OpenHarmony 源码解析之DFX子系统-Hiview（上） 原创 精华

/base/hiviewdfx/hiview.
├── adapter             #平台适配
│   ├── service        #服务适配
│   └── system_service #系统接口适配
├── base                #模块定义，工具类
│   └── utility
├── build               #编译脚本
├── core                #插件管理核心代码
├── include             #公共定义
├── plugins             #插件
├── service             #HiviewService服务
└── utility             #工具类
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{
    "jobs" : [{
            "name" : "post-fs-data",
            "cmds" : [
                "mkdir /data/log/ 0770 system log",
                "mkdir /data/log/faultlog/ 0770 system system",
                "mkdir /data/log/faultlog/temp/ 0770 system system",
                "mkdir /data/log/faultlog/faultlogger/ 0770 system system",
                "start hiview"
            ]
        }
    ],
    "services" : [{
            "name" : "hiview",
            "path" : ["/system/bin/hiview"],
            "uid" : "system",
            "gid" : ["system", "log"],
            "writepid" : [
                "/dev/cpuset/system-background/tasks"
            ],
            "socket" : [
                "hisysevent dgram 0666 root system passcred"
            ]
        }
    ]
}
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int main(int argc __UNUSED, char* argv[] __UNUSED)
{
    auto& hiview = OHOS::HiviewDFX::HiviewPlatform::GetInstance();
    // process cmdline
    hiview.ProcessArgsRequest(argc, argv);

    // 初始化环境，主要解析配置文件，加载插件
    if (!hiview.InitEnvironment()) {
        HIVIEW_LOGW("Fail to init plugin environment. exit");
        return -1;
    }

    // 启动HiviewService服务，该服务提供了hiview运行信息dump功能
    auto hiviewService = std::make_unique<OHOS::HiviewDFX::HiviewService>();
    hiviewService->StartService();
    return 0;
}
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bool HiviewPlatform::InitEnvironment(const std::string& defaultDir, const std::string& cloudUpdateDir,
                                     const std::string& workDir, const std::string& persistDir)
{
    // 创建工作目录，目前目录名使用了默认的空字符串，所以并未实际创建工作目录
    ValidateAndCreateDirectories(defaultDir, cloudUpdateDir, workDir, persistDir);

    // update beta config
    UpdateBetaConfigIfNeed();

    // check whether hiview is already started
    ExitHiviewIfNeed();

    // 解析"/system/etc/hiview/plugin_config"插件配置文件
    std::string cfgPath = GetPluginConfigPath();
    PluginConfig config(cfgPath);
    if (!config.StartParse()) { //...........注[1]
        HIVIEW_LOGE("Fail to parse plugin config. exit!");
        return false;
    }
    // 启动插件管理平台消息队列
    StartPlatformDispatchQueue();

    // init global context helper, remove in the future
    HiviewGlobal::CreateInstance(static_cast<HiviewContext&>(*this));
    //加载插件
    LoadBusinessPlugin(config);

    isReady_ = true;
    NotifyPluginReady();
    return true;
}
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       if (field == "plugins") {
           ParsePlugin(strTmp);
       } else if (field == "pipelines") {
           ParsePipeline(strTmp);
       } else if (field == "pipelinegroups") {
           ParsePipelineGroup(strTmp);
       }
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plugins:3
SysEventSource[thread:sysevent_source]:0 static
Faultlogger[]:0 static
SysEventService[thread:sysevent_service]:0 static
pipelines:1
SysEventPipeline:SysEventService Faultlogger
pipelinegroups:1
SysEventSource:SysEventPipeline
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void PluginConfig::ParsePipelineGroup(const std::string& pipelineGroup)
{
    std::smatch result;
    // EventSourceExample:FromTwo2Three FromThree2Two
    if (!regex_search(pipelineGroup, result, std::regex("(\\S+)\\s*:(.+)"))) {
        HIVIEW_LOGW("Fail to match pipeline group expression.");
        return;
    }

