ohos_bundles/foundation
2020-09-10 10:22:30 +08:00
..
bundle.json add OpenHarmony 1.0 baseline 2020-09-10 10:22:30 +08:00
LICENSE add OpenHarmony 1.0 baseline 2020-09-10 10:22:30 +08:00
README.md add OpenHarmony 1.0 baseline 2020-09-10 10:22:30 +08:00

系统服务框架子系统

简介

由于平台资源有限且硬件平台多样因此需要屏蔽不同硬件架构和资源的不同、以及运行形态的不同提供统一化的系统服务开发框架。根据RISC-V、Cortex-M、Cortex-A不同硬件平台分为两种硬件平台以下简称M核、A核。

M核处理架构为Cortex-M或同等处理能力的硬件平台系统内存一般低于512KB无文件系统或者仅提供一个可有限使用的轻量级文件系统遵循CMSIS接口规范。

A核处理架构为Cortex-A或同等处理能力的硬件平台内存资源大于512KB文件系统完善可存储大量数据遵循POSIX接口规范。

系统服务框架基于面向服务的架构,提供了服务开发、服务的子功能开发、对外接口的开发、以及多服务共进程、进程间服务调用等开发能力。其中:

  • M核包含服务开发、服务的子功能开发、对外接口的开发以及多服务共进程的开发框架。
  • A核在M核能力基础之上包含了进程间服务调用、进程间服务调用权限控制、进程间服务接口的开发等能力。

面向服务的架构:

Provider服务的提供者为系统提供能力对外接口

Consumer服务的消费者调用服务提供的功能对外接口

Samgr做为中介者管理Provider提供的能力同时帮助Consumer发现Provider的能力。

系统服务开发框架主体对象:

  • SamgrLite主要提供服务的注册与发现能力。
  • Service开发服务时需要实现的服务的生命周期接口。
  • Feature开发功能时需要实现的功能的生命周期接口。
  • IUnknown基于IUnknown开发服务或功能的对外接口。
  • IClientProxyIPC调用时消费者的消息发送代理。
  • IServerProxyIPC调用时开发者需要实现提供者的消息处理接口。

目录

表 1 系统服务框架源代码目录结构

名称

描述

interfaces/kits/samgr_lite/samgr

M核和A核系统服务框架对外接口定义。

interfaces/kits/samgr_lite/registry

A核进程间服务调用的对外接口定义。

interfaces/kits/samgr_lite/communication/broadcast

M核和A核进程内事件广播服务的对外接口定义。

services/samgr_lite/samgr/adapter

POSIX和CMSIS接口适配层来屏蔽A核M核接口差异。

services/samgr_lite/samgr/registry

M核服务注册发现的桩函数。

services/samgr_lite/samgr/source

M核和A核系统服务开发框架基础代码。

services/samgr_lite/samgr_client

A核进程间服务调用的注册与发现。

services/samgr_lite/samgr_server

A核进程间服务调用的IPC地址管理和访问控制。

services/samgr_lite/samgr_endpoint

A核IPC通信消息收发包管理。

services/samgr_lite/communication/broadcast

M核和A核进程内事件广播服务。

约束

系统服务开发框架统一使用C开发。

同进程内服务间调用统一使用IUnknown接口对外象消息接口统一由IUnknown接口传递给本服务。

服务名和功能名必需使用常量字符串且长度小于16个字节。

M核系统依赖上bootstrap服务在系统启动函数中调用OHOS_SystemInit()函数。

A核系统依赖samgr库在main函数中调用SAMGR_Bootstrap()函数。

开发服务

  • 继承并重新定义服务:

    typedef struct ExampleService {
        INHERIT_SERVICE;
        INHERIT_IUNKNOWNENTRY(DefaultFeatureApi);
        Identity identity;
    } ExampleService;
    
  • 实现服务的生命周期函数:

    static const char *GetName(Service *service)
    {
        return EXAMPLE_SERVICE;
    }
    
    static BOOL Initialize(Service *service, Identity identity)
    {
        ExampleService *example = (ExampleService *)service;
        // 保存服务的唯一身份标识用来自己的IUnknown接口对服务发消息时使用。
        example->identity = identity;
        return TRUE;
    }
    static BOOL MessageHandle(Service *service, Request *msg)
    {
        ExampleService *example = (ExampleService *)service;
        switch (msg->msgId) {
            case MSG_SYNC:
                // 业务处理
                break;
            default:break;
        }
        return FALSE;
    }
    static TaskConfig GetTaskConfig(Service *service)
    {
        TaskConfig config = {LEVEL_HIGH, PRI_BELOW_NORMAL,
                             0x800, 20, SHARED_TASK};
        return config;
    }
    
