| // 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 <vector> |
| |
| #include "dawn/native/BuddyAllocator.h" |
| #include "gtest/gtest.h" |
| |
| namespace dawn::native { |
| |
| constexpr uint64_t BuddyAllocator::kInvalidOffset; |
| |
| // Verify the buddy allocator with a basic test. |
| TEST(BuddyAllocatorTests, SingleBlock) { |
| // After one 32 byte allocation: |
| // |
| // Level -------------------------------- |
| // 0 32 | A | |
| // -------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 32; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| // Check that we cannot allocate a oversized block. |
| ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), BuddyAllocator::kInvalidOffset); |
| |
| // Check that we cannot allocate a zero sized block. |
| ASSERT_EQ(allocator.Allocate(0u), BuddyAllocator::kInvalidOffset); |
| |
| // Allocate the block. |
| uint64_t blockOffset = allocator.Allocate(maxBlockSize); |
| ASSERT_EQ(blockOffset, 0u); |
| |
| // Check that we are full. |
| ASSERT_EQ(allocator.Allocate(maxBlockSize), BuddyAllocator::kInvalidOffset); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u); |
| |
| // Deallocate the block. |
| allocator.Deallocate(blockOffset); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| } |
| |
| // Verify multiple allocations succeeds using a buddy allocator. |
| TEST(BuddyAllocatorTests, MultipleBlocks) { |
| // Fill every level in the allocator (order-n = 2^n) |
| const uint64_t maxBlockSize = (1ull << 16); |
| for (uint64_t order = 1; (1ull << order) <= maxBlockSize; order++) { |
| BuddyAllocator allocator(maxBlockSize); |
| |
| uint64_t blockSize = (1ull << order); |
| for (uint32_t blocki = 0; blocki < (maxBlockSize / blockSize); blocki++) { |
| ASSERT_EQ(allocator.Allocate(blockSize), blockSize * blocki); |
| } |
| } |
| } |
| |
| // Verify that a single allocation succeeds using a buddy allocator. |
| TEST(BuddyAllocatorTests, SingleSplitBlock) { |
| // After one 8 byte allocation: |
| // |
| // Level -------------------------------- |
| // 0 32 | S | |
| // -------------------------------- |
| // 1 16 | S | F | S - split |
| // -------------------------------- F - free |
| // 2 8 | A | F | | | A - allocated |
| // -------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 32; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| // Allocate block (splits two blocks). |
| uint64_t blockOffset = allocator.Allocate(8); |
| ASSERT_EQ(blockOffset, 0u); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Deallocate block (merges two blocks). |
| allocator.Deallocate(blockOffset); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Check that we cannot allocate a block that is oversized. |
| ASSERT_EQ(allocator.Allocate(maxBlockSize * 2), BuddyAllocator::kInvalidOffset); |
| |
| // Re-allocate the largest block allowed after merging. |
| blockOffset = allocator.Allocate(maxBlockSize); |
| ASSERT_EQ(blockOffset, 0u); |
| |
| allocator.Deallocate(blockOffset); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| } |
| |
| // Verify that a multiple allocated blocks can be removed in the free-list. |
| TEST(BuddyAllocatorTests, MultipleSplitBlocks) { |
| // After four 16 byte allocations: |
| // |
| // Level -------------------------------- |
| // 0 32 | S | |
| // -------------------------------- |
| // 1 16 | S | S | S - split |
| // -------------------------------- F - free |
| // 2 8 | Aa | Ab | Ac | Ad | A - allocated |
| // -------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 32; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| // Populates the free-list with four blocks at Level2. |
| |
| // Allocate "a" block (two splits). |
| constexpr uint64_t blockSizeInBytes = 8; |
| uint64_t blockOffsetA = allocator.Allocate(blockSizeInBytes); |
| ASSERT_EQ(blockOffsetA, 0u); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Allocate "b" block. |
