Merge "MessageQueue: dispose() from next()" into main (f1fccb2b) · Commits · e / os / android_frameworks_base

core/java/android/os/CombinedMessageQueue/MessageQueue.java

+89 −21

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ import java.util.concurrent.ConcurrentSkipListSet;
		import java.util.concurrent.atomic.AtomicInteger;
		import java.util.concurrent.atomic.AtomicLong;
		import java.util.concurrent.locks.Condition;
		import java.util.concurrent.locks.LockSupport;
		import java.util.concurrent.locks.ReentrantLock;

		/**
		@@ -396,8 +397,14 @@ public final class MessageQueue {

		private boolean isPollingConcurrent() {
		// If the loop is quitting then it must not be idling.
		// We can assume mPtr != 0 when sQuitting is false.
		return !((boolean) sQuitting.getVolatile(this)) && nativeIsPolling(mPtr);
		if (!incrementQuittingState()) {
		return false;
		}
		try {
		return nativeIsPolling(mPtr);
		} finally {
		decrementQuittingState();
		}
		}

		private boolean isPollingLegacy() {
		@@ -849,7 +856,9 @@ public final class MessageQueue {
		return msg;
		}

		if ((boolean) sQuitting.getVolatile(this)) {
		// Prevent any race between quit()/nativeWake() and dispose()
		if (checkQuittingAndWaitForRefsToDrop()) {
		dispose();
		return null;
		}

		@@ -1039,17 +1048,22 @@ public final class MessageQueue {
		}

		if (mUseConcurrent) {
		synchronized (mIdleHandlersLock) {
		if (sQuitting.compareAndSet(this, false, true)) {
		if (!incrementQuittingState()) {
		return;
		}
		try {
		if (setQuitting()) {
		if (safe) {
		removeAllFutureMessages();
		} else {
		removeAllMessages();
		}

		// We can assume mPtr != 0 because sQuitting was previously false.
		// We can assume mPtr != 0 while we hold a ref on our quitting state
		nativeWake(mPtr);
		}
		} finally {
		decrementQuittingState();
		}
		} else {
		synchronized (this) {
		@@ -2218,7 +2232,7 @@ public final class MessageQueue {
		n += dumpPriorityQueue(mAsyncPriorityQueue, pw, prefix, h, n);

		pw.println(prefix + "(Total messages: " + n + ", polling=" + isPolling()
		+ ", quitting=" + (boolean) sQuitting.getVolatile(this) + ")");
		+ ", quitting=" + getQuitting() + ")");
		return;
		}

		@@ -2266,7 +2280,7 @@ public final class MessageQueue {
		dumpPriorityQueue(mAsyncPriorityQueue, proto);

		proto.write(MessageQueueProto.IS_POLLING_LOCKED, isPolling());
		proto.write(MessageQueueProto.IS_QUITTING, (boolean) sQuitting.getVolatile(this));
		proto.write(MessageQueueProto.IS_QUITTING, getQuitting());
		proto.end(messageQueueToken);
		return;
		}
		@@ -2642,6 +2656,72 @@ public final class MessageQueue {

		}

		/*
		* Combine our quitting state with a ref count of access to mPtr.
		* next() doesn't want to dispose of mPtr until quit() is done processing messages.
		* isPolling() also needs to ensure safe access to mPtr.
		* So keep a ref count of access to mPtr. If quitting is set, we disallow new refs.
		* next() will only proceed with disposing of the pointer once all refs are dropped.
		*/
		private static VarHandle sQuittingRefCount;
		private volatile long mQuittingRefCountValue = 0;
		static {
		try {
		MethodHandles.Lookup l = MethodHandles.lookup();
		sQuittingRefCount = l.findVarHandle(MessageQueue.class, "mQuittingRefCountValue",
		long.class);
		} catch (Exception e) {
		Log.wtf(TAG_C, "VarHandle lookup failed with exception: " + e);
		throw new ExceptionInInitializerError(e);
		}
		}

