Add system ui background handlers dispatch and delivery logging thresholds

Those thresholds would help us to further investigate bugs like this
one. Looper#showSlowLog prints Slog.w when the threshold is met. This risk free change will help us investigate issues when something got stuck in the background thread.

I've also removed misleading `run` from `UserTrackerImpl` because those are kotlin run to change context, which doesn't change execution thread.

Bug: 281851220
Test: manual
Change-Id: I127ec03e15f76295484e34b0ff0f3e7ad9ac9b88

2 files changed, 24 insertions, 10 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/settings/UserTrackerImpl.kt b/packages/SystemUI/src/com/android/systemui/settings/UserTrackerImpl.kt
index fbf134db15f1..5fb3c01bbc1d 100644
--- a/packages/SystemUI/src/com/android/systemui/settings/UserTrackerImpl.kt
+++ b/packages/SystemUI/src/com/android/systemui/settings/UserTrackerImpl.kt
@@ -166,21 +166,19 @@ open class UserTrackerImpl internal constructor(
             }
 
             override fun onUserSwitching(newUserId: Int, reply: IRemoteCallback?) {
-                backgroundHandler.run {
-                    handleUserSwitching(newUserId)
-                    reply?.sendResult(null)
-                }
+                handleUserSwitching(newUserId)
+                reply?.sendResult(null)
             }
 
             override fun onUserSwitchComplete(newUserId: Int) {
-                backgroundHandler.run {
-                    handleUserSwitchComplete(newUserId)
-                }
+                handleUserSwitchComplete(newUserId)
             }
         }, TAG)
     }
 
+    @WorkerThread
     protected open fun handleBeforeUserSwitching(newUserId: Int) {
+        Assert.isNotMainThread()
         setUserIdInternal(newUserId)
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/util/concurrency/SysUIConcurrencyModule.java b/packages/SystemUI/src/com/android/systemui/util/concurrency/SysUIConcurrencyModule.java
index c72853ef37be..7b652c11e9ec 100644
--- a/packages/SystemUI/src/com/android/systemui/util/concurrency/SysUIConcurrencyModule.java
+++ b/packages/SystemUI/src/com/android/systemui/util/concurrency/SysUIConcurrencyModule.java
@@ -29,18 +29,28 @@ import com.android.systemui.dagger.qualifiers.BroadcastRunning;
 import com.android.systemui.dagger.qualifiers.LongRunning;
 import com.android.systemui.dagger.qualifiers.Main;
 
+import dagger.Module;
+import dagger.Provides;
+
 import java.util.concurrent.Executor;
 
 import javax.inject.Named;
 
-import dagger.Module;
-import dagger.Provides;
-
 /**
  * Dagger Module for classes found within the concurrent package.
  */
 @Module
 public abstract class SysUIConcurrencyModule {
+
+    // Slow BG executor can potentially affect UI if UI is waiting for an updated state from this
+    // thread
+    private static final Long BG_SLOW_DISPATCH_THRESHOLD = 1000L;
+    private static final Long BG_SLOW_DELIVERY_THRESHOLD = 1000L;
+    private static final Long LONG_SLOW_DISPATCH_THRESHOLD = 2500L;
+    private static final Long LONG_SLOW_DELIVERY_THRESHOLD = 2500L;
+    private static final Long BROADCAST_SLOW_DISPATCH_THRESHOLD = 1000L;
+    private static final Long BROADCAST_SLOW_DELIVERY_THRESHOLD = 1000L;
+
     /** Background Looper */
     @Provides
     @SysUISingleton
@@ -49,6 +59,8 @@ public abstract class SysUIConcurrencyModule {
         HandlerThread thread = new HandlerThread("SysUiBg",
                 Process.THREAD_PRIORITY_BACKGROUND);
         thread.start();
+        thread.getLooper().setSlowLogThresholdMs(BG_SLOW_DISPATCH_THRESHOLD,
+                BG_SLOW_DELIVERY_THRESHOLD);
         return thread.getLooper();
     }
 
@@ -60,6 +72,8 @@ public abstract class SysUIConcurrencyModule {
         HandlerThread thread = new HandlerThread("BroadcastRunning",
                 Process.THREAD_PRIORITY_BACKGROUND);
         thread.start();
+        thread.getLooper().setSlowLogThresholdMs(BROADCAST_SLOW_DISPATCH_THRESHOLD,
+                BROADCAST_SLOW_DELIVERY_THRESHOLD);
         return thread.getLooper();
     }
 
@@ -71,6 +85,8 @@ public abstract class SysUIConcurrencyModule {
         HandlerThread thread = new HandlerThread("SysUiLng",
                 Process.THREAD_PRIORITY_BACKGROUND);
         thread.start();
+        thread.getLooper().setSlowLogThresholdMs(LONG_SLOW_DISPATCH_THRESHOLD,
+                LONG_SLOW_DELIVERY_THRESHOLD);
         return thread.getLooper();
     }