Workaround memory leaks in Looper (d577e728) · Commits · e / os / android_frameworks_base

core/java/android/os/Looper.java

+106 −90

Original line number	Diff line number	Diff line
		@@ -94,6 +94,11 @@ public final class Looper {
		*/
		private long mSlowDeliveryThresholdMs;

		/**
		* True if a message delivery takes longer than {@link #mSlowDeliveryThresholdMs}.
		*/
		private boolean mSlowDeliveryDetected;

		/** Initialize the current thread as a looper.
		* This gives you a chance to create handlers that then reference
		* this looper, before actually starting the loop. Be sure to call
		@@ -148,49 +153,21 @@ public final class Looper {
		}

		/**
		* Run the message queue in this thread. Be sure to call
		* {@link #quit()} to end the loop.
		* Poll and deliver single message, return true if the outer loop should continue.
		*/
		public static void loop() {
		final Looper me = myLooper();
		if (me == null) {
		throw new RuntimeException("No Looper; Looper.prepare() wasn't called on this thread.");
		}
		if (me.mInLoop) {
		Slog.w(TAG, "Loop again would have the queued messages be executed"
		+ " before this one completed.");
		}

		me.mInLoop = true;
		final MessageQueue queue = me.mQueue;

		// Make sure the identity of this thread is that of the local process,
		// and keep track of what that identity token actually is.
		Binder.clearCallingIdentity();
		final long ident = Binder.clearCallingIdentity();

		// Allow overriding a threshold with a system prop. e.g.
		// adb shell 'setprop log.looper.1000.main.slow 1 && stop && start'
		final int thresholdOverride =
		SystemProperties.getInt("log.looper."
		+ Process.myUid() + "."
		+ Thread.currentThread().getName()
		+ ".slow", 0);

		boolean slowDeliveryDetected = false;

		for (;;) {
		Message msg = queue.next(); // might block
		private static boolean loopOnce(final Looper me,
		final long ident, final int thresholdOverride) {
		Message msg = me.mQueue.next(); // might block
		if (msg == null) {
		// No message indicates that the message queue is quitting.
		return;
		return false;
		}

		// This must be in a local variable, in case a UI event sets the logger
		final Printer logging = me.mLogging;
		if (logging != null) {
		logging.println(">>>>> Dispatching to " + msg.target + " " +
		msg.callback + ": " + msg.what);
		logging.println(">>>>> Dispatching to " + msg.target + " "
		+ msg.callback + ": " + msg.what);
		}
		// Make sure the observer won't change while processing a transaction.
		final Observer observer = sObserver;
		@@ -237,16 +214,16 @@ public final class Looper {
		}
		}
		if (logSlowDelivery) {
		if (slowDeliveryDetected) {
		if (me.mSlowDeliveryDetected) {
		if ((dispatchStart - msg.when) <= 10) {
		Slog.w(TAG, "Drained");
		slowDeliveryDetected = false;
		me.mSlowDeliveryDetected = false;
		}
		} else {
		if (showSlowLog(slowDeliveryThresholdMs, msg.when, dispatchStart, "delivery",
		msg)) {
		// Once we write a slow delivery log, suppress until the queue drains.
		slowDeliveryDetected = true;
		me.mSlowDeliveryDetected = true;
		}
		}
		}
		@@ -270,6 +247,45 @@ public final class Looper {
		}

		msg.recycleUnchecked();

		return true;
		}

		/**
		* Run the message queue in this thread. Be sure to call
		* {@link #quit()} to end the loop.
		*/
		public static void loop() {
		final Looper me = myLooper();
		if (me == null) {
		throw new RuntimeException("No Looper; Looper.prepare() wasn't called on this thread.");
		}
		if (me.mInLoop) {
		Slog.w(TAG, "Loop again would have the queued messages be executed"
		+ " before this one completed.");
		}

		me.mInLoop = true;

		// Make sure the identity of this thread is that of the local process,
		// and keep track of what that identity token actually is.
		Binder.clearCallingIdentity();
		final long ident = Binder.clearCallingIdentity();

		// Allow overriding a threshold with a system prop. e.g.
		// adb shell 'setprop log.looper.1000.main.slow 1 && stop && start'
		final int thresholdOverride =
		SystemProperties.getInt("log.looper."
		+ Process.myUid() + "."
		+ Thread.currentThread().getName()
		+ ".slow", 0);

		me.mSlowDeliveryDetected = false;

		for (;;) {
		if (!loopOnce(me, ident, thresholdOverride)) {
		return;
		}
		}
		}