OpenHarmony鸿蒙开发（ Beta5.0）轻量型系统服务管理部件详解

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。

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;
    ent