    const int pipelineGroupNameField = 1;
    const int pipelineNameListField = 2;
    std::string eventSourceName = StringUtil::TrimStr(result.str(pipelineGroupNameField));
    auto ret = std::find_if(pluginInfoList_.begin(), pluginInfoList_.end(), [&](PluginInfo& info) {
        if (info.name == eventSourceName) {
            info.isEventSource = true;
            info.pipelineNameList = StringUtil::SplitStr(result.str(pipelineNameListField));
            return true;
        }
        return false;
    });
    if (ret != std::end(pluginInfoList_)) {
        HIVIEW_LOGD("%s is an event source.", eventSourceName.c_str());
    }
}
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void HiviewPlatform::LoadBusinessPlugin(const PluginConfig& config)
{
    // start to load plugin
    // 1. 遍历pluginInfoList，根据插件名创建插件。因为目前配置的插件加载延时(loadDelay)为0，所以直接走[2]，调用CreatePlugin()创建插件并添加到pluginMap_中。
    auto const& pluginInfoList = config.GetPluginInfoList();
    for (auto const& pluginInfo : pluginInfoList) {
        HIVIEW_LOGI("Start to create plugin %{public}s delay:%{public}d", pluginInfo.name.c_str(),
                    pluginInfo.loadDelay);
        if (pluginInfo.loadDelay > 0) { //.............[1]
            auto task = std::bind(&HiviewPlatform::ScheduleCreateAndInitPlugin, this, pluginInfo);
            sharedWorkLoop_->AddTimerEvent(nullptr, nullptr, task, pluginInfo.loadDelay, false);
        } else {       //...............[2]
            CreatePlugin(pluginInfo);
        }
    }
    // 2. 遍历pipelineInfoList,调用CreatePipeline()创建管道并添加到pipelines_中。
    auto const& pipelineInfoList = config.GetPipelineInfoList();
    for (auto const& pipelineInfo : pipelineInfoList) {
        HIVIEW_LOGI("Start to create pipeline %{public}s", pipelineInfo.name.c_str());
        CreatePipeline(pipelineInfo);
    }

    // 3. 遍历pluginInfoList，调用InitPlugin()初始化插件
    for (auto const& pluginInfo : pluginInfoList) {
        HIVIEW_LOGI("Start to Load plugin %{public}s", pluginInfo.name.c_str());
        InitPlugin(config, pluginInfo); //............注[1]
    }

    CleanupUnusedResources();
}
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void HiviewPlatform::InitPlugin(const PluginConfig& config __UNUSED, const PluginConfig::PluginInfo& pluginInfo)
{
    auto& plugin = pluginMap_[pluginInfo.name];
    if (plugin == nullptr) {
        return;
    }
    // 如果插件的workHandlerType为thread，则绑定工作线程EventLoop。
    if (pluginInfo.workHandlerType == "thread") {
        auto workLoop = GetAvaliableWorkLoop(pluginInfo.workHandlerName);
        plugin->BindWorkLoop(workLoop);
    }

    auto begin = TimeUtil::GenerateTimestamp();
    plugin->OnLoad();
    // 如果插件是EventSource类型,则添加管道Pipeline，并且调用StartEventSource开启消息监听
    if (pluginInfo.isEventSource) {
        auto sharedSource = std::static_pointer_cast<EventSource>(plugin);
        if (sharedSource == nullptr) {
            HIVIEW_LOGE("Fail to cast plugin to event source!");
            return;
        }
        for (auto& pipelineName : pluginInfo.pipelineNameList) {
            sharedSource->AddPipeline(pipelines_[pipelineName]);
        }
        StartEventSource(sharedSource);
    }
    auto end = TimeUtil::GenerateTimestamp();
    HIVIEW_LOGI("Plugin %{public}s loadtime:%{public}" PRIu64 ".", pluginInfo.name.c_str(), end - begin);
}
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void SysEventSource::StartEventSource()
{
    HIVIEW_LOGI("SysEventSource start");
    std::shared_ptr<EventReceiver> sysEventReceiver = std::make_shared<SysEventReceiver>(*this);
    eventServer.AddReceiver(sysEventReceiver);

