File: | var/lib/jenkins/workspace/firefox-scan-build/js/src/threading/LockGuard.h |
Warning: | line 31, column 19 Called C++ object pointer is uninitialized |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
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 | /* Various JS utility functions. */ | |||
8 | ||||
9 | #include "js/Utility.h" | |||
10 | ||||
11 | #include "mozilla/Assertions.h" | |||
12 | #include "mozilla/Atomics.h" | |||
13 | #include "mozilla/Maybe.h" | |||
14 | #include "mozilla/ThreadLocal.h" | |||
15 | ||||
16 | #include <stdio.h> | |||
17 | ||||
18 | #include "jstypes.h" | |||
19 | ||||
20 | #include "util/Poison.h" | |||
21 | #include "vm/HelperThreads.h" | |||
22 | #include "vm/JSContext.h" | |||
23 | ||||
24 | using namespace js; | |||
25 | ||||
26 | using mozilla::Maybe; | |||
27 | ||||
28 | #if defined(DEBUG1) || defined(JS_OOM_BREAKPOINT) | |||
29 | /* For OOM testing functionality in Utility.h. */ | |||
30 | namespace js { | |||
31 | ||||
32 | mozilla::Atomic<AutoEnterOOMUnsafeRegion*> AutoEnterOOMUnsafeRegion::owner_; | |||
33 | ||||
34 | namespace oom { | |||
35 | ||||
36 | JS_PUBLIC_DATA FailureSimulator simulator; | |||
37 | static MOZ_THREAD_LOCAL(uint32_t)__thread ::mozilla::detail::ThreadLocal< uint32_t, ::mozilla ::detail::ThreadLocalNativeStorage> threadType; | |||
38 | ||||
39 | bool InitThreadType() { return threadType.init(); } | |||
40 | ||||
41 | void SetThreadType(ThreadType type) { threadType.set(type); } | |||
42 | ||||
43 | uint32_t GetThreadType(void) { return threadType.get(); } | |||
44 | ||||
45 | static inline bool IsHelperThreadType(uint32_t thread) { | |||
46 | return thread != THREAD_TYPE_NONE && thread != THREAD_TYPE_MAIN; | |||
47 | } | |||
48 | ||||
49 | void FailureSimulator::simulateFailureAfter(Kind kind, uint64_t checks, | |||
50 | uint32_t thread, bool always) { | |||
51 | Maybe<AutoLockHelperThreadState> lock; | |||
52 | if (IsHelperThreadType(targetThread_) || IsHelperThreadType(thread)) { | |||
53 | lock.emplace(); | |||
54 | WaitForAllHelperThreads(lock.ref()); | |||
55 | } | |||
56 | ||||
57 | MOZ_ASSERT(counter_ + checks > counter_)do { static_assert( mozilla::detail::AssertionConditionType< decltype(counter_ + checks > counter_)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(counter_ + checks > counter_ ))), 0))) { do { } while (false); MOZ_ReportAssertionFailure( "counter_ + checks > counter_", "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 57); AnnotateMozCrashReason("MOZ_ASSERT" "(" "counter_ + checks > counter_" ")"); do { *((volatile int*)__null) = 57; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | |||
58 | MOZ_ASSERT(thread > js::THREAD_TYPE_NONE && thread < js::THREAD_TYPE_MAX)do { static_assert( mozilla::detail::AssertionConditionType< decltype(thread > js::THREAD_TYPE_NONE && thread < js::THREAD_TYPE_MAX)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(thread > js::THREAD_TYPE_NONE && thread < js::THREAD_TYPE_MAX))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("thread > js::THREAD_TYPE_NONE && thread < js::THREAD_TYPE_MAX" , "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 58); AnnotateMozCrashReason("MOZ_ASSERT" "(" "thread > js::THREAD_TYPE_NONE && thread < js::THREAD_TYPE_MAX" ")"); do { *((volatile int*)__null) = 58; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | |||
59 | targetThread_ = thread; | |||
60 | maxChecks_ = counter_ + checks; | |||
61 | failAlways_ = always; | |||
62 | kind_ = kind; | |||
63 | } | |||
64 | ||||
65 | void FailureSimulator::reset() { | |||
66 | Maybe<AutoLockHelperThreadState> lock; | |||
67 | if (IsHelperThreadType(targetThread_)) { | |||
| ||||
68 | lock.emplace(); | |||
69 | WaitForAllHelperThreads(lock.ref()); | |||
70 | } | |||
71 | ||||
72 | targetThread_ = THREAD_TYPE_NONE; | |||
73 | maxChecks_ = UINT64_MAX(18446744073709551615UL); | |||
74 | failAlways_ = false; | |||
75 | kind_ = Kind::Nothing; | |||
76 | } | |||
77 | ||||
78 | } // namespace oom | |||
79 | } // namespace js | |||
80 | #endif // defined(DEBUG) || defined(JS_OOM_BREAKPOINT) | |||
81 | ||||
82 | #if defined(FUZZING) | |||
83 | namespace js { | |||
84 | namespace oom { | |||
85 | JS_PUBLIC_DATA size_t largeAllocLimit = 0; | |||
86 | void InitLargeAllocLimit() { | |||
87 | char* limitStr = getenv("MOZ_FUZZ_LARGE_ALLOC_LIMIT"); | |||
88 | if (limitStr) { | |||
89 | largeAllocLimit = atoll(limitStr); | |||
90 | } | |||
91 | } | |||
92 | } // namespace oom | |||
93 | } // namespace js | |||
94 | #endif | |||
95 | ||||
96 | JS_PUBLIC_DATA arena_id_t js::MallocArena; | |||
97 | JS_PUBLIC_DATA arena_id_t js::ArrayBufferContentsArena; | |||
98 | JS_PUBLIC_DATA arena_id_t js::StringBufferArena; | |||
99 | ||||
100 | void js::InitMallocAllocator() { | |||
101 | arena_params_t mallocArenaParams; | |||
102 | mallocArenaParams.mMaxDirtyIncreaseOverride = 5; | |||
103 | MallocArena = moz_create_arena_with_params(&mallocArenaParams); | |||
104 | ||||
105 | arena_params_t params; | |||
106 | params.mMaxDirtyIncreaseOverride = 5; | |||
107 | params.mFlags |= ARENA_FLAG_RANDOMIZE_SMALL_ENABLED1; | |||
108 | ArrayBufferContentsArena = moz_create_arena_with_params(¶ms); | |||
109 | StringBufferArena = moz_create_arena_with_params(¶ms); | |||
110 | } | |||
111 | ||||
112 | void js::ShutDownMallocAllocator() { | |||
113 | // Until Bug 1364359 is fixed it is unsafe to call moz_dispose_arena. | |||
114 | // moz_dispose_arena(MallocArena); | |||
115 | // moz_dispose_arena(ArrayBufferContentsArena); | |||
116 | } | |||
117 | ||||
118 | extern void js::AssertJSStringBufferInCorrectArena(const void* ptr) { | |||
119 | // `jemalloc_ptr_info()` only exists if MOZ_MEMORY is defined, and it only | |||
120 | // returns an arenaId if MOZ_DEBUG is defined. Otherwise, this function is | |||
121 | // a no-op. | |||
122 | #if defined(MOZ_MEMORY1) && defined(MOZ_DEBUG1) | |||
123 | if (ptr && !TlsContext.get()->nursery().isInside(ptr)) { | |||
124 | jemalloc_ptr_info_t ptrInfo{}; | |||
125 | jemalloc_ptr_info(ptr, &ptrInfo); | |||
126 | MOZ_ASSERT(ptrInfo.tag != TagUnknown)do { static_assert( mozilla::detail::AssertionConditionType< decltype(ptrInfo.tag != TagUnknown)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(ptrInfo.tag != TagUnknown))) , 0))) { do { } while (false); MOZ_ReportAssertionFailure("ptrInfo.tag != TagUnknown" , "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 126); AnnotateMozCrashReason("MOZ_ASSERT" "(" "ptrInfo.tag != TagUnknown" ")"); do { *((volatile int*)__null) = 126; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | |||
127 | MOZ_ASSERT(ptrInfo.arenaId == js::StringBufferArena)do { static_assert( mozilla::detail::AssertionConditionType< decltype(ptrInfo.arenaId == js::StringBufferArena)>::isValid , "invalid assertion condition"); if ((__builtin_expect(!!(!( !!(ptrInfo.arenaId == js::StringBufferArena))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("ptrInfo.arenaId == js::StringBufferArena" , "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 127); AnnotateMozCrashReason("MOZ_ASSERT" "(" "ptrInfo.arenaId == js::StringBufferArena" ")"); do { *((volatile int*)__null) = 127; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | |||
128 | } | |||
129 | #endif | |||
130 | } | |||
131 | ||||
132 | JS_PUBLIC_API void JS_Assert(const char* s, const char* file, int ln) { | |||
133 | MOZ_ReportAssertionFailure(s, file, ln); | |||
134 | MOZ_CRASH()do { do { } while (false); MOZ_ReportCrash("" , "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 134); AnnotateMozCrashReason("MOZ_CRASH(" ")"); do { *((volatile int*)__null) = 134; __attribute__((nomerge)) ::abort(); } while (false); } while (false); | |||
135 | } | |||
136 | ||||
137 | #ifdef __linux__1 | |||
138 | ||||
139 | # include <malloc.h> | |||
140 | # include <stdlib.h> | |||
141 | ||||
142 | namespace js { | |||
143 | ||||
144 | // This function calls all the vanilla heap allocation functions. It is never | |||
145 | // called, and exists purely to help config/check_vanilla_allocations.py. See | |||
146 | // that script for more details. | |||
147 | extern MOZ_COLD__attribute__((cold)) void AllTheNonBasicVanillaNewAllocations() { | |||
148 | // posix_memalign and aligned_alloc aren't available on all Linux | |||
149 | // configurations. | |||
150 | // valloc was deprecated in Android 5.0 | |||
151 | // char* q; | |||
152 | // posix_memalign((void**)&q, 16, 16); | |||
153 | ||||
154 | intptr_t p = intptr_t(malloc(16)) + intptr_t(calloc(1, 16)) + | |||
155 | intptr_t(realloc(nullptr, 16)) + intptr_t(new char) + | |||
156 | intptr_t(new char) + intptr_t(new char) + | |||
157 | intptr_t(new char[16]) + intptr_t(memalign(16, 16)) + | |||
158 | // intptr_t(q) + | |||
159 | // intptr_t(aligned_alloc(16, 16)) + | |||
160 | // intptr_t(valloc(4096)) + | |||
161 | intptr_t(strdup("dummy")); | |||
162 | ||||
163 | printf("%u\n", uint32_t(p)); // make sure |p| is not optimized away | |||
164 | ||||
165 | free((int*)p); // this would crash if ever actually called | |||
166 | ||||
167 | MOZ_CRASH()do { do { } while (false); MOZ_ReportCrash("" , "/var/lib/jenkins/workspace/firefox-scan-build/js/src/util/Utility.cpp" , 167); AnnotateMozCrashReason("MOZ_CRASH(" ")"); do { *((volatile int*)__null) = 167; __attribute__((nomerge)) ::abort(); } while (false); } while (false); | |||
168 | } | |||
169 | ||||
170 | } // namespace js | |||
171 | ||||
172 | #endif // __linux__ |
1 | /* -*- Mode: C++; tab-width: 2; 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 | /* A class for optional values and in-place lazy construction. */ | ||||||||||
8 | |||||||||||
9 | #ifndef mozilla_Maybe_h | ||||||||||
10 | #define mozilla_Maybe_h | ||||||||||
11 | |||||||||||
12 | #include <functional> | ||||||||||
13 | #include <new> // for placement new | ||||||||||