		// Use MSB to indicate quitting state. Lower 63 bits hold ref count.
		private static final long QUITTING_MASK = ~(-1L >>> 1);

		private boolean incrementQuittingState() {
		long oldVal = (long)sQuittingRefCount.getAndAdd(this, 1);
		if ((oldVal & QUITTING_MASK) != 0) {
		// If we're quitting we need to drop our ref and indicate to the caller
		sQuittingRefCount.getAndAdd(this, -1);
		return false;
		}
		return true;
		}

		private void decrementQuittingState() {
		long oldVal = (long)sQuittingRefCount.getAndAdd(this, -1);
		// If quitting and we were the last ref, wake up looper thread
		if ((oldVal & QUITTING_MASK) != 0 && (oldVal & ~QUITTING_MASK) == 1L) {
		LockSupport.unpark(mLooperThread);
		}
		}

		private boolean setQuitting() {
		long oldVal = (long)sQuittingRefCount.getAndBitwiseOr(this, QUITTING_MASK);
		if ((oldVal & QUITTING_MASK) != 0) {
		return false;
		}
		return true;
		}

		private boolean getQuitting() {
		return (mQuittingRefCountValue & QUITTING_MASK) != 0;
		}

		private volatile Thread mLooperThread = null;
		// Must only be called from looper thread
		private boolean checkQuittingAndWaitForRefsToDrop() {
		if (!getQuitting()) {
		return false;
		}
		mLooperThread = Thread.currentThread();
		while ((mQuittingRefCountValue & ~QUITTING_MASK) != 0) {
		LockSupport.park();
		}
		return true;
		}

		/*
		* Tracks the number of queued and cancelled messages in our stack.
		*
		@@ -2731,18 +2811,6 @@ public final class MessageQueue {
		private final Object mIdleHandlersLock = new Object();
		private final Object mFileDescriptorRecordsLock = new Object();

		private static final VarHandle sQuitting;
		private boolean mQuittingValue = false;
		static {
		try {
		MethodHandles.Lookup l = MethodHandles.lookup();
		sQuitting = l.findVarHandle(MessageQueue.class, "mQuittingValue", boolean.class);
		} catch (Exception e) {
		Log.wtf(TAG_C, "VarHandle lookup failed with exception: " + e);
		throw new ExceptionInInitializerError(e);
		}
		}

		// The next barrier token.
		// Barriers are indicated by messages with a null target whose arg1 field carries the token.
		private final AtomicInteger mNextBarrierTokenAtomic = new AtomicInteger(1);
		@@ -2757,7 +2825,7 @@ public final class MessageQueue {
		private final Condition mDrainCompleted = mDrainingLock.newCondition();

		private boolean enqueueMessageUnchecked(@NonNull Message msg, long when) {
		if ((boolean) sQuitting.getVolatile(this)) {
		if (getQuitting()) {
		IllegalStateException e = new IllegalStateException(
		msg.target + " sending message to a Handler on a dead thread");
		Log.w(TAG_C, e.getMessage(), e);

core/java/android/os/ConcurrentMessageQueue/MessageQueue.java

+89 −21

Original line number	Diff line number	Diff line
		@@ -48,6 +48,7 @@ import java.util.concurrent.ConcurrentSkipListSet;
		import java.util.concurrent.atomic.AtomicInteger;
		import java.util.concurrent.atomic.AtomicLong;
		import java.util.concurrent.locks.Condition;
		import java.util.concurrent.locks.LockSupport;
		import java.util.concurrent.locks.ReentrantLock;

		/**
		@@ -237,7 +238,72 @@ public final class MessageQueue {
		Log.wtf(TAG, "VarHandle lookup failed with exception: " + e);
		throw new ExceptionInInitializerError(e);
		}
		}

		/*
		* Combine our quitting state with a ref count of access to mPtr.
		* next() doesn't want to dispose of mPtr until quit() is done processing messages.
		* isPolling() also needs to ensure safe access to mPtr.
		* So keep a ref count of access to mPtr. If quitting is set, we disallow new refs.
		* next() will only proceed with disposing of the pointer once all refs are dropped.
		*/
		private static VarHandle sQuittingRefCount;
		private volatile long mQuittingRefCountValue = 0;
		static {
		try {
		MethodHandles.Lookup l = MethodHandles.lookup();
		sQuittingRefCount = l.findVarHandle(MessageQueue.class, "mQuittingRefCountValue",
		long.class);
		} catch (Exception e) {
		Log.wtf(TAG_C, "VarHandle lookup failed with exception: " + e);
		throw new ExceptionInInitializerError(e);
		}
		}

		// Use MSB to indicate quitting state. Lower 63 bits hold ref count.
		private static final long QUITTING_MASK = ~(-1L >>> 1);

		private boolean incrementQuittingState() {
		long oldVal = (long)sQuittingRefCount.getAndAdd(this, 1);
		if ((oldVal & QUITTING_MASK) != 0) {
		// If we're quitting we need to drop our ref and indicate to the caller
		sQuittingRefCount.getAndAdd(this, -1);
		return false;
		}
		return true;
		}

		private void decrementQuittingState() {
		long oldVal = (long)sQuittingRefCount.getAndAdd(this, -1);
		// If quitting and we were the last ref, wake up looper thread
		if ((oldVal & QUITTING_MASK) != 0 && (oldVal & ~QUITTING_MASK) == 1L) {
		LockSupport.unpark(mLooperThread);
		}
		}

