Merge "Optimizing :enter - :exit pairs." into ub-launcher3-master (8efd6782) · Commits · e / os / android_packages_apps_Trebuchet

src/com/android/launcher3/util/RaceConditionTracker.java

+3 −1

Original line number	Diff line number	Diff line
		@@ -24,6 +24,8 @@ package com.android.launcher3.util;
		public class RaceConditionTracker {
		public final static boolean ENTER = true;
		public final static boolean EXIT = false;
		static final String ENTER_POSTFIX = "enter";
		static final String EXIT_POSTFIX = "exit";

		public interface EventProcessor {
		void onEvent(String eventName);
		@@ -46,7 +48,7 @@ public class RaceConditionTracker {
		}

		public static String enterExitEvt(String eventName, boolean isEnter) {
		return eventName + ":" + (isEnter ? "enter" : "exit");
		return eventName + ":" + (isEnter ? ENTER_POSTFIX : EXIT_POSTFIX);
		}

		public static String enterEvt(String eventName) {

tests/src/com/android/launcher3/util/RaceConditionReproducer.java

+83 −10

Original line number	Diff line number	Diff line
		@@ -16,6 +16,9 @@

		package com.android.launcher3.util;

		import static com.android.launcher3.util.RaceConditionTracker.ENTER_POSTFIX;
		import static com.android.launcher3.util.RaceConditionTracker.EXIT_POSTFIX;

		import static org.junit.Assert.assertTrue;
		import static org.junit.Assert.fail;

		@@ -58,6 +61,8 @@ import java.util.concurrent.TimeUnit;
		* Phase 3. Releasing all threads and letting the test iteration run till its end.
		*
		* The iterations end when all seen paths have been declared “uncontinuable”.
		*
		* When we register event XXX:enter, we hold all other events until we register XXX:exit.
		*/
		public class RaceConditionReproducer implements RaceConditionTracker.EventProcessor {
		private static final String TAG = "RaceConditionReproducer";
		@@ -81,7 +86,7 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		private final Map<String, EventNode> mNextEvents = new HashMap<>();
		// Whether we believe that further iterations will not be able to add more events to
		// mNextEvents.
		private boolean mStoppedAddingChildren = false;
		private boolean mStoppedAddingChildren = true;

		private void debugDump(StringBuilder sb, int indent, String name) {
		for (int i = 0; i < indent; ++i) sb.append('.');
		@@ -134,6 +139,8 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		}
		}
		if (!mStoppedAddingChildren) {
		// Mark that we have finished adding children. It will remain true if no new
		// children are added, or will be set to false upon adding a new child.
		mStoppedAddingChildren = true;
		return true;
		}
		@@ -216,6 +223,7 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		RaceConditionTracker.setEventProcessor(null);
		runResumeAllEventsCallbackLocked();
		assertTrue("Non-empty postponed events", mPostponedEvents.isEmpty());
		assertTrue("Last registered event is :enter", lastEventAsEnter() == null);

		// No events came after mLastRegisteredEvent. It doesn't make sense to come to it again
		// because we won't see new continuations.
		@@ -245,6 +253,26 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		}
		}

		/**
		* Returns whether the last event was not an XXX:enter, or this event is a matching XXX:exit.
		*/
		private boolean canRegisterEventNowLocked(String event) {
		final String lastEventAsEnter = lastEventAsEnter();
		final String thisEventAsExit = eventAsExit(event);

		if (lastEventAsEnter != null) {
		if (!lastEventAsEnter.equals(thisEventAsExit)) {
		assertTrue("YYY:exit after XXX:enter", thisEventAsExit == null);
		// Last event was :enter, but this event is not :exit.
		return false;
		}
		} else {
		// Previous event was not :enter.
		assertTrue(":exit after a non-enter event", thisEventAsExit == null);
		}
		return true;
		}

		/**
		* Registers an event issued by the app and returns null or decides that the event must be
		* postponed, and returns an object to wait on.
		@@ -252,6 +280,10 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		private synchronized Semaphore tryRegisterEvent(String event) {
		Log.d(TAG, "Event issued by the app: " + event);

		if (!canRegisterEventNowLocked(event)) {
		return createWaitObjectForPostponedEventLocked(event);
		}

		if (mRegisteredEventCount < mSequenceToFollow.size()) {
		// We are in the first part of the iteration. We only register events that follow the
		// mSequenceToFollow and postponing all other events.
		@@ -288,9 +320,14 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		return createWaitObjectForPostponedEventLocked(event);
		}
		} else {
		// The second phase of the iteration. We are past the growth point and register
		// The third phase of the iteration. We are past the growth point and register
		// everything that comes.
		registerEventLocked(event);
		// Register events that may have been postponed while waiting for an :exit event
		// during the third phase. We don't do this if just registered event is :enter.
		if (eventAsEnter(event) == null && mRegisteredEventCount > mSequenceToFollow.size()) {
		registerPostponedEventsLocked(new HashSet<>(mPostponedEvents.keySet()));
		}
		}
		return null;
		}
		@@ -347,6 +384,11 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		private void registerPostponedEventsLocked(Collection<String> events) {
		for (String event : events) {
		registerPostponedEventLocked(event);
		if (eventAsEnter(event) != null) {
		// Once :enter is registered, switch to waiting for :exit to come. Won't register
		// other postponed events.
		break;
		}
		}
		}

		@@ -355,14 +397,51 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		registerEventLocked(event);
		}

		/**
		* If the last registered event was XXX:enter, returns XXX, otherwise, null.
		*/
		private String lastEventAsEnter() {
		return eventAsEnter(mCurrentSequence.substring(mCurrentSequence.lastIndexOf("\|") + 1));
		}

