From aaf4c5e47b0876f46b5d3151b4068a32d0bfdf27 Mon Sep 17 00:00:00 2001
From: Fabian Kozynski <kozynski@google.com>
Date: Fri, 27 Mar 2020 13:29:15 -0400
Subject: [PATCH] Use bg thread for BroadcastDispatcher registering

There is no need for the broadcastdispatcher to register in the main
thread. Moving to the bg thread reduces the chance of our main thread
being busy when many classes subscribe in a short period of time.

Test: manual (logs show BroadcastDispatcher is receiving broadcasts)
Test: atest UserBroadcastDispatcherTest
Fixes: 151684085
Change-Id: Iac6fd9e3b9f7bed3879620b4f262cc68f8ffdcd3
---
 .../android/systemui/broadcast/BroadcastDispatcher.kt  |  2 +-
 .../systemui/broadcast/UserBroadcastDispatcher.kt      | 10 ++++------
 .../systemui/broadcast/UserBroadcastDispatcherTest.kt  |  2 +-
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/broadcast/BroadcastDispatcher.kt b/packages/SystemUI/src/com/android/systemui/broadcast/BroadcastDispatcher.kt
index e89c66e0137c5..74b94e76dfc19 100644
--- a/packages/SystemUI/src/com/android/systemui/broadcast/BroadcastDispatcher.kt
+++ b/packages/SystemUI/src/com/android/systemui/broadcast/BroadcastDispatcher.kt
@@ -166,7 +166,7 @@ open class BroadcastDispatcher @Inject constructor (
 
     @VisibleForTesting
     protected open fun createUBRForUser(userId: Int) =
-            UserBroadcastDispatcher(context, userId, mainHandler, bgLooper)
+            UserBroadcastDispatcher(context, userId, bgLooper)
 
     override fun dump(fd: FileDescriptor, pw: PrintWriter, args: Array<out String>) {
         pw.println("Broadcast dispatcher:")
diff --git a/packages/SystemUI/src/com/android/systemui/broadcast/UserBroadcastDispatcher.kt b/packages/SystemUI/src/com/android/systemui/broadcast/UserBroadcastDispatcher.kt
index 0c631aacab825..4e84f06f51a7c 100644
--- a/packages/SystemUI/src/com/android/systemui/broadcast/UserBroadcastDispatcher.kt
+++ b/packages/SystemUI/src/com/android/systemui/broadcast/UserBroadcastDispatcher.kt
@@ -27,7 +27,6 @@ import android.os.UserHandle
 import android.util.ArrayMap
 import android.util.ArraySet
 import android.util.Log
-import androidx.annotation.MainThread
 import androidx.annotation.VisibleForTesting
 import com.android.internal.util.Preconditions
 import com.android.systemui.Dumpable
@@ -46,11 +45,13 @@ private const val DEBUG = false
  *
  * Created by [BroadcastDispatcher] as needed by users. The value of [userId] can be
  * [UserHandle.USER_ALL].
+ *
+ * Each instance of this class will register itself exactly once with [Context]. Updates to the
+ * [IntentFilter] will be done in the background thread.
  */
 class UserBroadcastDispatcher(
     private val context: Context,
     private val userId: Int,
-    private val mainHandler: Handler,
     private val bgLooper: Looper
 ) : BroadcastReceiver(), Dumpable {
 
@@ -168,7 +169,7 @@ class UserBroadcastDispatcher(
     // Only call this from a BG thread
     private fun createFilterAndRegisterReceiverBG() {
         val intentFilter = createFilter()
-        mainHandler.post(RegisterReceiverRunnable(intentFilter))
+        bgHandler.post(RegisterReceiverRunnable(intentFilter))
     }
 
     override fun dump(fd: FileDescriptor, pw: PrintWriter, args: Array<out String>) {
@@ -207,10 +208,7 @@ class UserBroadcastDispatcher(
 
         /*
          * Registers and unregisters the BroadcastReceiver
-         *
-         * Must be called from Main Thread
          */
-        @MainThread
         override fun run() {
             if (registered.get()) {
                 context.unregisterReceiver(this@UserBroadcastDispatcher)
diff --git a/packages/SystemUI/tests/src/com/android/systemui/broadcast/UserBroadcastDispatcherTest.kt b/packages/SystemUI/tests/src/com/android/systemui/broadcast/UserBroadcastDispatcherTest.kt
index 7821ae29592eb..847e442f1a495 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/broadcast/UserBroadcastDispatcherTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/broadcast/UserBroadcastDispatcherTest.kt
@@ -91,7 +91,7 @@ class UserBroadcastDispatcherTest : SysuiTestCase() {
         fakeExecutor = FakeExecutor(FakeSystemClock())
 
         userBroadcastDispatcher = UserBroadcastDispatcher(
-                mockContext, USER_ID, handler, testableLooper.looper)
+                mockContext, USER_ID, testableLooper.looper)
         userBroadcastDispatcher.pendingResult = mPendingResult
     }