MNN Interpreter and Session

淡淡的烟草味﹌ 2022-12-06 05:23 273阅读 0赞

MNN 中 [Interpreter][] 和 [Session][] 之间的关系如下图所示：

Interpreter

Session0

Session1

Pipeline0

Pipeline1

Pipeline2

Pipeline3

Pipeline4

Net

*  [Interpreter][] 为模型解释器，亦为会话管理器，负责从文件加载模型，创建并执行会话；
 *  一个 [Interpreter][] 对应到一个 [Net][]，管理基于该网络的多个任务；
 *  [Session][] 表示推理任务，由 [Pipeline][] 数组和输入输出张量字典组成；
 *  [Session][] 根据 [Schedule::schedule][Schedule_schedule] 生成的 [Schedule::ScheduleInfo][Schedule_ScheduleInfo] 创建；
 *  归属于同一 [Net][] 的不同 [Session][] 间不能并发调用。

## [Interpreter][] ##

[Interpreter][] 由模型文件构建，不允许复制或拷贝构造。

### [Interpreter::createFromFile][Interpreter_createFromFile] ###

Created with Raphaël 2.2.0Interpreter::createFromFilefileFileLoaderFileLoader::validYes or No?FileLoader::readContentFileLoader::mergecreateFromBufferInternalEndyesno

[Interpreter::createFromFile][Interpreter_createFromFile] 首先借助 [FileLoader][] 分块读取文件内容，合并后由 [Interpreter::createFromBufferInternal][Interpreter_createFromBufferInternal] 创建一个 [Interpreter][] 对象。  
[FileLoader::valid][FileLoader_valid] 判断文件句柄是否为空。  
[FileLoader::read][FileLoader_read] 分块读取。  
[Content][] 包含读取的缓存以及由此构建出的网络、会话和张量信息。  
[FileLoader::merge][FileLoader_merge] 合并读取的结果到给定的缓存。

if (nullptr == file) {
        
            MNN_PRINT("NULL file for create interpreter\n");
            return nullptr;
        }
        std::unique_ptr<FileLoader> loader(new FileLoader(file));
        if (!loader->valid()) {
        
            MNN_PRINT("Create interpreter failed, open %s error\n", file);
            return nullptr;
        }
        bool result = loader->read();
        if (!result) {
        
            MNN_PRINT("Read file error\n");
            return nullptr;
        }
        if (loader->size() == 0) {
        
            MNN_PRINT("Create interpreter failed, %s is empty\n", file);
            return nullptr;
        }
        auto net     = new Content;
        bool success = loader->merge(net->buffer);
        if (!success) {
        
            return nullptr;
        }
        loader.reset();
        return createFromBufferInternal(net);

### [Interpreter::createFromBufferInternal][Interpreter_createFromBufferInternal] ###

Interpreter::createFromBufferInternal

Interpreter::Interpreter

[Verifier][] 检查缓存完整性。

if (nullptr == net) {
        
            MNN_PRINT("Buffer is null for create interpreter\n");
            return nullptr;
        }
        flatbuffers::Verifier verify((const uint8_t*)(net->buffer.get()), net->buffer.size());
        if (false == VerifyNetBuffer(verify)) {
        
            MNN_PRINT("Invalidate buffer to create interpreter\n");
            delete net;
            return nullptr;
        }

从缓存中获取定义的 [Net][]，检查其中的 op 列表。

net->net = GetNet(net->buffer.get());
        if (nullptr == net->net->oplists()) {
        
            MNN_ERROR("Model has no oplist\n");
            delete net;
            return nullptr;
        }
        int opSize = net->net->oplists()->size();
        for (int i=0; i<opSize; ++i) {
        
            auto op = net->net->oplists()->GetAs<Op>(i);
            if (nullptr == op || nullptr == op->outputIndexes()) {
        
                MNN_ERROR("Invalid Model, the %d op is empty\n", i);
                delete net;
                return nullptr;
            }
        }