14 | #include <ostream> | ||||||||||
15 | #include <type_traits> | ||||||||||
16 | #include <utility> | ||||||||||
17 | |||||||||||
18 | #include "mozilla/Alignment.h" | ||||||||||
19 | #include "mozilla/Assertions.h" | ||||||||||
20 | #include "mozilla/Attributes.h" | ||||||||||
21 | #include "mozilla/MaybeStorageBase.h" | ||||||||||
22 | #include "mozilla/MemoryChecking.h" | ||||||||||
23 | #include "mozilla/OperatorNewExtensions.h" | ||||||||||
24 | #include "mozilla/Poison.h" | ||||||||||
25 | #include "mozilla/ThreadSafety.h" | ||||||||||
26 | |||||||||||
27 | class nsCycleCollectionTraversalCallback; | ||||||||||
28 | |||||||||||
29 | template <typename T> | ||||||||||
30 | inline void CycleCollectionNoteChild( | ||||||||||
31 | nsCycleCollectionTraversalCallback& aCallback, T* aChild, const char* aName, | ||||||||||
32 | uint32_t aFlags); | ||||||||||
33 | |||||||||||
34 | namespace mozilla { | ||||||||||
35 | |||||||||||
36 | struct Nothing {}; | ||||||||||
37 | |||||||||||
38 | inline constexpr bool operator==(const Nothing&, const Nothing&) { | ||||||||||
39 | return true; | ||||||||||
40 | } | ||||||||||
41 | |||||||||||
42 | template <class T> | ||||||||||
43 | class Maybe; | ||||||||||
44 | |||||||||||
45 | namespace detail { | ||||||||||
46 | |||||||||||
47 | // You would think that poisoning Maybe instances could just be a call | ||||||||||
48 | // to mozWritePoison. Unfortunately, using a simple call to | ||||||||||
49 | // mozWritePoison generates poor code on MSVC for small structures. The | ||||||||||
50 | // generated code contains (always not-taken) branches and does a bunch | ||||||||||
51 | // of setup for `rep stos{l,q}`, even though we know at compile time | ||||||||||
52 | // exactly how many words we're poisoning. Instead, we're going to | ||||||||||
53 | // force MSVC to generate the code we want via recursive templates. | ||||||||||
54 | |||||||||||
55 | // Write the given poisonValue into p at offset*sizeof(uintptr_t). | ||||||||||
56 | template <size_t offset> | ||||||||||
57 | inline void WritePoisonAtOffset(void* p, const uintptr_t poisonValue) { | ||||||||||
58 | memcpy(static_cast<char*>(p) + offset * sizeof(poisonValue), &poisonValue, | ||||||||||
59 | sizeof(poisonValue)); | ||||||||||
60 | } | ||||||||||
61 | |||||||||||
62 | template <size_t Offset, size_t NOffsets> | ||||||||||
63 | struct InlinePoisoner { | ||||||||||
64 | static void poison(void* p, const uintptr_t poisonValue) { | ||||||||||
65 | WritePoisonAtOffset<Offset>(p, poisonValue); | ||||||||||
66 | InlinePoisoner<Offset + 1, NOffsets>::poison(p, poisonValue); | ||||||||||
67 | } | ||||||||||
68 | }; | ||||||||||
69 | |||||||||||
70 | template <size_t N> | ||||||||||
71 | struct InlinePoisoner<N, N> { | ||||||||||
72 | static void poison(void*, const uintptr_t) { | ||||||||||
73 | // All done! | ||||||||||
74 | } | ||||||||||
75 | }; | ||||||||||
76 | |||||||||||
77 | // We can't generate inline code for large structures, though, because we'll | ||||||||||
78 | // blow out recursive template instantiation limits, and the code would be | ||||||||||
79 | // bloated to boot. So provide a fallback to the out-of-line poisoner. | ||||||||||
80 | template <size_t ObjectSize> | ||||||||||
81 | struct OutOfLinePoisoner { | ||||||||||
82 | static MOZ_NEVER_INLINE__attribute__((noinline)) void poison(void* p, const uintptr_t) { | ||||||||||
83 | mozWritePoison(p, ObjectSize); | ||||||||||
84 | } | ||||||||||
85 | }; | ||||||||||
86 | |||||||||||
87 | template <typename T> | ||||||||||
88 | inline void PoisonObject(T* p) { | ||||||||||
89 | const uintptr_t POISON = mozPoisonValue(); | ||||||||||
90 | std::conditional_t<(sizeof(T) <= 8 * sizeof(POISON)), | ||||||||||
91 | InlinePoisoner<0, sizeof(T) / sizeof(POISON)>, | ||||||||||
92 | OutOfLinePoisoner<sizeof(T)>>::poison(p, POISON); | ||||||||||
93 | } | ||||||||||
94 | |||||||||||
95 | template <typename T> | ||||||||||
96 | struct MaybePoisoner { | ||||||||||
97 | static const size_t N = sizeof(T); | ||||||||||
98 | |||||||||||
99 | static void poison(void* aPtr) { | ||||||||||
100 | #ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED1 | ||||||||||
101 | if (N >= sizeof(uintptr_t)) { | ||||||||||
102 | PoisonObject(static_cast<std::remove_cv_t<T>*>(aPtr)); | ||||||||||
103 | } | ||||||||||
104 | #endif | ||||||||||
105 | MOZ_MAKE_MEM_UNDEFINED(aPtr, N)do { } while (0); | ||||||||||
106 | } | ||||||||||
107 | }; | ||||||||||
108 | |||||||||||
109 | template <typename T, | ||||||||||
110 | bool TriviallyDestructibleAndCopyable = | ||||||||||
111 | IsTriviallyDestructibleAndCopyable<T>, | ||||||||||
112 | bool Copyable = std::is_copy_constructible_v<T>, | ||||||||||
113 | bool Movable = std::is_move_constructible_v<T>> | ||||||||||
114 | class Maybe_CopyMove_Enabler; | ||||||||||
115 | |||||||||||
116 | #define MOZ_MAYBE_COPY_OPS() \ | ||||||||||
117 | Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler& aOther) { \ | ||||||||||
118 | if (downcast(aOther).isSome()) { \ | ||||||||||
119 | downcast(*this).emplace(*downcast(aOther)); \ | ||||||||||
120 | } \ | ||||||||||
121 | } \ | ||||||||||
122 | \ | ||||||||||
123 | Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler& aOther) { \ | ||||||||||
124 | return downcast(*this).template operator= <T>(downcast(aOther)); \ | ||||||||||
125 | } | ||||||||||
126 | |||||||||||
127 | #define MOZ_MAYBE_MOVE_OPS() \ | ||||||||||
128 | constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) { \ | ||||||||||
129 | if (downcast(aOther).isSome()) { \ | ||||||||||
130 | downcast(*this).emplace(std::move(*downcast(aOther))); \ | ||||||||||
131 | downcast(aOther).reset(); \ | ||||||||||
132 | } \ | ||||||||||
133 | } \ | ||||||||||
134 | \ | ||||||||||
135 | constexpr Maybe_CopyMove_Enabler& operator=( \ | ||||||||||
136 | Maybe_CopyMove_Enabler&& aOther) { \ | ||||||||||
137 | downcast(*this).template operator= <T>(std::move(downcast(aOther))); \ | ||||||||||
138 | \ | ||||||||||
139 | return *this; \ | ||||||||||
140 | } | ||||||||||
141 | |||||||||||
142 | #define MOZ_MAYBE_DOWNCAST() \ | ||||||||||
143 | static constexpr Maybe<T>& downcast(Maybe_CopyMove_Enabler& aObj) { \ | ||||||||||
144 | return static_cast<Maybe<T>&>(aObj); \ | ||||||||||
145 | } \ | ||||||||||
146 | static constexpr const Maybe<T>& downcast( \ | ||||||||||
147 | const Maybe_CopyMove_Enabler& aObj) { \ | ||||||||||
148 | return static_cast<const Maybe<T>&>(aObj); \ | ||||||||||
149 | } | ||||||||||
150 | |||||||||||
151 | template <typename T> | ||||||||||
152 | class Maybe_CopyMove_Enabler<T, true, true, true> { | ||||||||||
153 | public: | ||||||||||
154 | Maybe_CopyMove_Enabler() = default; | ||||||||||
155 | |||||||||||
156 | Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = default; | ||||||||||
157 | Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = default; | ||||||||||
158 | constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) { | ||||||||||
159 | downcast(aOther).reset(); | ||||||||||
160 | } | ||||||||||
161 | constexpr Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&& aOther) { | ||||||||||
162 | downcast(aOther).reset(); | ||||||||||
163 | return *this; | ||||||||||
164 | } | ||||||||||
165 | |||||||||||
166 | private: | ||||||||||
167 | MOZ_MAYBE_DOWNCAST() | ||||||||||
168 | }; | ||||||||||
169 | |||||||||||
170 | template <typename T> | ||||||||||
171 | class Maybe_CopyMove_Enabler<T, true, false, true> { | ||||||||||
172 | public: | ||||||||||
173 | Maybe_CopyMove_Enabler() = default; | ||||||||||
174 | |||||||||||
175 | Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
176 | Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
177 | constexpr Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&& aOther) { | ||||||||||
178 | downcast(aOther).reset(); | ||||||||||
179 | } | ||||||||||
180 | constexpr Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&& aOther) { | ||||||||||
181 | downcast(aOther).reset(); | ||||||||||
182 | return *this; | ||||||||||
183 | } | ||||||||||
184 | |||||||||||
185 | private: | ||||||||||
186 | MOZ_MAYBE_DOWNCAST() | ||||||||||
187 | }; | ||||||||||
188 | |||||||||||
189 | template <typename T> | ||||||||||
190 | class Maybe_CopyMove_Enabler<T, false, true, true> { | ||||||||||
191 | public: | ||||||||||
192 | Maybe_CopyMove_Enabler() = default; | ||||||||||
193 | |||||||||||
194 | MOZ_MAYBE_COPY_OPS() | ||||||||||
195 | MOZ_MAYBE_MOVE_OPS() | ||||||||||
196 | |||||||||||
197 | private: | ||||||||||
198 | MOZ_MAYBE_DOWNCAST() | ||||||||||
199 | }; | ||||||||||
200 | |||||||||||
201 | template <typename T> | ||||||||||
202 | class Maybe_CopyMove_Enabler<T, false, false, true> { | ||||||||||
203 | public: | ||||||||||
204 | Maybe_CopyMove_Enabler() = default; | ||||||||||
205 | |||||||||||
206 | Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
207 | Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
208 | MOZ_MAYBE_MOVE_OPS() | ||||||||||
209 | |||||||||||
210 | private: | ||||||||||
211 | MOZ_MAYBE_DOWNCAST() | ||||||||||
212 | }; | ||||||||||
213 | |||||||||||
214 | template <typename T> | ||||||||||
215 | class Maybe_CopyMove_Enabler<T, false, true, false> { | ||||||||||
216 | public: | ||||||||||
217 | Maybe_CopyMove_Enabler() = default; | ||||||||||
218 | |||||||||||
219 | MOZ_MAYBE_COPY_OPS() | ||||||||||
220 | Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&&) = delete; | ||||||||||
221 | Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&&) = delete; | ||||||||||
222 | |||||||||||
223 | private: | ||||||||||
224 | MOZ_MAYBE_DOWNCAST() | ||||||||||
225 | }; | ||||||||||
226 | |||||||||||
227 | template <typename T, bool TriviallyDestructibleAndCopyable> | ||||||||||
228 | class Maybe_CopyMove_Enabler<T, TriviallyDestructibleAndCopyable, false, | ||||||||||
229 | false> { | ||||||||||
