Code size analysis

pw_multibuf: A buffer API optimized for zero-copy messaging

The following table shows the code size cost of using pw_multibuf. These size reports compare a fake MultiBuf implementation against the v1 and v2 pw_multibuf implementations, and also compares the two pw_multibuf implementations against each other.

The scenarios being measured involve sending and receiving data using a fake protocol stack. At the lowest layer, “DemoLink” frames carry “DemoNetwork” packets, which in turn carry segments of a “DemoTransport” message. This layered protocol demonstrates how different MultiBuf implementations can handle data encapsulation and fragmentation.

The v0 implementation uses simple, contiguous spans of memory, requiring data to be copied at each protocol layer. In contrast, pw_multibuf is designed to avoid these copies. It allows for reserving space for headers and footers, and can represent data as a collection of discontiguous memory chunks. This reduces memory usage and improves performance by minimizing data movement.

The key difference between pw_multibuf v1 and v2 lies in their approach to memory management. Version 1 integrates memory allocation directly, with a MultiBufAllocator that handles the creation of MultiBuf objects. Version 2 separates memory allocation from the buffer logic, allowing users to provide their own allocation schemes. Additionally, v2 introduces the concept of “layers” to more explicitly manage different views of the data, such as protocol layers.

Label	Segment	Delta
Cost of using MultiBuf v1 vs. a fake implementation	FLASH +504 [section .rodata] DEL -424 pw::multibuf::size_report::ReceiverV0 DEL -424 pw::multibuf::size_report::SenderV0 +6 pw::multibuf::size_report::Sender<>::DoPend() +48 pw::multibuf::size_report::Receiver<>::DoPend() -4 pw::multibuf::size_report::Sender<>::MakeDemoLinkFrame() +8 pw::multibuf::size_report::TransferMessage() +32 pw::multibuf::size_report::TransferMessage<>() -12 pw::multibuf::size_report::Sender<>::MakeDemoTransportSegment() +52 pw::async2::ReceiveFuture<>::DoPend() -20 pw::multibuf::size_report::Receiver<>::HandleDemoLinkFrame() -2 pw::Allocator::DoReallocate() -4 pw::multibuf::size_report::Sender<>::MakeDemoNetworkPacket() DEL -100 pw::multibuf::size_report::FakeMultiBuf::PushBack() DEL -98 pw::multibuf::size_report::ReceiverV0::~ReceiverV0() DEL -98 pw::multibuf::size_report::SenderV0::~SenderV0() +40 pw::multibuf::size_report::FrameHandler<>::CalculateChecksum() +4 pw::multibuf::size_report::Receiver<>::HandleDemoNetworkPacket() DEL -92 pw::multibuf::size_report::SenderV0::SenderV0() DEL -88 pw::multibuf::size_report::ReceiverV0::ReceiverV0() DEL -72 pw::multibuf::size_report::FrameHandlerV0::DoAllocateFrame() -4 pw::multibuf::size_report::Receiver<>::HandleDemoTransportFirstSegment() +54 std::__2::__optional_destruct_base<>::~__optional_destruct_base[abi:nqn240000]() DEL -60 pw::multibuf::size_report::FakeMultiBuf::set_view() DEL -50 pw::multibuf::size_report::FrameHandlerV0::DoPushBack() +12 vPortSVCHandler_C +12 pw::containers::internal::GenericDeque<>::pop_front() +8 pw::multibuf::size_report::Receiver<>::~Receiver() +2 pw::containers::internal::GenericIntrusiveQueue::remove() -6 pw::multibuf::size_report::Receiver<>::Receiver<>() +40 pw::Result<>::operator->() -8 pw::async2::internal::BaseChannelStorage<>::BaseChannelStorage() +16 pw::multibuf::size_report::FrameHandler<>::Truncate() DEL -40 pw::multibuf::size_report::FrameHandlerV0::DoNarrow() +12 pw::async2::internal::Channel<>::PopAndWake() DEL -36 pw::multibuf::size_report::FrameHandlerV0::DoWiden() +2 std::__2::__optional_destruct_base<>::reset[abi:nqn240000]() DEL -34 memcmp +4 pw::FixedDeque<>::~FixedDeque() +20 std::__2::equal[abi:nqn240000]<>() +2 pw::containers::internal::GenericIntrusiveList<>::insert_after() DEL -28 pw::multibuf::size_report::FrameHandlerV0::DoTruncate() -2 pw::containers::internal::GenericIntrusiveList<>::~GenericIntrusiveList() +2 pw::containers::internal::GenericDeque<>::EmplaceBackUnchecked<>() -2 pw::containers::internal::IntrusiveListItemBase<>::~IntrusiveListItemBase() +2 pw::async2::Waker::~Waker() DEL -16 pw::multibuf::size_report::FrameHandlerV0::GetEnd() DEL -14 std::__2::__constexpr_memcmp_equal[abi:nqn240000]<>() +2 __llvm_libc_24_0_0_git::internal::exit() DEL -8 pw::multibuf::size_report::FrameHandlerV0::GetBegin() DEL -8 