Merge "[adb] Optimize adbd's usb reading" (faa9de52) · Commits · e / os / android_system_core

adb/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -134,6 +134,7 @@ libadb_srcs = [
		"transport_fd.cpp",
		"transport_local.cpp",
		"transport_usb.cpp",
		"types.cpp",
		]

		libadb_posix_srcs = [

adb/daemon/usb.cpp

+60 −48

Original line number	Diff line number	Diff line
		@@ -117,14 +117,18 @@ struct TransferId {
		}
		};

		template <class Payload>
		struct IoBlock {
		bool pending = false;
		struct iocb control = {};
		std::shared_ptr<Block> payload;
		Payload payload;

		TransferId id() const { return TransferId::from_value(control.aio_data); }
		};

		using IoReadBlock = IoBlock<Block>;
		using IoWriteBlock = IoBlock<std::shared_ptr<Block>>;

		struct ScopedAioContext {
		ScopedAioContext() = default;
		~ScopedAioContext() { reset(); }
		@@ -208,16 +212,17 @@ struct UsbFfsConnection : public Connection {

		virtual bool Write(std::unique_ptr<apacket> packet) override final {
		LOG(DEBUG) << "USB write: " << dump_header(&packet->msg);
		Block header(sizeof(packet->msg));
		memcpy(header.data(), &packet->msg, sizeof(packet->msg));
		auto header = std::make_shared<Block>(sizeof(packet->msg));
		memcpy(header->data(), &packet->msg, sizeof(packet->msg));

		std::lock_guard<std::mutex> lock(write_mutex_);
		write_requests_.push_back(CreateWriteBlock(std::move(header), next_write_id_++));
		write_requests_.push_back(
		CreateWriteBlock(std::move(header), 0, sizeof(packet->msg), next_write_id_++));
		if (!packet->payload.empty()) {
		// The kernel attempts to allocate a contiguous block of memory for each write,
		// which can fail if the write is large and the kernel heap is fragmented.
		// Split large writes into smaller chunks to avoid this.
		std::shared_ptr<Block> payload = std::make_shared<Block>(std::move(packet->payload));
		auto payload = std::make_shared<Block>(std::move(packet->payload));
		size_t offset = 0;
		size_t len = payload->size();

		@@ -464,16 +469,20 @@ struct UsbFfsConnection : public Connection {
		worker_thread_.join();
		}

		void PrepareReadBlock(IoBlock* block, uint64_t id) {
		void PrepareReadBlock(IoReadBlock* block, uint64_t id) {
		block->pending = false;
		block->payload = std::make_shared<Block>(kUsbReadSize);
		if (block->payload.capacity() >= kUsbReadSize) {
		block->payload.resize(kUsbReadSize);
		} else {
		block->payload = Block(kUsbReadSize);
		}
		block->control.aio_data = static_cast<uint64_t>(TransferId::read(id));
		block->control.aio_buf = reinterpret_cast<uintptr_t>(block->payload->data());
		block->control.aio_nbytes = block->payload->size();
		block->control.aio_buf = reinterpret_cast<uintptr_t>(block->payload.data());
		block->control.aio_nbytes = block->payload.size();
		}

		IoBlock CreateReadBlock(uint64_t id) {
		IoBlock block;
		IoReadBlock CreateReadBlock(uint64_t id) {
		IoReadBlock block;
		PrepareReadBlock(&block, id);
		block.control.aio_rw_flags = 0;
		block.control.aio_lio_opcode = IOCB_CMD_PREAD;
		@@ -518,9 +527,9 @@ struct UsbFfsConnection : public Connection {

		void HandleRead(TransferId id, int64_t size) {
		uint64_t read_idx = id.id % kUsbReadQueueDepth;
		IoBlock* block = &read_requests_[read_idx];
		IoReadBlock* block = &read_requests_[read_idx];
		block->pending = false;
		block->payload->resize(size);
		block->payload.resize(size);