230 | public: | ||||||||||
231 | Maybe_CopyMove_Enabler() = default; | ||||||||||
232 | |||||||||||
233 | Maybe_CopyMove_Enabler(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
234 | Maybe_CopyMove_Enabler& operator=(const Maybe_CopyMove_Enabler&) = delete; | ||||||||||
235 | Maybe_CopyMove_Enabler(Maybe_CopyMove_Enabler&&) = delete; | ||||||||||
236 | Maybe_CopyMove_Enabler& operator=(Maybe_CopyMove_Enabler&&) = delete; | ||||||||||
237 | }; | ||||||||||
238 | |||||||||||
239 | #undef MOZ_MAYBE_COPY_OPS | ||||||||||
240 | #undef MOZ_MAYBE_MOVE_OPS | ||||||||||
241 | #undef MOZ_MAYBE_DOWNCAST | ||||||||||
242 | |||||||||||
243 | template <typename T, bool TriviallyDestructibleAndCopyable = | ||||||||||
244 | IsTriviallyDestructibleAndCopyable<T>> | ||||||||||
245 | struct MaybeStorage; | ||||||||||
246 | |||||||||||
247 | template <typename T> | ||||||||||
248 | struct MaybeStorage<T, false> : MaybeStorageBase<T> { | ||||||||||
249 | protected: | ||||||||||
250 | char mIsSome = false; // not bool -- guarantees minimal space consumption | ||||||||||
251 | |||||||||||
252 | MaybeStorage() = default; | ||||||||||
253 | explicit MaybeStorage(const T& aVal) | ||||||||||
254 | : MaybeStorageBase<T>{aVal}, mIsSome{true} {} | ||||||||||
255 | explicit MaybeStorage(T&& aVal) | ||||||||||
256 | : MaybeStorageBase<T>{std::move(aVal)}, mIsSome{true} {} | ||||||||||
257 | |||||||||||
258 | template <typename... Args> | ||||||||||
259 | explicit MaybeStorage(std::in_place_t, Args&&... aArgs) | ||||||||||
260 | : MaybeStorageBase<T>{std::in_place, std::forward<Args>(aArgs)...}, | ||||||||||
261 | mIsSome{true} {} | ||||||||||
262 | |||||||||||
263 | public: | ||||||||||
264 | // Copy and move operations are no-ops, since copying is moving is implemented | ||||||||||
265 | // by Maybe_CopyMove_Enabler. | ||||||||||
266 | |||||||||||
267 | MaybeStorage(const MaybeStorage&) : MaybeStorageBase<T>{} {} | ||||||||||
268 | MaybeStorage& operator=(const MaybeStorage&) { return *this; } | ||||||||||
269 | MaybeStorage(MaybeStorage&&) : MaybeStorageBase<T>{} {} | ||||||||||
270 | MaybeStorage& operator=(MaybeStorage&&) { return *this; } | ||||||||||
271 | |||||||||||
272 | ~MaybeStorage() { | ||||||||||
273 | if (mIsSome
| ||||||||||
274 | this->addr()->T::~T(); | ||||||||||
275 | } | ||||||||||
276 | } | ||||||||||
277 | }; | ||||||||||
278 | |||||||||||
279 | template <typename T> | ||||||||||
280 | struct MaybeStorage<T, true> : MaybeStorageBase<T> { | ||||||||||
281 | protected: | ||||||||||
282 | char mIsSome = false; // not bool -- guarantees minimal space consumption | ||||||||||
283 | |||||||||||
284 | constexpr MaybeStorage() = default; | ||||||||||
285 | constexpr explicit MaybeStorage(const T& aVal) | ||||||||||
286 | : MaybeStorageBase<T>{aVal}, mIsSome{true} {} | ||||||||||
287 | constexpr explicit MaybeStorage(T&& aVal) | ||||||||||
288 | : MaybeStorageBase<T>{std::move(aVal)}, mIsSome{true} {} | ||||||||||
289 | |||||||||||
290 | template <typename... Args> | ||||||||||
291 | constexpr explicit MaybeStorage(std::in_place_t, Args&&... aArgs) | ||||||||||
292 | : MaybeStorageBase<T>{std::in_place, std::forward<Args>(aArgs)...}, | ||||||||||
293 | mIsSome{true} {} | ||||||||||
294 | }; | ||||||||||
295 | |||||||||||
296 | template <typename T> | ||||||||||
297 | struct IsMaybeImpl : std::false_type {}; | ||||||||||
298 | |||||||||||
299 | template <typename T> | ||||||||||
300 | struct IsMaybeImpl<Maybe<T>> : std::true_type {}; | ||||||||||
301 | |||||||||||
302 | template <typename T> | ||||||||||
303 | using IsMaybe = IsMaybeImpl<std::decay_t<T>>; | ||||||||||
304 | |||||||||||
305 | } // namespace detail | ||||||||||
306 | |||||||||||
307 | template <typename T, typename U = typename std::remove_cv< | ||||||||||
308 | typename std::remove_reference<T>::type>::type> | ||||||||||
309 | constexpr Maybe<U> Some(T&& aValue); | ||||||||||
310 | |||||||||||
311 | /* | ||||||||||
312 | * Maybe is a container class which contains either zero or one elements. It | ||||||||||
313 | * serves two roles. It can represent values which are *semantically* optional, | ||||||||||
314 | * augmenting a type with an explicit 'Nothing' value. In this role, it provides | ||||||||||
315 | * methods that make it easy to work with values that may be missing, along with | ||||||||||
316 | * equality and comparison operators so that Maybe values can be stored in | ||||||||||
317 | * containers. Maybe values can be constructed conveniently in expressions using | ||||||||||
318 | * type inference, as follows: | ||||||||||
319 | * | ||||||||||
320 | * void doSomething(Maybe<Foo> aFoo) { | ||||||||||
321 | * if (aFoo) // Make sure that aFoo contains a value... | ||||||||||
322 | * aFoo->takeAction(); // and then use |aFoo->| to access it. | ||||||||||
323 | * } // |*aFoo| also works! | ||||||||||
324 | * | ||||||||||
325 | * doSomething(Nothing()); // Passes a Maybe<Foo> containing no value. | ||||||||||
326 | * doSomething(Some(Foo(100))); // Passes a Maybe<Foo> containing |Foo(100)|. | ||||||||||
327 | * | ||||||||||
328 | * You'll note that it's important to check whether a Maybe contains a value | ||||||||||
329 | * before using it, using conversion to bool, |isSome()|, or |isNothing()|. You | ||||||||||
330 | * can avoid these checks, and sometimes write more readable code, using | ||||||||||
331 | * |valueOr()|, |ptrOr()|, and |refOr()|, which allow you to retrieve the value | ||||||||||
332 | * in the Maybe and provide a default for the 'Nothing' case. You can also use | ||||||||||
333 | * |apply()| to call a function only if the Maybe holds a value, and |map()| to | ||||||||||
334 | * transform the value in the Maybe, returning another Maybe with a possibly | ||||||||||
335 | * different type. | ||||||||||
336 | * | ||||||||||
337 | * Maybe's other role is to support lazily constructing objects without using | ||||||||||
338 | * dynamic storage. A Maybe directly contains storage for a value, but it's | ||||||||||
339 | * empty by default. |emplace()|, as mentioned above, can be used to construct a | ||||||||||
340 | * value in Maybe's storage. The value a Maybe contains can be destroyed by | ||||||||||
341 | * calling |reset()|; this will happen automatically if a Maybe is destroyed | ||||||||||
342 | * while holding a value. | ||||||||||
343 | * | ||||||||||
344 | * It's a common idiom in C++ to use a pointer as a 'Maybe' type, with a null | ||||||||||
345 | * value meaning 'Nothing' and any other value meaning 'Some'. You can convert | ||||||||||
346 | * from such a pointer to a Maybe value using 'ToMaybe()'. | ||||||||||
347 | * | ||||||||||
348 | * Maybe is inspired by similar types in the standard library of many other | ||||||||||
349 | * languages (e.g. Haskell's Maybe and Rust's Option). In the C++ world it's | ||||||||||
350 | * very similar to std::optional, which was proposed for C++14 and originated in | ||||||||||
351 | * Boost. The most important differences between Maybe and std::optional are: | ||||||||||
352 | * | ||||||||||
353 | * - std::optional<T> may be compared with T. We deliberately forbid that. | ||||||||||
354 | * - std::optional has |valueOr()|, equivalent to Maybe's |valueOr()|, but | ||||||||||
355 | * lacks corresponding methods for |refOr()| and |ptrOr()|. | ||||||||||
356 | * - std::optional lacks |map()| and |apply()|, making it less suitable for | ||||||||||
357 | * functional-style code. | ||||||||||
358 | * - std::optional lacks many convenience functions that Maybe has. Most | ||||||||||
359 | * unfortunately, it lacks equivalents of the type-inferred constructor | ||||||||||
360 | * functions |Some()| and |Nothing()|. | ||||||||||
361 | */ | ||||||||||
362 | template <class T> | ||||||||||
363 | class MOZ_INHERIT_TYPE_ANNOTATIONS_FROM_TEMPLATE_ARGS Maybe | ||||||||||
364 | : private detail::MaybeStorage<T>, | ||||||||||
365 | public detail::Maybe_CopyMove_Enabler<T> { | ||||||||||
366 | template <typename, bool, bool, bool> | ||||||||||
367 | friend class detail::Maybe_CopyMove_Enabler; | ||||||||||
368 | |||||||||||
369 | template <typename U, typename V> | ||||||||||
370 | friend constexpr Maybe<V> Some(U&& aValue); | ||||||||||
371 | |||||||||||
372 | struct SomeGuard {}; | ||||||||||
373 | |||||||||||
374 | template <typename U> | ||||||||||
375 | constexpr Maybe(U&& aValue, SomeGuard) | ||||||||||
376 | : detail::MaybeStorage<T>{std::forward<U>(aValue)} {} | ||||||||||
377 | |||||||||||
378 | using detail::MaybeStorage<T>::mIsSome; | ||||||||||
379 | using detail::MaybeStorage<T>::mStorage; | ||||||||||
380 | |||||||||||
381 | void poisonData() { detail::MaybePoisoner<T>::poison(&mStorage.val); } | ||||||||||
382 | |||||||||||
383 | public: | ||||||||||
384 | using ValueType = T; | ||||||||||
385 | |||||||||||
386 | MOZ_ALLOW_TEMPORARY constexpr Maybe() = default; | ||||||||||
387 | |||||||||||
388 | MOZ_ALLOW_TEMPORARY MOZ_IMPLICIT constexpr Maybe(Nothing) : Maybe{} {} | ||||||||||
389 | |||||||||||
390 | template <typename... Args> | ||||||||||
391 | constexpr explicit Maybe(std::in_place_t, Args&&... aArgs) | ||||||||||
392 | : detail::MaybeStorage<T>{std::in_place, std::forward<Args>(aArgs)...} {} | ||||||||||
393 | |||||||||||
394 | /** | ||||||||||
395 | * Maybe<T> can be copy-constructed from a Maybe<U> if T is constructible from | ||||||||||
396 | * a const U&. | ||||||||||
397 | */ | ||||||||||
398 | template <typename U, | ||||||||||
399 | std::enable_if_t<std::is_constructible_v<T, const U&>, bool> = true> | ||||||||||
400 | MOZ_IMPLICIT Maybe(const Maybe<U>& aOther) { | ||||||||||
401 | if (aOther.isSome()) { | ||||||||||
402 | emplace(*aOther); | ||||||||||
403 | } | ||||||||||
404 | } | ||||||||||
405 | |||||||||||
406 | template <typename U, std::enable_if_t<!std::is_constructible_v<T, const U&>, | ||||||||||
