Relocate ExecutionBurst* classes to NN util code
The only changes when copying these files were .clang-format differences
and correcting a typo in a comment.
Bug: 177267324
Test: mma
Change-Id: I96cc2402642e1e3076ac7e78e06163c1d3d41701
Merged-In: I96cc2402642e1e3076ac7e78e06163c1d3d41701
(cherry picked from commit 87e83068784b65ab851e4ff65a1099de4e777c9e)
diff --git a/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp b/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp
new file mode 100644
index 0000000..212863e
--- /dev/null
+++ b/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp
@@ -0,0 +1,631 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "ExecutionBurstController"
+
+#include "ExecutionBurstController.h"
+
+#include <android-base/logging.h>
+
+#include <algorithm>
+#include <cstring>
+#include <limits>
+#include <memory>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "HalInterfaces.h"
+#include "Tracing.h"
+#include "Utils.h"
+
+namespace android::nn {
+namespace {
+
+using V1_2::FmqRequestDatum;
+using V1_2::FmqResultDatum;
+using V1_2::IBurstCallback;
+using V1_2::IBurstContext;
+using FmqRequestDescriptor = hardware::MQDescriptorSync<FmqRequestDatum>;
+using FmqResultDescriptor = hardware::MQDescriptorSync<FmqResultDatum>;
+
+constexpr V1_2::Timing kNoTiming12 = {std::numeric_limits<uint64_t>::max(),
+ std::numeric_limits<uint64_t>::max()};
+
+class BurstContextDeathHandler : public hardware::hidl_death_recipient {
+ public:
+ using Callback = std::function<void()>;
+
+ BurstContextDeathHandler(const Callback& onDeathCallback) : mOnDeathCallback(onDeathCallback) {
+ CHECK(onDeathCallback != nullptr);
+ }
+
+ void serviceDied(uint64_t /*cookie*/, const wp<hidl::base::V1_0::IBase>& /*who*/) override {
+ LOG(ERROR) << "BurstContextDeathHandler::serviceDied -- service unexpectedly died!";
+ mOnDeathCallback();
+ }
+
+ private:
+ const Callback mOnDeathCallback;
+};
+
+} // anonymous namespace
+
+// serialize a request into a packet
+std::vector<FmqRequestDatum> serialize(const V1_0::Request& request, V1_2::MeasureTiming measure,
+ const std::vector<int32_t>& slots) {
+ // count how many elements need to be sent for a request
+ size_t count = 2 + request.inputs.size() + request.outputs.size() + request.pools.size();
+ for (const auto& input : request.inputs) {
+ count += input.dimensions.size();
+ }
+ for (const auto& output : request.outputs) {
+ count += output.dimensions.size();
+ }
+
+ // create buffer to temporarily store elements
+ std::vector<FmqRequestDatum> data;
+ data.reserve(count);
+
+ // package packetInfo
+ {
+ FmqRequestDatum datum;
+ datum.packetInformation(
+ {/*.packetSize=*/static_cast<uint32_t>(count),
+ /*.numberOfInputOperands=*/static_cast<uint32_t>(request.inputs.size()),
+ /*.numberOfOutputOperands=*/static_cast<uint32_t>(request.outputs.size()),
+ /*.numberOfPools=*/static_cast<uint32_t>(request.pools.size())});
+ data.push_back(datum);
+ }
+
+ // package input data
+ for (const auto& input : request.inputs) {
+ // package operand information
+ FmqRequestDatum datum;
+ datum.inputOperandInformation(
+ {/*.hasNoValue=*/input.hasNoValue,
+ /*.location=*/input.location,
+ /*.numberOfDimensions=*/static_cast<uint32_t>(input.dimensions.size())});
+ data.push_back(datum);
+
+ // package operand dimensions
+ for (uint32_t dimension : input.dimensions) {
+ FmqRequestDatum datum;
+ datum.inputOperandDimensionValue(dimension);
+ data.push_back(datum);
+ }
+ }
+
+ // package output data
+ for (const auto& output : request.outputs) {
+ // package operand information
+ FmqRequestDatum datum;
+ datum.outputOperandInformation(
+ {/*.hasNoValue=*/output.hasNoValue,
+ /*.location=*/output.location,
+ /*.numberOfDimensions=*/static_cast<uint32_t>(output.dimensions.size())});
+ data.push_back(datum);
+
+ // package operand dimensions
+ for (uint32_t dimension : output.dimensions) {
+ FmqRequestDatum datum;
+ datum.outputOperandDimensionValue(dimension);
+ data.push_back(datum);
+ }
+ }
+
+ // package pool identifier
+ for (int32_t slot : slots) {
+ FmqRequestDatum datum;
+ datum.poolIdentifier(slot);
+ data.push_back(datum);
+ }
+
+ // package measureTiming
+ {
+ FmqRequestDatum datum;
+ datum.measureTiming(measure);
+ data.push_back(datum);
+ }
+
+ // return packet
+ return data;
+}
+
+// deserialize a packet into the result
+std::optional<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>>
+deserialize(const std::vector<FmqResultDatum>& data) {
+ using discriminator = FmqResultDatum::hidl_discriminator;
+
+ std::vector<V1_2::OutputShape> outputShapes;
+ size_t index = 0;
+
+ // validate packet information
+ if (data.size() == 0 || data[index].getDiscriminator() != discriminator::packetInformation) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage packet information
+ const FmqResultDatum::PacketInformation& packetInfo = data[index].packetInformation();
+ index++;
+ const uint32_t packetSize = packetInfo.packetSize;
+ const V1_0::ErrorStatus errorStatus = packetInfo.errorStatus;
+ const uint32_t numberOfOperands = packetInfo.numberOfOperands;
+
+ // verify packet size
+ if (data.size() != packetSize) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage operands
+ for (size_t operand = 0; operand < numberOfOperands; ++operand) {