pw::multibuf::size_report::FrameHandlerV0::~FrameHandlerV0() NEW +424 pw::multibuf::size_report::ReceiverV1 NEW +424 pw::multibuf::size_report::SenderV1 NEW +372 xQueueSemaphoreTake NEW +336 pw::multibuf::v1::SimpleAllocator::DoAllocate() NEW +216 pw::multibuf::v1::SimpleAllocator::DoAllocate()::$_0::operator()() NEW +168 pw::multibuf::v1::SimpleAllocator::InternalAllocateContiguous()::$_0::operator()() NEW +168 vTaskPriorityDisinheritAfterTimeout NEW +162 pw::multibuf::v1::MultiBuf::CopyFromAndOptionallyTruncate() NEW +140 xTaskPriorityInherit NEW +120 pw::multibuf::v1::SimpleAllocator::InternalAllocateContiguous() NEW +120 pw::multibuf::v1::SimpleAllocator::SimpleAllocator() NEW +106 pw::multibuf::v1::Chunk::ClaimPrefix() NEW +106 pw::multibuf::v1::MultiBuf::CopyTo() NEW +104 pw::multibuf::v1::Chunk::Slice() NEW +102 pw::multibuf::v1::Chunk::ClaimSuffix() NEW +98 pw::multibuf::size_report::ReceiverV1::~ReceiverV1() NEW +98 pw::multibuf::size_report::SenderV1::~SenderV1() NEW +96 pw::multibuf::v1::MultiBuf::DiscardPrefix() NEW +94 pw::multibuf::v1::SimpleAllocator::InsertRegion() NEW +92 pw::multibuf::size_report::FrameHandlerV1::DoWiden() NEW +90 pw::multibuf::v1::Chunk::Free() NEW +90 pw::multibuf::v1::MultiBufAllocator::MoreMemoryAvailable() NEW +90 pw::multibuf::v1::SimpleAllocator::GetAvailableMemorySize() NEW +84 pw::multibuf::v1::MultiBuf::const_iterator::operator+=() NEW +82 pw::containers::internal::GenericDeque<>::contiguous_data() NEW +80 pw::Result<>::operator*() NEW +80 pw::multibuf::size_report::FrameHandlerV1::DoAllocateFrame() NEW +80 pw::multibuf::size_report::SenderV1::SenderV1() NEW +80 pw::multibuf::v1::MultiBuf::TruncateAfter() NEW +76 pw::multibuf::size_report::ReceiverV1::ReceiverV1() NEW +72 vQueueUnregisterQueue NEW +70 pw::multibuf::v1::ChunkRegionTracker::CreateFirstChunk() NEW +70 pw::multibuf::v1::internal::LinkedRegionTracker::~LinkedRegionTracker() NEW +68 std::__2::__equal_impl[abi:nqn240000]<>() NEW +66 pw::multibuf::v1::internal::LinkedRegionTracker::Destroy() NEW +62 pw::multibuf::v1::MultiBufAllocator::AllocateContiguous() NEW +60 pw::sync::Mutex::lock() NEW +60 pw::sync::Mutex::unlock() NEW +54 pw::multibuf::v1::SimpleAllocator::~SimpleAllocator() NEW +52 pw::multibuf::v1::MultiBuf::Truncate() NEW +52 pw::multibuf::v1::MultiBufChunks::push_front() NEW +52 pw::multibuf::v1::MultiBufChunks::take_front() NEW +44 pw::containers::internal::OptionalData<>::AssignState() NEW +44 pw::multibuf::size_report::FrameHandlerV1::DoNarrow() NEW +40 pw::Result<>::value() NEW +40 pw::allocator::BumpAllocator::BumpAllocator() NEW +40 pw::multibuf::v1::MultiBuf::const_iterator::operator++() NEW +40 vQueueDelete NEW +38 pw::multibuf::size_report::Receiver<>::TakeReceived() NEW +38 pw::multibuf::v1::MultiBufAllocator::~MultiBufAllocator() NEW +36 pw::Deallocator::DeleteArray<>() NEW +36 pw::containers::internal::GenericDeque<>::DestroyAll() NEW +36 pw::containers::internal::OptionalData<>::OptionalData() NEW +36 pw::multibuf::v1::internal::LinkedRegionTracker::LinkedRegionTracker() NEW +32 pw::containers::internal::OptionalData<>::Clear() NEW +32 pw::containers::internal::OptionalData<>::operator=() NEW +32 pw::multibuf::v1::ChunkRegionTracker NEW +32 pw::multibuf::v1::MultiBuf::begin() NEW +32 pw::multibuf::v1::MultiBufAllocator::MultiBufAllocator() NEW +32 pw::multibuf::v1::internal::LinkedRegionTracker NEW +28 pw::Allocator::New<>() NEW +28 pw::multibuf::v1::ChunkRegionTracker::~ChunkRegionTracker() NEW +28 pw::multibuf::v1::MultiBufChunks::PushSuffix() NEW +26 pw::multibuf::v1::MultiBuf::ClaimSuffix() NEW +24 prvIsQueueEmpty NEW +24 pw::containers::internal::OptionalData<>::Assign<>() NEW +24 pw::multibuf::size_report::FrameHandlerV1::DoPushBack() NEW +24 pw::multibuf::size_report::FrameHandlerV1::DoTruncate() NEW +24 pw::multibuf::v1::Chunk::RemoveFromRegionList() NEW +24 pw::multibuf::v1::ChunkRegionTracker::ChunkRegionTracker() NEW +24 pw::multibuf::v1::MultiBufAllocator NEW +24 pw::multibuf::v1::MultiBufChunks::operator=() NEW +24 pw::multibuf::v1::SimpleAllocator NEW +24 std::__2::__destroy[abi:nqn240000]<>() NEW +22 pw::multibuf::v1::MultiBuf::empty() NEW +22 pw::multibuf::v1::MultiBufChunks::Release() NEW +20 pvTaskIncrementMutexHeldCount NEW +20 pw::multibuf::size_report::FrameHandlerV1::GetBegin() NEW +20 pw::multibuf::v1::MultiBuf::const_iterator::AdvanceToData() NEW +20 pw::multibuf::v1::MultiBufChunks::size_bytes() NEW +20 pw::multibuf::v1::OwnedChunk::Release() NEW +20 pw::multibuf::v1::internal::LinkedRegionTracker::DeallocateChunkClass() NEW +20 std::__2::destroy_n[abi:nqn240000]<>() NEW +18 pw::containers::internal::GenericDeque<>::clear() NEW +18 pw::containers::internal::LegacyIntrusiveList<>::Item::~Item() NEW +18 pw::multibuf::v1::MultiBuf::ClaimPrefix() NEW +18 pw::multibuf::v1::internal::LinkedRegionTracker::AllocateChunkClass() NEW +16 pw::containers::internal::GenericIntrusiveList<>::clear() NEW +16 pw::containers::internal::LegacyIntrusiveList<>::~LegacyIntrusiveList() NEW +16 pw::multibuf::size_report::FrameHandlerV1::GetEnd() NEW +16 pw::multibuf::v1::MultiBuf::iterator::end() NEW +14 pw::multibuf::v1::MultiBuf::const_iterator::end() NEW +14 pw::multibuf::v1::SimpleAllocator::DoGetBackingCapacity() NEW +12 pw::multibuf::v1::Chunk::DiscardPrefix() NEW +12 pw::multibuf::v1::Chunk::Truncate() NEW +12 pw::multibuf::v1::MultiBuf::CopyFrom() NEW +12 pw::multibuf::v1::MultiBufChunks::back() NEW +10 pw::Deallocator::Delete<>() NEW +10 pw::multibuf::v1::internal::LinkedRegionTracker::Region() NEW +8 pw::multibuf::size_report::FrameHandlerV1::~FrameHandlerV1()	+5,680
	RAM NEW +1,024 pw::multibuf::size_report::metadata_region NEW +80 xQueueRegistry	+1,104
Cost of using MultiBuf v2 vs. a fake implementation	FLASH +1,280 [section .rodata] DEL -424 pw::multibuf::size_report::ReceiverV0 DEL -424 pw::multibuf::size_report::SenderV0 +6 pw::multibuf::size_report::Sender<>::DoPend() +30 pw::multibuf::size_report::Receiver<>::DoPend() -4 pw::multibuf::size_report::Sender<>::MakeDemoLinkFrame() +28 pw::multibuf::size_report::TransferMessage() +40 pw::multibuf::size_report::TransferMessage<>() -12 pw::multibuf::size_report::Sender<>::MakeDemoTransportSegment() +44 pw::async2::ReceiveFuture<>::DoPend() -20 pw::multibuf::size_report::Receiver<>::HandleDemoLinkFrame() -4 pw::multibuf::size_report::Sender<>::MakeDemoNetworkPacket() DEL -100 pw::multibuf::size_report::FakeMultiBuf::PushBack() DEL -98 pw::multibuf::size_report::ReceiverV0::~ReceiverV0() DEL -98 pw::multibuf::size_report::SenderV0::~SenderV0() +52 pw::multibuf::size_report::FrameHandler<>::CalculateChecksum() +4 pw::multibuf::size_report::Receiver<>::HandleDemoNetworkPacket() DEL -92 pw::multibuf::size_report::SenderV0::SenderV0() DEL -88 pw::multibuf::size_report::ReceiverV0::ReceiverV0() +72 pw::SharedPtr<>::reset() +2 pw::GetAlignedSubspan() DEL -72 pw::multibuf::size_report::FrameHandlerV0::DoAllocateFrame() -4 pw::multibuf::size_report::Receiver<>::HandleDemoTransportFirstSegment() +28 std::__2::__optional_destruct_base<>::~__optional_destruct_base[abi:nqn240000]() DEL -60 pw::multibuf::size_report::FakeMultiBuf::set_view() DEL -50 pw::multibuf::size_report::FrameHandlerV0::DoPushBack() +48 pw::containers::internal::GenericDeque<>::front() +56 pw::containers::internal::GenericDeque<>::pop_front() +8 pw::multibuf::size_report::Receiver<>::~Receiver() +10 pw::multibuf::size_report::Receiver<>::Receiver<>() +16 pw::multibuf::size_report::FrameHandler<>::Truncate() DEL -40 pw::multibuf::size_report::FrameHandlerV0::DoNarrow() -2 pw::async2::internal::BaseChannel::RemoveRefAndDestroyIfUnreferenced() +22 pw::async2::internal::Channel<>::PopAndWake() +60 pw::containers::internal::GenericDeque<>::try_emplace_back<>() DEL -36 pw::multibuf::size_report::FrameHandlerV0::DoWiden() +2 std::__2::__optional_destruct_base<>::reset[abi:nqn240000]() DEL -34 memcmp +4 pw::FixedDeque<>::~FixedDeque() +74 std::__2::equal[abi:nqn240000]<>() +4 __aeabi_dcmpun DEL -28 pw::multibuf::size_report::FrameHandlerV0::DoTruncate() +12 std::__2::__optional_storage_base<>::__construct[abi:nqn240000]<>() +46 pw::containers::internal::GenericDeque<>::EmplaceBackUnchecked<>() DEL -16 pw::multibuf::size_report::FrameHandlerV0::GetEnd() DEL -14 std::__2::__constexpr_memcmp_equal[abi:nqn240000]<>() +4 __bi_84 +2 __llvm_libc_24_0_0_git::internal::exit() +2 pw::allocator::AbstractAllocator::DoMeasureFragmentation() DEL -8 pw::multibuf::size_report::FrameHandlerV0::GetBegin() DEL -8 pw::multibuf::size_report::FrameHandlerV0::~FrameHandlerV0() -2 pw::multibuf::size_report::FrameHandler<>::~FrameHandler() NEW +716 pw::multibuf::v2::internal::GenericMultiBuf::Insert() NEW +484 pw::multibuf::v2::internal::GenericMultiBuf::AddLayer() NEW +424 pw::multibuf::size_report::ReceiverV2 NEW +424 pw::multibuf::size_report::SenderV2 