| // 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" |
| |
| namespace dawn_native { |
| |
| BuddyMemoryAllocator::BuddyMemoryAllocator(uint64_t maxBlockSize, |
| uint64_t memorySize, |
| std::unique_ptr<MemoryAllocator> client) |
| : mMemorySize(memorySize), mBuddyBlockAllocator(maxBlockSize), mClient(std::move(client)) { |
| ASSERT(memorySize <= maxBlockSize); |
| ASSERT(IsPowerOfTwo(mMemorySize)); |
| ASSERT(maxBlockSize % mMemorySize == 0); |
| |
| mTrackedSubAllocations.resize(maxBlockSize / mMemorySize); |
| } |
| |
| uint64_t BuddyMemoryAllocator::GetMemoryIndex(uint64_t offset) const { |
| ASSERT(offset != BuddyAllocator::kInvalidOffset); |
| return offset / mMemorySize; |
| } |
| |
| ResultOrError<ResourceMemoryAllocation> BuddyMemoryAllocator::Allocate(uint64_t allocationSize, |
| uint64_t alignment, |
| int memoryFlags) { |
| ResourceMemoryAllocation invalidAllocation = ResourceMemoryAllocation{}; |
| |
| // Allocation cannot exceed the memory size. |
| if (allocationSize == 0 || allocationSize > mMemorySize) { |
| return invalidAllocation; |
| } |
| |
| // Attempt to sub-allocate a block of the requested size. |
| const uint64_t blockOffset = mBuddyBlockAllocator.Allocate(allocationSize, alignment); |
| if (blockOffset == BuddyAllocator::kInvalidOffset) { |
| return 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, mClient->Allocate(mMemorySize, memoryFlags)); |
| 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 % mMemorySize; |
| |
| return ResourceMemoryAllocation{ |
| info, memoryOffset, mTrackedSubAllocations[memoryIndex].mMemoryAllocation.get()}; |
| } // namespace dawn_native |
| |
| 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) { |
| mClient->Deallocate(std::move(mTrackedSubAllocations[memoryIndex].mMemoryAllocation)); |
| } |
| |
| mBuddyBlockAllocator.Deallocate(info.mBlockOffset); |
| } |
| |
| uint64_t BuddyMemoryAllocator::GetMemorySize() const { |
| return mMemorySize; |
| } |
| |
| uint64_t BuddyMemoryAllocator::ComputeTotalNumOfHeapsForTesting() const { |
| uint64_t count = 0; |
| for (const TrackedSubAllocations& allocation : mTrackedSubAllocations) { |
| if (allocation.refcount > 0) { |
| count++; |
| } |
| } |
| return count; |
| } |
| } // namespace dawn_native |