+ // validate operand information
+ if (data[index].getDiscriminator() != discriminator::operandInformation) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage operand information
+ const FmqResultDatum::OperandInformation& operandInfo = data[index].operandInformation();
+ index++;
+ const bool isSufficient = operandInfo.isSufficient;
+ const uint32_t numberOfDimensions = operandInfo.numberOfDimensions;
+
+ // unpackage operand dimensions
+ std::vector<uint32_t> dimensions;
+ dimensions.reserve(numberOfDimensions);
+ for (size_t i = 0; i < numberOfDimensions; ++i) {
+ // validate dimension
+ if (data[index].getDiscriminator() != discriminator::operandDimensionValue) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage dimension
+ const uint32_t dimension = data[index].operandDimensionValue();
+ index++;
+
+ // store result
+ dimensions.push_back(dimension);
+ }
+
+ // store result
+ outputShapes.push_back({/*.dimensions=*/dimensions, /*.isSufficient=*/isSufficient});
+ }
+
+ // validate execution timing
+ if (data[index].getDiscriminator() != discriminator::executionTiming) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage execution timing
+ const V1_2::Timing timing = data[index].executionTiming();
+ index++;
+
+ // validate packet information
+ if (index != packetSize) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // return result
+ return std::make_tuple(errorStatus, std::move(outputShapes), timing);
+}
+
+V1_0::ErrorStatus legacyConvertResultCodeToErrorStatus(int resultCode) {
+ return convertToV1_0(convertResultCodeToErrorStatus(resultCode));
+}
+
+std::pair<std::unique_ptr<ResultChannelReceiver>, const FmqResultDescriptor*>
+ResultChannelReceiver::create(size_t channelLength, std::chrono::microseconds pollingTimeWindow) {
+ std::unique_ptr<FmqResultChannel> fmqResultChannel =
+ std::make_unique<FmqResultChannel>(channelLength, /*confEventFlag=*/true);
+ if (!fmqResultChannel->isValid()) {
+ LOG(ERROR) << "Unable to create ResultChannelReceiver";
+ return {nullptr, nullptr};
+ }
+
+ const FmqResultDescriptor* descriptor = fmqResultChannel->getDesc();
+ return std::make_pair(
+ std::make_unique<ResultChannelReceiver>(std::move(fmqResultChannel), pollingTimeWindow),
+ descriptor);
+}
+
+ResultChannelReceiver::ResultChannelReceiver(std::unique_ptr<FmqResultChannel> fmqResultChannel,
+ std::chrono::microseconds pollingTimeWindow)
+ : mFmqResultChannel(std::move(fmqResultChannel)), kPollingTimeWindow(pollingTimeWindow) {}
+
+std::optional<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>>
+ResultChannelReceiver::getBlocking() {
+ const auto packet = getPacketBlocking();
+ if (!packet) {
+ return std::nullopt;
+ }
+
+ return deserialize(*packet);
+}
+
+void ResultChannelReceiver::invalidate() {
+ mValid = false;
+
+ // force unblock
+ // ExecutionBurstController waits on a result packet after sending a
+ // request. If the driver containing ExecutionBurstServer crashes, the
+ // controller may be waiting on the futex. This force unblock wakes up any
+ // thread waiting on the futex.
+ // TODO: look for a different/better way to signal/notify the futex to
+ // wake up any thread waiting on it
+ FmqResultDatum datum;
+ datum.packetInformation({/*.packetSize=*/0,
+ /*.errorStatus=*/V1_0::ErrorStatus::GENERAL_FAILURE,
+ /*.numberOfOperands=*/0});
+ mFmqResultChannel->writeBlocking(&datum, 1);
+}
+
+std::optional<std::vector<FmqResultDatum>> ResultChannelReceiver::getPacketBlocking() {
+ if (!mValid) {
+ return std::nullopt;
+ }
+
+ // First spend time polling if results are available in FMQ instead of
+ // waiting on the futex. Polling is more responsive (yielding lower
+ // latencies), but can take up more power, so only poll for a limited period
+ // of time.
+
+ auto& getCurrentTime = std::chrono::high_resolution_clock::now;
+ const auto timeToStopPolling = getCurrentTime() + kPollingTimeWindow;
+
+ while (getCurrentTime() < timeToStopPolling) {
+ // if class is being torn down, immediately return
+ if (!mValid.load(std::memory_order_relaxed)) {
+ return std::nullopt;
+ }
+
+ // Check if data is available. If it is, immediately retrieve it and
+ // return.
+ const size_t available = mFmqResultChannel->availableToRead();
+ if (available > 0) {
+ std::vector<FmqResultDatum> packet(available);
+ const bool success = mFmqResultChannel->read(packet.data(), available);
+ if (!success) {
+ LOG(ERROR) << "Error receiving packet";
+ return std::nullopt;
+ }
+ return std::make_optional(std::move(packet));
+ }
+ }
+
+ // If we get to this point, we either stopped polling because it was taking
+ // too long or polling was not allowed. Instead, perform a blocking call
+ // which uses a futex to save power.
+
+ // wait for result packet and read first element of result packet
+ FmqResultDatum datum;
+ bool success = mFmqResultChannel->readBlocking(&datum, 1);
+
+ // retrieve remaining elements
+ // NOTE: all of the data is already available at this point, so there's no
+ // need to do a blocking wait to wait for more data. This is known because
+ // in FMQ, all writes are published (made available) atomically. Currently,
+ // the producer always publishes the entire packet in one function call, so
+ // if the first element of the packet is available, the remaining elements
+ // are also available.
