系统服务框架子系统

    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：

    系统服务框架子系统 - 图1

    • 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。
    • IClientProxy：IPC调用时，消费者的消息发送代理。
    • IServerProxy：IPC调用时，开发者需要实现的，生产者的消息处理代理。

    目录

    表 1 系统服务框架源代码目录结构

    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HOS_SystemInit()函数。

    A核：系统依赖samgr库，在main函数中调用SAMGR_Bootstrap()函数。

    • 继承并重新定义服务：

    • 实现服务的生命周期函数：

      2. {
      3.     return EXAMPLE_SERVICE;
      4. }
      6. static BOOL Initialize(Service *service, Identity identity)
      7. {
      8.     ExampleService *example = (ExampleService *)service;
      9.     // 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。
      10.     example->identity = identity;
      11.     return TRUE;
      12. }
      13. static BOOL MessageHandle(Service *service, Request *msg)
      14. {
      15.     ExampleService *example = (ExampleService *)service;
      16.     switch (msg->msgId) {
      17.         case MSG_SYNC:
      18.             // 业务处理
      19.             break;
      20.         default:break;
      21.     }
      22.     return FALSE;
      23. }
      24. static TaskConfig GetTaskConfig(Service *service)
      25. {
      26.     TaskConfig config = {LEVEL_HIGH, PRI_BELOW_NORMAL,
      27.                          0x800, 20, SHARED_TASK};
      28.     return config;
      29. }

    • 创建服务对象：

      1. static ExampleService g_example = {
      2.     .GetName = GetName,
      3.     .Initialize = Initialize,
      4.     .MessageHandle = MessageHandle,
      5.     .GetTaskConfig = GetTaskConfig,
      6.     SERVER_IPROXY_IMPL_BEGIN,
      7.         .Invoke = NULL,
      8.         .SyncCall = SyncCall,
      9.     IPROXY_END,
      10. };

    • 向SAMGR注册服务及接口：

      1. static void Init(void)
      2. {
      3.     SAMGR_GetInstance()->RegisterService((Service *)&g_example);
      4.     SAMGR_GetInstance()->RegisterDefaultFeatureApi(EXAMPLE_SERVICE, GET_IUNKNOWN(g_example));
      5. }

    • 定义服务的初始化入口：

      1. SYSEX_SERVICE_INIT(Init);

    开发服务的子功能

    • 继承并重新定义功能：

      1. typedef struct DemoFeature {
      2.     INHERIT_FEATURE;
      3.     INHERIT_IUNKNOWNENTRY(DemoApi);
      4.     Identity identity;
      5.     Service *parent;
      6. } DemoFeature;

    • 实现功能的生命周期函数：

      1. static const char *FEATURE_GetName(Feature *feature)
      2. {
      3.     return EXAMPLE_FEATURE;
      4. }
      6. static void FEATURE_OnInitialize(Feature *feature, Service *parent, Identity identity)
      7. {
      8.     DemoFeature *demoFeature = (DemoFeature *)feature;
      9.     demoFeature->identity = identity;
      10.     demoFeature->parent = parent;
      11. }
      13. static void FEATURE_OnStop(Feature *feature, Identity identity)
      14. {
      15.     g_example.identity.queueId = NULL;
      16.     g_example.identity.featureId = -1;
      17.     g_example.identity.serviceId = -1;
      18. }
      20. static BOOL FEATURE_OnMessage(Feature *feature, Request *request)
      21. {
      22.     if (request->msgId == MSG_PROC) {
      23.         Response response = {.data = "Yes, you did!", .len = 0};
      24.         SAMGR_SendResponse(request, &response);
      25.         return TRUE;
      26.     } else {
      27.         if (request->msgId == MSG_TIME_PROC) {
      28.             LOS_Msleep(WAIT_FEATURE_PROC * 10);
      29.             if (request->msgValue) {
      30.                 SAMGR_PrintServices();
      31.             } else {
      32.                 SAMGR_PrintOperations();
      33.             }
      34.             AsyncTimeCall(GET_IUNKNOWN(g_example));
      35.             return FALSE;
      36.         }
      37.     }
      38.     return FALSE;
      39. }

