mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-24 13:21:05 +00:00
265e672179
# ignore-this-changeset --HG-- extra : amend_source : 4d301d3b0b8711c4692392aa76088ba7fd7d1022
93 lines
2.7 KiB
C++
93 lines
2.7 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef mozilla_ChaosMode_h
|
|
#define mozilla_ChaosMode_h
|
|
|
|
#include "mozilla/Atomics.h"
|
|
#include "mozilla/EnumSet.h"
|
|
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
|
|
namespace mozilla {
|
|
|
|
enum ChaosFeature {
|
|
None = 0x0,
|
|
// Altering thread scheduling.
|
|
ThreadScheduling = 0x1,
|
|
// Altering network request scheduling.
|
|
NetworkScheduling = 0x2,
|
|
// Altering timer scheduling.
|
|
TimerScheduling = 0x4,
|
|
// Read and write less-than-requested amounts.
|
|
IOAmounts = 0x8,
|
|
// Iterate over hash tables in random order.
|
|
HashTableIteration = 0x10,
|
|
// Randomly refuse to use cached version of image (when allowed by spec).
|
|
ImageCache = 0x20,
|
|
// Delay dispatching threads to encourage dispatched tasks to run.
|
|
TaskDispatching = 0x40,
|
|
// Delay task running to encourage sending threads to run.
|
|
TaskRunning = 0x80,
|
|
Any = 0xffffffff,
|
|
};
|
|
|
|
namespace detail {
|
|
extern MFBT_DATA Atomic<uint32_t, SequentiallyConsistent,
|
|
recordreplay::Behavior::DontPreserve>
|
|
gChaosModeCounter;
|
|
extern MFBT_DATA ChaosFeature gChaosFeatures;
|
|
} // namespace detail
|
|
|
|
/**
|
|
* When "chaos mode" is activated, code that makes implicitly nondeterministic
|
|
* choices is encouraged to make random and extreme choices, to test more
|
|
* code paths and uncover bugs.
|
|
*/
|
|
class ChaosMode {
|
|
public:
|
|
static void SetChaosFeature(ChaosFeature aChaosFeature) {
|
|
detail::gChaosFeatures = aChaosFeature;
|
|
}
|
|
|
|
static bool isActive(ChaosFeature aFeature) {
|
|
if (detail::gChaosModeCounter > 0) {
|
|
return true;
|
|
}
|
|
return detail::gChaosFeatures & aFeature;
|
|
}
|
|
|
|
/**
|
|
* Increase the chaos mode activation level. An equivalent number of
|
|
* calls to leaveChaosMode must be made in order to restore the original
|
|
* chaos mode state. If the activation level is nonzero all chaos mode
|
|
* features are activated.
|
|
*/
|
|
static void enterChaosMode() { detail::gChaosModeCounter++; }
|
|
|
|
/**
|
|
* Decrease the chaos mode activation level. See enterChaosMode().
|
|
*/
|
|
static void leaveChaosMode() {
|
|
MOZ_ASSERT(detail::gChaosModeCounter > 0);
|
|
detail::gChaosModeCounter--;
|
|
}
|
|
|
|
/**
|
|
* Returns a somewhat (but not uniformly) random uint32_t < aBound.
|
|
* Not to be used for anything except ChaosMode, since it's not very random.
|
|
*/
|
|
static uint32_t randomUint32LessThan(uint32_t aBound) {
|
|
MOZ_ASSERT(aBound != 0);
|
|
return uint32_t(rand()) % aBound;
|
|
}
|
|
};
|
|
|
|
} /* namespace mozilla */
|
|
|
|
#endif /* mozilla_ChaosMode_h */
|