NEW +272 pw::multibuf::v2::internal::GenericMultiBuf::PopLayer() NEW +260 pw::multibuf::v2::internal::GenericMultiBuf::InsertChunks() NEW +238 std::__2::__cxx_atomic_compare_exchange_weak[abi:nqn240000]<>() NEW +204 pw::multibuf::v2::internal::GenericMultiBuf::TruncateTopLayer() NEW +192 pw::multibuf::v2::internal::GenericMultiBuf::SplitAfter() NEW +180 pw::multibuf::v2::internal::GenericMultiBuf::TryReserveForInsert() NEW +166 pw::containers::internal::GenericDeque<>::contiguous_data() NEW +158 pw::multibuf::v2::internal::GenericMultiBuf::EraseRange() NEW +156 pw::containers::internal::GenericDeque<>::erase() NEW +156 pw::multibuf::v2::internal::GenericMultiBuf::ClearRange() NEW +148 pw::multibuf::v2::internal::GenericMultiBuf::SplitBase() NEW +148 pw::multibuf::v2::internal::operator-() NEW +144 pw::multibuf::v2::internal::BasicByteIterator::Increment() NEW +144 pw::multibuf::v2::internal::GenericMultiBuf::SplitBefore() NEW +136 pw::allocator::ChunkPool::ChunkPool() NEW +132 pw::multibuf::size_report::FrameHandlerV2::DoAllocateFrame() NEW +126 pw::DynamicDeque<>::ReallocateBuffer() NEW +120 pw::containers::internal::GenericDeque<>::operator[]() NEW +120 pw::multibuf::v2::internal::BasicByteIterator::Decrement() NEW +108 std::__2::__copy_move_unwrap_iters[abi:nqn240000]<>() NEW +104 pw::multibuf::v2::internal::CheckedCast<>() NEW +104 pw::multibuf::v2::internal::GenericMultiBuf::CopyToImpl() NEW +104 pw::multibuf::v2::internal::GenericMultiBuf::TryConvertToShared() NEW +102 pw::multibuf::v2::internal::GenericMultiBuf::CopyFrom() NEW +100 pw::multibuf::v2::internal::GenericMultiBuf::UnsealTopLayer() NEW +100 std::__2::__move_backward_impl<>::operator()[abi:nqn240000]<>() NEW +100 std::__2::__move_impl<>::operator()[abi:nqn240000]<>() NEW +98 pw::multibuf::size_report::ReceiverV2::~ReceiverV2() NEW +98 pw::multibuf::size_report::SenderV2::~SenderV2() NEW +96 pw::multibuf::size_report::ReceiverV2::ReceiverV2() NEW +96 pw::multibuf::size_report::SenderV2::SenderV2() NEW +92 pw::multibuf::v2::internal::GenericMultiBuf::Clear() NEW +88 pw::allocator::internal::ControlBlock::IncrementShared() NEW +82 pw::allocator::ChunkPool::DoGetInfo() NEW +80 pw::containers::internal::GenericDeque<>::push_back() NEW +80 pw::multibuf::v2::internal::GenericMultiBuf::TryReserveEntries() NEW +78 pw::multibuf::v2::internal::Entry::GetView() NEW +76 pw::DynamicDeque<>::try_reserve() NEW +74 pw::multibuf::v2::internal::BasicByteIterator::Compare() NEW +72 pw::allocator::Pool::NewArray<>() NEW +72 pw::allocator::internal::ControlBlock::ControlBlock() NEW +68 __atomic_compare_exchange_4 NEW +68 pw::DynamicDeque<>::IncreaseCapacity() NEW +68 std::__2::__equal_iter_impl[abi:nqn240000]<>() NEW +60 pw::multibuf::size_report::FrameHandlerV2::DoNarrow() NEW +56 pw::multibuf::v2::internal::ByteIterator<>::operator*() NEW +56 pw::multibuf::v2::internal::Entry::GetControlBlock() NEW +56 pw::multibuf::v2::internal::Entry::GetDeallocator() NEW +52 pw::allocator::Hardening::Multiply<>() NEW +52 pw::allocator::internal::ControlBlock::Create() NEW +52 pw::containers::internal::GenericDequeBase<>::AbsoluteIndexChecked() NEW +50 pw::multibuf::size_report::FrameHandlerV2::DoWiden() NEW +50 pw::multibuf::v2::BasicMultiBuf<>::PushBack() NEW +48 pw::multibuf::size_report::Receiver<>::TakeReceived() NEW +48 pw::multibuf::v2::BasicMultiBuf<>::PushBack<>() NEW +48 pw::multibuf::v2::internal::Entry::GetLength() NEW +48 pw::multibuf::v2::internal::Entry::GetOffset() NEW +46 pw::multibuf::v2::internal::operator+<>() NEW +44 pw::DynamicDeque<>::operator=() NEW +42 pw::multibuf::v2::internal::Entry::IsBoundary() NEW +40 pw::Result<>::value() NEW +40 pw::allocator::Layout::Of<>() NEW +38 pw::containers::internal::GenericDeque<>::DestroyAll() NEW +38 pw::multibuf::v2::internal::ByteIterator<>::operator ?<>() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::cend() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::operator=() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::size() NEW +36 pw::multibuf::v2::internal::BasicByteIterator::deque() NEW +36 std::__2::move[abi:nqn240000]<>() NEW +36 std::__2::move_backward[abi:nqn240000]<>() NEW +34 pw::UniquePtr<>::operator=<>() NEW +32 __atomic_load_4 NEW +32 pw::multibuf::v2::internal::GenericMultiBuf::GenericMultiBuf() NEW +30 pw::multibuf::v2::internal::Entry::IsSealed() NEW +28 pw::UniquePtr<>::Reset() NEW +28 pw::allocator::ChunkPool NEW +28 pw::allocator::Pool NEW +28 pw::containers::internal::GenericDequeBase<>::MoveAssignIndices() NEW +28 pw::multibuf::v2::internal::ByteIterator<>::operator++() NEW +28 pw::multibuf::v2::internal::GenericMultiBuf::end() NEW +26 pw::multibuf::v2::internal::GenericMultiBuf::cbegin() NEW +26 std::__2::optional<>::optional[abi:nqn240000]<>() NEW +24 pw::multibuf::size_report::FrameHandlerV2::DoPushBack() NEW +24 pw::multibuf::size_report::FrameHandlerV2::DoTruncate() NEW +24 pw::multibuf::v2::internal::operator!