Merge "Reduce system calls of ThreadPriorityBooster" into qt-dev (c7ae454f) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/ThreadPriorityBooster.java

+12 −14

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@ import static android.os.Process.setThreadPriority;
		public class ThreadPriorityBooster {

		private static final boolean ENABLE_LOCK_GUARD = false;
		private static final int PRIORITY_NOT_ADJUSTED = Integer.MAX_VALUE;

		private volatile int mBoostToPriority;
		private final int mLockGuardIndex;
		@@ -42,13 +43,12 @@ public class ThreadPriorityBooster {
		}

		public void boost() {
		final int tid = myTid();
		final PriorityState state = mThreadState.get();
		if (state.regionCounter == 0) {
		final int prevPriority = getThreadPriority(tid);
		state.prevPriority = prevPriority;
		final int prevPriority = getThreadPriority(state.tid);
		if (prevPriority > mBoostToPriority) {
		setThreadPriority(tid, mBoostToPriority);
		setThreadPriority(state.tid, mBoostToPriority);
		state.prevPriority = prevPriority;
		}
		}
		state.regionCounter++;
		@@ -60,11 +60,9 @@ public class ThreadPriorityBooster {
		public void reset() {
		final PriorityState state = mThreadState.get();
		state.regionCounter--;
		if (state.regionCounter == 0) {
		final int currentPriority = getThreadPriority(myTid());
		if (state.prevPriority != currentPriority) {
		setThreadPriority(myTid(), state.prevPriority);
		}
		if (state.regionCounter == 0 && state.prevPriority != PRIORITY_NOT_ADJUSTED) {
		setThreadPriority(state.tid, state.prevPriority);
		state.prevPriority = PRIORITY_NOT_ADJUSTED;
		}
		}

		@@ -78,16 +76,16 @@ public class ThreadPriorityBooster {
		// variable immediately.
		mBoostToPriority = priority;
		final PriorityState state = mThreadState.get();
		final int tid = myTid();
		if (state.regionCounter != 0) {
		final int prevPriority = getThreadPriority(tid);
		final int prevPriority = getThreadPriority(state.tid);
		if (prevPriority != priority) {
		setThreadPriority(tid, priority);
		setThreadPriority(state.tid, priority);
		}
		}
		}

		private static class PriorityState {
		final int tid = myTid();

		/**
		* Acts as counter for number of synchronized region that needs to acquire 'this' as a lock
		@@ -99,6 +97,6 @@ public class ThreadPriorityBooster {
		/**
		* The thread's previous priority before boosting.
		*/
		int prevPriority;
		int prevPriority = PRIORITY_NOT_ADJUSTED;
		}
		}

services/tests/servicestests/src/com/android/server/ThreadPriorityBoosterTest.java

0 → 100644

+97 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 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 com.android.server;

		import static android.os.Process.getThreadPriority;
		import static android.os.Process.myTid;
		import static android.os.Process.setThreadPriority;

		import static org.junit.Assert.assertEquals;

		import android.os.Process;
		import android.platform.test.annotations.Presubmit;

		import androidx.test.filters.SmallTest;

		import org.junit.Test;

		/**
		* Tests for {@link ThreadPriorityBooster}.
		* Build/Install/Run:
		* atest FrameworksServicesTests:ThreadPriorityBoosterTest
		*/
		@SmallTest
		@Presubmit
		public class ThreadPriorityBoosterTest {
		private static final int PRIORITY_BOOST = Process.THREAD_PRIORITY_FOREGROUND;
		private static final int PRIORITY_BOOST_MORE = Process.THREAD_PRIORITY_DISPLAY;

		private final ThreadPriorityBooster mBooster = new ThreadPriorityBooster(PRIORITY_BOOST,
		0 /* lockGuardIndex */);

		@Test
		public void testThreadPriorityBooster() {
		joinNewThread(() -> {
		final int origPriority = Process.THREAD_PRIORITY_DEFAULT;
		setThreadPriority(origPriority);

		boost(() -> {
		assertThreadPriority(PRIORITY_BOOST);
		boost(() -> {
		// Inside the boost region, the priority should also apply to current thread.
		mBooster.setBoostToPriority(PRIORITY_BOOST_MORE);
		assertThreadPriority(PRIORITY_BOOST_MORE);
		});
		// It is still in the boost region so the set priority should be kept.
		assertThreadPriority(PRIORITY_BOOST_MORE);

		joinNewThread(() -> boost(() -> assertThreadPriority(PRIORITY_BOOST_MORE)));
		});
		// The priority should be restored after leaving the boost region.
		assertThreadPriority(origPriority);

		// It doesn't apply to current thread because outside of the boost region, but the boost
		// in other threads will use the set priority.
		mBooster.setBoostToPriority(PRIORITY_BOOST);
		joinNewThread(() -> boost(() -> assertThreadPriority(PRIORITY_BOOST)));

		assertThreadPriority(origPriority);
		});
		}

		private static void assertThreadPriority(int expectedPriority) {
		assertEquals(expectedPriority, getThreadPriority(myTid()));
		}

		private static void joinNewThread(Runnable action) {
		final Thread thread = new Thread(action);
		thread.start();
		try {
		thread.join();
		} catch (InterruptedException ignored) {
		}
		}

		private void boost(Runnable action) {
		try {
		mBooster.boost();
		action.run();
		} finally {
		mBooster.reset();
		}
		}
		}