1# samgr组件<a name="ZH-CN_TOPIC_0000001162068341"></a> 2## 简介<a name="section11660541593"></a> 3 4samgr组件是OpenHarmony的核心组件，提供OpenHarmony系统服务启动、注册、查询等功能。 5 6 7 8## 目录<a name="section161941989596"></a> 9 10``` 11/foundation/distributedschedule 12├── samgr 13│ ├── bundle.json # 部件描述及编译文件 14│ ├── frameworks # 框架实现存在目录 15│ ├── interfaces # 接口目录 16│ ├── services # 组件服务端目录 17│ ├── test # 测试代码存放目录 18│ ├── utils # 工具类目录 19``` 20 21## 说明<a name="section1312121216216"></a> 22 231. samgr服务接收到sa框架层发送的注册消息，会在本地缓存中存入系统服务相关信息。 24 25 ``` 26 int32_t SystemAbilityManager::AddSystemAbility(int32_t systemAbilityId, const sptr<IRemoteObject>& ability, 27 const SAExtraProp& extraProp) 28 { 29 if (!CheckInputSysAbilityId(systemAbilityId) || ability == nullptr) { 30 HILOGE("AddSystemAbilityExtra input params is invalid."); 31 return ERR_INVALID_VALUE; 32 } 33 { 34 unique_lock<shared_mutex> writeLock(abilityMapLock_); 35 auto saSize = abilityMap_.size(); 36 if (saSize >= MAX_SERVICES) { 37 HILOGE("map size error, (Has been greater than %zu)", saSize); 38 return ERR_INVALID_VALUE; 39 } 40 SAInfo saInfo; 41 saInfo.remoteObj = ability; 42 saInfo.isDistributed = extraProp.isDistributed; 43 saInfo.capability = extraProp.capability; 44 saInfo.permission = Str16ToStr8(extraProp.permission); 45 abilityMap_[systemAbilityId] = std::move(saInfo); 46 HILOGI("insert %{public}d. size : %{public}zu", systemAbilityId, abilityMap_.size()); 47 } 48 RemoveCheckLoadedMsg(systemAbilityId); 49 if (abilityDeath_ != nullptr) { 50 ability->AddDeathRecipient(abilityDeath_); 51 } 52 53 u16string strName = Str8ToStr16(to_string(systemAbilityId)); 54 if (extraProp.isDistributed && dBinderService_ != nullptr) { 55 dBinderService_->RegisterRemoteProxy(strName, systemAbilityId); 56 HILOGD("AddSystemAbility RegisterRemoteProxy, serviceId is %{public}d", systemAbilityId); 57 } 58 if (systemAbilityId == SOFTBUS_SERVER_SA_ID && !isDbinderStart_) { 59 if (dBinderService_ != nullptr && rpcCallbackImp_ != nullptr) { 60 bool ret = dBinderService_->StartDBinderService(rpcCallbackImp_); 61 HILOGI("start result is %{public}s", ret ? "succeed" : "fail"); 62 isDbinderStart_ = true; 63 } 64 } 65 SendSystemAbilityAddedMsg(systemAbilityId, ability); 66 return ERR_OK; 67 } 68 ``` 69 702. 对于本地服务而言，samgr服务接收到sa框架层发送的获取消息，会通过服务id，查找到对应服务的代理对象，然后返回给sa框架。 71 72 ``` 73 sptr<IRemoteObject> SystemAbilityManager::CheckSystemAbility(int32_t systemAbilityId) 74 { 75 if (!CheckInputSysAbilityId(systemAbilityId)) { 76 HILOGW("CheckSystemAbility CheckSystemAbility invalid!"); 77 return nullptr; 78 } 79 80 shared_lock<shared_mutex> readLock(abilityMapLock_); 81 auto iter = abilityMap_.find(systemAbilityId); 82 if (iter != abilityMap_.end()) { 83 HILOGI("found service : %{public}d.", systemAbilityId); 84 return iter->second.remoteObj; 85 } 86 HILOGI("NOT found service : %{public}d", systemAbilityId); 87 return nullptr; 88 } 89 ``` 90 913. 