xref: /aosp_15_r20/system/libhidl/transport/manager/1.0/IServiceManager.hal (revision 8222fbe171c3d6fadfe95119c180cf3010c392a8)

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package [email protected];

import IServiceNotification;
import [email protected]::DebugInfo.Architecture;

/**
 * Manages all the hidl hals on a device.
 *
 * All examples in this file assume that there is one service registered with
 * the service manager, "[email protected]::IServiceManager/manager"
 *
 * Terminology:
 *   Package: "android.hidl.manager"
 *   Major version: "1"
 *   Minor version: "0"
 *   Version: "1.0"
 *   Interface name: "IServiceManager"
 *   Fully-qualified interface name: "[email protected]::IServiceManager"
 *   Instance name: "manager"
 *   Fully-qualified instance name: "[email protected]::IServiceManager/manager"
 */
interface IServiceManager {

    /**
     * Retrieve an existing service that supports the requested version.
     *
     * WARNING: This function is for libhidl/HwBinder use only. You are likely
     * looking for 'IMyInterface::getService("name")' instead.
     *
     * @param fqName   Fully-qualified interface name.
     * @param name     Instance name. Same as in IServiceManager::add.
     *
     * @return service Handle to requested service, same as provided in
     *                 IServiceManager::add. Will be nullptr if not available.
     */
    get(string fqName, string name) generates (interface service);

    /**
     * Register a service. The service manager must retrieve the (inherited)
     * interfaces that this service implements, and register them along with
     * the service.
     *
     * Each interface must have its own namespace for instance names. If you
     * have two unrelated interfaces IFoo and IBar, it must be valid to call:
     *
     * add("my_instance", foo); // foo implements IFoo
     * add("my_instance", bar); // bar implements IBar
     *
     * WARNING: This function is for libhidl/HwBinder use only. You are likely
     * looking for 'INTERFACE::registerAsService("name")' instead.
     *
     * @param name           Instance name. Must also be used to retrieve service.
     * @param service        Handle to registering service.
     *
     * @return success       Whether or not the service was registered.
     *
     */
    add(string name, interface service) generates (bool success);

    enum Transport : uint8_t {
        EMPTY,
        HWBINDER,
        PASSTHROUGH,
    };

    /**
     * Get the transport of a service.
     *
     * @param fqName     Fully-qualified interface name.
     * @param name       Instance name. Same as in IServiceManager::add
     *
     * @return transport Transport of service if known.
     */
    getTransport(string fqName, string name) generates (Transport transport);

    /**
     * List all registered services. Must be sorted.
     *
     * @return fqInstanceNames List of fully-qualified instance names.
     */
    list() generates (vec<string> fqInstanceNames);

    /**
     * List all instances of a particular service. Must be sorted.
     *
     * @param fqName         Fully-qualified interface name.
     *
     * @return instanceNames List of instance names running the particular service.
     */
    listByInterface(string fqName) generates (vec<string> instanceNames);

    /**
     * Register for service notifications for a particular service. Must support
     * multiple registrations.
     *
     * onRegistration must be sent out for all services which support the
     * version provided in the fqName. For instance, if a client registers for
     * notifications from "[email protected]", they must also get
     * notifications from "[email protected]". If a matching service
     * is already registered, onRegistration must be sent out with preexisting
     * = true.
     *
     * @param fqName   Fully-qualified interface name.
     * @param name     Instance name. If name is empty, notifications must be
     *                 sent out for all names.
     * @param callback Client callback to recieve notifications.
     *
     * @return success Whether or not registration was successful.
     */
    registerForNotifications(string fqName,
                             string name,
                             IServiceNotification callback)
        generates (bool success);

    /**
     * Special values for InstanceDebugInfo pids.
     */
    enum PidConstant : int32_t {
        NO_PID = -1,
    };

    /**
     * Returned object for debugDump().
     */
    struct InstanceDebugInfo {
        string interfaceName;
        string instanceName;
        int32_t pid; // PidConstants:NO_PID if unavailable
        vec<int32_t> clientPids;
        Architecture arch;
    };

    /**
     * Similar to list, but contains more information for each instance.
     * @return info a vector where each item contains debug information for each
     *         instance.
     */
    debugDump() generates (vec<InstanceDebugInfo> info);

    /**
     * When the passthrough service manager returns a service via
     * get(string, string), it must dispatch a registerPassthroughClient call
     * to the binderized service manager to indicate the current process has
     * called get(). Binderized service manager must record this PID, which can
     * be retrieved via debugDump.
     */
    registerPassthroughClient(string fqName, string name);
};