创建一个 [Interpreter][] 对象，使用 create 函数的好处是及时检查错误并返回，但不能返回错误码。

return new Interpreter(net);
    }

### [Interpreter::createSession][Interpreter_createSession] ###

Interpreter::createSession

Interpreter::createMultiPathSession

根据 [ScheduleConfig][] 创建会话。

return createMultiPathSession({
        config});

### [Interpreter::createMultiPathSession][Interpreter_createMultiPathSession] ###

Created with Raphaël 2.2.0Interpreter::createMultiPathSessionconfigsSchedule::scheduleSessionSession::validYes or No?validForResize?Session::resizenewSessionEndyesnoyesno

检查网络的缓存是否已释放。

if (nullptr == mNet->buffer.get()) {
        
            MNN_ERROR("The model buffer has been released. Can't create session\n");
            return nullptr;
        }

[Schedule::schedule][Schedule_schedule] 函数由网络和配置创建 [Schedule::ScheduleInfo][Schedule_ScheduleInfo 1] 结构体，进而根据该结果创建 [Session][]。  
[Session::resize][Session_resize] 将创建的 [Session][] 追加到 [Interpreter][] 存储的队列中。

auto info       = Schedule::schedule(mNet->net, configs);
        auto newSession = std::unique_ptr<Session>(new Session(info));
        if (!newSession->valid()) {
        
            MNN_PRINT("Invalide Session!!\n");
            return nullptr;
        }
        auto result = newSession.get();
        if (info.validForResize) {
        
            result->resize();
        }
        mNet->sessions.emplace_back(std::move(newSession));
        return result;

### [Interpreter::getSessionInput][Interpreter_getSessionInput] ###

Interpreter::getSessionInput

Session::getInput

[Session::getInput][Session_getInput] 根据名字从输入字典中找到张量。  
将张量与 [Session][] 的对应关系记录到`tensorMap`中。

MNN_ASSERT(nullptr != session);
        if (session == nullptr) {
        
            return nullptr;
        }
        auto tensor = session->getInput(name);
        mNet->tensorMap.insert(std::make_pair(tensor, session));
        return tensor;

### [Interpreter::resizeTensor][Interpreter_resizeTensor] ###

维度检查。

MNN_ASSERT(nullptr != tensor);
        bool dirty = false;
        if (tensor->buffer().dimensions != dims.size()) {
        
            dirty = true;
        } else {
        
            for (int i = 0; i < dims.size(); ++i) {
        
                if (tensor->buffer().dim[i].extent != dims[i]) {
        
                    dirty = true;
                    break;
                }
            }
        }
    
        if (!dirty) {
        
            return;
        }

设置张量的维度。

tensor->buffer().dimensions = (int)dims.size();
        for (int i = 0; i < dims.size(); ++i) {
        
            tensor->buffer().dim[i].extent = dims[i];
        }

设置该张量相关 [Session][] 的状态。  
[Session::setNeedResize][Session_setNeedResize]

auto relatedSessionIter = mNet->tensorMap.find(tensor);
        MNN_ASSERT(relatedSessionIter != mNet->tensorMap.end());
        ((MNN::Session*)relatedSessionIter->second)->setNeedResize();

### [Interpreter::resizeSession][Interpreter_resizeSession] ###

Interpreter::resizeSession

Session::resize

[Session::resize][Session_resize]

if (mNet->buffer.get() == nullptr) {
        
            MNN_ERROR("The model buffer has been released. Can't resize session\n");
            return;
        }
        if (session->getNeedResize()) {
        
            session->resize();
        }

### [Interpreter::runSession][Interpreter_runSession] ###

Interpreter::runSession

Session::run

[Session::run][Session_run]

return session->run();

### [Interpreter::runSessionWithCallBack][Interpreter_runSessionWithCallBack] ###

Interpreter::runSessionWithCallBack

Interpreter::runSessionWithCallBackInfo

封装回调函数。

auto beforeWrap = [&before](const std::vector<Tensor*>& tensors, const OperatorInfo* info) {
        
            return before(tensors, info->name());
        };
        auto afterWrap = [&after](const std::vector<Tensor*>& tensors, const OperatorInfo* info) {
        
            return after(tensors, info->name());
        };
        return runSessionWithCallBackInfo(session, beforeWrap, afterWrap, sync);