动态加载系统服务进程及SystemAbility, 系统进程无需开机启动，而是在SystemAbility被访问的时候按需拉起，并加载指定SystemAbility。 92 3.1 继承SystemAbilityLoadCallbackStub类，并覆写OnLoadSystemAbilitySuccess(int32_t systemAbilityId, const sptr<IRemoteObject>& remoteObject)、OnLoadSystemAbilityFail(int32_t systemAbilityId)方法。 93 94 ``` 95 class OnDemandLoadCallback : public SystemAbilityLoadCallbackStub { 96 public: 97 void OnLoadSystemAbilitySuccess(int32_t systemAbilityId, const sptr<IRemoteObject>& remoteObject) override; 98 void OnLoadSystemAbilityFail(int32_t systemAbilityId) override; 99 }; 100 101 void OnDemandLoadCallback::OnLoadSystemAbilitySuccess(int32_t systemAbilityId, 102 const sptr<IRemoteObject>& remoteObject) // systemAbilityId为指定加载的SAID，remoteObject为指定systemAbility的代理对象 103 { 104 cout << "OnLoadSystemAbilitySuccess systemAbilityId:" << systemAbilityId << " IRemoteObject result:" << 105 ((remoteObject != nullptr) ? "succeed" : "failed") << endl; 106 } 107 108 void OnDemandLoadCallback::OnLoadSystemAbilityFail(int32_t systemAbilityId) // systemAbilityId为指定加载的SAID 109 { 110 cout << "OnLoadSystemAbilityFail systemAbilityId:" << systemAbilityId << endl; 111 } 112 ``` 113 114 3.2 调用samgr提供的动态加载接口LoadSystemAbility(int32_t systemAbilityId, const sptr<ISystemAbilityLoadCallback>& callback)。 115 ``` 116 // 构造步骤1的SystemAbilityLoadCallbackStub子类的实例 117 sptr<OnDemandLoadCallback> loadCallback_ = new OnDemandLoadCallback(); 118 // 调用LoadSystemAbility方法 119 sptr<ISystemAbilityManager> sm = SystemAbilityManagerClient::GetInstance().GetSystemAbilityManager(); 120 if (sm == nullptr) { 121 cout << "GetSystemAbilityManager samgr object null!" << endl; 122 return; 123 } 124 int32_t result = sm->LoadSystemAbility(systemAbilityId, loadCallback_); 125 if (result != ERR_OK) { 126 cout << "systemAbilityId:" << systemAbilityId << " load failed, result code:" << result << endl; 127 return; 128 } 129 ``` 130>说明： 131>1.LoadSystemAbility方法调用成功后，指定SystemAbility加载成功后会触发回调OnLoadSystemAbilitySuccess，加载失败触发回调OnLoadSystemAbilityFail。 132>2.动态加载的进程cfg文件不能配置为开机启动，需指定"dynamic" : true, 示例如下: 133>``` 134>{ 135> "services" : [{ 136> "name" : "listen_test", 137> "path" : ["/system/bin/sa_main", "/system/profile/listen_test.xml"], 138> "dynamic" : true, 139> "uid" : "system", 140> "gid" : ["system", "shell"] 141> } 142> ] 143>} 144>``` 145>3.LoadSystemAbility方法适用于动态加载场景，其他获取SystemAbility场景建议使用CheckSystemAbility方法。 146 147## 相关仓<a name="section1371113476307"></a> 148 149系统服务管理子系统 150 151[distributedschedule\_safwk](https://gitee.com/openharmony/distributedschedule_safwk) 152 153[**distributedschedule\_samgr**](https://gitee.com/openharmony/distributedschedule_samgr) 154 155[distributedschedule\_safwk\_lite](https://gitee.com/openharmony/distributedschedule_safwk_lite) 156 157[distributedschedule\_samgr\_lite](https://gitee.com/openharmony/distributedschedule_samgr_lite) 158 159