=() NEW +22 pw::DynamicDeque<>::~DynamicDeque() NEW +22 pw::allocator::Pool::MakeUnique<>() NEW +22 pw::containers::internal::GenericDeque<>::CheckCapacityAdd() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::GetLength() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::GetOffset() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::IsBoundary() NEW +20 pw::UniquePtr<>::UniquePtr<>() NEW +20 pw::multibuf::size_report::FrameHandlerV2::GetBegin() NEW +20 pw::multibuf::size_report::FrameHandlerV2::GetEnd() NEW +20 pw::multibuf::v2::internal::Entry::IsShared() NEW +20 std::__2::__destroy[abi:nqn240000]<>() NEW +20 std::__2::__optional_move_base<>::__optional_move_base[abi:nqn240000]() NEW +18 pw::DynamicDeque<>::try_reserve_exact() NEW +18 pw::containers::internal::GenericDeque<>::clear() NEW +18 pw::multibuf::v2::internal::Entry::IsOwned() NEW +18 pw::multibuf::v2::internal::GenericMultiBuf::MakeIterator() NEW +16 __aeabi_idivmod NEW +16 pw::multibuf::v2::internal::Entry::GetData() NEW +16 pw::multibuf::v2::internal::GenericMultiBuf::~GenericMultiBuf() NEW +14 pw::allocator::ChunkPool::DoAllocate() NEW +14 pw::containers::internal::GenericDeque<>::at() NEW +14 pw::multibuf::v2::internal::GenericMultiBuf::begin() NEW +14 std::__2::__optional_storage_base<>::__construct_from[abi:nqn240000]<>() NEW +12 pw::allocator::ChunkPool::DoDeallocate() NEW +12 pw::containers::internal::DequeIterator<>::operator*() NEW +12 pw::multibuf::v2::internal::ByteIterator<>::operator+=<>() NEW +12 pw::multibuf::v2::internal::GenericMultiBuf::CopyTo() NEW +12 pw::multibuf::v2::internal::GenericMultiBuf::IsOwned() NEW +12 std::__2::__atomic_base<>::compare_exchange_weak[abi:nqn240000]() NEW +10 pw::allocator::ChunkPool::~ChunkPool() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetControlBlock() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetData() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetDeallocator() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetView() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::IsSealed() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::IsShared() NEW +8 pw::allocator::internal::ControlBlockHandle::GetInstance_DO_NOT_USE() NEW +8 pw::multibuf::size_report::FrameHandlerV2::kLayout NEW +8 pw::multibuf::size_report::FrameHandlerV2::~FrameHandlerV2() NEW +6 pw::Deallocator::DoGetInfo() NEW +4 pw::allocator::internal::ControlBlockHandle::GetInstance_DO_NOT_USE()::kControlBlockHandle NEW +2 pw::Deallocator::~Deallocator() NEW +2 pw::allocator::Pool::~Pool()	+9,888
	RAM NEW +1,024 pw::multibuf::size_report::metadata_region	+1,024
Cost of using MultiBuf v2 vs. v1	FLASH +776 [section .rodata] DEL -424 pw::multibuf::size_report::ReceiverV1 DEL -424 pw::multibuf::size_report::SenderV1 DEL -372 xQueueSemaphoreTake DEL -336 pw::multibuf::v1::SimpleAllocator::DoAllocate() -18 pw::multibuf::size_report::Receiver<>::DoPend() DEL -216 pw::multibuf::v1::SimpleAllocator::DoAllocate()::$_0::operator()() -8 pw::async2::ReceiveFuture<>::DoPend() +8 pw::multibuf::size_report::TransferMessage<>() DEL -168 pw::multibuf::v1::SimpleAllocator::InternalAllocateContiguous()::$_0::operator()() DEL -168 vTaskPriorityDisinheritAfterTimeout DEL -162 pw::multibuf::v1::MultiBuf::CopyFromAndOptionallyTruncate() +20 pw::multibuf::size_report::TransferMessage() DEL -140 xTaskPriorityInherit +12 pw::multibuf::size_report::FrameHandler<>::CalculateChecksum() DEL -120 pw::multibuf::v1::SimpleAllocator::InternalAllocateContiguous() DEL -120 pw::multibuf::v1::SimpleAllocator::SimpleAllocator() -26 std::__2::__optional_destruct_base<>::~__optional_destruct_base[abi:nqn240000]() +2 pw::Allocator::DoReallocate() DEL -106 pw::multibuf::v1::Chunk::ClaimPrefix() DEL -106 pw::multibuf::v1::MultiBuf::CopyTo() DEL -104 pw::multibuf::v1::Chunk::Slice() DEL -102 pw::multibuf::v1::Chunk::ClaimSuffix() DEL -98 