Reduce unnecessary overhead of SystemUiContext

- Do not report change when initializing DisplayContent
  (DisplayContent#isReady() is false).
  This reduces boot time by dozen of milliseconds
  (RootWindowContainer#setWindowManager).
- Only create SystemUiContext if needed. Most of processes don't
  use it. This reduces many registrations (e.g. according to the
  number of processes, it maybe from ~60 to ~10), which involve
  binder/listener creation/invocation, especially the extra cost
  of dispatching configuration to the context which no one uses.
- Store token as IWindowToken to avoid object creation every time
  by asInterface.

Bug: 207620458
Test: atest InputMethodMenuControllerTest WindowContextControllerTest
Change-Id: I867e9f81116796c42048195406d74feccf4772d3

1 files changed, 7 insertions, 3 deletions

diff --git a/core/java/android/app/ConfigurationController.java b/core/java/android/app/ConfigurationController.java
index 8637e31eb122..58f60a6a59a7 100644
--- a/core/java/android/app/ConfigurationController.java
+++ b/core/java/android/app/ConfigurationController.java
@@ -154,9 +154,12 @@ class ConfigurationController {
         int configDiff;
         boolean equivalent;
 
+        // Get theme outside of synchronization to avoid nested lock.
+        final Resources.Theme systemTheme = mActivityThread.getSystemContext().getTheme();
+        final ContextImpl systemUiContext = mActivityThread.getSystemUiContextNoCreate();
+        final Resources.Theme systemUiTheme =
+                systemUiContext != null ? systemUiContext.getTheme() : null;
         synchronized (mResourcesManager) {
-            final Resources.Theme systemTheme = mActivityThread.getSystemContext().getTheme();
-            final Resources.Theme systemUiTheme = mActivityThread.getSystemUiContext().getTheme();
             if (mPendingConfiguration != null) {
                 if (!mPendingConfiguration.isOtherSeqNewer(config)) {
                     config = mPendingConfiguration;
@@ -207,7 +210,8 @@ class ConfigurationController {
                 systemTheme.rebase();
             }
 
-            if ((systemUiTheme.getChangingConfigurations() & configDiff) != 0) {
+            if (systemUiTheme != null
+                    && (systemUiTheme.getChangingConfigurations() & configDiff) != 0) {
                 systemUiTheme.rebase();
             }
         }