    • 创建功能对象：

      1. static DemoFeature g_example = {
      2.     .GetName = FEATURE_GetName,
      3.     .OnInitialize = FEATURE_OnInitialize,
      4.     .OnMessage = FEATURE_OnMessage,
      5.     DEFAULT_IUNKNOWN_ENTRY_BEGIN,
      6.         .AsyncCall = AsyncCall,
      7.         .AsyncTimeCall = AsyncTimeCall,
      8.         .SyncCall = SyncCall,
      9.         .AsyncCallBack = AsyncCallBack,
      10.     DEFAULT_IUNKNOWN_ENTRY_END,
      11.     .identity = {-1, -1, NULL},
      12. };
      1. static void Init(void){
      3.     SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE, GET_IUNKNOWN(g_example));
      4. }

    • 定义功能的初始化入口：

      1. SYSEX_FEATURE_INIT(Init);

    开发进程内对外接口

    • 定义IUnknown接口：

    • 定义IUnknown的引用对象：

      1. typedef struct DemoRefApi {
      2.     INHERIT_IUNKNOWNENTRY(DemoApi);
      3. } DemoRefApi;

    • 初始化接口对象：

      1. static DemoRefApi api = {
      2.     DEFAULT_IUNKNOWN_ENTRY_BEGIN,
      3.         .AsyncCall = AsyncCall,
      4.         .AsyncTimeCall = AsyncTimeCall,
      5.         .SyncCall = SyncCall,
      6.         .AsyncCallBack = AsyncCallBack,
      7.     DEFAULT_IUNKNOWN_ENTRY_END,
      8. };

    • 注册服务接口：

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

    • 获取服务的对外接口：

      1. DemoApi *demoApi = NULL;
      2. IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
      3. if (iUnknown == NULL) {
      4.     return NULL;
      5. }
      6. int result = iUnknown->QueryInterface(iUnknown, DEFAULT_VERSION, (void **)&demoApi);
      7. if (result != 0 || demoApi == NULL) {
      8.     return NULL;
      9. }

    • 接口调用：

      1. if (demoApi->AsyncCallBack == NULL) {
      2.     return NULL;
      3. }
      4. demoApi->AsyncCallBack((IUnknown *)demoApi, "I wanna async call callback good result!", AsyncHandler);

    • 释放接口：

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

    开发跨进程间对外接口

    • 继承IServerProxy替代继承IUnknown：INHERIT_SERVER_IPROXY

      1. typedef struct DemoFeatureApi {
      2.     INHERIT_SERVER_IPROXY;
      3.     BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);
      4.     BOOL (*AsyncTimeCall)(IUnknown *iUnknown);
      5.     BOOL (*SyncCall)(IUnknown *iUnknown, struct Payload *payload);
      6.     BOOL (*AsyncCallBack)(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler);
      7. } DemoFeatureApi;

    • 初始化IServerProxy的Invoke函数：

      1. static DemoFeature g_example = {
      2.     SERVER_IPROXY_IMPL_BEGIN,
      3.     .Invoke = Invoke,
      4.     .AsyncCall = AsyncCall,
      5.     .AsyncTimeCall = AsyncTimeCall,
      6.     .SyncCall = SyncCall,
      7.     .AsyncCallBack = AsyncCallBack,
      8.     IPROXY_END,
      9. };