407 | bool> = true> | ||||||||||
408 | explicit Maybe(const Maybe<U>& aOther) = delete; | ||||||||||
409 | |||||||||||
410 | /** | ||||||||||
411 | * Maybe<T> can be move-constructed from a Maybe<U> if T is constructible from | ||||||||||
412 | * a U&&. | ||||||||||
413 | */ | ||||||||||
414 | template <typename U, | ||||||||||
415 | std::enable_if_t<std::is_constructible_v<T, U&&>, bool> = true> | ||||||||||
416 | MOZ_IMPLICIT Maybe(Maybe<U>&& aOther) { | ||||||||||
417 | if (aOther.isSome()) { | ||||||||||
418 | emplace(std::move(*aOther)); | ||||||||||
419 | aOther.reset(); | ||||||||||
420 | } | ||||||||||
421 | } | ||||||||||
422 | template <typename U, | ||||||||||
423 | std::enable_if_t<!std::is_constructible_v<T, U&&>, bool> = true> | ||||||||||
424 | explicit Maybe(Maybe<U>&& aOther) = delete; | ||||||||||
425 | |||||||||||
426 | template <typename U, | ||||||||||
427 | std::enable_if_t<std::is_constructible_v<T, const U&>, bool> = true> | ||||||||||
428 | Maybe& operator=(const Maybe<U>& aOther) { | ||||||||||
429 | if (aOther.isSome()) { | ||||||||||
430 | if (mIsSome) { | ||||||||||
431 | ref() = aOther.ref(); | ||||||||||
432 | } else { | ||||||||||
433 | emplace(*aOther); | ||||||||||
434 | } | ||||||||||
435 | } else { | ||||||||||
436 | reset(); | ||||||||||
437 | } | ||||||||||
438 | return *this; | ||||||||||
439 | } | ||||||||||
440 | |||||||||||
441 | template <typename U, std::enable_if_t<!std::is_constructible_v<T, const U&>, | ||||||||||
442 | bool> = true> | ||||||||||
443 | Maybe& operator=(const Maybe<U>& aOther) = delete; | ||||||||||
444 | |||||||||||
445 | template <typename U, | ||||||||||
446 | std::enable_if_t<std::is_constructible_v<T, U&&>, bool> = true> | ||||||||||
447 | Maybe& operator=(Maybe<U>&& aOther) { | ||||||||||
448 | if (aOther.isSome()) { | ||||||||||
449 | if (mIsSome) { | ||||||||||
450 | ref() = std::move(aOther.ref()); | ||||||||||
451 | } else { | ||||||||||
452 | emplace(std::move(*aOther)); | ||||||||||
453 | } | ||||||||||
454 | aOther.reset(); | ||||||||||
455 | } else { | ||||||||||
456 | reset(); | ||||||||||
457 | } | ||||||||||
458 | |||||||||||
459 | return *this; | ||||||||||
460 | } | ||||||||||
461 | |||||||||||
462 | template <typename U, | ||||||||||
463 | std::enable_if_t<!std::is_constructible_v<T, U&&>, bool> = true> | ||||||||||
464 | Maybe& operator=(Maybe<U>&& aOther) = delete; | ||||||||||
465 | |||||||||||
466 | constexpr Maybe& operator=(Nothing) { | ||||||||||
467 | reset(); | ||||||||||
468 | return *this; | ||||||||||
469 | } | ||||||||||
470 | |||||||||||
471 | /* Methods that check whether this Maybe contains a value */ | ||||||||||
472 | constexpr explicit operator bool() const { return isSome(); } | ||||||||||
473 | constexpr bool isSome() const { return mIsSome; } | ||||||||||
474 | constexpr bool isNothing() const { return !mIsSome; } | ||||||||||
475 | |||||||||||
476 | /* Returns the contents of this Maybe<T> by value. Unsafe unless |isSome()|. | ||||||||||
477 | */ | ||||||||||
478 | constexpr T value() const&; | ||||||||||
479 | constexpr T value() &&; | ||||||||||
480 | constexpr T value() const&&; | ||||||||||
481 | |||||||||||
482 | /** | ||||||||||
483 | * Move the contents of this Maybe<T> out of internal storage and return it | ||||||||||
484 | * without calling the destructor. The internal storage is also reset to | ||||||||||
485 | * avoid multiple calls. Unsafe unless |isSome()|. | ||||||||||
486 | */ | ||||||||||
487 | constexpr T extract() { | ||||||||||
488 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 488); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 488; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
489 | T v = std::move(mStorage.val); | ||||||||||
490 | reset(); | ||||||||||
491 | return v; | ||||||||||
492 | } | ||||||||||
493 | |||||||||||
494 | /** | ||||||||||
495 | * Returns the value (possibly |Nothing()|) by moving it out of this Maybe<T> | ||||||||||
496 | * and leaving |Nothing()| in its place. | ||||||||||
497 | */ | ||||||||||
498 | Maybe<T> take() { return std::exchange(*this, Nothing()); } | ||||||||||
499 | |||||||||||
500 | /* | ||||||||||
501 | * Returns the contents of this Maybe<T> by value. If |isNothing()|, returns | ||||||||||
502 | * the default value provided. | ||||||||||
503 | * | ||||||||||
504 | * Note: If the value passed to aDefault is not the result of a trivial | ||||||||||
505 | * expression, but expensive to evaluate, e.g. |valueOr(ExpensiveFunction())|, | ||||||||||
506 | * use |valueOrFrom| instead, e.g. | ||||||||||
507 | * |valueOrFrom([arg] { return ExpensiveFunction(arg); })|. This ensures | ||||||||||
508 | * that the expensive expression is only evaluated when its result will | ||||||||||
509 | * actually be used. | ||||||||||
510 | */ | ||||||||||
511 | template <typename V> | ||||||||||
512 | constexpr T valueOr(V&& aDefault) const { | ||||||||||
513 | if (isSome()) { | ||||||||||
514 | return ref(); | ||||||||||
515 | } | ||||||||||
516 | return std::forward<V>(aDefault); | ||||||||||
517 | } | ||||||||||
518 | |||||||||||
519 | /* | ||||||||||
520 | * Returns the contents of this Maybe<T> by value. If |isNothing()|, returns | ||||||||||
521 | * the value returned from the function or functor provided. | ||||||||||
522 | */ | ||||||||||
523 | template <typename F> | ||||||||||
524 | constexpr T valueOrFrom(F&& aFunc) const { | ||||||||||
525 | if (isSome()) { | ||||||||||
526 | return ref(); | ||||||||||
527 | } | ||||||||||
528 | return aFunc(); | ||||||||||
529 | } | ||||||||||
530 | |||||||||||
531 | /* Returns the contents of this Maybe<T> by pointer. Unsafe unless |isSome()|. | ||||||||||
532 | */ | ||||||||||
533 | T* ptr(); | ||||||||||
534 | constexpr const T* ptr() const; | ||||||||||
535 | |||||||||||
536 | /* | ||||||||||
537 | * Returns the contents of this Maybe<T> by pointer. If |isNothing()|, | ||||||||||
538 | * returns the default value provided. | ||||||||||
539 | */ | ||||||||||
540 | T* ptrOr(T* aDefault) { | ||||||||||
541 | if (isSome()) { | ||||||||||
542 | return ptr(); | ||||||||||
543 | } | ||||||||||
544 | return aDefault; | ||||||||||
545 | } | ||||||||||
546 | |||||||||||
547 | constexpr const T* ptrOr(const T* aDefault) const { | ||||||||||
548 | if (isSome()) { | ||||||||||
549 | return ptr(); | ||||||||||
550 | } | ||||||||||
551 | return aDefault; | ||||||||||
552 | } | ||||||||||
553 | |||||||||||
554 | /* | ||||||||||
555 | * Returns the contents of this Maybe<T> by pointer. If |isNothing()|, | ||||||||||
556 | * returns the value returned from the function or functor provided. | ||||||||||
557 | */ | ||||||||||
558 | template <typename F> | ||||||||||
559 | T* ptrOrFrom(F&& aFunc) { | ||||||||||
560 | if (isSome()) { | ||||||||||
561 | return ptr(); | ||||||||||
562 | } | ||||||||||
563 | return aFunc(); | ||||||||||
564 | } | ||||||||||
565 | |||||||||||
566 | template <typename F> | ||||||||||
567 | const T* ptrOrFrom(F&& aFunc) const { | ||||||||||
568 | if (isSome()) { | ||||||||||
569 | return ptr(); | ||||||||||
570 | } | ||||||||||
571 | return aFunc(); | ||||||||||
572 | } | ||||||||||
573 | |||||||||||
574 | constexpr T* operator->(); | ||||||||||
575 | constexpr const T* operator->() const; | ||||||||||
576 | |||||||||||
577 | /* Returns the contents of this Maybe<T> by ref. Unsafe unless |isSome()|. */ | ||||||||||
578 | constexpr T& ref() &; | ||||||||||
579 | constexpr const T& ref() const&; | ||||||||||
580 | constexpr T&& ref() &&; | ||||||||||
581 | constexpr const T&& ref() const&&; | ||||||||||
582 | |||||||||||
583 | /* | ||||||||||
584 | * Returns the contents of this Maybe<T> by ref. If |isNothing()|, returns | ||||||||||
585 | * the default value provided. | ||||||||||
586 | */ | ||||||||||
587 | constexpr T& refOr(T& aDefault) { | ||||||||||
588 | if (isSome()) { | ||||||||||
589 | return ref(); | ||||||||||
590 | } | ||||||||||
591 | return aDefault; | ||||||||||
592 | } | ||||||||||
593 | |||||||||||
594 | constexpr const T& refOr(const T& aDefault) const { | ||||||||||
595 | if (isSome()) { | ||||||||||
596 | return ref(); | ||||||||||
597 | } | ||||||||||
598 | return aDefault; | ||||||||||
599 | } | ||||||||||
600 | |||||||||||
601 | /* | ||||||||||
602 | * Returns the contents of this Maybe<T> by ref. If |isNothing()|, returns the | ||||||||||
603 | * value returned from the function or functor provided. | ||||||||||
604 | */ | ||||||||||
605 | template <typename F> | ||||||||||
606 | constexpr T& refOrFrom(F&& aFunc) { | ||||||||||
607 | if (isSome()) { | ||||||||||
608 | return ref(); | ||||||||||
609 | } | ||||||||||
610 | return aFunc(); | ||||||||||
611 | } | ||||||||||
612 | |||||||||||
613 | template <typename F> | ||||||||||
614 | constexpr const T& refOrFrom(F&& aFunc) const { | ||||||||||
615 | if (isSome()) { | ||||||||||
616 | return ref(); | ||||||||||
617 | } | ||||||||||
618 | return aFunc(); | ||||||||||
619 | } | ||||||||||
620 | |||||||||||
621 | constexpr T& operator*() &; | ||||||||||
622 | constexpr const T& operator*() const&; | ||||||||||
623 | constexpr T&& operator*() &&; | ||||||||||
624 | constexpr const T&& operator*() const&&; | ||||||||||
625 | |||||||||||
626 | /* If |isSome()|, runs the provided function or functor on the contents of | ||||||||||
627 | * this Maybe. */ | ||||||||||
628 | template <typename Func> | ||||||||||
629 | constexpr Maybe& apply(Func&& aFunc) & { | ||||||||||
630 | if (isSome()) { | ||||||||||
631 | std::forward<Func>(aFunc)(ref()); | ||||||||||
632 | } | ||||||||||
633 | return *this; | ||||||||||
634 | } | ||||||||||
635 | |||||||||||
636 | template <typename Func> | ||||||||||
637 | constexpr const Maybe& apply(Func&& aFunc) const& { | ||||||||||
638 | if (isSome()) { | ||||||||||
639 | std::forward<Func>(aFunc)(ref()); | ||||||||||