  • 创建服务对象:

    static ExampleService g_example = {
        .GetName = GetName,
        .Initialize = Initialize,
        .MessageHandle = MessageHandle,
        .GetTaskConfig = GetTaskConfig,
        SERVER_IPROXY_IMPL_BEGIN,
            .Invoke = NULL,
            .SyncCall = SyncCall,
        IPROXY_END,
    };
    
  • 向SAMGR注册服务及接口

    static void Init(void)
    {
        SAMGR_GetInstance()->RegisterService((Service *)&g_example);
        SAMGR_GetInstance()->RegisterDefaultFeatureApi(EXAMPLE_SERVICE, GET_IUNKNOWN(g_example));
    }
    
  • 定义服务的初始化入口:

    SYSEX_SERVICE_INIT(Init);
    
    

开发服务的子功能

  • 继承并重新定义功能:

    typedef struct DemoFeature {
        INHERIT_FEATURE;
        INHERIT_IUNKNOWNENTRY(DemoApi);
        Identity identity;
        Service *parent;
    } DemoFeature;
    
  • 实现功能的生命周期函数:

    static const char *FEATURE_GetName(Feature *feature)
    {
        return EXAMPLE_FEATURE;
    }
    
    static void FEATURE_OnInitialize(Feature *feature, Service *parent, Identity identity)
    {
        DemoFeature *demoFeature = (DemoFeature *)feature;
        demoFeature->identity = identity;
        demoFeature->parent = parent;
    }
    
    static void FEATURE_OnStop(Feature *feature, Identity identity)
    {
        g_example.identity.queueId = NULL;
        g_example.identity.featureId = -1;
        g_example.identity.serviceId = -1;
    }
    
    static BOOL FEATURE_OnMessage(Feature *feature, Request *request)
    {
        if (request->msgId == MSG_PROC) {
            Response response = {.data = "Yes, you did!", .len = 0};
            SAMGR_SendResponse(request, &response);
            return TRUE;
        } else {
            if (request->msgId == MSG_TIME_PROC) {
                LOS_Msleep(WAIT_FEATURE_PROC * 10);
                if (request->msgValue) {
                    SAMGR_PrintServices();
                } else {
                    SAMGR_PrintOperations();
                }
                AsyncTimeCall(GET_IUNKNOWN(g_example));
                return FALSE;
            }
        }
        return FALSE;
    }
    
  • 创建功能对象:

    static DemoFeature g_example = {
        .GetName = FEATURE_GetName,
        .OnInitialize = FEATURE_OnInitialize,
        .OnStop = FEATURE_OnStop,
        .OnMessage = FEATURE_OnMessage,
        DEFAULT_IUNKNOWN_ENTRY_BEGIN,
            .AsyncCall = AsyncCall,
            .AsyncTimeCall = AsyncTimeCall,
            .SyncCall = SyncCall,
            .AsyncCallBack = AsyncCallBack,
        DEFAULT_IUNKNOWN_ENTRY_END,
        .identity = {-1, -1, NULL},
    };
    
  • 向SAMGR注册功能及接口

    static void Init(void){
        SAMGR_GetInstance()->RegisterFeature(EXAMPLE_SERVICE, (Feature *)&g_example);
        SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE, GET_IUNKNOWN(g_example));
    }
    
  • 定义功能的初始化入口:

    SYSEX_FEATURE_INIT(Init);
    
    

开发进程内对外接口

  • 定义IUnknown接口

    typedef struct DemoApi {
        INHERIT_IUNKNOWN;
        BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);
        BOOL (*AsyncTimeCall)(IUnknown *iUnknown);
        BOOL (*SyncCall)(IUnknown *iUnknown, struct Payload *payload);
        BOOL (*AsyncCallBack)(IUnknown *iUnknown, const char *buff, Handler handler);
    } DemoApi;
    
  • 定义IUnknown的引用对象

    typedef struct DemoRefApi {
        INHERIT_IUNKNOWNENTRY(DemoApi);
    } DemoRefApi;
    
  • 初始化接口对象:

    static DemoRefApi api = {
        DEFAULT_IUNKNOWN_ENTRY_BEGIN,
            .AsyncCall = AsyncCall,
            .AsyncTimeCall = AsyncTimeCall,
            .SyncCall = SyncCall,
            .AsyncCallBack = AsyncCallBack,
        DEFAULT_IUNKNOWN_ENTRY_END,
    };
    
  • 注册服务接口:

    SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE, GET_IUNKNOWN(api));
    
    

调用进程内服务

  • 获取服务的对外接口:

