Fix change of behavior in Looper.quit(). (8b60e451) · Commits · e / os / android_frameworks_base

api/current.txt

+2 −0

Original line number	Diff line number	Diff line
		@@ -17116,6 +17116,7 @@ package android.os {
		method public int getThreadId();
		method protected void onLooperPrepared();
		method public boolean quit();
		method public boolean quitSafely();
		}

		public abstract interface IBinder {
		@@ -17156,6 +17157,7 @@ package android.os {
		method public static void prepare();
		method public static void prepareMainLooper();
		method public void quit();
		method public void quitSafely();
		method public void setMessageLogging(android.util.Printer);
		}

core/java/android/os/Handler.java

+10 −5

Original line number	Diff line number	Diff line
		@@ -413,27 +413,32 @@ public class Handler {

		/**
		* Runs the specified task synchronously.
		*
		* <p>
		* If the current thread is the same as the handler thread, then the runnable
		* runs immediately without being enqueued. Otherwise, posts the runnable
		* to the handler and waits for it to complete before returning.
		*
		* </p><p>
		* This method is dangerous! Improper use can result in deadlocks.
		* Never call this method while any locks are held or use it in a
		* possibly re-entrant manner.
		*
		* </p><p>
		* This method is occasionally useful in situations where a background thread
		* must synchronously await completion of a task that must run on the
		* handler's thread. However, this problem is often a symptom of bad design.
		* Consider improving the design (if possible) before resorting to this method.
		*
		* </p><p>
		* One example of where you might want to use this method is when you just
		* set up a Handler thread and need to perform some initialization steps on
		* it before continuing execution.
		*
		* </p><p>
		* If timeout occurs then this method returns <code>false</code> but the runnable
		* will remain posted on the handler and may already be in progress or
		* complete at a later time.
		* </p><p>
		* When using this method, be sure to use {@link Looper#quitSafely} when
		* quitting the looper. Otherwise {@link #runWithScissors} may hang indefinitely.
		* (TODO: We should fix this by making MessageQueue aware of blocking runnables.)
		* </p>
		*
		* @param r The Runnable that will be executed synchronously.
		* @param timeout The timeout in milliseconds, or 0 to wait indefinitely.

core/java/android/os/HandlerThread.java

+47 −6

Original line number	Diff line number	Diff line
		@@ -48,6 +48,7 @@ public class HandlerThread extends Thread {
		protected void onLooperPrepared() {
		}

		@Override
		public void run() {
		mTid = Process.myTid();
		Looper.prepare();
		@@ -85,10 +86,23 @@ public class HandlerThread extends Thread {
		}

		/**
		* Ask the currently running looper to quit. If the thread has not
		* been started or has finished (that is if {@link #getLooper} returns
		* null), then false is returned. Otherwise the looper is asked to
		* quit and true is returned.
		* Quits the handler thread's looper.
		* <p>
		* Causes the handler thread's looper to terminate without processing any
		* more messages in the message queue.
		* </p><p>
		* Any attempt to post messages to the queue after the looper is asked to quit will fail.
		* For example, the {@link Handler#sendMessage(Message)} method will return false.
		* </p><p class="note">
		* Using this method may be unsafe because some messages may not be delivered
		* before the looper terminates. Consider using {@link #quitSafely} instead to ensure
		* that all pending work is completed in an orderly manner.
		* </p>
		*
		* @return True if the looper looper has been asked to quit or false if the
		* thread had not yet started running.
		*
		* @see #quitSafely
		*/
		public boolean quit() {
		Looper looper = getLooper();
		@@ -99,6 +113,33 @@ public class HandlerThread extends Thread {
		return false;
		}

		/**
		* Quits the handler thread's looper safely.
		* <p>
		* Causes the handler thread's looper to terminate as soon as all remaining messages
		* in the message queue that are already due to be delivered have been handled.
		* Pending delayed messages with due times in the future will not be delivered.
		* </p><p>
		* Any attempt to post messages to the queue after the looper is asked to quit will fail.
		* For example, the {@link Handler#sendMessage(Message)} method will return false.
		* </p><p>
		* If the thread has not been started or has finished (that is if
		* {@link #getLooper} returns null), then false is returned.
		* Otherwise the looper is asked to quit and true is returned.
		* </p>
		*
		* @return True if the looper looper has been asked to quit or false if the
		* thread had not yet started running.
		*/
		public boolean quitSafely() {
		Looper looper = getLooper();
		if (looper != null) {
		looper.quitSafely();
		return true;
		}
		return false;
		}

		/**
		* Returns the identifier of this thread. See Process.myTid().
		*/

core/java/android/os/Looper.java

+26 −7

Original line number	Diff line number	Diff line
		@@ -202,18 +202,37 @@ public final class Looper {
		/**
		* Quits the looper.
		* <p>
		* Causes the {@link #loop} method to terminate without processing any
		* more messages in the message queue.
		* </p><p>
		* Any attempt to post messages to the queue after the looper is asked to quit will fail.
		* For example, the {@link Handler#sendMessage(Message)} method will return false.
		* </p><p class="note">
		* Using this method may be unsafe because some messages may not be delivered
		* before the looper terminates. Consider using {@link #quitSafely} instead to ensure
		* that all pending work is completed in an orderly manner.
		* </p>
		*
		* @see #quitSafely
		*/
		public void quit() {
		mQueue.quit(false);
		}

		/**
		* Quits the looper safely.
		* <p>
		* Causes the {@link #loop} method to terminate as soon as all remaining messages
		* in the message queue that are already due to be delivered have been handled.
		* However delayed messages with due times in the future may not be handled before
		* the loop terminates.
		* However pending delayed messages with due times in the future will not be
		* delivered before the loop terminates.
		* </p><p>
		* Any attempt to post messages to the queue after {@link #quit} has been called
		* will fail. For example, the {@link Handler#sendMessage(Message)} method will
		* return false when the looper is being terminated.
		* Any attempt to post messages to the queue after the looper is asked to quit will fail.
		* For example, the {@link Handler#sendMessage(Message)} method will return false.
		* </p>
		*/
		public void quit() {
		mQueue.quit();
		public void quitSafely() {
		mQueue.quit(true);
		}

		/**

core/java/android/os/MessageQueue.java

+45 −1

Original line number	Diff line number	Diff line
		@@ -219,7 +219,7 @@ public final class MessageQueue {
		}
		}

		void quit() {
		void quit(boolean safe) {
		if (!mQuitAllowed) {
		throw new RuntimeException("Main thread not allowed to quit.");
		}
		@@ -229,6 +229,12 @@ public final class MessageQueue {
		return;
		}
		mQuiting = true;

		if (safe) {
		removeAllFutureMessagesLocked();
		} else {
		removeAllMessagesLocked();
		}
		}
		nativeWake(mPtr);
		}
		@@ -473,4 +479,42 @@ public final class MessageQueue {
		}
		}
		}

		private void removeAllMessagesLocked() {
		Message p = mMessages;
		while (p != null) {
		Message n = p.next;
		p.recycle();
		p = n;
		}
		mMessages = null;
		}

		private void removeAllFutureMessagesLocked() {
		final long now = SystemClock.uptimeMillis();
		Message p = mMessages;
		if (p != null) {
		if (p.when > now) {
		removeAllMessagesLocked();
		} else {
		Message n;
		for (;;) {
		n = p.next;
		if (n == null) {
		return;
		}
		if (n.when > now) {
		break;
		}
		p = n;
		}
		p.next = null;
		do {
		p = n;
		n = p.next;
		p.recycle();
		} while (n != null);
		}
		}
		}
		}