rand_util.cc (801B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 // Copyright (c) 2008 The Chromium Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style license that can be 5 // found in the LICENSE file. 6 7 #include "base/rand_util.h" 8 9 #include <math.h> 10 11 #include "base/basictypes.h" 12 #include "base/logging.h" 13 #include "mozilla/RandomNum.h" 14 15 namespace base { 16 17 int RandInt(int min, int max) { 18 DCHECK(min <= max); 19 20 uint64_t range = static_cast<int64_t>(max) - min + 1; 21 mozilla::Maybe<uint64_t> number = mozilla::RandomUint64(); 22 MOZ_RELEASE_ASSERT(number.isSome()); 23 int result = min + static_cast<int>(number.value() % range); 24 DCHECK(result >= min && result <= max); 25 return result; 26 } 27 28 } // namespace base