Merge "Avoid races between nextMessage() and stackHasMessages()" into main (43e4a4ec) · Commits · e / os / android_frameworks_base

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

+5 −14

Original line number	Diff line number	Diff line
		@@ -148,10 +148,6 @@ public final class MessageQueue {
		return mMessage.when;
		}

		boolean isRemovedFromStack() {
		return mRemovedFromStackValue;
		}

		boolean removeFromStack() {
		return sRemovedFromStack.compareAndSet(this, false, true);
		}
		@@ -1221,16 +1217,10 @@ public final class MessageQueue {
		StateNode bottom = getStateNode(top);

		/*
		* If the top node is a state node, there are no reachable messages.
		* If it's anything other than Active, we can quit as we know that next() is not
		* consuming items.
		* If the top node is Active then we know that next() is currently consuming items.
		* In that case we should wait next() has drained the stack.
		* If the top node is a state node, there are no reachable messages. We should still
		* wait for next to complete draining the stack.
		*/
		if (top == bottom) {
		if (bottom != sStackStateActive) {
		return false;
		}
		waitForDrainCompleted();
		return false;
		}
		@@ -1258,7 +1248,7 @@ public final class MessageQueue {
		}
		}
		} else {
		return true;
		break;
		}
		}

		@@ -1268,7 +1258,6 @@ public final class MessageQueue {
		if (DEBUG) {
		Log.d(TAG, "stackHasMessages next() is walking the stack, we must re-sample");
		}
		waitForDrainCompleted();
		break;
		}
		if (!n.isMessageNode()) {
		@@ -1278,6 +1267,8 @@ public final class MessageQueue {
		p = (MessageNode) n;
		}

		waitForDrainCompleted();

		return found;
		}