    eventServer.Start();
}
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bool EventSource::PublishPipelineEvent(std::shared_ptr<PipelineEvent> event)
{
    HIVIEW_LOGD("EventSource PublishPipelineEvent");
    if (event == nullptr) {
        return false;
    }

    if (Audit::IsEnabled()) {
        auto digest = GetPluginInfo() + Audit::DOMAIN_DELIMITER + event->GetEventInfo();
        Audit::WriteAuditEvent(Audit::StatsEvent::PIPELINE_EVENT_CREATE, event->createTime_, digest);
    }

    for (auto& pipeline : listeners_) {
        if ((pipeline != nullptr) && (pipeline->CanProcessEvent(event))) {
            // one event can only be processed by one pipeline
            pipeline->ProcessEvent(event);
            return true;
        }
    }
    return false;
}
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void Pipeline::ProcessEvent(std::shared_ptr<PipelineEvent> event)
{
    event->SetPipelineInfo(name_, processors_);
    event->OnContinue();
}
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bool PipelineEvent::OnContinue()
{
    // 判断hasFinish_标志位和processors_列表是否已经为空，如已为空，结束本次事件传递
    if ((!hasFinish_) && processors_.empty()) {
        return OnFinish();
    }

    // once the event start delivering
    // the call OnContinue means one has done the processing of the event
    // this may be called by upstream event processor or the framework
    if (Audit::IsEnabled() && startDeliver_) {
        Audit::WriteAuditEvent(Audit::StatsEvent::PIPELINE_EVENT_HANDLE_OUT,
            createTime_, std::to_string(Thread::GetTid()));
    }

    // the framework will call OnContinue when the event is assigned to a pipeline
    if (!startDeliver_) {
        startDeliver_ = true;
    }

    // 取出processors_列表中第一个Plugin元素，并从列表弹出
    std::weak_ptr<Plugin> plugin = processors_.front();
    processors_.pop_front();
    if (auto pluginPtr = plugin.lock()) {
        if (!pluginPtr->CanProcessMoreEvents()) {
            handler_->PauseDispatch(plugin);
        }

        if (Audit::IsEnabled()) {
            Audit::WriteAuditEvent(Audit::StatsEvent::PIPELINE_EVENT_HANDLE_IN, createTime_,
                                   pluginPtr->GetHandlerInfo());
        }
        // 判断当前Plugin是否开启了事件工作队列，如有则加入事件队列处理，如没有直接调用OnEventProxy
        if (auto workLoop = pluginPtr->GetWorkLoop()) {
            workLoop->AddEvent(pluginPtr, shared_from_this()); //............[1]
        } else {
            pluginPtr->OnEventProxy(shared_from_this()); //..........[2]
        }
    } else {
        return OnContinue();
    }
    return true;
}
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bool Plugin::OnEventProxy(std::shared_ptr<Event> event)
{
    if (event == nullptr) {

        return false;
    }

    std::shared_ptr<Event> dupEvent = event;
    auto processorSize = dupEvent->GetPendingProcessorSize();
    dupEvent->ResetPendingStatus();
    bool ret = OnEvent(dupEvent); //..............注[1]

    if (!dupEvent->IsPipelineEvent()) {
        if (Audit::IsEnabled()) {
            Audit::WriteAuditEvent(Audit::StatsEvent::QUEUE_EVENT_OUT, dupEvent->createTime_,
                std::to_string(Thread::GetTid()));
        }
    } else {
        if ((!dupEvent->HasFinish() && !dupEvent->HasPending()) &&
            (processorSize == dupEvent->GetPendingProcessorSize())) {
            dupEvent->OnContinue();//.............注[2]
        }
    }
    return ret;
}
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