640 | } | ||||||||||
641 | return *this; | ||||||||||
642 | } | ||||||||||
643 | |||||||||||
644 | template <typename Func> | ||||||||||
645 | constexpr Maybe& apply(Func&& aFunc) && { | ||||||||||
646 | if (isSome()) { | ||||||||||
647 | std::forward<Func>(aFunc)(extract()); | ||||||||||
648 | } | ||||||||||
649 | return *this; | ||||||||||
650 | } | ||||||||||
651 | |||||||||||
652 | template <typename Func> | ||||||||||
653 | constexpr Maybe& apply(Func&& aFunc) const&& { | ||||||||||
654 | if (isSome()) { | ||||||||||
655 | std::forward<Func>(aFunc)(extract()); | ||||||||||
656 | } | ||||||||||
657 | return *this; | ||||||||||
658 | } | ||||||||||
659 | |||||||||||
660 | /* | ||||||||||
661 | * If |isSome()|, runs the provided function and returns the result wrapped | ||||||||||
662 | * in a Maybe. If |isNothing()|, returns an empty Maybe value with the same | ||||||||||
663 | * value type as what the provided function would have returned. | ||||||||||
664 | */ | ||||||||||
665 | template <typename Func> | ||||||||||
666 | constexpr auto map(Func&& aFunc) & { | ||||||||||
667 | if (isSome()) { | ||||||||||
668 | return Some(std::forward<Func>(aFunc)(ref())); | ||||||||||
669 | } | ||||||||||
670 | return Maybe<decltype(std::forward<Func>(aFunc)(ref()))>{}; | ||||||||||
671 | } | ||||||||||
672 | |||||||||||
673 | template <typename Func> | ||||||||||
674 | constexpr auto map(Func&& aFunc) const& { | ||||||||||
675 | if (isSome()) { | ||||||||||
676 | return Some(std::forward<Func>(aFunc)(ref())); | ||||||||||
677 | } | ||||||||||
678 | return Maybe<decltype(std::forward<Func>(aFunc)(ref()))>{}; | ||||||||||
679 | } | ||||||||||
680 | |||||||||||
681 | template <typename Func> | ||||||||||
682 | constexpr auto map(Func&& aFunc) && { | ||||||||||
683 | if (isSome()) { | ||||||||||
684 | return Some(std::forward<Func>(aFunc)(extract())); | ||||||||||
685 | } | ||||||||||
686 | return Maybe<decltype(std::forward<Func>(aFunc)(extract()))>{}; | ||||||||||
687 | } | ||||||||||
688 | |||||||||||
689 | template <typename Func> | ||||||||||
690 | constexpr auto map(Func&& aFunc) const&& { | ||||||||||
691 | if (isSome()) { | ||||||||||
692 | return Some(std::forward<Func>(aFunc)(extract())); | ||||||||||
693 | } | ||||||||||
694 | return Maybe<decltype(std::forward<Func>(aFunc)(extract()))>{}; | ||||||||||
695 | } | ||||||||||
696 | |||||||||||
697 | /* | ||||||||||
698 | * If |isSome()|, runs the provided function or functor on the contents of | ||||||||||
699 | * this Maybe and returns the result. Note that the provided function or | ||||||||||
700 | * functor must return a Maybe<U> of any type U. | ||||||||||
701 | * If |isNothing()|, returns an empty Maybe value with the same type as what | ||||||||||
702 | * the provided function would have returned. | ||||||||||
703 | */ | ||||||||||
704 | template <typename Func> | ||||||||||
705 | constexpr auto andThen(Func&& aFunc) & { | ||||||||||
706 | static_assert(std::is_invocable_v<Func, T&>); | ||||||||||
707 | using U = std::invoke_result_t<Func, T&>; | ||||||||||
708 | static_assert(detail::IsMaybe<U>::value); | ||||||||||
709 | if (isSome()) { | ||||||||||
710 | return std::invoke(std::forward<Func>(aFunc), ref()); | ||||||||||
711 | } | ||||||||||
712 | return std::remove_cv_t<std::remove_reference_t<U>>{}; | ||||||||||
713 | } | ||||||||||
714 | |||||||||||
715 | template <typename Func> | ||||||||||
716 | constexpr auto andThen(Func&& aFunc) const& { | ||||||||||
717 | static_assert(std::is_invocable_v<Func, const T&>); | ||||||||||
718 | using U = std::invoke_result_t<Func, const T&>; | ||||||||||
719 | static_assert(detail::IsMaybe<U>::value); | ||||||||||
720 | if (isSome()) { | ||||||||||
721 | return std::invoke(std::forward<Func>(aFunc), ref()); | ||||||||||
722 | } | ||||||||||
723 | return std::remove_cv_t<std::remove_reference_t<U>>{}; | ||||||||||
724 | } | ||||||||||
725 | |||||||||||
726 | template <typename Func> | ||||||||||
727 | constexpr auto andThen(Func&& aFunc) && { | ||||||||||
728 | static_assert(std::is_invocable_v<Func, T&&>); | ||||||||||
729 | using U = std::invoke_result_t<Func, T&&>; | ||||||||||
730 | static_assert(detail::IsMaybe<U>::value); | ||||||||||
731 | if (isSome()) { | ||||||||||
732 | return std::invoke(std::forward<Func>(aFunc), extract()); | ||||||||||
733 | } | ||||||||||
734 | return std::remove_cv_t<std::remove_reference_t<U>>{}; | ||||||||||
735 | } | ||||||||||
736 | |||||||||||
737 | template <typename Func> | ||||||||||
738 | constexpr auto andThen(Func&& aFunc) const&& { | ||||||||||
739 | static_assert(std::is_invocable_v<Func, const T&&>); | ||||||||||
740 | using U = std::invoke_result_t<Func, const T&&>; | ||||||||||
741 | static_assert(detail::IsMaybe<U>::value); | ||||||||||
742 | if (isSome()) { | ||||||||||
743 | return std::invoke(std::forward<Func>(aFunc), extract()); | ||||||||||
744 | } | ||||||||||
745 | return std::remove_cv_t<std::remove_reference_t<U>>{}; | ||||||||||
746 | } | ||||||||||
747 | |||||||||||
748 | /* | ||||||||||
749 | * If |isNothing()|, runs the provided function or functor and returns its | ||||||||||
750 | * result. If |isSome()|, returns the contained value wrapped in a Maybe. | ||||||||||
751 | */ | ||||||||||
752 | template <typename Func> | ||||||||||
753 | constexpr Maybe orElse(Func&& aFunc) & { | ||||||||||
754 | static_assert(std::is_invocable_v<Func>); | ||||||||||
755 | using U = std::invoke_result_t<Func>; | ||||||||||
756 | static_assert( | ||||||||||
757 | std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>); | ||||||||||
758 | if (isSome()) { | ||||||||||
759 | return *this; | ||||||||||
760 | } | ||||||||||
761 | return std::invoke(std::forward<Func>(aFunc)); | ||||||||||
762 | } | ||||||||||
763 | |||||||||||
764 | template <typename Func> | ||||||||||
765 | constexpr Maybe orElse(Func&& aFunc) const& { | ||||||||||
766 | static_assert(std::is_invocable_v<Func>); | ||||||||||
767 | using U = std::invoke_result_t<Func>; | ||||||||||
768 | static_assert( | ||||||||||
769 | std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>); | ||||||||||
770 | if (isSome()) { | ||||||||||
771 | return *this; | ||||||||||
772 | } | ||||||||||
773 | return std::invoke(std::forward<Func>(aFunc)); | ||||||||||
774 | } | ||||||||||
775 | |||||||||||
776 | template <typename Func> | ||||||||||
777 | constexpr Maybe orElse(Func&& aFunc) && { | ||||||||||
778 | static_assert(std::is_invocable_v<Func>); | ||||||||||
779 | using U = std::invoke_result_t<Func>; | ||||||||||
780 | static_assert( | ||||||||||
781 | std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>); | ||||||||||
782 | if (isSome()) { | ||||||||||
783 | return std::move(*this); | ||||||||||
784 | } | ||||||||||
785 | return std::invoke(std::forward<Func>(aFunc)); | ||||||||||
786 | } | ||||||||||
787 | |||||||||||
788 | template <typename Func> | ||||||||||
789 | constexpr Maybe orElse(Func&& aFunc) const&& { | ||||||||||
790 | static_assert(std::is_invocable_v<Func>); | ||||||||||
791 | using U = std::invoke_result_t<Func>; | ||||||||||
792 | static_assert( | ||||||||||
793 | std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>); | ||||||||||
794 | if (isSome()) { | ||||||||||
795 | return std::move(*this); | ||||||||||
796 | } | ||||||||||
797 | return std::invoke(std::forward<Func>(aFunc)); | ||||||||||
798 | } | ||||||||||
799 | |||||||||||
800 | /* If |isSome()|, empties this Maybe and destroys its contents. */ | ||||||||||
801 | constexpr void reset() { | ||||||||||
802 | if (isSome()) { | ||||||||||
803 | if constexpr (!std::is_trivially_destructible_v<T>) { | ||||||||||
804 | /* | ||||||||||
805 | * Static analyzer gets confused if we have Maybe<MutexAutoLock>, | ||||||||||
806 | * so we suppress thread-safety warnings here | ||||||||||
807 | */ | ||||||||||
808 | MOZ_PUSH_IGNORE_THREAD_SAFETYGCC diagnostic push
GCC diagnostic ignored "-Wthread-safety" | ||||||||||
809 | ref().T::~T(); | ||||||||||
810 | MOZ_POP_THREAD_SAFETYGCC diagnostic pop | ||||||||||
811 | poisonData(); | ||||||||||
812 | } | ||||||||||
813 | mIsSome = false; | ||||||||||
814 | } | ||||||||||
815 | } | ||||||||||
816 | |||||||||||
817 | /* | ||||||||||
818 | * Constructs a T value in-place in this empty Maybe<T>'s storage. The | ||||||||||
819 | * arguments to |emplace()| are the parameters to T's constructor. | ||||||||||
820 | */ | ||||||||||
821 | template <typename... Args> | ||||||||||
822 | constexpr void emplace(Args&&... aArgs); | ||||||||||
823 | |||||||||||
824 | template <typename U> | ||||||||||
825 | constexpr std::enable_if_t<std::is_same_v<T, U> && | ||||||||||
826 | std::is_copy_constructible_v<U> && | ||||||||||
827 | !std::is_move_constructible_v<U>> | ||||||||||
828 | emplace(U&& aArgs) { | ||||||||||
829 | emplace(aArgs); | ||||||||||
830 | } | ||||||||||
831 | |||||||||||
832 | friend std::ostream& operator<<(std::ostream& aStream, | ||||||||||
833 | const Maybe<T>& aMaybe) { | ||||||||||
834 | if (aMaybe) { | ||||||||||
835 | aStream << aMaybe.ref(); | ||||||||||
836 | } else { | ||||||||||
837 | aStream << "<Nothing>"; | ||||||||||
838 | } | ||||||||||
839 | return aStream; | ||||||||||
840 | } | ||||||||||
841 | }; | ||||||||||
842 | |||||||||||
843 | template <typename T> | ||||||||||
844 | class Maybe<T&> { | ||||||||||
845 | public: | ||||||||||
846 | constexpr Maybe() = default; | ||||||||||
847 | constexpr MOZ_IMPLICIT Maybe(Nothing) {} | ||||||||||
848 | |||||||||||
849 | void emplace(T& aRef) { mValue = &aRef; } | ||||||||||
850 | |||||||||||
851 | /* Methods that check whether this Maybe contains a value */ | ||||||||||
852 | constexpr explicit operator bool() const { return isSome(); } | ||||||||||
853 | constexpr bool isSome() const { return mValue; } | ||||||||||