    • 实现Invoke函数来处理Ipc消息：

      1. static int32 Invoke(IServerProxy *iProxy, int funcId, void *origin, IpcIo *req, IpcIo *reply)
      2. {
      3.     DemoFeatureApi *api = (DemoFeatureApi *)iProxy;
      4.     BOOL ret;
      5.     size_t len = 0;
      6.     switch (funcId) {
      7.         case ID_ASYNCALL:
      8.             ret = api->AsyncCall((IUnknown *)iProxy, (char *)IpcIoPopString(req, &len));
      9.             IpcIoPushBool(reply, ret);
      10.             break;
      11.         case ID_ASYNTIMECALL:
      12.             ret = api->AsyncTimeCall((IUnknown *)iProxy);
      13.             IpcIoPushBool(reply, ret);
      14.             break;
      15.         case ID_SYNCCALL: {
      16.             struct Payload payload;
      17.             payload.id = IpcIoPopInt32(req);
      18.             payload.value = IpcIoPopInt32(req);
      19.             payload.name = (char *)IpcIoPopString(req, &len);
      20.             ret = api->SyncCall((IUnknown *)iProxy, &payload);
      21.             IpcIoPushString(reply, ret ? "TRUE" : "FALSE");
      22.         }
      23.             break;
      24.         case ID_ASYNCCALLBACK: { // convert to sync proxy
      25.             IpcIoPushString(reply, "Yes, you did!");
      26.             IpcIoPushBool(reply, TRUE);
      27.         }
      28.             break;
      29.         default:
      30.             IpcIoPushBool(reply, FALSE);
      31.             break;
      32.     }
      33.     return EC_SUCCESS;
      34. }

    • 注册接口：与进程内接口注册一致

    调用跨进程间服务

    • 获取跨进程服务的对外接口：

      1. IClientProxy *demoApi = NULL;
      2. IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
      3. if (iUnknown == NULL) {
      4.     return NULL;
      5. }
      6. int result = iUnknown->QueryInterface(iUnknown, CLIENT_PROXY_VER, (void **)&demoApi);
      7. if (result != 0 || demoApi == NULL) {
      8.     return NULL;
      9. }

    • 调用Ipc消息接口：

      1. IpcIo request;char data[250];
      2. IpcIoInit(&request, data, sizeof(data), 0);
      3. demoApi->Invoke(demoApi, 0, &request, NULL, NULL);

    • 释放接口：

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

    • 定义IPC接口客户端代理：

      1.     INHERIT_CLIENT_IPROXY;
      2.     BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);
      3.     BOOL (*AsyncTimeCall)(IUnknown *iUnknown);
      4.     BOOL (*SyncCall)(IUnknown *iUnknown, struct Payload *payload);
      5.     BOOL (*AsyncCallBack)(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler);
      6. } DemoClientProxy;
      7. typedef struct DemoClientEntry {
      8.     INHERIT_IUNKNOWNENTRY(DemoClientProxy);
      9. } DemoClientEntry;

    • 实现客户端代理封装Ipc消息接口：

      1. static BOOL AsyncCall(IUnknown *iUnknown, const char *buff)
      3.     DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
      4.     IpcIo request;
      5.     char data[MAX_DATA_LEN];
      6.     IpcIoInit(&request, data, MAX_DATA_LEN, 0);
      7.     IpcIoPushString(&request, buff);
      8.     int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNCALL, &request, NULL, NULL);
      9.     return ret == EC_SUCCESS;
      10. }
      12. static BOOL AsyncTimeCall(IUnknown *iUnknown)
      13. {
      14.     DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
      15.     IpcIo request;
      16.     char data[MAX_DATA_LEN];
      17.     IpcIoInit(&request, data, MAX_DATA_LEN, 0);
      18.     int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNTIMECALL, &request, NULL, NULL);
      19.     return ret == EC_SUCCESS;
      20. }
      22. static int Callback(IOwner owner, int code, IpcIo *reply)
      23. {
      24.     size_t len = 0;
      25.     return strcpy_s(owner, MAX_DATA_LEN, (char *)IpcIoPopString(reply, &len));
      26. }
      28. static BOOL SyncCall(IUnknown *iUnknown, struct Payload *payload)
      29. {
      30.     DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
      31.     IpcIo request;
      32.     char data[MAX_DATA_LEN];
      33.     IpcIoInit(&request, data, MAX_DATA_LEN, 0);
      34.     IpcIoPushInt32(&request, payload->id);
      35.     IpcIoPushInt32(&request, payload->value);
      36.     IpcIoPushString(&request, payload->name);
      37.     int ret = proxy->Invoke((IClientProxy *)proxy, ID_SYNCCALL, &request, data, Callback);
      38.     data[MAX_DATA_LEN - 1] = 0;
      39.     HILOG_INFO(HILOG_MODULE_APP, "[TID:0x%lx]Remote response is %s!", pthread_self(), data);
      40.     return ret == EC_SUCCESS;
      41. }
      43. struct CurrentNotify {
      44.     IOwner notify;
      45.     INotifyFunc handler;
      46. };
      48. static int CurrentCallback(IOwner owner, int code, IpcIo *reply)
      49. {
      50.     struct CurrentNotify *notify = (struct CurrentNotify *)owner;
      51.     size_t len = 0;
      52.     char *response = (char *)IpcIoPopString(reply, &len);
      53.     HILOG_INFO(HILOG_MODULE_APP, "[TID:0x%lx]Notify Remote response is %s!", pthread_self(), response);
      54.     notify->handler(notify->notify, response);
      55.     return EC_SUCCESS;
      56. }
      58. static BOOL AsyncCallBack(IUnknown *iUnknown, const char *buff, IOwner notify, INotifyFunc handler)
      59. {
      60.     struct CurrentNotify owner = {notify, handler};
      61.     DemoClientProxy *proxy = (DemoClientProxy *)iUnknown;
      62.     IpcIo request;
      63.     char data[MAX_DATA_LEN];
      64.     IpcIoInit(&request, data, MAX_DATA_LEN, 0);
      65.     IpcIoPushString(&request, buff);
      66.     int ret = proxy->Invoke((IClientProxy *)proxy, ID_ASYNCCALLBACK, &request, &owner, CurrentCallback);
      67.     return ret == EC_SUCCESS;
      68. }

