/work/obj-fuzz/dist/include/mozilla/ChaosMode.h
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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 | | #ifndef mozilla_ChaosMode_h |
8 | | #define mozilla_ChaosMode_h |
9 | | |
10 | | #include "mozilla/Atomics.h" |
11 | | #include "mozilla/EnumSet.h" |
12 | | |
13 | | #include <stdint.h> |
14 | | #include <stdlib.h> |
15 | | |
16 | | namespace mozilla { |
17 | | |
18 | | enum ChaosFeature { |
19 | | None = 0x0, |
20 | | // Altering thread scheduling. |
21 | | ThreadScheduling = 0x1, |
22 | | // Altering network request scheduling. |
23 | | NetworkScheduling = 0x2, |
24 | | // Altering timer scheduling. |
25 | | TimerScheduling = 0x4, |
26 | | // Read and write less-than-requested amounts. |
27 | | IOAmounts = 0x8, |
28 | | // Iterate over hash tables in random order. |
29 | | HashTableIteration = 0x10, |
30 | | // Randomly refuse to use cached version of image (when allowed by spec). |
31 | | ImageCache = 0x20, |
32 | | // Delay dispatching threads to encourage dispatched tasks to run. |
33 | | TaskDispatching = 0x40, |
34 | | // Delay task running to encourage sending threads to run. |
35 | | TaskRunning = 0x80, |
36 | | Any = 0xffffffff, |
37 | | }; |
38 | | |
39 | | namespace detail { |
40 | | extern MFBT_DATA Atomic<uint32_t, |
41 | | SequentiallyConsistent, |
42 | | recordreplay::Behavior::DontPreserve> gChaosModeCounter; |
43 | | extern MFBT_DATA ChaosFeature gChaosFeatures; |
44 | | } // namespace detail |
45 | | |
46 | | /** |
47 | | * When "chaos mode" is activated, code that makes implicitly nondeterministic |
48 | | * choices is encouraged to make random and extreme choices, to test more |
49 | | * code paths and uncover bugs. |
50 | | */ |
51 | | class ChaosMode |
52 | | { |
53 | | public: |
54 | | static void SetChaosFeature(ChaosFeature aChaosFeature) |
55 | 0 | { |
56 | 0 | detail::gChaosFeatures = aChaosFeature; |
57 | 0 | } |
58 | | |
59 | | static bool isActive(ChaosFeature aFeature) |
60 | | { |
61 | | if (detail::gChaosModeCounter > 0) { |
62 | | return true; |
63 | | } |
64 | | return detail::gChaosFeatures & aFeature; |
65 | | } |
66 | | |
67 | | /** |
68 | | * Increase the chaos mode activation level. An equivalent number of |
69 | | * calls to leaveChaosMode must be made in order to restore the original |
70 | | * chaos mode state. If the activation level is nonzero all chaos mode |
71 | | * features are activated. |
72 | | */ |
73 | | static void enterChaosMode() |
74 | 0 | { |
75 | 0 | detail::gChaosModeCounter++; |
76 | 0 | } |
77 | | |
78 | | /** |
79 | | * Decrease the chaos mode activation level. See enterChaosMode(). |
80 | | */ |
81 | | static void leaveChaosMode() |
82 | 0 | { |
83 | 0 | MOZ_ASSERT(detail::gChaosModeCounter > 0); |
84 | 0 | detail::gChaosModeCounter--; |
85 | 0 | } Unexecuted instantiation: mozilla::ChaosMode::leaveChaosMode() Unexecuted instantiation: mozilla::ChaosMode::leaveChaosMode() |
86 | | |
87 | | /** |
88 | | * Returns a somewhat (but not uniformly) random uint32_t < aBound. |
89 | | * Not to be used for anything except ChaosMode, since it's not very random. |
90 | | */ |
91 | | static uint32_t randomUint32LessThan(uint32_t aBound) |
92 | 0 | { |
93 | 0 | MOZ_ASSERT(aBound != 0); |
94 | 0 | return uint32_t(rand()) % aBound; |
95 | 0 | } Unexecuted instantiation: mozilla::ChaosMode::randomUint32LessThan(unsigned int) Unexecuted instantiation: mozilla::ChaosMode::randomUint32LessThan(unsigned int) |
96 | | }; |
97 | | |
98 | | } /* namespace mozilla */ |
99 | | |
100 | | #endif /* mozilla_ChaosMode_h */ |