		private boolean setQuitting() {
		long oldVal = (long)sQuittingRefCount.getAndBitwiseOr(this, QUITTING_MASK);
		if ((oldVal & QUITTING_MASK) != 0) {
		return false;
		}
		return true;
		}

		private boolean getQuitting() {
		return (mQuittingRefCountValue & QUITTING_MASK) != 0;
		}

		private volatile Thread mLooperThread = null;
		// Must only be called from looper thread
		private boolean checkQuittingAndWaitForRefsToDrop() {
		if (!getQuitting()) {
		return false;
		}
		mLooperThread = Thread.currentThread();
		while ((mQuittingRefCountValue & ~QUITTING_MASK) != 0) {
		LockSupport.park();
		}
		return true;
		}

		/*
		@@ -335,18 +401,6 @@ public final class MessageQueue {
		@GuardedBy("mFileDescriptorRecordsLock")
		private SparseArray<FileDescriptorRecord> mFileDescriptorRecords;

		private static final VarHandle sQuitting;
		private boolean mQuittingValue = false;
		static {
		try {
		MethodHandles.Lookup l = MethodHandles.lookup();
		sQuitting = l.findVarHandle(MessageQueue.class, "mQuittingValue", boolean.class);
		} catch (Exception e) {
		Log.wtf(TAG, "VarHandle lookup failed with exception: " + e);
		throw new ExceptionInInitializerError(e);
		}
		}

		// The next barrier token.
		// Barriers are indicated by messages with a null target whose arg1 field carries the token.
		private final AtomicInteger mNextBarrierToken = new AtomicInteger(1);
		@@ -523,8 +577,14 @@ public final class MessageQueue {
		*/
		public boolean isPolling() {
		// If the loop is quitting then it must not be idling.
		// We can assume mPtr != 0 when sQuitting is false.
		return !((boolean) sQuitting.getVolatile(this)) && nativeIsPolling(mPtr);
		if (!incrementQuittingState()) {
		return false;
		}
		try {
		return nativeIsPolling(mPtr);
		} finally {
		decrementQuittingState();
		}
		}

		/* Helper to choose the correct queue to insert into. */
		@@ -804,7 +864,9 @@ public final class MessageQueue {
		return msg;
		}

		if ((boolean) sQuitting.getVolatile(this)) {
		// Prevent any race between quit()/nativeWake() and dispose()
		if (checkQuittingAndWaitForRefsToDrop()) {
		dispose();
		return null;
		}

		@@ -860,17 +922,23 @@ public final class MessageQueue {
		if (!mQuitAllowed) {
		throw new IllegalStateException("Main thread not allowed to quit.");
		}
		synchronized (mIdleHandlersLock) {
		if (sQuitting.compareAndSet(this, false, true)) {

		if (!incrementQuittingState()) {
		return;
		}
		try {
		if (setQuitting()) {
		if (safe) {
		removeAllFutureMessages();
		} else {
		removeAllMessages();
		}

		// We can assume mPtr != 0 because sQuitting was previously false.
		// We can assume mPtr != 0 while we hold a ref on our quitting state
		nativeWake(mPtr);
		}
		} finally {
		decrementQuittingState();
		}
		}

		@@ -887,7 +955,7 @@ public final class MessageQueue {
		}

		private boolean enqueueMessageUnchecked(@NonNull Message msg, long when) {
		if ((boolean) sQuitting.getVolatile(this)) {
		if (getQuitting()) {
		IllegalStateException e = new IllegalStateException(
		msg.target + " sending message to a Handler on a dead thread");
		Log.w(TAG, e.getMessage(), e);
		@@ -1513,7 +1581,7 @@ public final class MessageQueue {
		n += dumpPriorityQueue(mAsyncPriorityQueue, pw, prefix, h, n);

		pw.println(prefix + "(Total messages: " + n + ", polling=" + isPolling()
		+ ", quitting=" + (boolean) sQuitting.getVolatile(this) + ")");
		+ ", quitting=" + getQuitting() + ")");
		}

		@NeverCompile
		@@ -1544,7 +1612,7 @@ public final class MessageQueue {
		dumpPriorityQueue(mAsyncPriorityQueue, proto);

		proto.write(MessageQueueProto.IS_POLLING_LOCKED, isPolling());
		proto.write(MessageQueueProto.IS_QUITTING, (boolean) sQuitting.getVolatile(this));
		proto.write(MessageQueueProto.IS_QUITTING, getQuitting());
		proto.end(messageQueueToken);
		}