| // Copyright 2019 The Dawn Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "dawn_native/BuddyMemoryAllocator.h" |
| |
| #include "common/Math.h" |
| #include "dawn_native/ResourceHeapAllocator.h" |
| |
| namespace dawn::native { |
| |
| BuddyMemoryAllocator::BuddyMemoryAllocator(uint64_t maxSystemSize, |
| uint64_t memoryBlockSize, |
| ResourceHeapAllocator* heapAllocator) |
| : mMemoryBlockSize(memoryBlockSize), |
| mBuddyBlockAllocator(maxSystemSize), |
| mHeapAllocator(heapAllocator) { |
| ASSERT(memoryBlockSize <= maxSystemSize); |
| ASSERT(IsPowerOfTwo(mMemoryBlockSize)); |
| ASSERT(maxSystemSize % mMemoryBlockSize == 0); |
| |
| mTrackedSubAllocations.resize(maxSystemSize / mMemoryBlockSize); |
| } |
| |
| uint64_t BuddyMemoryAllocator::GetMemoryIndex(uint64_t offset) const { |
| ASSERT(offset != BuddyAllocator::kInvalidOffset); |
| return offset / mMemoryBlockSize; |
| } |
| |
| ResultOrError<ResourceMemoryAllocation> BuddyMemoryAllocator::Allocate(uint64_t allocationSize, |
| uint64_t alignment) { |
| ResourceMemoryAllocation invalidAllocation = ResourceMemoryAllocation{}; |
| |
| if (allocationSize == 0) { |
| return std::move(invalidAllocation); |
| } |
| |
| // Check the unaligned size to avoid overflowing NextPowerOfTwo. |
| if (allocationSize > mMemoryBlockSize) { |
| return std::move(invalidAllocation); |
| } |
| |
| // Round allocation size to nearest power-of-two. |
| allocationSize = NextPowerOfTwo(allocationSize); |
| |
| // Allocation cannot exceed the memory size. |
| if (allocationSize > mMemoryBlockSize) { |
| return std::move(invalidAllocation); |
| } |
| |
| // Attempt to sub-allocate a block of the requested size. |
| const uint64_t blockOffset = mBuddyBlockAllocator.Allocate(allocationSize, alignment); |
| if (blockOffset == BuddyAllocator::kInvalidOffset) { |
| return std::move(invalidAllocation); |
| } |
| |
| const uint64_t memoryIndex = GetMemoryIndex(blockOffset); |
| if (mTrackedSubAllocations[memoryIndex].refcount == 0) { |
| // Transfer ownership to this allocator |
| std::unique_ptr<ResourceHeapBase> memory; |
| DAWN_TRY_ASSIGN(memory, mHeapAllocator->AllocateResourceHeap(mMemoryBlockSize)); |
| mTrackedSubAllocations[memoryIndex] = {/*refcount*/ 0, std::move(memory)}; |
| } |
| |
| mTrackedSubAllocations[memoryIndex].refcount++; |
| |
| AllocationInfo info; |
| info.mBlockOffset = blockOffset; |
| info.mMethod = AllocationMethod::kSubAllocated; |
| |
| // Allocation offset is always local to the memory. |
| const uint64_t memoryOffset = blockOffset % mMemoryBlockSize; |
| |
| return ResourceMemoryAllocation{ |
| info, memoryOffset, mTrackedSubAllocations[memoryIndex].mMemoryAllocation.get()}; |
| } |
| |
| void BuddyMemoryAllocator::Deallocate(const ResourceMemoryAllocation& allocation) { |
| const AllocationInfo info = allocation.GetInfo(); |
| |
| ASSERT(info.mMethod == AllocationMethod::kSubAllocated); |
| |
| const uint64_t memoryIndex = GetMemoryIndex(info.mBlockOffset); |
| |
| ASSERT(mTrackedSubAllocations[memoryIndex].refcount > 0); |
| mTrackedSubAllocations[memoryIndex].refcount--; |
| |
| if (mTrackedSubAllocations[memoryIndex].refcount == 0) { |
| mHeapAllocator->DeallocateResourceHeap( |
| std::move(mTrackedSubAllocations[memoryIndex].mMemoryAllocation)); |
| } |
| |
| mBuddyBlockAllocator.Deallocate(info.mBlockOffset); |
| } |
| |
| uint64_t BuddyMemoryAllocator::GetMemoryBlockSize() const { |
| return mMemoryBlockSize; |
| } |
| |
| uint64_t BuddyMemoryAllocator::ComputeTotalNumOfHeapsForTesting() const { |
| uint64_t count = 0; |
| for (const TrackedSubAllocations& allocation : mTrackedSubAllocations) { |
| if (allocation.refcount > 0) { |
| count++; |
| } |
| } |
| return count; |
| } |
| |
| } // namespace dawn::native |