854 | constexpr bool isNothing() const { return !mValue; } | ||||||||||
855 | |||||||||||
856 | T& ref() const { | ||||||||||
857 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 857); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 857; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
858 | return *mValue; | ||||||||||
859 | } | ||||||||||
860 | |||||||||||
861 | T* operator->() const { return &ref(); } | ||||||||||
862 | T& operator*() const { return ref(); } | ||||||||||
863 | |||||||||||
864 | // Deliberately not defining value and ptr accessors, as these may be | ||||||||||
865 | // confusing on a reference-typed Maybe. | ||||||||||
866 | |||||||||||
867 | // XXX Should we define refOr? | ||||||||||
868 | |||||||||||
869 | void reset() { mValue = nullptr; } | ||||||||||
870 | |||||||||||
871 | template <typename Func> | ||||||||||
872 | const Maybe& apply(Func&& aFunc) const { | ||||||||||
873 | if (isSome()) { | ||||||||||
874 | std::forward<Func>(aFunc)(ref()); | ||||||||||
875 | } | ||||||||||
876 | return *this; | ||||||||||
877 | } | ||||||||||
878 | |||||||||||
879 | template <typename Func> | ||||||||||
880 | auto map(Func&& aFunc) const { | ||||||||||
881 | Maybe<decltype(std::forward<Func>(aFunc)(ref()))> val; | ||||||||||
882 | if (isSome()) { | ||||||||||
883 | val.emplace(std::forward<Func>(aFunc)(ref())); | ||||||||||
884 | } | ||||||||||
885 | return val; | ||||||||||
886 | } | ||||||||||
887 | |||||||||||
888 | template <typename Func> | ||||||||||
889 | constexpr auto andThen(Func&& aFunc) const { | ||||||||||
890 | static_assert(std::is_invocable_v<Func, T&>); | ||||||||||
891 | using U = std::invoke_result_t<Func, T&>; | ||||||||||
892 | static_assert(detail::IsMaybe<U>::value); | ||||||||||
893 | if (isSome()) { | ||||||||||
894 | return std::invoke(std::forward<Func>(aFunc), ref()); | ||||||||||
895 | } | ||||||||||
896 | return std::remove_cv_t<std::remove_reference_t<U>>{}; | ||||||||||
897 | } | ||||||||||
898 | |||||||||||
899 | template <typename Func> | ||||||||||
900 | constexpr Maybe orElse(Func&& aFunc) const { | ||||||||||
901 | static_assert(std::is_invocable_v<Func>); | ||||||||||
902 | using U = std::invoke_result_t<Func>; | ||||||||||
903 | static_assert( | ||||||||||
904 | std::is_same_v<Maybe, std::remove_cv_t<std::remove_reference_t<U>>>); | ||||||||||
905 | if (isSome()) { | ||||||||||
906 | return *this; | ||||||||||
907 | } | ||||||||||
908 | return std::invoke(std::forward<Func>(aFunc)); | ||||||||||
909 | } | ||||||||||
910 | |||||||||||
911 | bool refEquals(const Maybe<T&>& aOther) const { | ||||||||||
912 | return mValue == aOther.mValue; | ||||||||||
913 | } | ||||||||||
914 | |||||||||||
915 | bool refEquals(const T& aOther) const { return mValue == &aOther; } | ||||||||||
916 | |||||||||||
917 | private: | ||||||||||
918 | T* mValue = nullptr; | ||||||||||
919 | }; | ||||||||||
920 | |||||||||||
921 | template <typename T> | ||||||||||
922 | constexpr T Maybe<T>::value() const& { | ||||||||||
923 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 923); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 923; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
924 | return ref(); | ||||||||||
925 | } | ||||||||||
926 | |||||||||||
927 | template <typename T> | ||||||||||
928 | constexpr T Maybe<T>::value() && { | ||||||||||
929 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 929); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 929; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
930 | return std::move(ref()); | ||||||||||
931 | } | ||||||||||
932 | |||||||||||
933 | template <typename T> | ||||||||||
934 | constexpr T Maybe<T>::value() const&& { | ||||||||||
935 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 935); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 935; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
936 | return std::move(ref()); | ||||||||||
937 | } | ||||||||||
938 | |||||||||||
939 | template <typename T> | ||||||||||
940 | T* Maybe<T>::ptr() { | ||||||||||
941 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 941); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 941; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
942 | return &ref(); | ||||||||||
943 | } | ||||||||||
944 | |||||||||||
945 | template <typename T> | ||||||||||
946 | constexpr const T* Maybe<T>::ptr() const { | ||||||||||
947 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 947); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 947; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
948 | return &ref(); | ||||||||||
949 | } | ||||||||||
950 | |||||||||||
951 | template <typename T> | ||||||||||
952 | constexpr T* Maybe<T>::operator->() { | ||||||||||
953 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 953); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 953; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
954 | return ptr(); | ||||||||||
955 | } | ||||||||||
956 | |||||||||||
957 | template <typename T> | ||||||||||
958 | constexpr const T* Maybe<T>::operator->() const { | ||||||||||
959 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 959); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 959; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
960 | return ptr(); | ||||||||||
961 | } | ||||||||||
962 | |||||||||||
963 | template <typename T> | ||||||||||
964 | constexpr T& Maybe<T>::ref() & { | ||||||||||
965 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 965); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 965; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
966 | return mStorage.val; | ||||||||||
967 | } | ||||||||||
968 | |||||||||||
969 | template <typename T> | ||||||||||
970 | constexpr const T& Maybe<T>::ref() const& { | ||||||||||
971 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 971); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 971; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
972 | return mStorage.val; | ||||||||||
973 | } | ||||||||||
974 | |||||||||||
975 | template <typename T> | ||||||||||
976 | constexpr T&& Maybe<T>::ref() && { | ||||||||||
977 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 977); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 977; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
978 | return std::move(mStorage.val); | ||||||||||
979 | } | ||||||||||
980 | |||||||||||
981 | template <typename T> | ||||||||||
982 | constexpr const T&& Maybe<T>::ref() const&& { | ||||||||||
983 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 983); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 983; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
984 | return std::move(mStorage.val); | ||||||||||
985 | } | ||||||||||
986 | |||||||||||
987 | template <typename T> | ||||||||||
988 | constexpr T& Maybe<T>::operator*() & { | ||||||||||
989 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 989); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 989; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
990 | return ref(); | ||||||||||
991 | } | ||||||||||
992 | |||||||||||
993 | template <typename T> | ||||||||||
994 | constexpr const T& Maybe<T>::operator*() const& { | ||||||||||
995 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 995); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 995; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
996 | return ref(); | ||||||||||
997 | } | ||||||||||
998 | |||||||||||
999 | template <typename T> | ||||||||||
1000 | constexpr T&& Maybe<T>::operator*() && { | ||||||||||
1001 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 1001); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 1001; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
1002 | return std::move(ref()); | ||||||||||
1003 | } | ||||||||||
1004 | |||||||||||
1005 | template <typename T> | ||||||||||
1006 | constexpr const T&& Maybe<T>::operator*() const&& { | ||||||||||
1007 | MOZ_RELEASE_ASSERT(isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 1007); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "isSome()" ")"); do { *((volatile int*)__null) = 1007; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
1008 | return std::move(ref()); | ||||||||||
1009 | } | ||||||||||
1010 | |||||||||||
1011 | template <typename T> | ||||||||||
1012 | template <typename... Args> | ||||||||||
1013 | constexpr void Maybe<T>::emplace(Args&&... aArgs) { | ||||||||||
1014 | MOZ_RELEASE_ASSERT(!isSome())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!isSome())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!isSome()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("!isSome()", "/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/mozilla/Maybe.h" , 1014); AnnotateMozCrashReason("MOZ_RELEASE_ASSERT" "(" "!isSome()" ")"); do { *((volatile int*)__null) = 1014; __attribute__((nomerge )) ::abort(); } while (false); } } while (false); | ||||||||||
1015 | ::new (KnownNotNull, &mStorage.val) T(std::forward<Args>(aArgs)...); | ||||||||||
1016 | mIsSome = true; | ||||||||||
1017 | } | ||||||||||
1018 | |||||||||||
1019 | /* | ||||||||||
1020 | * Some() creates a Maybe<T> value containing the provided T value. If T has a | ||||||||||
1021 | * move constructor, it's used to make this as efficient as possible. | ||||||||||
1022 | * | ||||||||||
1023 | * Some() selects the type of Maybe it returns by removing any const, volatile, | ||||||||||
1024 | * or reference qualifiers from the type of the value you pass to it. This gives | ||||||||||
1025 | * it more intuitive behavior when used in expressions, but it also means that | ||||||||||
1026 | * if you need to construct a Maybe value that holds a const, volatile, or | ||||||||||
1027 | * reference value, you need to use emplace() instead. | ||||||||||
1028 | */ | ||||||||||