+ const size_t count = mFmqResultChannel->availableToRead();
+ std::vector<FmqResultDatum> packet(count + 1);
+ std::memcpy(&packet.front(), &datum, sizeof(datum));
+ success &= mFmqResultChannel->read(packet.data() + 1, count);
+
+ if (!mValid) {
+ return std::nullopt;
+ }
+
+ // ensure packet was successfully received
+ if (!success) {
+ LOG(ERROR) << "Error receiving packet";
+ return std::nullopt;
+ }
+
+ return std::make_optional(std::move(packet));
+}
+
+std::pair<std::unique_ptr<RequestChannelSender>, const FmqRequestDescriptor*>
+RequestChannelSender::create(size_t channelLength) {
+ std::unique_ptr<FmqRequestChannel> fmqRequestChannel =
+ std::make_unique<FmqRequestChannel>(channelLength, /*confEventFlag=*/true);
+ if (!fmqRequestChannel->isValid()) {
+ LOG(ERROR) << "Unable to create RequestChannelSender";
+ return {nullptr, nullptr};
+ }
+
+ const FmqRequestDescriptor* descriptor = fmqRequestChannel->getDesc();
+ return std::make_pair(std::make_unique<RequestChannelSender>(std::move(fmqRequestChannel)),
+ descriptor);
+}
+
+RequestChannelSender::RequestChannelSender(std::unique_ptr<FmqRequestChannel> fmqRequestChannel)
+ : mFmqRequestChannel(std::move(fmqRequestChannel)) {}
+
+bool RequestChannelSender::send(const V1_0::Request& request, V1_2::MeasureTiming measure,
+ const std::vector<int32_t>& slots) {
+ const std::vector<FmqRequestDatum> serialized = serialize(request, measure, slots);
+ return sendPacket(serialized);
+}
+
+bool RequestChannelSender::sendPacket(const std::vector<FmqRequestDatum>& packet) {
+ if (!mValid) {
+ return false;
+ }
+
+ if (packet.size() > mFmqRequestChannel->availableToWrite()) {
+ LOG(ERROR)
+ << "RequestChannelSender::sendPacket -- packet size exceeds size available in FMQ";
+ return false;
+ }
+
+ // Always send the packet with "blocking" because this signals the futex and
+ // unblocks the consumer if it is waiting on the futex.
+ return mFmqRequestChannel->writeBlocking(packet.data(), packet.size());
+}
+
+void RequestChannelSender::invalidate() {
+ mValid = false;
+}
+
+hardware::Return<void> ExecutionBurstController::ExecutionBurstCallback::getMemories(
+ const hardware::hidl_vec<int32_t>& slots, getMemories_cb cb) {
+ std::lock_guard<std::mutex> guard(mMutex);
+
+ // get all memories
+ hardware::hidl_vec<hardware::hidl_memory> memories(slots.size());
+ std::transform(slots.begin(), slots.end(), memories.begin(), [this](int32_t slot) {
+ return slot < mMemoryCache.size() ? mMemoryCache[slot] : hardware::hidl_memory{};
+ });
+
+ // ensure all memories are valid
+ if (!std::all_of(memories.begin(), memories.end(),
+ [](const hardware::hidl_memory& memory) { return memory.valid(); })) {
+ cb(V1_0::ErrorStatus::INVALID_ARGUMENT, {});
+ return hardware::Void();
+ }
+
+ // return successful
+ cb(V1_0::ErrorStatus::NONE, std::move(memories));
+ return hardware::Void();
+}
+
+std::vector<int32_t> ExecutionBurstController::ExecutionBurstCallback::getSlots(
+ const hardware::hidl_vec<hardware::hidl_memory>& memories,
+ const std::vector<intptr_t>& keys) {
+ std::lock_guard<std::mutex> guard(mMutex);
+
+ // retrieve (or bind) all slots corresponding to memories
+ std::vector<int32_t> slots;
+ slots.reserve(memories.size());
+ for (size_t i = 0; i < memories.size(); ++i) {
+ slots.push_back(getSlotLocked(memories[i], keys[i]));
+ }
+ return slots;
+}
+
+std::pair<bool, int32_t> ExecutionBurstController::ExecutionBurstCallback::freeMemory(
+ intptr_t key) {
+ std::lock_guard<std::mutex> guard(mMutex);
+
+ auto iter = mMemoryIdToSlot.find(key);
+ if (iter == mMemoryIdToSlot.end()) {
+ return {false, 0};
+ }
+ const int32_t slot = iter->second;
+ mMemoryIdToSlot.erase(key);
+ mMemoryCache[slot] = {};
+ mFreeSlots.push(slot);
+ return {true, slot};
+}
+
+int32_t ExecutionBurstController::ExecutionBurstCallback::getSlotLocked(
+ const hardware::hidl_memory& memory, intptr_t key) {
+ auto iter = mMemoryIdToSlot.find(key);
+ if (iter == mMemoryIdToSlot.end()) {
+ const int32_t slot = allocateSlotLocked();
+ mMemoryIdToSlot[key] = slot;
+ mMemoryCache[slot] = memory;
+ return slot;
+ } else {
+ const int32_t slot = iter->second;
+ return slot;
+ }
+}
+
+int32_t ExecutionBurstController::ExecutionBurstCallback::allocateSlotLocked() {
+ constexpr size_t kMaxNumberOfSlots = std::numeric_limits<int32_t>::max();
+
+ // if there is a free slot, use it
+ if (mFreeSlots.size() > 0) {
+ const int32_t slot = mFreeSlots.top();
+ mFreeSlots.pop();
+ return slot;
+ }
+
+ // otherwise use a slot for the first time
+ CHECK(mMemoryCache.size() < kMaxNumberOfSlots) << "Exceeded maximum number of slots!";
+ const int32_t slot = static_cast<int32_t>(mMemoryCache.size());
+ mMemoryCache.emplace_back();
+
+ return slot;
+}
+
+std::unique_ptr<ExecutionBurstController> ExecutionBurstController::create(
+ const sp<V1_2::IPreparedModel>& preparedModel,
+ std::chrono::microseconds pollingTimeWindow) {
+ // check inputs
+ if (preparedModel == nullptr) {
+ LOG(ERROR) << "ExecutionBurstController::create passed a nullptr";
+ return nullptr;
+ }
+
+ // create callback object
+ sp<ExecutionBurstCallback> callback = new ExecutionBurstCallback();
+
+ // create FMQ objects
+ auto [requestChannelSenderTemp, requestChannelDescriptor] =
+ RequestChannelSender::create(kExecutionBurstChannelLength);
+ auto [resultChannelReceiverTemp, resultChannelDescriptor] =
+ ResultChannelReceiver::create(kExecutionBurstChannelLength, pollingTimeWindow);
+ std::shared_ptr<RequestChannelSender> requestChannelSender =
+ std::move(requestChannelSenderTemp);
+ std::shared_ptr<ResultChannelReceiver> resultChannelReceiver =
+ std::move(resultChannelReceiverTemp);
+
+ // check FMQ objects
+ if (!requestChannelSender || !resultChannelReceiver || !requestChannelDescriptor ||
+ !resultChannelDescriptor) {
+ LOG(ERROR) << "ExecutionBurstController::create failed to create FastMessageQueue";
+ return nullptr;
+ }
+
+ // configure burst
+ V1_0::ErrorStatus errorStatus;
+ sp<IBurstContext> burstContext;
+ const hardware::Return<void> ret = preparedModel->configureExecutionBurst(
+ callback, *requestChannelDescriptor, *resultChannelDescriptor,
+ [&errorStatus, &burstContext](V1_0::ErrorStatus status,
+ const sp<IBurstContext>& context) {
+ errorStatus = status;