		// Notification for completed reads can be received out of order.
		if (block->id().id != needed_read_id_) {
		@@ -531,7 +540,7 @@ struct UsbFfsConnection : public Connection {

		for (uint64_t id = needed_read_id_;; ++id) {
		size_t read_idx = id % kUsbReadQueueDepth;
		IoBlock* current_block = &read_requests_[read_idx];
		IoReadBlock* current_block = &read_requests_[read_idx];
		if (current_block->pending) {
		break;
		}
		@@ -540,19 +549,19 @@ struct UsbFfsConnection : public Connection {
		}
		}

		void ProcessRead(IoBlock* block) {
		if (!block->payload->empty()) {
		void ProcessRead(IoReadBlock* block) {
		if (!block->payload.empty()) {
		if (!incoming_header_.has_value()) {
		CHECK_EQ(sizeof(amessage), block->payload->size());
		amessage msg;
		memcpy(&msg, block->payload->data(), sizeof(amessage));
		CHECK_EQ(sizeof(amessage), block->payload.size());
		amessage& msg = incoming_header_.emplace();
		memcpy(&msg, block->payload.data(), sizeof(msg));
		LOG(DEBUG) << "USB read:" << dump_header(&msg);
		incoming_header_ = msg;
		} else {
		size_t bytes_left = incoming_header_->data_length - incoming_payload_.size();
		Block payload = std::move(*block->payload);
		Block payload = std::move(block->payload);
		CHECK_LE(payload.size(), bytes_left);
		incoming_payload_.append(std::make_unique<Block>(std::move(payload)));
		incoming_payload_.append(std::move(payload));
		}

		if (incoming_header_->data_length == incoming_payload_.size()) {
		@@ -560,11 +569,15 @@ struct UsbFfsConnection : public Connection {
		packet->msg = *incoming_header_;

		// TODO: Make apacket contain an IOVector so we don't have to coalesce.
		packet->payload = incoming_payload_.coalesce();
		packet->payload = std::move(incoming_payload_).coalesce();
		read_callback_(this, std::move(packet));

		incoming_header_.reset();
		incoming_payload_.clear();
		// reuse the capacity of the incoming payload while we can.
		auto free_block = incoming_payload_.clear();
		if (block->payload.capacity() == 0) {
		block->payload = std::move(free_block);
		}
		}
		}

		@@ -572,7 +585,7 @@ struct UsbFfsConnection : public Connection {
		SubmitRead(block);
		}

		bool SubmitRead(IoBlock* block) {
		bool SubmitRead(IoReadBlock* block) {
		block->pending = true;
		struct iocb* iocb = &block->control;
		if (io_submit(aio_context_.get(), 1, &iocb) != 1) {
		@@ -594,7 +607,7 @@ struct UsbFfsConnection : public Connection {
		std::lock_guard<std::mutex> lock(write_mutex_);
		auto it =
		std::find_if(write_requests_.begin(), write_requests_.end(), [id](const auto& req) {
		return static_cast<uint64_t>(req->id()) == static_cast<uint64_t>(id);
		return static_cast<uint64_t>(req.id()) == static_cast<uint64_t>(id);
		});
		CHECK(it != write_requests_.end());

		@@ -605,27 +618,26 @@ struct UsbFfsConnection : public Connection {
		SubmitWrites();
		}

		std::unique_ptr<IoBlock> CreateWriteBlock(std::shared_ptr<Block> payload, size_t offset,
		size_t len, uint64_t id) {
		auto block = std::make_unique<IoBlock>();
		block->payload = std::move(payload);
		block->control.aio_data = static_cast<uint64_t>(TransferId::write(id));
		block->control.aio_rw_flags = 0;
		block->control.aio_lio_opcode = IOCB_CMD_PWRITE;
		block->control.aio_reqprio = 0;
		block->control.aio_fildes = write_fd_.get();
		block->control.aio_buf = reinterpret_cast<uintptr_t>(block->payload->data() + offset);
		block->control.aio_nbytes = len;
		block->control.aio_offset = 0;
		block->control.aio_flags = IOCB_FLAG_RESFD;
		block->control.aio_resfd = worker_event_fd_.get();
		IoWriteBlock CreateWriteBlock(std::shared_ptr<Block> payload, size_t offset, size_t len,
		uint64_t id) {
		auto block = IoWriteBlock();
		block.payload = std::move(payload);
		block.control.aio_data = static_cast<uint64_t>(TransferId::write(id));
		block.control.aio_rw_flags = 0;
		block.control.aio_lio_opcode = IOCB_CMD_PWRITE;
		block.control.aio_reqprio = 0;
		block.control.aio_fildes = write_fd_.get();
		block.control.aio_buf = reinterpret_cast<uintptr_t>(block.payload->data() + offset);
		block.control.aio_nbytes = len;
		block.control.aio_offset = 0;
		block.control.aio_flags = IOCB_FLAG_RESFD;
		block.control.aio_resfd = worker_event_fd_.get();
		return block;
		}