1029 | template <typename T, typename U> | ||||||||||
1030 | constexpr Maybe<U> Some(T&& aValue) { | ||||||||||
1031 | return {std::forward<T>(aValue), typename Maybe<U>::SomeGuard{}}; | ||||||||||
1032 | } | ||||||||||
1033 | |||||||||||
1034 | template <typename T> | ||||||||||
1035 | constexpr Maybe<T&> SomeRef(T& aValue) { | ||||||||||
1036 | Maybe<T&> value; | ||||||||||
1037 | value.emplace(aValue); | ||||||||||
1038 | return value; | ||||||||||
1039 | } | ||||||||||
1040 | |||||||||||
1041 | template <typename T> | ||||||||||
1042 | constexpr Maybe<T&> ToMaybeRef(T* const aPtr) { | ||||||||||
1043 | return aPtr ? SomeRef(*aPtr) : Nothing{}; | ||||||||||
1044 | } | ||||||||||
1045 | |||||||||||
1046 | template <typename T> | ||||||||||
1047 | Maybe<std::remove_cv_t<std::remove_reference_t<T>>> ToMaybe(T* aPtr) { | ||||||||||
1048 | if (aPtr) { | ||||||||||
1049 | return Some(*aPtr); | ||||||||||
1050 | } | ||||||||||
1051 | return Nothing(); | ||||||||||
1052 | } | ||||||||||
1053 | |||||||||||
1054 | /* | ||||||||||
1055 | * Two Maybe<T> values are equal if | ||||||||||
1056 | * - both are Nothing, or | ||||||||||
1057 | * - both are Some, and the values they contain are equal. | ||||||||||
1058 | */ | ||||||||||
1059 | template <typename T> | ||||||||||
1060 | constexpr bool operator==(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1061 | static_assert(!std::is_reference_v<T>, | ||||||||||
1062 | "operator== is not defined for Maybe<T&>, compare values or " | ||||||||||
1063 | "addresses explicitly instead"); | ||||||||||
1064 | if (aLHS.isNothing() != aRHS.isNothing()) { | ||||||||||
1065 | return false; | ||||||||||
1066 | } | ||||||||||
1067 | return aLHS.isNothing() || *aLHS == *aRHS; | ||||||||||
1068 | } | ||||||||||
1069 | |||||||||||
1070 | template <typename T> | ||||||||||
1071 | constexpr bool operator!=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1072 | return !(aLHS == aRHS); | ||||||||||
1073 | } | ||||||||||
1074 | |||||||||||
1075 | /* | ||||||||||
1076 | * We support comparison to Nothing to allow reasonable expressions like: | ||||||||||
1077 | * if (maybeValue == Nothing()) { ... } | ||||||||||
1078 | */ | ||||||||||
1079 | template <typename T> | ||||||||||
1080 | constexpr bool operator==(const Maybe<T>& aLHS, const Nothing& aRHS) { | ||||||||||
1081 | return aLHS.isNothing(); | ||||||||||
1082 | } | ||||||||||
1083 | |||||||||||
1084 | template <typename T> | ||||||||||
1085 | constexpr bool operator!=(const Maybe<T>& aLHS, const Nothing& aRHS) { | ||||||||||
1086 | return !(aLHS == aRHS); | ||||||||||
1087 | } | ||||||||||
1088 | |||||||||||
1089 | template <typename T> | ||||||||||
1090 | constexpr bool operator==(const Nothing& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1091 | return aRHS.isNothing(); | ||||||||||
1092 | } | ||||||||||
1093 | |||||||||||
1094 | template <typename T> | ||||||||||
1095 | constexpr bool operator!=(const Nothing& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1096 | return !(aLHS == aRHS); | ||||||||||
1097 | } | ||||||||||
1098 | |||||||||||
1099 | /* | ||||||||||
1100 | * Maybe<T> values are ordered in the same way T values are ordered, except that | ||||||||||
1101 | * Nothing comes before anything else. | ||||||||||
1102 | */ | ||||||||||
1103 | template <typename T> | ||||||||||
1104 | constexpr bool operator<(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1105 | if (aLHS.isNothing()) { | ||||||||||
1106 | return aRHS.isSome(); | ||||||||||
1107 | } | ||||||||||
1108 | if (aRHS.isNothing()) { | ||||||||||
1109 | return false; | ||||||||||
1110 | } | ||||||||||
1111 | return *aLHS < *aRHS; | ||||||||||
1112 | } | ||||||||||
1113 | |||||||||||
1114 | template <typename T> | ||||||||||
1115 | constexpr bool operator>(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1116 | return !(aLHS < aRHS || aLHS == aRHS); | ||||||||||
1117 | } | ||||||||||
1118 | |||||||||||
1119 | template <typename T> | ||||||||||
1120 | constexpr bool operator<=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1121 | return aLHS < aRHS || aLHS == aRHS; | ||||||||||
1122 | } | ||||||||||
1123 | |||||||||||
1124 | template <typename T> | ||||||||||
1125 | constexpr bool operator>=(const Maybe<T>& aLHS, const Maybe<T>& aRHS) { | ||||||||||
1126 | return !(aLHS < aRHS); | ||||||||||
1127 | } | ||||||||||
1128 | |||||||||||
1129 | template <typename T> | ||||||||||
1130 | inline void ImplCycleCollectionTraverse( | ||||||||||
1131 | nsCycleCollectionTraversalCallback& aCallback, mozilla::Maybe<T>& aField, | ||||||||||
1132 | const char* aName, uint32_t aFlags = 0) { | ||||||||||
1133 | if (aField) { | ||||||||||
1134 | ImplCycleCollectionTraverse(aCallback, aField.ref(), aName, aFlags); | ||||||||||
1135 | } | ||||||||||
1136 | } | ||||||||||
1137 | |||||||||||
1138 | template <typename T> | ||||||||||
1139 | inline void ImplCycleCollectionUnlink(mozilla::Maybe<T>& aField) { | ||||||||||
1140 | if (aField) { | ||||||||||
1141 | ImplCycleCollectionUnlink(aField.ref()); | ||||||||||
1142 | } | ||||||||||
1143 | } | ||||||||||
1144 | |||||||||||
1145 | } // namespace mozilla | ||||||||||
1146 | |||||||||||
1147 | #endif /* mozilla_Maybe_h */ |
1 | /* -*- Mode: C++; tab-width: 2; 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 | /* Internal storage class used e.g. by Maybe and Result. This file doesn't |
8 | * contain any public declarations. */ |
9 | |
10 | #ifndef mfbt_MaybeStorageBase_h |
11 | #define mfbt_MaybeStorageBase_h |
12 | |
13 | #include <type_traits> |
14 | #include <utility> |
15 | |
16 | namespace mozilla::detail { |
17 | |
18 | template <typename T> |
19 | constexpr bool IsTriviallyDestructibleAndCopyable = |
20 | std::is_trivially_destructible_v<T> && |
21 | (std::is_trivially_copy_constructible_v<T> || |
22 | !std::is_copy_constructible_v<T>); |
23 | |
24 | template <typename T, bool TriviallyDestructibleAndCopyable = |
25 | IsTriviallyDestructibleAndCopyable<T>> |
26 | struct MaybeStorageBase; |
27 | |
28 | template <typename T> |
29 | struct MaybeStorageBase<T, false> { |
30 | protected: |
31 | using NonConstT = std::remove_const_t<T>; |
32 | |
33 | union Union { |
34 | Union() {} |
35 | explicit Union(const T& aVal) : val{aVal} {} |
36 | template <typename U, |
37 | typename = std::enable_if_t<std::is_move_constructible_v<U>>> |
38 | explicit Union(U&& aVal) : val{std::forward<U>(aVal)} {} |
39 | template <typename... Args> |
40 | explicit Union(std::in_place_t, Args&&... aArgs) |
41 | : val{std::forward<Args>(aArgs)...} {} |
42 | |
43 | ~Union() {} |
44 | |
45 | NonConstT val; |
46 | } mStorage; |
47 | |
48 | public: |
49 | MaybeStorageBase() = default; |
50 | explicit MaybeStorageBase(const T& aVal) : mStorage{aVal} {} |
51 | explicit MaybeStorageBase(T&& aVal) : mStorage{std::move(aVal)} {} |
52 | template <typename... Args> |
53 | explicit MaybeStorageBase(std::in_place_t, Args&&... aArgs) |
54 | : mStorage{std::in_place, std::forward<Args>(aArgs)...} {} |
55 | |
56 | const T* addr() const { return &mStorage.val; } |
57 | T* addr() { return &mStorage.val; } |
58 | }; |
59 | |
60 | template <typename T> |
61 | struct MaybeStorageBase<T, true> { |
62 | protected: |
63 | using NonConstT = std::remove_const_t<T>; |
64 | |
65 | union Union { |
66 | constexpr Union() : dummy() {} |
67 | constexpr explicit Union(const T& aVal) : val{aVal} {} |
68 | constexpr explicit Union(T&& aVal) : val{std::move(aVal)} {} |
69 | template <typename... Args> |
70 | constexpr explicit Union(std::in_place_t, Args&&... aArgs) |
71 | : val{std::forward<Args>(aArgs)...} {} |
72 | |
73 | NonConstT val; |
74 | char dummy; |
75 | } mStorage; |
76 | |
77 | public: |
78 | constexpr MaybeStorageBase() = default; |
79 | constexpr explicit MaybeStorageBase(const T& aVal) : mStorage{aVal} {} |
80 | constexpr explicit MaybeStorageBase(T&& aVal) : mStorage{std::move(aVal)} {} |
81 | |
82 | template <typename... Args> |
83 | constexpr explicit MaybeStorageBase(std::in_place_t, Args&&... aArgs) |
84 | : mStorage{std::in_place, std::forward<Args>(aArgs)...} {} |
85 | |
86 | constexpr const T* addr() const { return &mStorage.val; } |
87 | constexpr T* addr() { return &mStorage.val; } |
88 | }; |
89 | |
90 | } // namespace mozilla::detail |
91 | |
92 | #endif |
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 | /* |
8 | * API for managing off-thread work. |
9 | */ |
10 | |
11 | #ifndef vm_HelperThreads_h |
12 | #define vm_HelperThreads_h |
13 | |
14 | #include "mozilla/Variant.h" |
15 | |
16 | #include "js/AllocPolicy.h" |
17 | #include "js/HelperThreadAPI.h" |
18 | #include "js/shadow/Zone.h" |
19 | #include "js/UniquePtr.h" |
20 | #include "js/Vector.h" |
21 | #include "threading/LockGuard.h" |
22 | #include "threading/Mutex.h" |
23 | #include "wasm/WasmConstants.h" |
24 | |
25 | namespace mozilla { |
26 | union Utf8Unit; |
27 | } |
28 | |
29 | namespace JS { |
30 | class JS_PUBLIC_API ReadOnlyCompileOptions; |
31 | class JS_PUBLIC_API ReadOnlyDecodeOptions; |
32 | class Zone; |
33 | |
34 | template <typename UnitT> |
35 | class SourceText; |
36 | } // namespace JS |
37 | |
38 | namespace js { |
39 | |
40 | class AutoLockHelperThreadState; |
41 | struct PromiseHelperTask; |
42 | class SourceCompressionTask; |
43 | |
44 | namespace frontend { |
45 | struct CompilationStencil; |
46 | } |
47 | |
48 | namespace gc { |
49 | class GCRuntime; |
50 | } |
51 | |
52 | namespace jit { |
53 | class IonCompileTask; |
54 | class IonFreeTask; |
55 | class JitRuntime; |
56 | using IonFreeCompileTasks = Vector<IonCompileTask*, 8, SystemAllocPolicy>; |
57 | } // namespace jit |
58 | |
59 | namespace wasm { |
60 | struct CompileTask; |
61 | struct CompileTaskState; |
62 | struct Tier2GeneratorTask; |
63 | using UniqueTier2GeneratorTask = UniquePtr<Tier2GeneratorTask>; |
