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// Copyright Epic Games, Inc. All Rights Reserved.
#include <zencore/intmath.h>
#include <zencore/memory.h>
#include <zencore/testing.h>
#include <zencore/zencore.h>
#if ZEN_PLATFORM_WINDOWS
# include <malloc.h>
ZEN_THIRD_PARTY_INCLUDES_START
# include <mimalloc.h>
ZEN_THIRD_PARTY_INCLUDES_END
#else
# include <cstdlib>
#endif
namespace zen {
//////////////////////////////////////////////////////////////////////////
static void*
AlignedAllocImpl(size_t Size, size_t Alignment)
{
#if ZEN_PLATFORM_WINDOWS
# if ZEN_USE_MIMALLOC && 0 /* this path is not functional */
return mi_aligned_alloc(Alignment, Size);
# else
return _aligned_malloc(Size, Alignment);
# endif
#else
// aligned_alloc() states that size must be a multiple of alignment. Some
// platforms return null if this requirement isn't met.
Size = (Size + Alignment - 1) & ~(Alignment - 1);
return std::aligned_alloc(Alignment, Size);
#endif
}
void
AlignedFreeImpl(void* ptr)
{
if (ptr == nullptr)
return;
#if ZEN_PLATFORM_WINDOWS
# if ZEN_USE_MIMALLOC && 0 /* this path is not functional */
return mi_free(ptr);
# else
_aligned_free(ptr);
# endif
#else
std::free(ptr);
#endif
}
//////////////////////////////////////////////////////////////////////////
MemoryArena::MemoryArena()
{
}
MemoryArena::~MemoryArena()
{
}
void*
MemoryArena::Alloc(size_t Size, size_t Alignment)
{
return AlignedAllocImpl(Size, Alignment);
}
void
MemoryArena::Free(void* ptr)
{
AlignedFreeImpl(ptr);
}
//////////////////////////////////////////////////////////////////////////
void*
Memory::Alloc(size_t Size, size_t Alignment)
{
return AlignedAllocImpl(Size, Alignment);
}
void
Memory::Free(void* ptr)
{
AlignedFreeImpl(ptr);
}
//////////////////////////////////////////////////////////////////////////
ChunkingLinearAllocator::ChunkingLinearAllocator(uint64_t ChunkSize, uint64_t ChunkAlignment)
: m_ChunkSize(ChunkSize)
, m_ChunkAlignment(ChunkAlignment)
{
}
ChunkingLinearAllocator::~ChunkingLinearAllocator()
{
Reset();
}
void
ChunkingLinearAllocator::Reset()
{
for (void* ChunkEntry : m_ChunkList)
{
Memory::Free(ChunkEntry);
}
m_ChunkList.clear();
m_ChunkCursor = nullptr;
m_ChunkBytesRemain = 0;
}
void*
ChunkingLinearAllocator::Alloc(size_t Size, size_t Alignment)
{
ZEN_ASSERT_SLOW(zen::IsPow2(Alignment));
// This could be improved in a bunch of ways
//
// * We pessimistically allocate memory even though there may be enough memory available for a single allocation due to the way we take
// alignment into account below
// * The block allocation size could be chosen to minimize slack for the case when multiple oversize allocations are made rather than
// minimizing the number of chunks
// * ...
const uint64_t AllocationSize = zen::RoundUp(Size, Alignment);
if (m_ChunkBytesRemain < (AllocationSize + Alignment - 1))
{
const uint64_t ChunkSize = zen::RoundUp(zen::Max(m_ChunkSize, Size), m_ChunkSize);
void* ChunkPtr = Memory::Alloc(ChunkSize, m_ChunkAlignment);
m_ChunkCursor = reinterpret_cast<uint8_t*>(ChunkPtr);
m_ChunkBytesRemain = ChunkSize;
m_ChunkList.push_back(ChunkPtr);
}
const uint64_t AlignFixup = (Alignment - reinterpret_cast<uintptr_t>(m_ChunkCursor)) & (Alignment - 1);
void* ReturnPtr = m_ChunkCursor + AlignFixup;
const uint64_t Delta = AlignFixup + AllocationSize;
ZEN_ASSERT_SLOW(m_ChunkBytesRemain >= Delta);
m_ChunkCursor += Delta;
m_ChunkBytesRemain -= Delta;
ZEN_ASSERT_SLOW(IsPointerAligned(ReturnPtr, Alignment));
return ReturnPtr;
}
//////////////////////////////////////////////////////////////////////////
//
// Unit tests
//
#if ZEN_WITH_TESTS
TEST_CASE("ChunkingLinearAllocator")
{
ChunkingLinearAllocator Allocator(4096);
void* p1 = Allocator.Alloc(1, 1);
void* p2 = Allocator.Alloc(1, 1);
CHECK(p1 != p2);
void* p3 = Allocator.Alloc(1, 4);
CHECK(IsPointerAligned(p3, 4));
void* p3_2 = Allocator.Alloc(1, 4);
CHECK(IsPointerAligned(p3_2, 4));
void* p4 = Allocator.Alloc(1, 8);
CHECK(IsPointerAligned(p4, 8));
for (int i = 0; i < 100; ++i)
{
void* p0 = Allocator.Alloc(64);
ZEN_UNUSED(p0);
}
}
TEST_CASE("MemoryView")
{
{
uint8_t Array1[16] = {};
MemoryView View1 = MakeMemoryView(Array1);
CHECK(View1.GetSize() == 16);
}
{
uint32_t Array2[16] = {};
MemoryView View2 = MakeMemoryView(Array2);
CHECK(View2.GetSize() == 64);
}
CHECK(MakeMemoryView<float>({1.0f, 1.2f}).GetSize() == 8);
}
void
memory_forcelink()
{
}
#endif
} // namespace zen
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