Add CopyOnLoopListenerSet which may be faster (315db32e) · Commits · e / os / android_frameworks_base

packages/SystemUI/multivalentTests/src/com/android/systemui/util/CopyOnLoopListenerSetTest.kt

0 → 100644

+27 −0

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		/*
		* Copyright (C) 2024 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 com.android.systemui.util

		import androidx.test.ext.junit.runners.AndroidJUnit4
		import androidx.test.filters.SmallTest
		import org.junit.runner.RunWith

		@SmallTest
		@RunWith(AndroidJUnit4::class)
		class CopyOnLoopListenerSetTest : ListenerSetTest() {
		override fun makeRunnableListenerSet(): IListenerSet<Runnable> = CopyOnLoopListenerSet()
		}

packages/SystemUI/tests/src/com/android/systemui/util/ListenerSetTest.kt→packages/SystemUI/multivalentTests/src/com/android/systemui/util/ListenerSetTest.kt

+21 −26

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		@@ -168,15 +168,14 @@ open class ListenerSetTest : SysuiTestCase() {
		// Setup and preconditions
		val runnablesCalled = mutableListOf<Int>()
		// runnable1 is configured to remove itself
		val runnable1 = object : Runnable {
		val runnable1 =
		object : Runnable {
		override fun run() {
		runnableSet.remove(this)
		runnablesCalled.add(1)
		}
		}
		val runnable2 = Runnable {
		runnablesCalled.add(2)
		}
		val runnable2 = Runnable { runnablesCalled.add(2) }
		assertThat(runnableSet).isEmpty()
		runnableSet.addIfAbsent(runnable1)
		runnableSet.addIfAbsent(runnable2)
		@@ -194,17 +193,13 @@ open class ListenerSetTest : SysuiTestCase() {
		fun addIfAbsent_isReentrantSafe() {
		// Setup and preconditions
		val runnablesCalled = mutableListOf<Int>()
		val runnable99 = Runnable {
		runnablesCalled.add(99)
		}
		val runnable99 = Runnable { runnablesCalled.add(99) }
		// runnable1 is configured to add runnable99
		val runnable1 = Runnable {
		runnableSet.addIfAbsent(runnable99)
		runnablesCalled.add(1)
		}
		val runnable2 = Runnable {
		runnablesCalled.add(2)
		}
		val runnable2 = Runnable { runnablesCalled.add(2) }
		assertThat(runnableSet).isEmpty()
		runnableSet.addIfAbsent(runnable1)
		runnableSet.addIfAbsent(runnable2)

packages/SystemUI/tests/src/com/android/systemui/util/NamedListenerSetTest.kt→packages/SystemUI/multivalentTests/src/com/android/systemui/util/NamedListenerSetTest.kt

+0 −0

File moved.

View file

packages/SystemUI/src/com/android/systemui/util/CopyOnLoopListenerSet.kt

0 → 100644

+46 −0

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		/*
		* Copyright (C) 2024 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 com.android.systemui.util

		/**
		* A collection of listeners, observers, callbacks, etc.
		*
		* This container is optimized for frequent mutation and infrequent iteration, with reentrant-safety
		* guarantees but without thread-safety guarantees. Specifically, to ensure that
		* [ConcurrentModificationException] is not thrown when listeners mutate the set, this iterator will
		* not reflect changes made to the set after the iterator is constructed.
		*/
		class CopyOnLoopListenerSet<E : Any>
		/** Private constructor takes the internal list so that we can use auto-delegation */
		private constructor(private val listeners: ArrayList<E>) :
		Collection<E> by listeners, IListenerSet<E> {

		/** Create a new instance */
		constructor() : this(ArrayList())

		@Suppress("UNCHECKED_CAST")
		override fun iterator(): Iterator<E> = listeners.toArray().iterator() as Iterator<E>

		override fun addIfAbsent(element: E): Boolean =
		if (element in listeners) {
		false
		} else {
		listeners.add(element)
		}

		override fun remove(element: E): Boolean = listeners.remove(element)
		}