## [Interpreter::runSessionWithCallBackInfo][Interpreter_runSessionWithCallBackInfo] ##

Interpreter::runSessionWithCallBackInfo

Session::runWithCallBack

`callBack`的名字不太一致。  
[Session::runWithCallBack][Session_runWithCallBack]

return session->runWithCallBack(before, callBack, sync);

### [Interpreter::releaseModel][Interpreter_releaseModel] ###

[Session::releaseCache][Session_releaseCache]

mNet->buffer.release();
        for (auto& iter : mNet->sessions) {
        
            iter->releaseCache();
        }

### [Interpreter::updateSessionToModel][Interpreter_updateSessionToModel] ###

Interpreter::updateSessionToModel

Session::updateToModel

[Session::updateToModel][Session_updateToModel]

if (mNet->buffer.get() == nullptr) {
        
            MNN_ERROR("Can't updateSessionToModel because you called releaseModel before\n");
            return INPUT_DATA_ERROR;
        }
        return session->updateToModel((Net*)mNet->net);

## [Session][] ##

[Session][] 拥有多条 [Pipeline][] 并记录输入和输出。

### [Session::Session][Session_Session] ###

Session::Session

BackendFactory::create

Session::\_getDefaultBackend

Pipeline::Pipeline

if (info.pipelineInfo.empty()) {
        
            mValid = false;
            return;
        }

根据每个 [Schedule::PipelineInfo][Schedule_ScheduleInfo] 创建 [Pipeline][]。  
[BackendFactory::create][BackendFactory_create] 根据 [Backend::Info][Backend_Info] 创建后端。 `mBackends`字典按类型存储了已创建的后端。  
[Session::\_getDefaultBackend][Session_getDefaultBackend] 返回 [CPUBackend][]。  
ARMv8-A 支持 fp16。

mTensors = info.allTensors;
        for (auto& iter : info.pipelineInfo) {
        
            if (mBackends.find(iter.first.type) == mBackends.end()) {
        
                auto newBn = BackendFactory::create(iter.first);
                if (nullptr == newBn) {
        
                    mValid = false;
                    return;
                }
                mBackends[iter.first.type].reset(newBn);
            }
            auto backend    = mBackends.find(iter.first.type)->second.get();
            auto cpuBackend = _getDefaultBackend();
    
    #if defined(__aarch64__) && defined(ENABLE_ARMV82)
            // choose Arm82Backend only when setting BackendConfig PrecisionMode
            // to be Precision_Normal|Precision_Low
            auto precisionModeSatisfy = false;
            if(iter.first.user){
        
                auto precisionMode = iter.first.user->precision;
                if(precisionMode == BackendConfig::Precision_Low){
        
                    precisionModeSatisfy = true;
                }
            }
            if (iter.first.type == MNN_FORWARD_CPU && precisionModeSatisfy && cpuBackend->mIsSupportFp16arith) {
        
            // if (iter.first.type == MNN_FORWARD_CPU) { // debug on Mac
                // when enable armv82 extension instruction set and forward type is cpu and cpu isa support fp16arith
                // activate armv82 backend
                // check backend is equal to be cpuBackend
                MNN_ASSERT(backend == cpuBackend);
                if (mBackends.find(MNN_FORWARD_CPU_EXTENSION) == mBackends.end()) {
        
                    Backend::Info bnInfo;
                    bnInfo.type = MNN_FORWARD_CPU_EXTENSION;
                    BackendConfig config;
                    config.sharedContext = static_cast<void*>(cpuBackend);
                    bnInfo.user          = &config;
                    mBackends[bnInfo.type].reset(BackendFactory::create(bnInfo));
                }
                backend = mBackends.find(MNN_FORWARD_CPU_EXTENSION)->second.get();
                if (backend == nullptr) {
        