| uint64_t blockOffsetB = allocator.Allocate(blockSizeInBytes); |
| ASSERT_EQ(blockOffsetB, blockSizeInBytes); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Allocate "c" block (three splits). |
| uint64_t blockOffsetC = allocator.Allocate(blockSizeInBytes); |
| ASSERT_EQ(blockOffsetC, blockOffsetB + blockSizeInBytes); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Allocate "d" block. |
| uint64_t blockOffsetD = allocator.Allocate(blockSizeInBytes); |
| ASSERT_EQ(blockOffsetD, blockOffsetC + blockSizeInBytes); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u); |
| |
| // Deallocate "d" block. |
| // FreeList[Level2] = [BlockD] -> x |
| allocator.Deallocate(blockOffsetD); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Deallocate "b" block. |
| // FreeList[Level2] = [BlockB] -> [BlockD] -> x |
| allocator.Deallocate(blockOffsetB); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Deallocate "c" block (one merges). |
| // FreeList[Level1] = [BlockCD] -> x |
| // FreeList[Level2] = [BlockB] -> x |
| allocator.Deallocate(blockOffsetC); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Deallocate "a" block (two merges). |
| // FreeList[Level0] = [BlockABCD] -> x |
| allocator.Deallocate(blockOffsetA); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| } |
| |
| // Verify the buddy allocator can handle allocations of various sizes. |
| TEST(BuddyAllocatorTests, MultipleSplitBlockIncreasingSize) { |
| // After four Level4-to-Level1 byte then one L4 block allocations: |
| // |
| // Level ----------------------------------------------------------------- |
| // 0 512 | S | |
| // ----------------------------------------------------------------- |
| // 1 256 | S | A | |
| // ----------------------------------------------------------------- |
| // 2 128 | S | A | | | |
| // ----------------------------------------------------------------- |
| // 3 64 | S | A | | | | | | | |
| // ----------------------------------------------------------------- |
| // 4 32 | A | F | | | | | | | | | | | | | | | |
| // ----------------------------------------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 512; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| ASSERT_EQ(allocator.Allocate(32), 0ull); |
| ASSERT_EQ(allocator.Allocate(64), 64ull); |
| ASSERT_EQ(allocator.Allocate(128), 128ull); |
| ASSERT_EQ(allocator.Allocate(256), 256ull); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Fill in the last free block. |
| ASSERT_EQ(allocator.Allocate(32), 32ull); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u); |
| |
| // Check if we're full. |
| ASSERT_EQ(allocator.Allocate(32), BuddyAllocator::kInvalidOffset); |
| } |
| |
| // Verify very small allocations using a larger allocator works correctly. |
| TEST(BuddyAllocatorTests, MultipleSplitBlocksVariableSizes) { |
| // After allocating four pairs of one 64 byte block and one 32 byte block. |
| // |
| // Level ----------------------------------------------------------------- |
| // 0 512 | S | |
| // ----------------------------------------------------------------- |
| // 1 256 | S | S | |
| // ----------------------------------------------------------------- |
| // 2 128 | S | S | S | F | |
| // ----------------------------------------------------------------- |
| // 3 64 | A | S | A | A | S | A | | | |
| // ----------------------------------------------------------------- |
| // 4 32 | | | A | A | | | | | A | A | | | | | | | |
| // ----------------------------------------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 512; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| ASSERT_EQ(allocator.Allocate(64), 0ull); |
| ASSERT_EQ(allocator.Allocate(32), 64ull); |
| |
| ASSERT_EQ(allocator.Allocate(64), 128ull); |
| ASSERT_EQ(allocator.Allocate(32), 96ull); |
| |
| ASSERT_EQ(allocator.Allocate(64), 192ull); |
| ASSERT_EQ(allocator.Allocate(32), 256ull); |
| |
| ASSERT_EQ(allocator.Allocate(64), 320ull); |