		std::unique_ptr<IoBlock> CreateWriteBlock(Block payload, uint64_t id) {
		std::shared_ptr<Block> block = std::make_shared<Block>(std::move(payload));
		size_t len = block->size();
		return CreateWriteBlock(std::move(block), 0, len, id);
		IoWriteBlock CreateWriteBlock(Block&& payload, uint64_t id) {
		size_t len = payload.size();
		return CreateWriteBlock(std::make_shared<Block>(std::move(payload)), 0, len, id);
		}

		void SubmitWrites() REQUIRES(write_mutex_) {
		@@ -642,9 +654,9 @@ struct UsbFfsConnection : public Connection {

		struct iocb* iocbs[kUsbWriteQueueDepth];
		for (int i = 0; i < writes_to_submit; ++i) {
		CHECK(!write_requests_[writes_submitted_ + i]->pending);
		write_requests_[writes_submitted_ + i]->pending = true;
		iocbs[i] = &write_requests_[writes_submitted_ + i]->control;
		CHECK(!write_requests_[writes_submitted_ + i].pending);
		write_requests_[writes_submitted_ + i].pending = true;
		iocbs[i] = &write_requests_[writes_submitted_ + i].control;
		LOG(VERBOSE) << "submitting write_request " << static_cast<void*>(iocbs[i]);
		}

		@@ -689,7 +701,7 @@ struct UsbFfsConnection : public Connection {
		std::optional<amessage> incoming_header_;
		IOVector incoming_payload_;

		std::array<IoBlock, kUsbReadQueueDepth> read_requests_;
		std::array<IoReadBlock, kUsbReadQueueDepth> read_requests_;
		IOVector read_data_;

		// ID of the next request that we're going to send out.
		@@ -699,7 +711,7 @@ struct UsbFfsConnection : public Connection {
		size_t needed_read_id_ = 0;

		std::mutex write_mutex_;
		std::deque<std::unique_ptr<IoBlock>> write_requests_ GUARDED_BY(write_mutex_);
		std::deque<IoWriteBlock> write_requests_ GUARDED_BY(write_mutex_);
		size_t next_write_id_ GUARDED_BY(write_mutex_) = 0;
		size_t writes_submitted_ GUARDED_BY(write_mutex_) = 0;

adb/sockets.cpp

+1 −2

Original line number	Diff line number	Diff line
		@@ -125,8 +125,7 @@ static SocketFlushResult local_socket_flush_incoming(asocket* s) {
		if (rc > 0 && static_cast<size_t>(rc) == s->packet_queue.size()) {
		s->packet_queue.clear();
		} else if (rc > 0) {
		// TODO: Implement a faster drop_front?
		s->packet_queue.take_front(rc);
		s->packet_queue.drop_front(rc);
		fdevent_add(s->fde, FDE_WRITE);
		return SocketFlushResult::TryAgain;
		} else if (rc == -1 && errno == EAGAIN) {

adb/transport_fd.cpp

+7 −8

Original line number	Diff line number	Diff line
		@@ -93,8 +93,8 @@ struct NonblockingFdConnection : public Connection {