64 | } // namespace wasm |
65 | |
66 | /* |
67 | * Lock protecting all mutable shared state accessed by helper threads, and used |
68 | * by all condition variables. |
69 | */ |
70 | extern Mutex gHelperThreadLock MOZ_UNANNOTATED; |
71 | |
72 | // Set of tasks to dispatch when the helper thread state lock is released. |
73 | class AutoHelperTaskQueue { |
74 | public: |
75 | ~AutoHelperTaskQueue() { dispatchQueuedTasks(); } |
76 | bool hasQueuedTasks() const { return !tasksToDispatch.empty(); } |
77 | void queueTaskToDispatch(JS::HelperThreadTask* task) const; |
78 | void dispatchQueuedTasks(); |
79 | |
80 | private: |
81 | // TODO: Convert this to use a linked list. |
82 | mutable Vector<JS::HelperThreadTask*, 1, SystemAllocPolicy> tasksToDispatch; |
83 | }; |
84 | |
85 | // A lock guard for data protected by the helper thread lock. |
86 | // |
87 | // This can also queue helper thread tasks to be triggered when the lock is |
88 | // released. |
89 | class MOZ_RAII AutoLockHelperThreadState |
90 | : public AutoHelperTaskQueue, // Must come before LockGuard. |
91 | public LockGuard<Mutex> { |
92 | public: |
93 | AutoLockHelperThreadState() : LockGuard<Mutex>(gHelperThreadLock) {} |
94 | AutoLockHelperThreadState(const AutoLockHelperThreadState&) = delete; |
95 | |
96 | private: |
97 | friend class UnlockGuard<AutoLockHelperThreadState>; |
98 | void unlock() { |
99 | LockGuard<Mutex>::unlock(); |
100 | dispatchQueuedTasks(); |
101 | } |
102 | |
103 | friend class GlobalHelperThreadState; |
104 | }; |
105 | |
106 | using AutoUnlockHelperThreadState = UnlockGuard<AutoLockHelperThreadState>; |
107 | |
108 | // Create data structures used by helper threads. |
109 | bool CreateHelperThreadsState(); |
110 | |
111 | // Destroy data structures used by helper threads. |
112 | void DestroyHelperThreadsState(); |
113 | |
114 | // Initialize helper threads unless already initialized. |
115 | bool EnsureHelperThreadsInitialized(); |
116 | |
117 | size_t GetHelperThreadCount(); |
118 | size_t GetHelperThreadCPUCount(); |
119 | size_t GetMaxWasmCompilationThreads(); |
120 | |
121 | // This allows the JS shell to override GetCPUCount() when passed the |
122 | // --thread-count=N option. |
123 | bool SetFakeCPUCount(size_t count); |
124 | |
125 | // Enqueues a wasm compilation task. |
126 | bool StartOffThreadWasmCompile(wasm::CompileTask* task, |
127 | wasm::CompileState state); |
128 | |
129 | // Remove any pending wasm compilation tasks queued with |
130 | // StartOffThreadWasmCompile that match the arguments. Return the number |
131 | // removed. |
132 | size_t RemovePendingWasmCompileTasks(const wasm::CompileTaskState& taskState, |
133 | wasm::CompileState state, |
134 | const AutoLockHelperThreadState& lock); |
135 | |
136 | // Enqueues a wasm compilation task. |
137 | void StartOffThreadWasmTier2Generator(wasm::UniqueTier2GeneratorTask task); |
138 | |
139 | // Cancel all background Wasm Tier-2 compilations. |
140 | void CancelOffThreadWasmTier2Generator(); |
141 | |
142 | /* |
143 | * If helper threads are available, call execute() then dispatchResolve() on the |
144 | * given task in a helper thread. If no helper threads are available, the given |
145 | * task is executed and resolved synchronously. |
146 | * |
147 | * This function takes ownership of task unconditionally; if it fails, task is |
148 | * deleted. |
149 | */ |
150 | bool StartOffThreadPromiseHelperTask(JSContext* cx, |
151 | UniquePtr<PromiseHelperTask> task); |
152 | |
153 | /* |
154 | * Like the JSContext-accepting version, but only safe to use when helper |
155 | * threads are available, so we can be sure we'll never need to fall back on |
156 | * synchronous execution. |
157 | * |
158 | * This function can be called from any thread, but takes ownership of the task |
159 | * only on success. On OOM, it is the caller's responsibility to arrange for the |
160 | * task to be cleaned up properly. |
161 | */ |
162 | bool StartOffThreadPromiseHelperTask(PromiseHelperTask* task); |
163 | |
164 | /* |
165 | * Schedule an off-thread Ion compilation for a script, given a task. |
166 | */ |
167 | bool StartOffThreadIonCompile(jit::IonCompileTask* task, |
168 | const AutoLockHelperThreadState& lock); |
169 | |
170 | void FinishOffThreadIonCompile(jit::IonCompileTask* task, |
171 | const AutoLockHelperThreadState& lock); |
172 | |
173 | // RAII class to handle batching compile tasks and starting an IonFreeTask. |
174 | class MOZ_RAII AutoStartIonFreeTask { |
175 | jit::JitRuntime* jitRuntime_; |
176 | |
177 | // If true, start an IonFreeTask even if the batch is small. |
178 | bool force_; |
179 | |
180 | public: |
181 | explicit AutoStartIonFreeTask(jit::JitRuntime* jitRuntime, bool force = false) |
182 | : jitRuntime_(jitRuntime), force_(force) {} |
183 | ~AutoStartIonFreeTask(); |
184 | |
185 | [[nodiscard]] bool addIonCompileToFreeTaskBatch(jit::IonCompileTask* task); |
186 | }; |
187 | |
188 | struct ZonesInState { |
189 | JSRuntime* runtime; |
190 | JS::shadow::Zone::GCState state; |
191 | }; |
192 | |
193 | using CompilationSelector = |
194 | mozilla::Variant<JSScript*, JS::Zone*, ZonesInState, JSRuntime*>; |
195 | |
196 | /* |
197 | * Cancel scheduled or in progress Ion compilations. |
198 | */ |
199 | void CancelOffThreadIonCompile(const CompilationSelector& selector); |
200 | |
201 | inline void CancelOffThreadIonCompile(JSScript* script) { |
202 | CancelOffThreadIonCompile(CompilationSelector(script)); |
203 | } |
204 | |
205 | inline void CancelOffThreadIonCompile(JS::Zone* zone) { |
206 | CancelOffThreadIonCompile(CompilationSelector(zone)); |
207 | } |
208 | |
209 | inline void CancelOffThreadIonCompile(JSRuntime* runtime, |
210 | JS::shadow::Zone::GCState state) { |
211 | CancelOffThreadIonCompile(CompilationSelector(ZonesInState{runtime, state})); |
212 | } |
213 | |
214 | inline void CancelOffThreadIonCompile(JSRuntime* runtime) { |
215 | CancelOffThreadIonCompile(CompilationSelector(runtime)); |
216 | } |
217 | |
218 | #ifdef DEBUG1 |
219 | bool HasOffThreadIonCompile(JS::Zone* zone); |
220 | #endif |
221 | |
222 | /* |
223 | * Cancel all scheduled or in progress eager delazification phases for a |
224 | * runtime. |
225 | */ |
226 | void CancelOffThreadDelazify(JSRuntime* runtime); |
227 | |
228 | /* |
229 | * Wait for all delazification to complete. |
230 | */ |
231 | void WaitForAllDelazifyTasks(JSRuntime* rt); |
232 | |
233 | // Start off-thread delazification task, to race the delazification of inner |
234 | // functions. |
235 | void StartOffThreadDelazification(JSContext* maybeCx, |
236 | const JS::ReadOnlyCompileOptions& options, |
237 | const frontend::CompilationStencil& stencil); |
238 | |
239 | // Drain the task queues and wait for all helper threads to finish running. |
240 | // |
241 | // Note that helper threads are shared between runtimes and it's possible that |
242 | // another runtime could saturate the helper thread system and cause this to |
243 | // never return. |
244 | void WaitForAllHelperThreads(); |
245 | void WaitForAllHelperThreads(AutoLockHelperThreadState& lock); |
246 | |
247 | // Enqueue a compression job to be processed later. These are started at the |
248 | // start of the major GC after the next one. |
249 | bool EnqueueOffThreadCompression(JSContext* cx, |
250 | UniquePtr<SourceCompressionTask> task); |
251 | |
252 | // Start handling any compression tasks for this runtime. Called at the start of |
253 | // major GC. |
254 | void StartHandlingCompressionsOnGC(JSRuntime* rt); |
255 | |
256 | // Cancel all scheduled, in progress, or finished compression tasks for |
257 | // runtime. |
258 | void CancelOffThreadCompressions(JSRuntime* runtime); |
259 | |
260 | void AttachFinishedCompressions(JSRuntime* runtime, |
261 | AutoLockHelperThreadState& lock); |
262 | |
263 | // Sweep pending tasks that are holding onto should-be-dead ScriptSources. |
264 | void SweepPendingCompressions(AutoLockHelperThreadState& lock); |
265 | |
266 | // Run all pending source compression tasks synchronously, for testing purposes |
267 | void RunPendingSourceCompressions(JSRuntime* runtime); |
268 | |
269 | // False if the off-thread source compression mechanism isn't being used. This |
270 | // happens on low core count machines where we are concerned about blocking |
271 | // main-thread execution. |
272 | bool IsOffThreadSourceCompressionEnabled(); |
273 | |
274 | } // namespace js |
275 | |
276 | #endif /* vm_HelperThreads_h */ |
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 threading_LockGuard_h | |||
8 | #define threading_LockGuard_h | |||
9 | ||||
10 | #include "mozilla/Attributes.h" | |||
11 | ||||
12 | namespace js { | |||
13 | ||||
14 | template <typename GuardT> | |||
15 | class MOZ_RAII UnlockGuard; | |||
16 | ||||
17 | template <typename Mutex> | |||
18 | class MOZ_RAII LockGuard { | |||
19 | friend class UnlockGuard<LockGuard<Mutex>>; | |||
20 | friend class ConditionVariable; | |||
21 | Mutex& mutex; | |||
22 | ||||
23 | public: | |||
24 | explicit LockGuard(Mutex& mutex) : mutex(mutex) { lock(); } | |||
25 | ~LockGuard() { unlock(); } | |||
26 | ||||
27 | LockGuard(const LockGuard& other) = delete; | |||
28 | ||||
29 | protected: | |||
30 | void lock() { mutex.lock(); } | |||
31 | void unlock() { mutex.unlock(); } | |||
| ||||
32 | }; | |||
33 | ||||
34 | // RAII class to temporarily unlock a LockGuard. | |||
35 | template <typename GuardT> | |||
36 | class MOZ_RAII UnlockGuard { | |||
37 | GuardT& guard; | |||
38 | ||||
39 | public: | |||
40 | explicit UnlockGuard(GuardT& guard) : guard(guard) { guard.unlock(); } | |||
41 | ~UnlockGuard() { guard.lock(); } | |||
42 | ||||
43 | UnlockGuard(const UnlockGuard& other) = delete; | |||
44 | }; | |||
45 | ||||
46 | } // namespace js | |||
47 | ||||
48 | #endif // threading_LockGuard_h |