transport/token/1.0/ITokenManager.hal

/*
 * 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 android.hidl.token@1.0;

/**
 * This facilitates converting hidl interfaces into something that
 * are more easily transferrable to other processes.
 */
interface ITokenManager {

    /**
     * Register an interface. The server must only keep a weak reference
     * to the token. The lifetime of the token is thus linked to the
     * lifetime of the stored interface.
     *
     * @param store Interface which can later be fetched with the returned token.
     * @return token Opaque value which may be used as inputs to other functions.
     */
    createToken(interface store) generates (uint64_t token);

    /**
     * Explicitly unregister an interface. If the server still holds a weak reference
     * to an interface, but that interface interface is deleted and the reference
     * cannot be promoted, then success must be false.
     *
     * @param token Token recieved from createToken
     * @return success Whether or not an interface was successfully unregistered.
     */
    unregister(uint64_t token) generates (bool success);

    /**
     * Fetches an interface from a provided token. This must also unregister the
     * token.
     *
     * @param token Token recieved from createToken
     * @return store Interface registered with createToken and the corresponding
     *               token or nullptr.
     */
    get(uint64_t token) generates (interface store);
};