The samgr module is a core module of OpenHarmony. It provides functions related to system abilities (also called system services), including system ability (SA) startup, registration, and query.

Directory Structure

/foundation/distributedschedule/samgr/services/samgr/
├── native             
│   ├── BUILD.gn  # Compilation script
│   ├── include   # Header files
│   ├── samgr.rc  # RC file for starting samgr
│   ├── source    # Source code
│   ├── test      # Test code

Usage

After receiving the registration message from the SA framework, the samgr service saves information about the particular SA in the local cache.

int32_t SystemAbilityManager::AddSystemAbility(int32_t systemAbilityId, const sptr<IRemoteObject>& ability,
    const SAExtraProp& extraProp)
{
    if (!CheckInputSysAbilityId(systemAbilityId) || ability == nullptr || (!CheckCapability(extraProp.capability))) {
        HILOGE("AddSystemAbilityExtra input params is invalid.");
        return ERR_INVALID_VALUE;
    }
    {
        unique_lock<shared_mutex> writeLock(abilityMapLock_);
        auto saSize = abilityMap_.size();
        if (saSize >= MAX_SERVICES) {
            HILOGE("map size error, (Has been greater than %zu)", saSize);
            return ERR_INVALID_VALUE;
        }
        SAInfo saInfo;
        saInfo.remoteObj = ability;
        saInfo.isDistributed = extraProp.isDistributed;
        saInfo.capability = extraProp.capability;
        saInfo.permission = Str16ToStr8(extraProp.permission);
        abilityMap_[systemAbilityId] = std::move(saInfo);
        HILOGI("insert %{public}d. size : %zu,", systemAbilityId, abilityMap_.size());
    }
    if (abilityDeath_ != nullptr) {
        ability->AddDeathRecipient(abilityDeath_);
    }
    FindSystemAbilityManagerNotify(systemAbilityId, ADD_SYSTEM_ABILITY_TRANSACTION);
    u16string strName = Str8ToStr16(to_string(systemAbilityId));
    if (extraProp.isDistributed && dBinderService_ != nullptr) {
        dBinderService_->RegisterRemoteProxy(strName, ability);
        HILOGD("AddSystemAbility RegisterRemoteProxy, serviceId is %{public}d", systemAbilityId);
    }
    if (systemAbilityDataStorage_ == nullptr) {
        HILOGE("AddSystemAbility systemAbilityDataStorage not init!");
        return ERR_NO_INIT;
    }
    if (extraProp.isDistributed) {
        systemAbilityDataStorage_->ClearSyncRecords();
        DoInsertSaData(strName, ability, extraProp);
    }
}

If the SA requested by the SA framework is a local SA, the samgr service searches for the proxy object of the SA based on the SA ID and then returns the proxy object to the SA framework.

sptr<IRemoteObject> SystemAbilityManager::CheckSystemAbility(int32_t systemAbilityId)
{
    if (!CheckInputSysAbilityId(systemAbilityId)) {
        return nullptr;
    }

    std::string selectedDeviceId;
    if (CheckRemoteSa(to_string(systemAbilityId), selectedDeviceId)) {
       return CheckSystemAbility(systemAbilityId, selectedDeviceId);
    }

    shared_lock<shared_mutex> readLock(abilityMapLock_);
    auto iter = abilityMap_.find(systemAbilityId);
    if (iter != abilityMap_.end()) {
        auto callingUid = IPCSkeleton::GetCallingUid();
        if (IsSystemApp(callingUid) || CheckPermission(iter->second.permission)) {
             return iter->second.remoteObj;
        }
        return nullptr;
    }
    return nullptr;
}

Repositories Involved

Distributed Scheduler subsystem

distributedschedule_dms_fwk

distributedschedule_safwk

distributedschedule_samgr

distributedschedule_safwk_lite

hdistributedschedule_samgr_lite

distributedschedule_dms_fwk_lite