1 /*
2  * Copyright (C) 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.car.builtin.os;
18 
19 import android.annotation.NonNull;
20 import android.annotation.SystemApi;
21 import android.os.ParcelFileDescriptor;
22 import android.os.SharedMemory;
23 
24 import java.io.IOException;
25 
26 /**
27  * Helper for {@link SharedMemory}.
28  *
29  * @hide
30  */
31 @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
32 public final class SharedMemoryHelper {
SharedMemoryHelper()33     private SharedMemoryHelper() {
34         throw new UnsupportedOperationException();
35     }
36 
37     /** Returns the backing file for the shared memory wrapped in {@code ParcelFileDescriptor}*/
38     @NonNull
createParcelFileDescriptor( @onNull SharedMemory memory)39     public static ParcelFileDescriptor createParcelFileDescriptor(
40             @NonNull SharedMemory memory) throws IOException {
41         // Must duplicate the file descriptor because it is currently owned by memory, and we also
42         // want the returned ParcelFileDescriptor to own it.
43         return memory.getFdDup();
44     }
45 }
46