    DemoApi *demoApi = NULL;
    IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
    if (iUnknown == NULL) {
        return NULL;
    }
    int result = iUnknown->QueryInterface(iUnknown, DEFAULT_VERSION, (void **)&demoApi);
    if (result != 0 || demoApi == NULL) {
        return NULL;
    }
    
  • 接口调用:

    if (demoApi->AsyncCallBack == NULL) {
        return NULL;
    }
    demoApi->AsyncCallBack((IUnknown *)demoApi, "I wanna async call callback good result!", AsyncHandler);
    
  • 释放接口:

    int32 ref = demoApi->Release((IUnknown *)demoApi);
    
    

开发跨进程间对外接口

  • 继承IServerProxy替代继承IUnknownINHERIT_SERVER_IPROXY

    typedef struct DemoFeatureApi {
        INHERIT_SERVER_IPROXY;
        BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);
        BOOL (*AsyncTimeCall)(IUnknown *iUnknown);
        BOOL (*SyncCall)(IUnknown *iUnknown, struct Payload *payload);
        BOOL (*AsyncCallBack)(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler);
    } DemoFeatureApi;
    
  • 初始化IServerProxy对象

    static DemoFeature g_example = {
        SERVER_IPROXY_IMPL_BEGIN,
        .Invoke = Invoke,
        .AsyncCall = AsyncCall,
        .AsyncTimeCall = AsyncTimeCall,
        .SyncCall = SyncCall,
        .AsyncCallBack = AsyncCallBack,
        IPROXY_END,
    };
    
  • 实现Invoke函数来处理Ipc消息

    static int32 Invoke(IServerProxy *iProxy, int funcId, void *origin, IpcIo *req, IpcIo *reply)
    {
        DemoFeatureApi *api = (DemoFeatureApi *)iProxy;
        BOOL ret;
        size_t len = 0;
        switch (funcId) {
            case ID_ASYNCALL:
                ret = api->AsyncCall((IUnknown *)iProxy, (char *)IpcIoPopString(req, &len));
                IpcIoPushBool(reply, ret);
                break;
            case ID_ASYNTIMECALL:
                ret = api->AsyncTimeCall((IUnknown *)iProxy);
                IpcIoPushBool(reply, ret);
                break;
            case ID_SYNCCALL: {
                struct Payload payload;
                payload.id = IpcIoPopInt32(req);
                payload.value = IpcIoPopInt32(req);
                payload.name = (char *)IpcIoPopString(req, &len);
                ret = api->SyncCall((IUnknown *)iProxy, &payload);
                IpcIoPushString(reply, ret ? "TRUE" : "FALSE");
            }
                break;
            case ID_ASYNCCALLBACK: { // convert to sync proxy
                IpcIoPushString(reply, "Yes, you did!");
                IpcIoPushBool(reply, TRUE);
            }
                break;
            default:
                IpcIoPushBool(reply, FALSE);
                break;
        }
        return EC_SUCCESS;
    }
    
  • 注册接口:与进程内接口注册一致

    SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE, GET_IUNKNOWN(g_example));
    
    

调用跨进程间服务

  • 获取跨进程服务的对外接口:

    IClientProxy *demoApi = NULL;
    IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
    if (iUnknown == NULL) {
        return NULL;
    }
    int result = iUnknown->QueryInterface(iUnknown, CLIENT_PROXY_VER, (void **)&demoApi);
    if (result != 0 || demoApi == NULL) {
        return NULL;
    }
    
  • 调用Ipc消息接口

    IpcIo request;char data[250];
    IpcIoInit(&request, data, sizeof(data), 0);
    demoApi->Invoke(demoApi, 0, &request, NULL, NULL);
    
  • 释放接口:

    int32 ref = demoApi->Release((IUnknown *)demoApi);
    
    

开发跨进程间服务调用客户端代理

  • 定义IPC接口客户端代理

    typedef struct DemoClientProxy {
        INHERIT_CLIENT_IPROXY;
        BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);
        BOOL (*AsyncTimeCall)(IUnknown *iUnknown);
        BOOL (*SyncCall)(IUnknown *iUnknown, struct Payload *payload);
        BOOL (*AsyncCallBack)(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler);
    } DemoClientProxy;
    typedef struct DemoClientEntry {
        INHERIT_IUNKNOWNENTRY(DemoClientProxy);
    } DemoClientEntry;
    