pw::multibuf::size_report::ReceiverV1::~ReceiverV1() DEL -98 pw::multibuf::size_report::SenderV1::~SenderV1() DEL -96 pw::multibuf::v1::MultiBuf::DiscardPrefix() DEL -94 pw::multibuf::v1::SimpleAllocator::InsertRegion() DEL -92 pw::multibuf::size_report::FrameHandlerV1::DoWiden() DEL -90 pw::multibuf::v1::Chunk::Free() DEL -90 pw::multibuf::v1::MultiBufAllocator::MoreMemoryAvailable() DEL -90 pw::multibuf::v1::SimpleAllocator::GetAvailableMemorySize() +72 pw::SharedPtr<>::reset() DEL -84 pw::multibuf::v1::MultiBuf::const_iterator::operator+=() +84 pw::containers::internal::GenericDeque<>::contiguous_data() DEL -80 pw::Result<>::operator*() -40 pw::Result<>::operator->() DEL -80 pw::multibuf::size_report::FrameHandlerV1::DoAllocateFrame() DEL -80 pw::multibuf::size_report::SenderV1::SenderV1() DEL -80 pw::multibuf::v1::MultiBuf::TruncateAfter() DEL -76 pw::multibuf::size_report::ReceiverV1::ReceiverV1() +2 pw::GetAlignedSubspan() DEL -72 vQueueUnregisterQueue DEL -70 pw::multibuf::v1::ChunkRegionTracker::CreateFirstChunk() DEL -70 pw::multibuf::v1::internal::LinkedRegionTracker::~LinkedRegionTracker() DEL -68 std::__2::__equal_impl[abi:nqn240000]<>() DEL -66 pw::multibuf::v1::internal::LinkedRegionTracker::Destroy() DEL -62 pw::multibuf::v1::MultiBufAllocator::AllocateContiguous() DEL -60 pw::sync::Mutex::lock() DEL -60 pw::sync::Mutex::unlock() -12 vPortSVCHandler_C +44 pw::containers::internal::GenericDeque<>::pop_front() DEL -54 pw::multibuf::v1::SimpleAllocator::~SimpleAllocator() DEL -52 pw::multibuf::v1::MultiBuf::Truncate() DEL -52 pw::multibuf::v1::MultiBufChunks::push_front() DEL -52 pw::multibuf::v1::MultiBufChunks::take_front() +54 std::__2::equal[abi:nqn240000]<>() +10 pw::async2::internal::Channel<>::PopAndWake() +48 pw::containers::internal::GenericDeque<>::front() -2 pw::containers::internal::GenericIntrusiveQueue::remove() DEL -44 pw::containers::internal::OptionalData<>::AssignState() DEL -44 pw::multibuf::size_report::FrameHandlerV1::DoNarrow() DEL -40 pw::allocator::BumpAllocator::BumpAllocator() DEL -40 pw::multibuf::v1::MultiBuf::const_iterator::operator++() DEL -40 vQueueDelete +10 pw::multibuf::size_report::Receiver<>::TakeReceived() DEL -38 pw::multibuf::v1::MultiBufAllocator::~MultiBufAllocator() DEL -36 pw::Deallocator::DeleteArray<>() -2 pw::async2::internal::BaseChannel::RemoveRefAndDestroyIfUnreferenced() +2 pw::containers::internal::GenericDeque<>::DestroyAll() +60 pw::containers::internal::GenericDeque<>::try_emplace_back<>() DEL -36 pw::containers::internal::OptionalData<>::OptionalData() +16 pw::multibuf::size_report::Receiver<>::Receiver<>() DEL -36 pw::multibuf::v1::internal::LinkedRegionTracker::LinkedRegionTracker() +8 pw::async2::internal::BaseChannelStorage<>::BaseChannelStorage() DEL -32 pw::containers::internal::OptionalData<>::Clear() DEL -32 pw::containers::internal::OptionalData<>::operator=() DEL -32 pw::multibuf::v1::ChunkRegionTracker DEL -32 pw::multibuf::v1::MultiBuf::begin() DEL -32 pw::multibuf::v1::MultiBufAllocator::MultiBufAllocator() DEL -32 pw::multibuf::v1::internal::LinkedRegionTracker -2 pw::containers::internal::GenericIntrusiveList<>::insert_after() +4 __aeabi_dcmpun DEL -28 pw::Allocator::New<>() DEL -28 pw::multibuf::v1::ChunkRegionTracker::~ChunkRegionTracker() DEL -28 pw::multibuf::v1::MultiBufChunks::PushSuffix() DEL -26 pw::multibuf::v1::MultiBuf::ClaimSuffix() DEL -24 prvIsQueueEmpty +44 pw::containers::internal::GenericDeque<>::EmplaceBackUnchecked<>() +2 pw::containers::internal::GenericIntrusiveList<>::~GenericIntrusiveList() DEL -24 pw::containers::internal::OptionalData<>::Assign<>() DEL -24 pw::multibuf::size_report::FrameHandlerV1::DoPushBack() DEL -24 pw::multibuf::size_report::FrameHandlerV1::DoTruncate() DEL -24 pw::multibuf::v1::Chunk::RemoveFromRegionList() DEL -24 pw::multibuf::v1::ChunkRegionTracker::ChunkRegionTracker() DEL -24 pw::multibuf::v1::MultiBufAllocator DEL -24 pw::multibuf::v1::MultiBufChunks::operator=() DEL -24 pw::multibuf::v1::SimpleAllocator -4 std::__2::__destroy[abi:nqn240000]<>() +12 std::__2::__optional_storage_base<>::__construct[abi:nqn240000]<>() DEL -22 pw::multibuf::v1::MultiBuf::empty() DEL -22 pw::multibuf::v1::MultiBufChunks::Release() DEL -20 pvTaskIncrementMutexHeldCount +2 pw::containers::internal::IntrusiveListItemBase<>::~IntrusiveListItemBase() DEL -20 pw::multibuf::size_report::FrameHandlerV1::GetBegin() DEL -20 pw::multibuf::v1::MultiBuf::const_iterator::AdvanceToData() DEL -20 pw::multibuf::v1::MultiBufChunks::size_bytes() DEL -20 pw::multibuf::v1::OwnedChunk::Release() DEL -20 pw::multibuf::v1::internal::LinkedRegionTracker::DeallocateChunkClass() DEL -20 std::__2::destroy_n[abi:nqn240000]<>() -2 pw::async2::Waker::~Waker() DEL -18 pw::containers::internal::LegacyIntrusiveList<>::Item::~Item() DEL -18 pw::multibuf::v1::MultiBuf::ClaimPrefix() DEL -18 pw::multibuf::v1::internal::LinkedRegionTracker::AllocateChunkClass() DEL -16 pw::containers::internal::GenericIntrusiveList<>::clear() DEL -16 pw::containers::internal::LegacyIntrusiveList<>::~LegacyIntrusiveList() DEL -16 pw::multibuf::size_report::FrameHandlerV1::GetEnd() DEL -16 pw::multibuf::v1::MultiBuf::iterator::end() DEL -14 pw::multibuf::v1::MultiBuf::const_iterator::end() DEL -14 pw::multibuf::v1::SimpleAllocator::DoGetBackingCapacity() +4 __bi_84 DEL -12 pw::multibuf::v1::Chunk::DiscardPrefix() DEL -12 pw::multibuf::v1::Chunk::Truncate() DEL -12 pw::multibuf::v1::MultiBuf::CopyFrom() DEL -12 pw::multibuf::v1::MultiBufChunks::back() DEL -10 pw::Deallocator::Delete<>() DEL -10 pw::multibuf::v1::internal::LinkedRegionTracker::Region() +2 pw::allocator::AbstractAllocator::DoMeasureFragmentation() DEL -8 pw::multibuf::size_report::FrameHandlerV1::~FrameHandlerV1() -2 pw::multibuf::size_report::FrameHandler<>::~FrameHandler() NEW +716 pw::multibuf::v2::internal::GenericMultiBuf::Insert() NEW +484 pw::multibuf::v2::internal::GenericMultiBuf::AddLayer() NEW +424 pw::multibuf::size_report::ReceiverV2 NEW +424 pw::multibuf::size_report::SenderV2 NEW +272 pw::multibuf::v2::internal::GenericMultiBuf::PopLayer() NEW +260 pw::multibuf::v2::internal::GenericMultiBuf::InsertChunks() NEW +238 std::__2::__cxx_atomic_compare_exchange_weak[abi:nqn240000]<>() NEW +204 pw::multibuf::v2::internal::GenericMultiBuf::TruncateTopLayer() NEW +192 pw::multibuf::v2::internal::GenericMultiBuf::SplitAfter() NEW +180 pw::multibuf::v2::internal::GenericMultiBuf::TryReserveForInsert() NEW +158 pw::multibuf::v2::internal::GenericMultiBuf::EraseRange() NEW +156 pw::containers::internal::GenericDeque<>::erase() NEW +156 pw::multibuf::v2::internal::GenericMultiBuf::ClearRange() NEW +148 pw::multibuf::v2::internal::GenericMultiBuf::SplitBase() NEW +148 pw::multibuf::v2::internal::operator-() NEW +144 pw::multibuf::v2::internal::BasicByteIterator::Increment() NEW +144 pw::multibuf::v2::internal::GenericMultiBuf::SplitBefore() NEW +136 pw::allocator::ChunkPool::ChunkPool() NEW +132 pw::multibuf::size_report::FrameHandlerV2::DoAllocateFrame() NEW +126 pw::DynamicDeque<>::ReallocateBuffer() NEW +120 pw::containers::internal::GenericDeque<>::operator[]() NEW +120 pw::multibuf::v2::internal::BasicByteIterator::Decrement() NEW +108 std::__2::__copy_move_unwrap_iters[abi:nqn240000]<>() NEW +104 pw::multibuf::v2::internal::CheckedCast<>() NEW +104 pw::multibuf::v2::internal::GenericMultiBuf::CopyToImpl() NEW +104 pw::multibuf::v2::internal::GenericMultiBuf::TryConvertToShared() NEW +102 pw::multibuf::v2::internal::GenericMultiBuf::CopyFrom() NEW +100 pw::multibuf::v2::internal::GenericMultiBuf::UnsealTopLayer() NEW +100 std::__2::__move_backward_impl<>::operator()[abi:nqn240000]<>() NEW +100 std::__2::__move_impl<>::operator()[abi:nqn240000]<>() NEW +98 pw::multibuf::size_report::ReceiverV2::~ReceiverV2() NEW +98 pw::multibuf::size_report::SenderV2::~SenderV2() NEW +96 pw::multibuf::size_report::ReceiverV2::ReceiverV2() NEW +96 pw::multibuf::size_report::SenderV2::SenderV2() NEW +92 pw::multibuf::v2::internal::GenericMultiBuf::Clear() NEW +88 pw::allocator::internal::ControlBlock::IncrementShared() NEW +82 pw::allocator::ChunkPool::DoGetInfo() NEW +80 pw::containers::internal::GenericDeque<>::push_back() NEW +80 pw::multibuf::v2::internal::GenericMultiBuf::TryReserveEntries() NEW +78 pw::multibuf::v2::internal::Entry::GetView() NEW +76 pw::DynamicDeque<>::try_reserve() NEW +74 pw::multibuf::v2::internal::BasicByteIterator::Compare() NEW +72 pw::allocator::Pool::NewArray<>() NEW +72 pw::allocator::internal::ControlBlock::ControlBlock() NEW +68 __atomic_compare_exchange_4 NEW +68 pw::DynamicDeque<>::IncreaseCapacity() NEW +68 std::__2::__equal_iter_impl[abi:nqn240000]<>() NEW +60 pw::multibuf::size_report::FrameHandlerV2::DoNarrow() NEW +56 pw::multibuf::v2::internal::ByteIterator<>::operator*() NEW +56 