60 lines
1.7 KiB
Java
60 lines
1.7 KiB
Java
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/*
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* Copyright (C) 2020 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.media.permission;
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import android.annotation.NonNull;
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import android.os.Binder;
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/**
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* An RAII-style object, used to establish a scope in which the binder calling identity is cleared.
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*
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* <p>
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* Intended usage:
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* <pre>
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* void caller() {
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* try (SafeCloseable ignored = ClearCallingIdentityContext.create()) {
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* // Within this scope the binder calling identity is cleared.
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* ...
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* }
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* // Outside the scope the calling identity is restored to its prior state.
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* </pre>
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*
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* @hide
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*/
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public class ClearCallingIdentityContext implements SafeCloseable {
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private final long mRestoreKey;
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/**
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* Creates a new instance.
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* @return A {@link SafeCloseable}, intended to be used in a try-with-resource block.
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*/
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public static @NonNull
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SafeCloseable create() {
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return new ClearCallingIdentityContext();
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}
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@SuppressWarnings("ResultOfClearIdentityCallNotStoredInVariable")
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private ClearCallingIdentityContext() {
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mRestoreKey = Binder.clearCallingIdentity();
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}
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@Override
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public void close() {
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Binder.restoreCallingIdentity(mRestoreKey);
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}
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}
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