		if (pfds[0].revents & POLLIN) {
		// TODO: Should we be getting blocks from a free list?
		auto block = std::make_unique<IOVector::block_type>(MAX_PAYLOAD);
		rc = adb_read(fd_.get(), &(*block)[0], block->size());
		auto block = IOVector::block_type(MAX_PAYLOAD);
		rc = adb_read(fd_.get(), &block[0], block.size());
		if (rc == -1) {
		*error = std::string("read failed: ") + strerror(errno);
		return;
		@@ -102,7 +102,7 @@ struct NonblockingFdConnection : public Connection {
		*error = "read failed: EOF";
		return;
		}
		block->resize(rc);
		block.resize(rc);
		read_buffer_.append(std::move(block));

		if (!read_header_ && read_buffer_.size() >= sizeof(amessage)) {
		@@ -116,7 +116,7 @@ struct NonblockingFdConnection : public Connection {
		auto data_chain = read_buffer_.take_front(read_header_->data_length);

		// TODO: Make apacket carry around a IOVector instead of coalescing.
		auto payload = data_chain.coalesce<apacket::payload_type>();
		auto payload = std::move(data_chain).coalesce();
		auto packet = std::make_unique<apacket>();
		packet->msg = *read_header_;
		packet->payload = std::move(payload);
		@@ -184,8 +184,7 @@ struct NonblockingFdConnection : public Connection {
		return WriteResult::Error;
		}

		// TODO: Implement a more efficient drop_front?
		write_buffer_.take_front(rc);
		write_buffer_.drop_front(rc);
		writable_ = write_buffer_.empty();
		if (write_buffer_.empty()) {
		return WriteResult::Completed;
		@@ -199,10 +198,10 @@ struct NonblockingFdConnection : public Connection {
		std::lock_guard<std::mutex> lock(write_mutex_);
		const char* header_begin = reinterpret_cast<const char*>(&packet->msg);
		const char* header_end = header_begin + sizeof(packet->msg);
		auto header_block = std::make_unique<IOVector::block_type>(header_begin, header_end);
		auto header_block = IOVector::block_type(header_begin, header_end);
		write_buffer_.append(std::move(header_block));
		if (!packet->payload.empty()) {
		write_buffer_.append(std::make_unique<IOVector::block_type>(std::move(packet->payload)));
		write_buffer_.append(std::move(packet->payload));
		}

		WriteResult result = DispatchWrites();

adb/types.cpp

0 → 100644

+204 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2019 The Android Open Source Project
		*
		* 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 "types.h"

		IOVector& IOVector::operator=(IOVector&& move) noexcept {
		chain_ = std::move(move.chain_);
		chain_length_ = move.chain_length_;
		begin_offset_ = move.begin_offset_;
		start_index_ = move.start_index_;

		move.clear();
		return *this;
		}

		IOVector::block_type IOVector::clear() {
		chain_length_ = 0;
		begin_offset_ = 0;
		start_index_ = 0;
		block_type res;
		if (!chain_.empty()) {
		res = std::move(chain_.back());
		}
		chain_.clear();
		return res;
		}

		void IOVector::drop_front(IOVector::size_type len) {
		if (len == 0) {
		return;
		}
		if (len == size()) {
		clear();
		return;
		}
		CHECK_LT(len, size());

		auto dropped = 0u;
		while (dropped < len) {
		const auto next = chain_[start_index_].size() - begin_offset_;
		if (dropped + next < len) {
		pop_front_block();
		dropped += next;
		} else {
		const auto taken = len - dropped;
		begin_offset_ += taken;
		break;
		}
		}
		}

		IOVector IOVector::take_front(IOVector::size_type len) {
		if (len == 0) {
		return {};
		}
		if (len == size()) {
		return std::move(*this);
		}

		CHECK_GE(size(), len);
		IOVector res;
		// first iterate over the blocks that completely go into the other vector
		while (chain_[start_index_].size() - begin_offset_ <= len) {
		chain_length_ -= chain_[start_index_].size();
		len -= chain_[start_index_].size() - begin_offset_;
		if (chain_[start_index_].size() > begin_offset_) {
		res.append(std::move(chain_[start_index_]));
		if (begin_offset_) {
		res.begin_offset_ = std::exchange(begin_offset_, 0);
		}
		} else {
		begin_offset_ = 0;
		}
		++start_index_;
		}