| ASSERT_EQ(allocator.Allocate(32), 288ull); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| } |
| |
| // Verify the buddy allocator can deal with bad fragmentation. |
| TEST(BuddyAllocatorTests, MultipleSplitBlocksInterleaved) { |
| // Allocate every leaf then de-allocate every other of those allocations. |
| // |
| // Level ----------------------------------------------------------------- |
| // 0 512 | S | |
| // ----------------------------------------------------------------- |
| // 1 256 | S | S | |
| // ----------------------------------------------------------------- |
| // 2 128 | S | S | S | S | |
| // ----------------------------------------------------------------- |
| // 3 64 | S | S | S | S | S | S | S | S | |
| // ----------------------------------------------------------------- |
| // 4 32 | A | F | A | F | A | F | A | F | A | F | A | F | A | F | A | F | |
| // ----------------------------------------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 512; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| // Allocate leaf blocks |
| constexpr uint64_t minBlockSizeInBytes = 32; |
| std::vector<uint64_t> blockOffsets; |
| for (uint64_t i = 0; i < maxBlockSize / minBlockSizeInBytes; i++) { |
| blockOffsets.push_back(allocator.Allocate(minBlockSizeInBytes)); |
| } |
| |
| // Free every other leaf block. |
| for (size_t count = 1; count < blockOffsets.size(); count += 2) { |
| allocator.Deallocate(blockOffsets[count]); |
| } |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 8u); |
| } |
| |
| // Verify the buddy allocator can deal with multiple allocations with mixed alignments. |
| TEST(BuddyAllocatorTests, SameSizeVariousAlignment) { |
| // After two 8 byte allocations with 16 byte alignment then one 8 byte allocation with 8 |
| // byte alignment. |
| // |
| // Level -------------------------------- |
| // 0 32 | S | |
| // -------------------------------- |
| // 1 16 | S | S | S - split |
| // -------------------------------- F - free |
| // 2 8 | Aa | F | Ab | Ac | A - allocated |
| // -------------------------------- |
| // |
| BuddyAllocator allocator(32); |
| |
| // Allocate Aa (two splits). |
| ASSERT_EQ(allocator.Allocate(8, 16), 0u); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Allocate Ab (skip Aa buddy due to alignment and perform another split). |
| ASSERT_EQ(allocator.Allocate(8, 16), 16u); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Check that we cannot fit another. |
| ASSERT_EQ(allocator.Allocate(8, 16), BuddyAllocator::kInvalidOffset); |
| |
| // Allocate Ac (zero splits and Ab's buddy is now the first free block). |
| ASSERT_EQ(allocator.Allocate(8, 8), 24u); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| } |
| |
| // Verify the buddy allocator can deal with multiple allocations with equal alignments. |
| TEST(BuddyAllocatorTests, VariousSizeSameAlignment) { |
| // After two 8 byte allocations with 4 byte alignment then one 16 byte allocation with 4 |
| // byte alignment. |
| // |
| // Level -------------------------------- |
| // 0 32 | S | |
| // -------------------------------- |
| // 1 16 | S | Ac | S - split |
| // -------------------------------- F - free |
| // 2 8 | Aa | Ab | | A - allocated |
| // -------------------------------- |
| // |
| constexpr uint64_t maxBlockSize = 32; |
| constexpr uint64_t alignment = 4; |
| BuddyAllocator allocator(maxBlockSize); |
| |
| // Allocate block Aa (two splits) |
| ASSERT_EQ(allocator.Allocate(8, alignment), 0u); |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 2u); |
| |
| // Allocate block Ab (Aa's buddy) |
| ASSERT_EQ(allocator.Allocate(8, alignment), 8u); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 1u); |
| |
| // Check that we can still allocate Ac. |
| ASSERT_EQ(allocator.Allocate(16, alignment), 16ull); |
| |
| ASSERT_EQ(allocator.ComputeTotalNumOfFreeBlocksForTesting(), 0u); |
| } |
| |
| } // namespace dawn::native |