Merge "Add garbage collecion function to BufferHubService"

    return Void();

}

hidl_handle BufferHubService::registerToken(const BufferClient* client) {

hidl_handle BufferHubService::registerToken(const wp<BufferClient>& client) {

    uint32_t token;

    std::lock_guard<std::mutex> lock(mTokenMapMutex);

    do {

    // Non-binder functions

    // Internal help function for IBufferClient::duplicate.

    hidl_handle registerToken(const BufferClient* client);

    hidl_handle registerToken(const wp<BufferClient>& client);

private:

    // List of active BufferClient for bookkeeping.

    std::mutex mClientListMutex;

    std::vector<sp<BufferClient>> mClientList GUARDED_BY(mClientListMutex);

    std::vector<wp<BufferClient>> mClientList GUARDED_BY(mClientListMutex);

    // TODO(b/118180214): use a more secure implementation

    std::mt19937 mTokenEngine;

    // The mapping from token to the client creates it.

    std::mutex mTokenMapMutex;

    std::map<uint32_t, const BufferClient*> mTokenMap GUARDED_BY(mTokenMapMutex);

    std::map<uint32_t, const wp<BufferClient>> mTokenMap GUARDED_BY(mTokenMapMutex);

};

} // namespace implementation