                    MNN_PRINT("[MNNWarning]: armv82 backend is null\n");
                    backend = cpuBackend;
                }
                MNN_PRINT("\n[MNNInfo]:*************set armv82 backend*************\n");
            }
    #endif
            std::shared_ptr<Pipeline> newPipeline(new Pipeline(iter.second, backend, cpuBackend));
            mPipelines.emplace_back(std::move(newPipeline));
        }
        mInputs  = info.inputTensors;
        mOutputs = info.outputTensor;

### [Session::\_getDefaultBackend][Session_getDefaultBackend] ###

如果`MNN_FORWARD_CPU`不存在则创建并加入`mBackends`字典中。

auto defaultType = MNN_FORWARD_CPU;
        if (mBackends.find(defaultType) == mBackends.end()) {
        
            Backend::Info info;
            info.type      = defaultType;
            info.numThread = 1;
            mBackends[info.type].reset(BackendFactory::create(info));
        }
        auto cpuBackend = mBackends.find(defaultType)->second.get();
        return cpuBackend;

### [Session::~Session][Session_Session 1] ###

[TensorUtils::clearHandleData][TensorUtils_clearHandleData] 清除 [Tensor][] 的主端句柄。

for (auto& t : mTensors) {
        
            TensorUtils::clearHandleData(t.second.get());
        }
        mPipelines.clear();
        mBackends.clear();
        mTensors.clear();

### [Session::resize][Session_resize] ###

[Session::\_clearCache][Session_clearCache] 清除主端缓存。  
[Pipeline::Unit::prepare][Pipeline_Unit_prepare]

_clearCache();
        for (auto& b : mBackends) {
        
            // avoid library not loaded
            if(b.second){
        
                b.second->onClearBuffer();
            }
        }
    
        for (auto& iter : mPipelines) {
        
            auto error = iter->prepare();
            if (NO_ERROR != error) {
        
                return error;
            }
        }
        mNeedResize = false;
        for (auto& b : mBackends) {
        
            if(b.second){
        
                b.second->onAllocateBuffer();
            }
        }
    
        return NO_ERROR;

### [Session::\_clearCache][Session_clearCache] ###

[TensorUtils::getDescribe][TensorUtils_getDescribe] 返回 [Tensor::InsideDescribe][Tensor_InsideDescribe] 结构体，其记录了张量的布局和句柄数据类型。  
[TensorUtils::clearHandleData][TensorUtils_clearHandleData] 释放张量中的数据。

for (auto& t : mTensors) {
        
            auto describe = TensorUtils::getDescribe(t.second.get());
            TensorUtils::clearHandleData(t.second.get());
            describe->useCount = t.first;
            describe->backend  = nullptr;
        }

### [Session::run][Session_run] ###

Session::run

Pipeline::execute

[Pipeline::execute][Pipeline_execute]

if (mNeedResize) {
        
            MNN_ERROR("Can't run session because not resized\n");
            return COMPUTE_SIZE_ERROR;
        }
        for (auto& iter : mPipelines) {
        
            auto error = iter->execute();
            if (NO_ERROR != error) {
        
                return error;
            }
        }
        return NO_ERROR;

### [Session::runWithCallBack][Session_runWithCallBack] ###

Session::runWithCallBack

Pipeline::executeCallBack

Backend::onWaitFinish

[Pipeline::executeCallBack][Pipeline_executeCallBack]

if (mNeedResize) {
        
            MNN_ERROR("Can't run session because not resized\n");
            return COMPUTE_SIZE_ERROR;
        }
        for (auto& iter : mPipelines) {
        
            auto error = iter->executeCallBack(before, end);
            if (NO_ERROR != error) {
        
                return error;
            }
        }
        if (sync) {
        
            for (auto& bn : mBackends) {
        
                if(bn.second){
        
                    bn.second->onWaitFinish();
                }
            }
        }
        return NO_ERROR;

### [Session::releaseCache][Session_releaseCache] ###

[Pipeline::releaseCache][Pipeline_releaseCache]

for (auto& p : mPipelines) {
        
            auto code = p->releaseCache();
            if (NO_ERROR != code) {
        
                return code;
            }
        }
        return NO_ERROR;

