Threads.java
/*
* Copyright 2019 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 androidx.camera.core.impl.utils;
import android.os.Looper;
import androidx.core.util.Preconditions;
/**
* Helpers for {@link Thread}s.
*/
public final class Threads {
// Prevent instantiation.
private Threads() {
}
/** Returns true if we're currently running in the application's main thread. */
public static boolean isMainThread() {
return Looper.getMainLooper().getThread() == Thread.currentThread();
}
/** Returns true if we're currently running on a background thread. */
public static boolean isBackgroundThread() {
return !isMainThread();
}
/**
* Ensures that we're currently running in the application's main thread.
*
* @throws IllegalStateException If the caller is not running on the main thread,
*/
public static void checkMainThread() {
Preconditions.checkState(isMainThread(), "Not in application's main thread");
}
/**
* Ensures that we're currently not running in the application's main thread.
*
* @throws IllegalStateException if the caller is running on the main thread.
*/
public static void checkBackgroundThread() {
Preconditions.checkState(isBackgroundThread(), "In application's main thread");
}
}