+ burstContext = context;
+ });
+
+ // check burst
+ if (!ret.isOk()) {
+ LOG(ERROR) << "IPreparedModel::configureExecutionBurst failed with description "
+ << ret.description();
+ return nullptr;
+ }
+ if (errorStatus != V1_0::ErrorStatus::NONE) {
+ LOG(ERROR) << "IPreparedModel::configureExecutionBurst failed with status "
+ << toString(errorStatus);
+ return nullptr;
+ }
+ if (burstContext == nullptr) {
+ LOG(ERROR) << "IPreparedModel::configureExecutionBurst returned nullptr for burst";
+ return nullptr;
+ }
+
+ // create death handler object
+ BurstContextDeathHandler::Callback onDeathCallback = [requestChannelSender,
+ resultChannelReceiver] {
+ requestChannelSender->invalidate();
+ resultChannelReceiver->invalidate();
+ };
+ const sp<BurstContextDeathHandler> deathHandler = new BurstContextDeathHandler(onDeathCallback);
+
+ // linkToDeath registers a callback that will be invoked on service death to
+ // proactively handle service crashes. If the linkToDeath call fails,
+ // asynchronous calls are susceptible to hangs if the service crashes before
+ // providing the response.
+ const hardware::Return<bool> deathHandlerRet = burstContext->linkToDeath(deathHandler, 0);
+ if (!deathHandlerRet.isOk() || deathHandlerRet != true) {
+ LOG(ERROR) << "ExecutionBurstController::create -- Failed to register a death recipient "
+ "for the IBurstContext object.";
+ return nullptr;
+ }
+
+ // make and return controller
+ return std::make_unique<ExecutionBurstController>(requestChannelSender, resultChannelReceiver,
+ burstContext, callback, deathHandler);
+}
+
+ExecutionBurstController::ExecutionBurstController(
+ const std::shared_ptr<RequestChannelSender>& requestChannelSender,
+ const std::shared_ptr<ResultChannelReceiver>& resultChannelReceiver,
+ const sp<IBurstContext>& burstContext, const sp<ExecutionBurstCallback>& callback,
+ const sp<hardware::hidl_death_recipient>& deathHandler)
+ : mRequestChannelSender(requestChannelSender),
+ mResultChannelReceiver(resultChannelReceiver),
+ mBurstContext(burstContext),
+ mMemoryCache(callback),
+ mDeathHandler(deathHandler) {}
+
+ExecutionBurstController::~ExecutionBurstController() {
+ // It is safe to ignore any errors resulting from this unlinkToDeath call
+ // because the ExecutionBurstController object is already being destroyed
+ // and its underlying IBurstContext object is no longer being used by the NN
+ // runtime.
+ if (mDeathHandler) {
+ mBurstContext->unlinkToDeath(mDeathHandler).isOk();
+ }
+}
+
+static std::tuple<int, std::vector<V1_2::OutputShape>, V1_2::Timing, bool> getExecutionResult(
+ V1_0::ErrorStatus status, std::vector<V1_2::OutputShape> outputShapes, V1_2::Timing timing,
+ bool fallback) {
+ auto [n, checkedOutputShapes, checkedTiming] =
+ getExecutionResult(convertToV1_3(status), std::move(outputShapes), timing);
+ return {n, convertToV1_2(checkedOutputShapes), convertToV1_2(checkedTiming), fallback};
+}
+
+std::tuple<int, std::vector<V1_2::OutputShape>, V1_2::Timing, bool>
+ExecutionBurstController::compute(const V1_0::Request& request, V1_2::MeasureTiming measure,
+ const std::vector<intptr_t>& memoryIds) {
+ // This is the first point when we know an execution is occurring, so begin
+ // to collect systraces. Note that the first point we can begin collecting
+ // systraces in ExecutionBurstServer is when the RequestChannelReceiver
+ // realizes there is data in the FMQ, so ExecutionBurstServer collects
+ // systraces at different points in the code.
+ NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION, "ExecutionBurstController::compute");
+
+ std::lock_guard<std::mutex> guard(mMutex);
+
+ // send request packet
+ const std::vector<int32_t> slots = mMemoryCache->getSlots(request.pools, memoryIds);
+ const bool success = mRequestChannelSender->send(request, measure, slots);
+ if (!success) {
+ LOG(ERROR) << "Error sending FMQ packet";
+ // only use fallback execution path if the packet could not be sent
+ return getExecutionResult(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming12,
+ /*fallback=*/true);
+ }
+
+ // get result packet
+ const auto result = mResultChannelReceiver->getBlocking();
+ if (!result) {
+ LOG(ERROR) << "Error retrieving FMQ packet";
+ // only use fallback execution path if the packet could not be sent
+ return getExecutionResult(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming12,
+ /*fallback=*/false);
+ }
+
+ // unpack results and return (only use fallback execution path if the
+ // packet could not be sent)
+ auto [status, outputShapes, timing] = std::move(*result);
+ return getExecutionResult(status, std::move(outputShapes), timing, /*fallback=*/false);
+}
+
+void ExecutionBurstController::freeMemory(intptr_t key) {
+ std::lock_guard<std::mutex> guard(mMutex);
+
+ bool valid;
+ int32_t slot;
+ std::tie(valid, slot) = mMemoryCache->freeMemory(key);
+ if (valid) {
+ mBurstContext->freeMemory(slot).isOk();
+ }
+}
+
+} // namespace android::nn
diff --git a/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp b/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp
new file mode 100644
index 0000000..848c77b
--- /dev/null
+++ b/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp
@@ -0,0 +1,646 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "ExecutionBurstServer"
+
+#include "ExecutionBurstServer.h"
+
+#include <android-base/logging.h>
+
+#include <algorithm>
+#include <cstring>
+#include <limits>
+#include <map>
+#include <memory>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "HalInterfaces.h"
+#include "Tracing.h"
+
+namespace android::nn {
+namespace {
+
+using hardware::MQDescriptorSync;
+using V1_2::FmqRequestDatum;
+using V1_2::FmqResultDatum;
+using V1_2::IBurstCallback;
+using V1_2::IBurstContext;
+
+constexpr V1_2::Timing kNoTiming = {std::numeric_limits<uint64_t>::max(),
+ std::numeric_limits<uint64_t>::max()};
+
+// DefaultBurstExecutorWithCache adapts an IPreparedModel so that it can be
+// used as an IBurstExecutorWithCache. Specifically, the cache simply stores the
+// hidl_memory object, and the execution forwards calls to the provided
+// IPreparedModel's "executeSynchronously" method. With this class, hidl_memory
+// must be mapped and unmapped for each execution.