		/**
		* If the event is XXX:postfix, returns XXX, otherwise, null.
		*/
		private static String prefixFromPostfixedEvent(String event, String postfix) {
		final int columnPos = event.indexOf(':');
		if (columnPos != -1 && postfix.equals(event.substring(columnPos + 1))) {
		return event.substring(0, columnPos);
		}
		return null;
		}

		/**
		* If the event is XXX:enter, returns XXX, otherwise, null.
		*/
		private static String eventAsEnter(String event) {
		return prefixFromPostfixedEvent(event, ENTER_POSTFIX);
		}

		/**
		* If the event is XXX:exit, returns XXX, otherwise, null.
		*/
		private static String eventAsExit(String event) {
		return prefixFromPostfixedEvent(event, EXIT_POSTFIX);
		}

		private void registerEventLocked(String event) {
		assertTrue(canRegisterEventNowLocked(event));

		Log.d(TAG, "Actually registering event: " + event);
		EventNode next = mLastRegisteredEvent.mNextEvents.get(event);
		if (next == null) {
		// This event wasn't seen after mLastRegisteredEvent.
		next = new EventNode();
		mLastRegisteredEvent.mNextEvents.put(event, next);
		mLastRegisteredEvent.mStoppedAddingChildren = false;
		// The fact that we've added a new event after the previous one means that the
		// previous event is still a growth point, unless this event is :exit, which means
		// that the previous event is :enter.
		mLastRegisteredEvent.mStoppedAddingChildren = eventAsExit(event) != null;
		}

		mLastRegisteredEvent = next;
		@@ -371,12 +450,6 @@ public class RaceConditionReproducer implements RaceConditionTracker.EventProces
		if (mCurrentSequence.length() > 0) mCurrentSequence.append("\|");
		mCurrentSequence.append(event);
		Log.d(TAG, "Repro sequence: " + mCurrentSequence);

		if (mRegisteredEventCount == mSequenceToFollow.size() + 1) {
		// We just entered the third phase of the iteration, i.e. registered an event after
		// the growth point. Now we can let go of all postponed events.
		runResumeAllEventsCallbackLocked();
		}
		}

		private void runResumeAllEventsCallbackLocked() {

tests/src/com/android/launcher3/util/RaceConditionReproducerTest.java

+78 −0

Original line number	Diff line number	Diff line
		@@ -76,6 +76,46 @@ public class RaceConditionReproducerTest {
		assertTrue(sawTheValidSequence);
		}

		@Test
		@Ignore // The test is too long for continuous testing.
		// 2 threads, 3 events, including enter-exit pairs each.
		public void test3_3_enter_exit() throws Exception {
		final RaceConditionReproducer eventProcessor = new RaceConditionReproducer();
		boolean sawTheValidSequence = false;

		for (; ; ) {
		eventProcessor.startIteration();
		Thread tb = new Thread(() -> {
		RaceConditionTracker.onEvent("B1:enter");
		RaceConditionTracker.onEvent("B1:exit");
		RaceConditionTracker.onEvent("B2");
		RaceConditionTracker.onEvent("B3:enter");
		RaceConditionTracker.onEvent("B3:exit");
		});
		tb.start();

		RaceConditionTracker.onEvent("A1");
		RaceConditionTracker.onEvent("A2:enter");
		RaceConditionTracker.onEvent("A2:exit");
		RaceConditionTracker.onEvent("A3:enter");
		RaceConditionTracker.onEvent("A3:exit");

		tb.join();
		final boolean needMoreIterations = eventProcessor.finishIteration();

		sawTheValidSequence = sawTheValidSequence \|\|
		"B1:enter\|B1:exit\|A1\|A2:enter\|A2:exit\|B2\|A3:enter\|A3:exit\|B3:enter\|B3:exit".
		equals(eventProcessor.getCurrentSequenceString());

		if (!needMoreIterations) break;
		}

		assertEquals("Wrong number of leaf nodes",
		factorial(3 + 3) / (factorial(3) * factorial(3)),
		eventProcessor.numberOfLeafNodes());
		assertTrue(sawTheValidSequence);
		}

		@Test
		// 2 threads, 3 events each; reproducing a particular event sequence.
		public void test3_3_ReproMode() throws Exception {
		@@ -122,4 +162,42 @@ public class RaceConditionReproducerTest {
		factorial(2 + 2 + 1) / (factorial(2) * factorial(2) * factorial(1)),
		eventProcessor.numberOfLeafNodes());
		}

		@Test
		@Ignore // The test is too long for continuous testing.
		// 2 threads with 2 events; 1 thread with 1 event. Includes enter-exit pairs.
		public void test2_1_2_enter_exit() throws Exception {
		final RaceConditionReproducer eventProcessor = new RaceConditionReproducer();

		for (; ; ) {
		eventProcessor.startIteration();
		Thread tb = new Thread(() -> {
		RaceConditionTracker.onEvent("B1:enter");
		RaceConditionTracker.onEvent("B1:exit");
		RaceConditionTracker.onEvent("B2:enter");
		RaceConditionTracker.onEvent("B2:exit");
		});
		tb.start();

		Thread tc = new Thread(() -> {
		RaceConditionTracker.onEvent("C1:enter");
		RaceConditionTracker.onEvent("C1:exit");
		});
		tc.start();

		RaceConditionTracker.onEvent("A1:enter");
		RaceConditionTracker.onEvent("A1:exit");
		RaceConditionTracker.onEvent("A2:enter");
		RaceConditionTracker.onEvent("A2:exit");

		tb.join();
		tc.join();

		if (!eventProcessor.finishIteration()) break;
		}

		assertEquals("Wrong number of leaf nodes",
		factorial(2 + 2 + 1) / (factorial(2) * factorial(2) * factorial(1)),
		eventProcessor.numberOfLeafNodes());
		}
		}