRY(Random_initialSeed, 0) {
+  Random* rnd = isolate->random();
+  int64_t seed = rnd->NextUInt32();
+  seed |= (static_cast<int64_t>(rnd->NextUInt32())) << 32;

[siva, 2014/03/14 17:27:13]

I would prefer 
seed |= (static_cast<int64_t>(rnd->NextUInt32()) << 32);

+  return Integer::New(seed);
+}
+
 }  // namespace dart