### [Session::updateToModel][Session_updateToModel] ###

遍历网络的算子列表

*  网络用于推理时跳过不是常量的算子；
 *  用于训练时跳过非可训参数算子；
 *  跳过输出数量异常的算子。

int opSize = net->oplists()->size();
        for (int i = 0; i < opSize; ++i) {
        
            auto op = net->oplists()->GetAs<Op>(i);
            if (net->usage() == Usage_INFERENCE && op->type() != OpType_Const) {
        
                continue;
            }
            if (net->usage() == Usage_TRAIN && op->type() != OpType_TrainableParam) {
        
                continue;
            }
            if (!op->outputIndexes() || op->outputIndexes()->size() != 1) {
        
                continue;
            }

算子的参数为 [Blob][]，跳过非浮点的算子。

auto index = op->outputIndexes()->data()[0];
            auto blob  = op->main_as_Blob();
            if (blob->dataType() != DataType_DT_FLOAT) {
        
                continue;
            }

[Tensor::createHostTensorFromDevice][Tensor_createHostTensorFromDevice] 在主端创建张量。  
将 [Blob][] 复制到 [Tensor][]。

std::shared_ptr<Tensor> tensor = mTensors[index].second;
            if (tensor->host<void>() == nullptr && tensor->deviceId() != 0) {
        
                tensor.reset(Tensor::createHostTensorFromDevice(tensor.get(), true));
                if (tensor.get() == nullptr) {
        
                    MNN_ERROR("failed to copy trained param from device to host\n");
                    return INVALID_VALUE;
                }
            }
            ::memcpy((void*)blob->float32s()->data(), tensor->host<float>(), tensor->size());
        }
    
        return NO_ERROR;

## 参考资料： ##

*  [Use in C++][Use in C]
 *  [Flatbuffer fails to verify after adding a table offset][]
 *  [Flatbuffers verifier behaviour][]
 *  [Flatbuffers didn’t generate a Get\* method, but did generate \*Builder (in c++)?][Flatbuffers didn_t generate a Get_ method_ but did generate _Builder _in c]
 *  [MNN模型转化中的 算子转化][MNN_]
 *  [c++ set\_difference(STL set\_difference)算法详解][c_ set_difference_STL set_difference]
 *  [std::set\_difference][std_set_difference]
 *  [创建会话][Link 1]
 *  [使用教程][Link 2]
 *  [◆ device][device]