    • 实现客户端代理的工厂方法：

      1. void *DEMO_CreatClient(const char *service, const char *feature, uint32 size)
      2. {
      3.     (void)service;
      4.     (void)feature;
      5.     uint32 len = size + sizeof(DemoClientEntry);
      6.     uint8 *client = malloc(len);
      7.     (void)memset_s(client, len, 0, len);
      8.     DemoClientEntry *entry = (DemoClientEntry *)&client[size];
      9.     entry->ver = ((uint16)CLIENT_PROXY_VER | (uint16)DEFAULT_VERSION);
      10.     entry->ref = 1;
      11.     entry->iUnknown.QueryInterface = IUNKNOWN_QueryInterface;
      12.     entry->iUnknown.AddRef = IUNKNOWN_AddRef;
      13.     entry->iUnknown.Release = IUNKNOWN_Release;
      14.     entry->iUnknown.Invoke = NULL;
      15.     entry->iUnknown.AsyncCall = AsyncCall;
      16.     entry->iUnknown.AsyncTimeCall = AsyncTimeCall;
      17.     entry->iUnknown.SyncCall = SyncCall;
      18.     entry->iUnknown.AsyncCallBack = AsyncCallBack;
      19.     return client;
      20. }
      21. void DEMO_DestroyClient(const char *service, const char *feature, void *iproxy)
      22. {
      23.     free(iproxy);
      24. }

    • 将客户端代理的工厂方法注册到SAMGR：

      1. SAMGR_RegisterFactory(EXAMPLE_SERVICE, EXAMPLE_FEATURE, DEMO_CreatClient, DEMO_DestroyClient);

    • 获取跨进程服务的对外接口：

      1. DemoClientProxy *demoApi = NULL;
      2. IUnknown *iUnknown = SAMGR_GetInstance()->GetFeatureApi(EXAMPLE_SERVICE, EXAMPLE_FEATURE);
      3. if (iUnknown == NULL) {
      4.     return NULL;
      5. }
      6. int result = iUnknown->QueryInterface(iUnknown, DEFAULT_VERSION, (void **)&demoApi);
      7. if (result != 0 || demoApi == NULL) {
      8.     return NULL;
      9. }

    • 调用跨进程服务的客户端代理接口：

      1. if (demoApi->AsyncCallBack == NULL) {
      2.     return NULL;
      3. }

    • 释放接口：

    涉及仓

    distributedschedule_interfaces_innerkits_samgr_lite