Commit 7efc7748 authored Jun 21, 2019 by Yohei Yukawa

Recover simpler WM lock in REPORT_FOCUS_CHANGE

This CL follows up previous CLs [1][2][3] to recover the original
simplicity regarding WM lock handling in REPORT_FOCUS_CHANGE handler.

What happened are:

 1. The first CL [1] introduced an IPC that can be issued while WM
    holds its global lock in the REPORT_FOCUS_CHANGE handler, which
    ended up causing dead lock between WM and ViewRootImpl.

 2. The second CL [2] addressed the above dead lock by temporarily
    releasing WM lock when issuing IPC from WM to ViewRootImpl.

 3. The third CL [3] simplified the logic and removed the code path in
    question but didn't revert the second CL [2].

In short, this CL logically reverts the second CL [2] since it's not
necessary any more.

 [1]: Ia46738a5da6dbc334bf937b0f6656a57523c28a7
      6f13d20b
 [2]: Ia30a279441def501e53eeee8913d19ac50a620cd
      52ef1bf8
 [3]: Ie030eed523599b217060887171710692d050e5d8
      51c5a1d0

Bug: 119658889
Test: atest CtsWindowManagerDeviceTestCases
Change-Id: Id081851f60d6a2f8f17e9e21408f3052ff1f2cea

parent 564b6a14

services/core/java/com/android/server/wm/WindowManagerService.java

+4 −6

Original line number	Diff line number	Diff line
		@@ -4556,12 +4556,10 @@ public class WindowManagerService extends IWindowManager.Stub

		lastFocus = displayContent.mLastFocus;
		newFocus = displayContent.mCurrentFocus;
		}
		if (lastFocus == newFocus) {
		// Focus is not changing, so nothing to do.
		return;
		}
		synchronized (mGlobalLock) {
		displayContent.mLastFocus = newFocus;
		if (DEBUG_FOCUS_LIGHT) Slog.i(TAG_WM, "Focus moving from " + lastFocus +
		" to " + newFocus + " displayId=" + displayContent.getDisplayId());