[Interpreter]: https://github.com/alibaba/MNN/blob/master/include/MNN/Interpreter.hpp#L94
[Session]: https://github.com/alibaba/MNN/blob/master/source/core/Session.hpp#L25
[Net]: https://github.com/alibaba/MNN/blob/master/schema/default/MNN.fbs#L298
[Pipeline]: https://github.com/alibaba/MNN/blob/master/source/core/Pipeline.hpp#L24
[Schedule_schedule]: https://github.com/alibaba/MNN/blob/master/source/core/Schedule.cpp#L320
[Schedule_ScheduleInfo]: https://github.com/alibaba/MNN/blob/master/source/core/Schedule.hpp#L28
[Interpreter_createFromFile]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L27
[FileLoader]: https://github.com/alibaba/MNN/blob/master/source/core/FileLoader.hpp#L12
[Interpreter_createFromBufferInternal]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L70
[FileLoader_valid]: https://github.com/alibaba/MNN/blob/master/source/core/FileLoader.hpp#L20
[FileLoader_read]: https://github.com/alibaba/MNN/blob/master/source/core/FileLoader.cpp#L43
[Content]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L20
[FileLoader_merge]: https://github.com/alibaba/MNN/blob/master/source/core/FileLoader.cpp#L75
[Verifier]: https://github.com/google/flatbuffers/blob/master/include/flatbuffers/flatbuffers.h#L2137
[Interpreter_createSession]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L127
[ScheduleConfig]: https://github.com/alibaba/MNN/blob/master/include/MNN/Interpreter.hpp#L22
[Interpreter_createMultiPathSession]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L108
[Schedule_ScheduleInfo 1]: https://github.com/alibaba/MNN/blob/master/source/core/Schedule.hpp#L38
[Session_resize]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L148
[Interpreter_getSessionInput]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L154
[Session_getInput]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L177
[Interpreter_resizeTensor]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L232
[Session_setNeedResize]: https://github.com/alibaba/MNN/blob/master/source/core/Session.hpp#L73
[Interpreter_resizeSession]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L187
[Interpreter_runSession]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L150
[Session_run]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L103
[Interpreter_runSessionWithCallBack]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L197
[Interpreter_runSessionWithCallBackInfo]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L208
[Session_runWithCallBack]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L117
[Interpreter_releaseModel]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L217
[Session_releaseCache]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L212
[Interpreter_updateSessionToModel]: https://github.com/alibaba/MNN/blob/master/source/core/Interpreter.cpp#L268
[Session_updateToModel]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L221
[Session_Session]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L36
[BackendFactory_create]: https://github.com/alibaba/MNN/blob/master/source/core/BackendFactory.cpp#L14
[Backend_Info]: https://github.com/alibaba/MNN/blob/master/source/core/Backend.hpp#L31
[Session_getDefaultBackend]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L24
[CPUBackend]: https://github.com/alibaba/MNN/blob/master/source/backend/cpu/CPUBackend.hpp#L22
[Session_Session 1]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L94
[TensorUtils_clearHandleData]: https://github.com/alibaba/MNN/blob/master/source/core/TensorUtils.cpp#L47
[Tensor]: https://github.com/alibaba/MNN/blob/master/include/MNN/Tensor.hpp#L25
[Session_clearCache]: https://github.com/alibaba/MNN/blob/master/source/core/Session.cpp#L139
[Pipeline_Unit_prepare]: https://github.com/alibaba/MNN/blob/master/source/core/Pipeline.cpp#L158
[TensorUtils_getDescribe]: https://github.com/alibaba/MNN/blob/master/source/core/TensorUtils.cpp#L19
[Tensor_InsideDescribe]: https://github.com/alibaba/MNN/blob/master/include/MNN/Tensor.hpp#L27
[Pipeline_execute]: https://github.com/alibaba/MNN/blob/master/source/core/Pipeline.cpp#L329
[Pipeline_executeCallBack]: https://github.com/alibaba/MNN/blob/master/source/core/Pipeline.cpp#L343
[Pipeline_releaseCache]: https://github.com/alibaba/MNN/blob/master/source/core/Pipeline.cpp#L355
[Blob]: https://github.com/alibaba/MNN/blob/master/schema/default/Tensor.fbs#L20
[Tensor_createHostTensorFromDevice]: https://github.com/alibaba/MNN/blob/master/source/core/Tensor.cpp#L190
[Use in C]: https://google.github.io/flatbuffers/md__cpp_usage.html
[Flatbuffer fails to verify after adding a table offset]: https://stackoverflow.com/questions/39782411/flatbuffer-fails-to-verify-after-adding-a-table-offset
[Flatbuffers verifier behaviour]: https://stackoverflow.com/questions/37486992/flatbuffers-verifier-behaviour
[Flatbuffers didn_t generate a Get_ method_ but did generate _Builder _in c]: https://stackoverflow.com/questions/32595789/flatbuffers-didnt-generate-a-get-method-but-did-generate-builder-in-c
[MNN_]: https://zhuanlan.zhihu.com/p/124304103
[c_ set_difference_STL set_difference]: http://c.biancheng.net/view/557.html
[std_set_difference]: https://en.cppreference.com/w/cpp/algorithm/set_difference
[Link 1]: https://www.yuque.com/mnn/cn/create_session
[Link 2]: https://www.bookstack.cn/read/MNN-zh/doc-Tutorial_CN.md
[device]: https://halide-lang.org/docs/structhalide__buffer__t.html#a51aa231b39c37cb777369dda8825030f