pw::multibuf::v2::internal::Entry::GetControlBlock() NEW +56 pw::multibuf::v2::internal::Entry::GetDeallocator() NEW +52 pw::allocator::Hardening::Multiply<>() NEW +52 pw::allocator::internal::ControlBlock::Create() NEW +52 pw::containers::internal::GenericDequeBase<>::AbsoluteIndexChecked() NEW +50 pw::multibuf::size_report::FrameHandlerV2::DoWiden() NEW +50 pw::multibuf::v2::BasicMultiBuf<>::PushBack() NEW +48 pw::multibuf::v2::BasicMultiBuf<>::PushBack<>() NEW +48 pw::multibuf::v2::internal::Entry::GetLength() NEW +48 pw::multibuf::v2::internal::Entry::GetOffset() NEW +46 pw::multibuf::v2::internal::operator+<>() NEW +44 pw::DynamicDeque<>::operator=() NEW +42 pw::multibuf::v2::internal::Entry::IsBoundary() NEW +40 pw::allocator::Layout::Of<>() NEW +38 pw::multibuf::v2::internal::ByteIterator<>::operator ?<>() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::cend() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::operator=() NEW +38 pw::multibuf::v2::internal::GenericMultiBuf::size() NEW +36 pw::multibuf::v2::internal::BasicByteIterator::deque() NEW +36 std::__2::move[abi:nqn240000]<>() NEW +36 std::__2::move_backward[abi:nqn240000]<>() NEW +34 pw::UniquePtr<>::operator=<>() NEW +32 __atomic_load_4 NEW +32 pw::multibuf::v2::internal::GenericMultiBuf::GenericMultiBuf() NEW +30 pw::multibuf::v2::internal::Entry::IsSealed() NEW +28 pw::UniquePtr<>::Reset() NEW +28 pw::allocator::ChunkPool NEW +28 pw::allocator::Pool NEW +28 pw::containers::internal::GenericDequeBase<>::MoveAssignIndices() NEW +28 pw::multibuf::v2::internal::ByteIterator<>::operator++() NEW +28 pw::multibuf::v2::internal::GenericMultiBuf::end() NEW +26 pw::multibuf::v2::internal::GenericMultiBuf::cbegin() NEW +26 std::__2::optional<>::optional[abi:nqn240000]<>() NEW +24 pw::multibuf::size_report::FrameHandlerV2::DoPushBack() NEW +24 pw::multibuf::size_report::FrameHandlerV2::DoTruncate() NEW +24 pw::multibuf::v2::internal::operator!=() NEW +22 pw::DynamicDeque<>::~DynamicDeque() NEW +22 pw::allocator::Pool::MakeUnique<>() NEW +22 pw::containers::internal::GenericDeque<>::CheckCapacityAdd() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::GetLength() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::GetOffset() NEW +22 pw::multibuf::v2::internal::GenericMultiBuf::IsBoundary() NEW +20 pw::UniquePtr<>::UniquePtr<>() NEW +20 pw::multibuf::size_report::FrameHandlerV2::GetBegin() NEW +20 pw::multibuf::size_report::FrameHandlerV2::GetEnd() NEW +20 pw::multibuf::v2::internal::Entry::IsShared() NEW +20 std::__2::__optional_move_base<>::__optional_move_base[abi:nqn240000]() NEW +18 pw::DynamicDeque<>::try_reserve_exact() NEW +18 pw::multibuf::v2::internal::Entry::IsOwned() NEW +18 pw::multibuf::v2::internal::GenericMultiBuf::MakeIterator() NEW +16 __aeabi_idivmod NEW +16 pw::multibuf::v2::internal::Entry::GetData() NEW +16 pw::multibuf::v2::internal::GenericMultiBuf::~GenericMultiBuf() NEW +14 pw::allocator::ChunkPool::DoAllocate() NEW +14 pw::containers::internal::GenericDeque<>::at() NEW +14 pw::multibuf::v2::internal::GenericMultiBuf::begin() NEW +14 std::__2::__optional_storage_base<>::__construct_from[abi:nqn240000]<>() NEW +12 pw::allocator::ChunkPool::DoDeallocate() NEW +12 pw::containers::internal::DequeIterator<>::operator*() NEW +12 pw::multibuf::v2::internal::ByteIterator<>::operator+=<>() NEW +12 pw::multibuf::v2::internal::GenericMultiBuf::CopyTo() NEW +12 pw::multibuf::v2::internal::GenericMultiBuf::IsOwned() NEW +12 std::__2::__atomic_base<>::compare_exchange_weak[abi:nqn240000]() NEW +10 pw::allocator::ChunkPool::~ChunkPool() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetControlBlock() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetData() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetDeallocator() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::GetView() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::IsSealed() NEW +10 pw::multibuf::v2::internal::GenericMultiBuf::IsShared() NEW +8 pw::allocator::internal::ControlBlockHandle::GetInstance_DO_NOT_USE() NEW +8 pw::multibuf::size_report::FrameHandlerV2::kLayout NEW +8 pw::multibuf::size_report::FrameHandlerV2::~FrameHandlerV2() NEW +6 pw::Deallocator::DoGetInfo() NEW +4 pw::allocator::internal::ControlBlockHandle::GetInstance_DO_NOT_USE()::kControlBlockHandle NEW +2 pw::Deallocator::~Deallocator() NEW +2 pw::allocator::Pool::~Pool()	+4,208
	RAM DEL -80 xQueueRegistry	-80