+class DefaultBurstExecutorWithCache : public ExecutionBurstServer::IBurstExecutorWithCache {
+ public:
+ DefaultBurstExecutorWithCache(V1_2::IPreparedModel* preparedModel)
+ : mpPreparedModel(preparedModel) {}
+
+ bool isCacheEntryPresent(int32_t slot) const override {
+ const auto it = mMemoryCache.find(slot);
+ return (it != mMemoryCache.end()) && it->second.valid();
+ }
+
+ void addCacheEntry(const hardware::hidl_memory& memory, int32_t slot) override {
+ mMemoryCache[slot] = memory;
+ }
+
+ void removeCacheEntry(int32_t slot) override { mMemoryCache.erase(slot); }
+
+ std::tuple<V1_0::ErrorStatus, hardware::hidl_vec<V1_2::OutputShape>, V1_2::Timing> execute(
+ const V1_0::Request& request, const std::vector<int32_t>& slots,
+ V1_2::MeasureTiming measure) override {
+ // convert slots to pools
+ hardware::hidl_vec<hardware::hidl_memory> pools(slots.size());
+ std::transform(slots.begin(), slots.end(), pools.begin(),
+ [this](int32_t slot) { return mMemoryCache[slot]; });
+
+ // create full request
+ V1_0::Request fullRequest = request;
+ fullRequest.pools = std::move(pools);
+
+ // setup execution
+ V1_0::ErrorStatus returnedStatus = V1_0::ErrorStatus::GENERAL_FAILURE;
+ hardware::hidl_vec<V1_2::OutputShape> returnedOutputShapes;
+ V1_2::Timing returnedTiming;
+ auto cb = [&returnedStatus, &returnedOutputShapes, &returnedTiming](
+ V1_0::ErrorStatus status,
+ const hardware::hidl_vec<V1_2::OutputShape>& outputShapes,
+ const V1_2::Timing& timing) {
+ returnedStatus = status;
+ returnedOutputShapes = outputShapes;
+ returnedTiming = timing;
+ };
+
+ // execute
+ const hardware::Return<void> ret =
+ mpPreparedModel->executeSynchronously(fullRequest, measure, cb);
+ if (!ret.isOk() || returnedStatus != V1_0::ErrorStatus::NONE) {
+ LOG(ERROR) << "IPreparedModelAdapter::execute -- Error executing";
+ return {returnedStatus, std::move(returnedOutputShapes), kNoTiming};
+ }
+
+ return std::make_tuple(returnedStatus, std::move(returnedOutputShapes), returnedTiming);
+ }
+
+ private:
+ V1_2::IPreparedModel* const mpPreparedModel;
+ std::map<int32_t, hardware::hidl_memory> mMemoryCache;
+};
+
+} // anonymous namespace
+
+// serialize result
+std::vector<FmqResultDatum> serialize(V1_0::ErrorStatus errorStatus,
+ const std::vector<V1_2::OutputShape>& outputShapes,
+ V1_2::Timing timing) {
+ // count how many elements need to be sent for a request
+ size_t count = 2 + outputShapes.size();
+ for (const auto& outputShape : outputShapes) {
+ count += outputShape.dimensions.size();
+ }
+
+ // create buffer to temporarily store elements
+ std::vector<FmqResultDatum> data;
+ data.reserve(count);
+
+ // package packetInfo
+ {
+ FmqResultDatum datum;
+ datum.packetInformation({/*.packetSize=*/static_cast<uint32_t>(count),
+ /*.errorStatus=*/errorStatus,
+ /*.numberOfOperands=*/static_cast<uint32_t>(outputShapes.size())});
+ data.push_back(datum);
+ }
+
+ // package output shape data
+ for (const auto& operand : outputShapes) {
+ // package operand information
+ FmqResultDatum::OperandInformation info{};
+ info.isSufficient = operand.isSufficient;
+ info.numberOfDimensions = static_cast<uint32_t>(operand.dimensions.size());
+
+ FmqResultDatum datum;
+ datum.operandInformation(info);
+ data.push_back(datum);
+
+ // package operand dimensions
+ for (uint32_t dimension : operand.dimensions) {
+ FmqResultDatum datum;
+ datum.operandDimensionValue(dimension);
+ data.push_back(datum);
+ }
+ }
+
+ // package executionTiming
+ {
+ FmqResultDatum datum;
+ datum.executionTiming(timing);
+ data.push_back(datum);
+ }
+
+ // return result
+ return data;
+}
+
+// deserialize request
+std::optional<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>> deserialize(
+ const std::vector<FmqRequestDatum>& data) {
+ using discriminator = FmqRequestDatum::hidl_discriminator;
+
+ size_t index = 0;
+
+ // validate packet information
+ if (data.size() == 0 || data[index].getDiscriminator() != discriminator::packetInformation) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage packet information
+ const FmqRequestDatum::PacketInformation& packetInfo = data[index].packetInformation();
+ index++;
+ const uint32_t packetSize = packetInfo.packetSize;
+ const uint32_t numberOfInputOperands = packetInfo.numberOfInputOperands;
+ const uint32_t numberOfOutputOperands = packetInfo.numberOfOutputOperands;
+ const uint32_t numberOfPools = packetInfo.numberOfPools;
+
+ // verify packet size
+ if (data.size() != packetSize) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage input operands
+ std::vector<V1_0::RequestArgument> inputs;
+ inputs.reserve(numberOfInputOperands);
+ for (size_t operand = 0; operand < numberOfInputOperands; ++operand) {
+ // validate input operand information
+ if (data[index].getDiscriminator() != discriminator::inputOperandInformation) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage operand information
