0ca91ced2d
VirtualBuffer makes use of VirtualAlloc (on Windows) and mmap() (on other platforms). Neither of these ensure that non-trivial objects are properly constructed in the allocated memory. To prevent potential undefined behavior occurring due to that, we can add a static assert to loudly complain about cases where that is done.
77 lines
2.1 KiB
C++
77 lines
2.1 KiB
C++
// Copyright 2020 yuzu Emulator Project
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// Licensed under GPLv2 or any later version
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// Refer to the license.txt file included.
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#pragma once
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#include <type_traits>
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#include <utility>
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namespace Common {
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void* AllocateMemoryPages(std::size_t size) noexcept;
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void FreeMemoryPages(void* base, std::size_t size) noexcept;
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template <typename T>
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class VirtualBuffer final {
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public:
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static_assert(
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std::is_trivially_constructible_v<T>,
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"T must be trivially constructible, as non-trivial constructors will not be executed "
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"with the current allocator");
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constexpr VirtualBuffer() = default;
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explicit VirtualBuffer(std::size_t count) : alloc_size{count * sizeof(T)} {
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base_ptr = reinterpret_cast<T*>(AllocateMemoryPages(alloc_size));
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}
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~VirtualBuffer() noexcept {
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FreeMemoryPages(base_ptr, alloc_size);
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}
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VirtualBuffer(const VirtualBuffer&) = delete;
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VirtualBuffer& operator=(const VirtualBuffer&) = delete;
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VirtualBuffer(VirtualBuffer&& other) noexcept
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: alloc_size{std::exchange(other.alloc_size, 0)}, base_ptr{std::exchange(other.base_ptr),
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nullptr} {}
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VirtualBuffer& operator=(VirtualBuffer&& other) noexcept {
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alloc_size = std::exchange(other.alloc_size, 0);
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base_ptr = std::exchange(other.base_ptr, nullptr);
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return *this;
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}
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void resize(std::size_t count) {
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FreeMemoryPages(base_ptr, alloc_size);
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alloc_size = count * sizeof(T);
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base_ptr = reinterpret_cast<T*>(AllocateMemoryPages(alloc_size));
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}
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[[nodiscard]] constexpr const T& operator[](std::size_t index) const {
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return base_ptr[index];
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}
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[[nodiscard]] constexpr T& operator[](std::size_t index) {
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return base_ptr[index];
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}
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[[nodiscard]] constexpr T* data() {
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return base_ptr;
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}
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[[nodiscard]] constexpr const T* data() const {
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return base_ptr;
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}
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[[nodiscard]] constexpr std::size_t size() const {
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return alloc_size / sizeof(T);
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}
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private:
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std::size_t alloc_size{};
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T* base_ptr{};
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};
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} // namespace Common
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