		if (len > 0) {
		// what's left is a single buffer that needs to be split between the \|res\| and \|this\|
		// we know that it has to be split - there was a check for the case when it has to
		// go away as a whole.
		if (begin_offset_ != 0 \|\| len < chain_[start_index_].size() / 2) {
		// let's memcpy the data out
		block_type block(chain_[start_index_].begin() + begin_offset_,
		chain_[start_index_].begin() + begin_offset_ + len);
		res.append(std::move(block));
		begin_offset_ += len;
		} else {
		CHECK_EQ(begin_offset_, 0u);
		// move out the internal buffer out and copy only the tail of it back in
		block_type block(chain_[start_index_].begin() + len, chain_[start_index_].end());
		chain_length_ -= chain_[start_index_].size();
		chain_[start_index_].resize(len);
		res.append(std::move(chain_[start_index_]));
		chain_length_ += block.size();
		chain_[start_index_] = std::move(block);
		}
		}
		return res;
		}

		void IOVector::trim_front() {
		if ((begin_offset_ == 0 && start_index_ == 0) \|\| chain_.empty()) {
		return;
		}
		block_type& first_block = chain_[start_index_];
		if (begin_offset_ == first_block.size()) {
		++start_index_;
		} else {
		memmove(first_block.data(), first_block.data() + begin_offset_,
		first_block.size() - begin_offset_);
		first_block.resize(first_block.size() - begin_offset_);
		}
		chain_length_ -= begin_offset_;
		begin_offset_ = 0;
		trim_chain_front();
		}

		void IOVector::trim_chain_front() {
		if (start_index_) {
		chain_.erase(chain_.begin(), chain_.begin() + start_index_);
		start_index_ = 0;
		}
		}

		void IOVector::pop_front_block() {
		chain_length_ -= chain_[start_index_].size();
		begin_offset_ = 0;
		chain_[start_index_].clear();
		++start_index_;
		if (start_index_ > std::max<size_t>(4, chain_.size() / 2)) {
		trim_chain_front();
		}
		}

		IOVector::block_type IOVector::coalesce() && {
		// Destructive coalesce() may optimize for several cases when it doesn't need to allocate
		// new buffer, or even return one of the existing blocks as is. The only guarantee is that
		// after this call the IOVector is in some valid state. Nothing is guaranteed about the
		// specifics.
		if (size() == 0) {
		return {};
		}
		if (begin_offset_ == chain_[start_index_].size() && chain_.size() == start_index_ + 2) {
		chain_length_ -= chain_.back().size();
		auto res = std::move(chain_.back());
		chain_.pop_back();
		return res;
		}
		if (chain_.size() == start_index_ + 1) {
		chain_length_ -= chain_.back().size();
		auto res = std::move(chain_.back());
		chain_.pop_back();
		if (begin_offset_ != 0) {
		memmove(res.data(), res.data() + begin_offset_, res.size() - begin_offset_);
		res.resize(res.size() - begin_offset_);
		begin_offset_ = 0;
		}
		return res;
		}
		if (auto& firstBuffer = chain_[start_index_]; firstBuffer.capacity() >= size()) {
		auto res = std::move(chain_[start_index_]);
		auto size = res.size();
		chain_length_ -= size;
		if (begin_offset_ != 0) {
		memmove(res.data(), res.data() + begin_offset_, res.size() - begin_offset_);
		size -= begin_offset_;
		begin_offset_ = 0;
		}
		for (auto i = start_index_ + 1; i < chain_.size(); ++i) {
		memcpy(res.data() + size, chain_[i].data(), chain_[i].size());
		size += chain_[i].size();
		}
		res.resize(size);
		++start_index_;
		return res;
		}
		return const_cast<const IOVector*>(this)->coalesce<>();
		}

		std::vector<adb_iovec> IOVector::iovecs() const {
		std::vector<adb_iovec> result;
		result.reserve(chain_.size() - start_index_);
		iterate_blocks([&result](const char* data, size_t len) {
		adb_iovec iov;
		iov.iov_base = const_cast<char*>(data);
		iov.iov_len = len;
		result.emplace_back(iov);
		});

		return result;
		}