+ const FmqRequestDatum::OperandInformation& operandInfo =
+ data[index].inputOperandInformation();
+ index++;
+ const bool hasNoValue = operandInfo.hasNoValue;
+ const V1_0::DataLocation location = operandInfo.location;
+ const uint32_t numberOfDimensions = operandInfo.numberOfDimensions;
+
+ // unpackage operand dimensions
+ std::vector<uint32_t> dimensions;
+ dimensions.reserve(numberOfDimensions);
+ for (size_t i = 0; i < numberOfDimensions; ++i) {
+ // validate dimension
+ if (data[index].getDiscriminator() != discriminator::inputOperandDimensionValue) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage dimension
+ const uint32_t dimension = data[index].inputOperandDimensionValue();
+ index++;
+
+ // store result
+ dimensions.push_back(dimension);
+ }
+
+ // store result
+ inputs.push_back(
+ {/*.hasNoValue=*/hasNoValue, /*.location=*/location, /*.dimensions=*/dimensions});
+ }
+
+ // unpackage output operands
+ std::vector<V1_0::RequestArgument> outputs;
+ outputs.reserve(numberOfOutputOperands);
+ for (size_t operand = 0; operand < numberOfOutputOperands; ++operand) {
+ // validate output operand information
+ if (data[index].getDiscriminator() != discriminator::outputOperandInformation) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage operand information
+ const FmqRequestDatum::OperandInformation& operandInfo =
+ data[index].outputOperandInformation();
+ index++;
+ const bool hasNoValue = operandInfo.hasNoValue;
+ const V1_0::DataLocation location = operandInfo.location;
+ const uint32_t numberOfDimensions = operandInfo.numberOfDimensions;
+
+ // unpackage operand dimensions
+ std::vector<uint32_t> dimensions;
+ dimensions.reserve(numberOfDimensions);
+ for (size_t i = 0; i < numberOfDimensions; ++i) {
+ // validate dimension
+ if (data[index].getDiscriminator() != discriminator::outputOperandDimensionValue) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage dimension
+ const uint32_t dimension = data[index].outputOperandDimensionValue();
+ index++;
+
+ // store result
+ dimensions.push_back(dimension);
+ }
+
+ // store result
+ outputs.push_back(
+ {/*.hasNoValue=*/hasNoValue, /*.location=*/location, /*.dimensions=*/dimensions});
+ }
+
+ // unpackage pools
+ std::vector<int32_t> slots;
+ slots.reserve(numberOfPools);
+ for (size_t pool = 0; pool < numberOfPools; ++pool) {
+ // validate input operand information
+ if (data[index].getDiscriminator() != discriminator::poolIdentifier) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage operand information
+ const int32_t poolId = data[index].poolIdentifier();
+ index++;
+
+ // store result
+ slots.push_back(poolId);
+ }
+
+ // validate measureTiming
+ if (data[index].getDiscriminator() != discriminator::measureTiming) {
+ LOG(ERROR) << "FMQ Request packet ill-formed";
+ return std::nullopt;
+ }
+
+ // unpackage measureTiming
+ const V1_2::MeasureTiming measure = data[index].measureTiming();
+ index++;
+
+ // validate packet information
+ if (index != packetSize) {
+ LOG(ERROR) << "FMQ Result packet ill-formed";
+ return std::nullopt;
+ }
+
+ // return request
+ V1_0::Request request = {/*.inputs=*/inputs, /*.outputs=*/outputs, /*.pools=*/{}};
+ return std::make_tuple(std::move(request), std::move(slots), measure);
+}
+
+// RequestChannelReceiver methods
+
+std::unique_ptr<RequestChannelReceiver> RequestChannelReceiver::create(
+ const FmqRequestDescriptor& requestChannel, std::chrono::microseconds pollingTimeWindow) {
+ std::unique_ptr<FmqRequestChannel> fmqRequestChannel =
+ std::make_unique<FmqRequestChannel>(requestChannel);
+
+ if (!fmqRequestChannel->isValid()) {
+ LOG(ERROR) << "Unable to create RequestChannelReceiver";
+ return nullptr;
+ }
+ if (fmqRequestChannel->getEventFlagWord() == nullptr) {
+ LOG(ERROR)
+ << "RequestChannelReceiver::create was passed an MQDescriptor without an EventFlag";
+ return nullptr;
+ }
+
+ return std::make_unique<RequestChannelReceiver>(std::move(fmqRequestChannel),
+ pollingTimeWindow);
+}
+
+RequestChannelReceiver::RequestChannelReceiver(std::unique_ptr<FmqRequestChannel> fmqRequestChannel,
+ std::chrono::microseconds pollingTimeWindow)
+ : mFmqRequestChannel(std::move(fmqRequestChannel)), kPollingTimeWindow(pollingTimeWindow) {}
+
+std::optional<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>>
+RequestChannelReceiver::getBlocking() {
+ const auto packet = getPacketBlocking();
+ if (!packet) {
+ return std::nullopt;
+ }
+
+ return deserialize(*packet);
+}
+
+void RequestChannelReceiver::invalidate() {
+ mTeardown = true;
+
+ // force unblock
+ // ExecutionBurstServer is by default waiting on a request packet. If the
+ // client process destroys its burst object, the server may still be waiting
+ // on the futex. This force unblock wakes up any thread waiting on the
+ // futex.
