tools/fuzzing/common/FuzzingTraits.cpp

   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 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include <prinrval.h>
   8 #include <thread>
   9 #include <mutex>
  10 #include "FuzzingTraits.h"
  11
  12 namespace mozilla {
  13 namespace fuzzing {
  14
  15 /* static */
  16 unsigned int FuzzingTraits::Random(unsigned int aMax) {
  17   MOZ_ASSERT(aMax > 0, "aMax needs to be bigger than 0");
  18   std::uniform_int_distribution<unsigned int> d(0, aMax);
  19   return d(Rng());
  20 }
  21
  22 /* static */
  23 bool FuzzingTraits::Sometimes(unsigned int aProbability) {
  24   return FuzzingTraits::Random(aProbability) == 0;
  25 }
  26
  27 /* static */
  28 size_t FuzzingTraits::Frequency(const size_t aSize, const uint64_t aFactor) {
  29   return RandomIntegerRange<size_t>(0, ceil(float(aSize) / aFactor)) + 1;
  30 }
  31
  32 /* static */
  33 std::mt19937_64& FuzzingTraits::Rng() {
  34   static std::mt19937_64 rng;
  35   static std::once_flag flag;
  36   std::call_once(flag, [&] { rng.seed(PR_IntervalNow()); });
  37   return rng;
  38 }
  39
  40 }  // namespace fuzzing
  41 }  // namespace mozilla