  • 实现客户端代理封装Ipc消息接口

    static BOOL AsyncCall(IUnknown *iUnknown, const char *buff)
    {
        DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
        IpcIo request;
        char data[MAX_DATA_LEN];
        IpcIoInit(&request, data, MAX_DATA_LEN, 0);
        IpcIoPushString(&request, buff);
        int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNCALL, &request, NULL, NULL);
        return ret == EC_SUCCESS;
    }
    
    static BOOL AsyncTimeCall(IUnknown *iUnknown)
    {
        DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
        IpcIo request;
        char data[MAX_DATA_LEN];
        IpcIoInit(&request, data, MAX_DATA_LEN, 0);
        int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNTIMECALL, &request, NULL, NULL);
        return ret == EC_SUCCESS;
    }
    
    static int Callback(IOwner owner, int code, IpcIo *reply)
    {
        size_t len = 0;
        return strcpy_s(owner, MAX_DATA_LEN, (char *)IpcIoPopString(reply, &len));
    }
    
    static BOOL SyncCall(IUnknown *iUnknown, struct Payload *payload)
    {
        DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
        IpcIo request;
        char data[MAX_DATA_LEN];
        IpcIoInit(&request, data, MAX_DATA_LEN, 0);
        IpcIoPushInt32(&request, payload->id);
        IpcIoPushInt32(&request, payload->value);
        IpcIoPushString(&request, payload->name);
        int ret = proxy->Invoke((IClientProxy *)proxy, ID_SYNCCALL, &request, data, Callback);
        data[MAX_DATA_LEN - 1] = 0;
        HILOG_INFO(HILOG_MODULE_APP, "[TID:0x%lx]Remote response is %s!", pthread_self(), data);
        return ret == EC_SUCCESS;
    }
    
    struct CurrentNotify {
        IOwner notify;
        INotifyFunc handler;
    };
    
    static int CurrentCallback(IOwner owner, int code, IpcIo *reply)
    {
        struct CurrentNotify *notify = (struct CurrentNotify *)owner;
        size_t len = 0;
        char *response = (char *)IpcIoPopString(reply, &len);
        HILOG_INFO(HILOG_MODULE_APP, "[TID:0x%lx]Notify Remote response is %s!", pthread_self(), response);
        notify->handler(notify->notify, response);
        return EC_SUCCESS;
    }
    
    static BOOL AsyncCallBack(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler)
    {
        struct CurrentNotify owner = {notify, handler};
        DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
        IpcIo request;
        char data[MAX_DATA_LEN];
        IpcIoInit(&request, data, MAX_DATA_LEN, 0);
        IpcIoPushString(&request, buff);
        int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNCCALLBACK, &request, &owner, CurrentCallback);
        return ret == EC_SUCCESS;
    }
    
  • 实现客户端代理的工厂方法:

    void *DEMO_CreatClient(const char *service, const char *feature, uint32 size)
    {
        (void)service;
        (void)feature;
        uint32 len = size + sizeof(DemoClientEntry);
        uint8 *client = malloc(len);
        (void)memset_s(client, len, 0, len);
        DemoClientEntry *entry = (DemoClientEntry *)&client[size];
        entry->ver = ((uint16)CLIENT_PROXY_VER | (uint16)DEFAULT_VERSION);
        entry->ref = 1;
        entry->iUnknown.QueryInterface = IUNKNOWN_QueryInterface;
        entry->iUnknown.AddRef = IUNKNOWN_AddRef;
        entry->iUnknown.Release = IUNKNOWN_Release;
        entry->iUnknown.Invoke = NULL;
        entry->iUnknown.AsyncCall = AsyncCall;
        entry->iUnknown.AsyncTimeCall = AsyncTimeCall;
        entry->iUnknown.SyncCall = SyncCall;
        entry->iUnknown.AsyncCallBack = AsyncCallBack;
        return client;
    }
    void DEMO_DestroyClient(const char *service, const char *feature, void *iproxy)
    {
        free(iproxy);
    }
    
  • 将客户端代理的工厂方法注册到SAMGR

    SAMGR_RegisterFactory(EXAMPLE_SERVICE, EXAMPLE_FEATURE, DEMO_CreatClient, DEMO_DestroyClient);
    
  • 获取跨进程服务的对外接口:

    DemoClientProxy *demoApi = NULL;
    IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
    if (iUnknown == NULL) {
        return NULL;
    }
    int result = iUnknown->QueryInterface(iUnknown, DEFAULT_VERSION, (void **)&demoApi);
    if (result != 0 || demoApi == NULL) {
        return NULL;
    }
    
  • 调用跨进程服务的客户端代理接口:

    if (demoApi->AsyncCallBack == NULL) {
        return NULL;
    }
    demoApi->AsyncCallBack((IUnknown *)demoApi,
                           "I wanna async call callback good result!", NULL, AsyncHandler);
    
  • 释放接口:

    int32 ref = demoApi->Release((IUnknown *)demoApi);
    

涉及仓

distributedschedule_interfaces_kits_samgr_lite

distributedschedule_services_samgr_lite