+ // TODO: look for a different/better way to signal/notify the futex to wake
+ // up any thread waiting on it
+ FmqRequestDatum datum;
+ datum.packetInformation({/*.packetSize=*/0, /*.numberOfInputOperands=*/0,
+ /*.numberOfOutputOperands=*/0, /*.numberOfPools=*/0});
+ mFmqRequestChannel->writeBlocking(&datum, 1);
+}
+
+std::optional<std::vector<FmqRequestDatum>> RequestChannelReceiver::getPacketBlocking() {
+ if (mTeardown) {
+ return std::nullopt;
+ }
+
+ // First spend time polling if results are available in FMQ instead of
+ // waiting on the futex. Polling is more responsive (yielding lower
+ // latencies), but can take up more power, so only poll for a limited period
+ // of time.
+
+ auto& getCurrentTime = std::chrono::high_resolution_clock::now;
+ const auto timeToStopPolling = getCurrentTime() + kPollingTimeWindow;
+
+ while (getCurrentTime() < timeToStopPolling) {
+ // if class is being torn down, immediately return
+ if (mTeardown.load(std::memory_order_relaxed)) {
+ return std::nullopt;
+ }
+
+ // Check if data is available. If it is, immediately retrieve it and
+ // return.
+ const size_t available = mFmqRequestChannel->availableToRead();
+ if (available > 0) {
+ // This is the first point when we know an execution is occurring,
+ // so begin to collect systraces. Note that a similar systrace does
+ // not exist at the corresponding point in
+ // ResultChannelReceiver::getPacketBlocking because the execution is
+ // already in flight.
+ NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION,
+ "ExecutionBurstServer getting packet");
+ std::vector<FmqRequestDatum> packet(available);
+ const bool success = mFmqRequestChannel->read(packet.data(), available);
+ if (!success) {
+ LOG(ERROR) << "Error receiving packet";
+ return std::nullopt;
+ }
+ return std::make_optional(std::move(packet));
+ }
+ }
+
+ // If we get to this point, we either stopped polling because it was taking
+ // too long or polling was not allowed. Instead, perform a blocking call
+ // which uses a futex to save power.
+
+ // wait for request packet and read first element of request packet
+ FmqRequestDatum datum;
+ bool success = mFmqRequestChannel->readBlocking(&datum, 1);
+
+ // This is the first point when we know an execution is occurring, so begin
+ // to collect systraces. Note that a similar systrace does not exist at the
+ // corresponding point in ResultChannelReceiver::getPacketBlocking because
+ // the execution is already in flight.
+ NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION, "ExecutionBurstServer getting packet");
+
+ // retrieve remaining elements
+ // NOTE: all of the data is already available at this point, so there's no
+ // need to do a blocking wait to wait for more data. This is known because
+ // in FMQ, all writes are published (made available) atomically. Currently,
+ // the producer always publishes the entire packet in one function call, so
+ // if the first element of the packet is available, the remaining elements
+ // are also available.
+ const size_t count = mFmqRequestChannel->availableToRead();
+ std::vector<FmqRequestDatum> packet(count + 1);
+ std::memcpy(&packet.front(), &datum, sizeof(datum));
+ success &= mFmqRequestChannel->read(packet.data() + 1, count);
+
+ // terminate loop
+ if (mTeardown) {
+ return std::nullopt;
+ }
+
+ // ensure packet was successfully received
+ if (!success) {
+ LOG(ERROR) << "Error receiving packet";
+ return std::nullopt;
+ }
+
+ return std::make_optional(std::move(packet));
+}
+
+// ResultChannelSender methods
+
+std::unique_ptr<ResultChannelSender> ResultChannelSender::create(
+ const FmqResultDescriptor& resultChannel) {
+ std::unique_ptr<FmqResultChannel> fmqResultChannel =
+ std::make_unique<FmqResultChannel>(resultChannel);
+
+ if (!fmqResultChannel->isValid()) {
+ LOG(ERROR) << "Unable to create RequestChannelSender";
+ return nullptr;
+ }
+ if (fmqResultChannel->getEventFlagWord() == nullptr) {
+ LOG(ERROR) << "ResultChannelSender::create was passed an MQDescriptor without an EventFlag";
+ return nullptr;
+ }
+
+ return std::make_unique<ResultChannelSender>(std::move(fmqResultChannel));
+}
+
+ResultChannelSender::ResultChannelSender(std::unique_ptr<FmqResultChannel> fmqResultChannel)
+ : mFmqResultChannel(std::move(fmqResultChannel)) {}
+
+bool ResultChannelSender::send(V1_0::ErrorStatus errorStatus,
+ const std::vector<V1_2::OutputShape>& outputShapes,
+ V1_2::Timing timing) {
+ const std::vector<FmqResultDatum> serialized = serialize(errorStatus, outputShapes, timing);
+ return sendPacket(serialized);
+}
+
+bool ResultChannelSender::sendPacket(const std::vector<FmqResultDatum>& packet) {
+ if (packet.size() > mFmqResultChannel->availableToWrite()) {
+ LOG(ERROR)
+ << "ResultChannelSender::sendPacket -- packet size exceeds size available in FMQ";
+ const std::vector<FmqResultDatum> errorPacket =
+ serialize(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);
+
+ // Always send the packet with "blocking" because this signals the futex
+ // and unblocks the consumer if it is waiting on the futex.
+ return mFmqResultChannel->writeBlocking(errorPacket.data(), errorPacket.size());
+ }
+
+ // Always send the packet with "blocking" because this signals the futex and
+ // unblocks the consumer if it is waiting on the futex.
+ return mFmqResultChannel->writeBlocking(packet.data(), packet.size());
+}
+
+// ExecutionBurstServer methods
+
+sp<ExecutionBurstServer> ExecutionBurstServer::create(
+ const sp<IBurstCallback>& callback, const MQDescriptorSync<FmqRequestDatum>& requestChannel,
+ const MQDescriptorSync<FmqResultDatum>& resultChannel,
+ std::shared_ptr<IBurstExecutorWithCache> executorWithCache,
+ std::chrono::microseconds pollingTimeWindow) {
+ // check inputs
+ if (callback == nullptr || executorWithCache == nullptr) {
+ LOG(ERROR) << "ExecutionBurstServer::create passed a nullptr";
+ return nullptr;
+ }
+
+ // create FMQ objects
+ std::unique_ptr<RequestChannelReceiver> requestChannelReceiver =
+ RequestChannelReceiver::create(requestChannel, pollingTimeWindow);
+ std::unique_ptr<ResultChannelSender> resultChannelSender =
+ ResultChannelSender::create(resultChannel);
+
+ // check FMQ objects
+ if (!requestChannelReceiver || !resultChannelSender) {
+ LOG(ERROR) << "ExecutionBurstServer::create failed to create FastMessageQueue";
+ return nullptr;
+ }
+
+ // make and return context
+ return new ExecutionBurstServer(callback, std::move(requestChannelReceiver),
+ std::move(resultChannelSender), std::move(executorWithCache));
+}
+
+sp<ExecutionBurstServer> ExecutionBurstServer::create(
+ const sp<IBurstCallback>& callback, const MQDescriptorSync<FmqRequestDatum>& requestChannel,
+ const MQDescriptorSync<FmqResultDatum>& resultChannel, V1_2::IPreparedModel* preparedModel,
+ std::chrono::microseconds pollingTimeWindow) {
+ // check relevant input
+ if (preparedModel == nullptr) {
+ LOG(ERROR) << "ExecutionBurstServer::create passed a nullptr";
+ return nullptr;
+ }
+
+ // adapt IPreparedModel to have caching
+ const std::shared_ptr<DefaultBurstExecutorWithCache> preparedModelAdapter =
+ std::make_shared<DefaultBurstExecutorWithCache>(preparedModel);
+
+ // make and return context
+ return ExecutionBurstServer::create(callback, requestChannel, resultChannel,
+ preparedModelAdapter, pollingTimeWindow);
+}
+
+ExecutionBurstServer::ExecutionBurstServer(
+ const sp<IBurstCallback>& callback, std::unique_ptr<RequestChannelReceiver> requestChannel,
+ std::unique_ptr<ResultChannelSender> resultChannel,
+ std::shared_ptr<IBurstExecutorWithCache> executorWithCache)
+ : mCallback(callback),
+ mRequestChannelReceiver(std::move(requestChannel)),
+ mResultChannelSender(std::move(resultChannel)),
+ mExecutorWithCache(std::move(executorWithCache)) {
+ // TODO: highly document the threading behavior of this class
+ mWorker = std::thread([this] { task(); });
+}
+
+ExecutionBurstServer::~ExecutionBurstServer() {
+ // set teardown flag
+ mTeardown = true;
+ mRequestChannelReceiver->invalidate();
+
+ // wait for task thread to end
+ mWorker.join();
+}
+
+hardware::Return<void> ExecutionBurstServer::freeMemory(int32_t slot) {
+ std::lock_guard<std::mutex> hold(mMutex);
+ mExecutorWithCache->removeCacheEntry(slot);
+ return hardware::Void();
+}
+
+void ExecutionBurstServer::ensureCacheEntriesArePresentLocked(const std::vector<int32_t>& slots) {
+ const auto slotIsKnown = [this](int32_t slot) {
+ return mExecutorWithCache->isCacheEntryPresent(slot);
+ };
+
+ // find unique unknown slots
+ std::vector<int32_t> unknownSlots = slots;
+ auto unknownSlotsEnd = unknownSlots.end();
+ std::sort(unknownSlots.begin(), unknownSlotsEnd);
+ unknownSlotsEnd = std::unique(unknownSlots.begin(), unknownSlotsEnd);
+ unknownSlotsEnd = std::remove_if(unknownSlots.begin(), unknownSlotsEnd, slotIsKnown);
+ unknownSlots.erase(unknownSlotsEnd, unknownSlots.end());
+
+ // quick-exit if all slots are known
+ if (unknownSlots.empty()) {
+ return;
+ }
+
+ V1_0::ErrorStatus errorStatus = V1_0::ErrorStatus::GENERAL_FAILURE;
+ std::vector<hardware::hidl_memory> returnedMemories;
+ auto cb = [&errorStatus, &returnedMemories](
+ V1_0::ErrorStatus status,
+ const hardware::hidl_vec<hardware::hidl_memory>& memories) {
+ errorStatus = status;
+ returnedMemories = memories;
+ };
+
+ const hardware::Return<void> ret = mCallback->getMemories(unknownSlots, cb);
+
+ if (!ret.isOk() || errorStatus != V1_0::ErrorStatus::NONE ||
+ returnedMemories.size() != unknownSlots.size()) {
+ LOG(ERROR) << "Error retrieving memories";
+ return;
+ }
+
+ // add memories to unknown slots
+ for (size_t i = 0; i < unknownSlots.size(); ++i) {
+ mExecutorWithCache->addCacheEntry(returnedMemories[i], unknownSlots[i]);
+ }
+}
+
+void ExecutionBurstServer::task() {
+ // loop until the burst object is being destroyed
+ while (!mTeardown) {
+ // receive request
+ auto arguments = mRequestChannelReceiver->getBlocking();
+
+ // if the request packet was not properly received, return a generic
+ // error and skip the execution
+ //
+ // if the burst is being torn down, skip the execution so the "task"
+ // function can end
+ if (!arguments) {
+ if (!mTeardown) {
+ mResultChannelSender->send(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);
+ }
+ continue;
+ }
+
+ // otherwise begin tracing execution
+ NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION,
+ "ExecutionBurstServer getting memory, executing, and returning results");
+
+ // unpack the arguments; types are Request, std::vector<int32_t>, and
+ // MeasureTiming, respectively
+ const auto [requestWithoutPools, slotsOfPools, measure] = std::move(*arguments);
+
+ // ensure executor with cache has required memory
+ std::lock_guard<std::mutex> hold(mMutex);
+ ensureCacheEntriesArePresentLocked(slotsOfPools);
+
+ // perform computation; types are ErrorStatus, hidl_vec<OutputShape>,
+ // and Timing, respectively
+ const auto [errorStatus, outputShapes, returnedTiming] =
+ mExecutorWithCache->execute(requestWithoutPools, slotsOfPools, measure);
+
+ // return result
+ mResultChannelSender->send(errorStatus, outputShapes, returnedTiming);
+ }
+}
+
+} // namespace android::nn