From 86a7fe21b195ef34a5e41236674a043fda9b7620 Mon Sep 17 00:00:00 2001
From: Ugo Yu <ugoyu@google.com>
Date: Wed, 2 Jun 2021 14:30:37 +0800
Subject: [PATCH] Broadcast Bluetooth state to OFF properly

In current logic, we broadcast Bluetooth state OFF at BLE_ON state.
However, if Bluetooth gets crashed, we won't have the chance to send OFF
intent as we never get to BLE_ON.

This change makes the BluetoothManagerService skips the OFF intent only
if the previous state is a BLE state.

Bug: 189271317
Test: manual
Change-Id: I3936766ab8bdd45d59550dacb64bdc0323bb424d
Merged-In: I3936766ab8bdd45d59550dacb64bdc0323bb424d
---
 .../server/BluetoothManagerService.java       | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/BluetoothManagerService.java b/services/core/java/com/android/server/BluetoothManagerService.java
index 992ef2657a655..8dcd9410a6b28 100644
--- a/services/core/java/com/android/server/BluetoothManagerService.java
+++ b/services/core/java/com/android/server/BluetoothManagerService.java
@@ -2452,6 +2452,16 @@ class BluetoothManagerService extends IBluetoothManager.Stub {
         mContext.sendBroadcastAsUser(intent, UserHandle.ALL, BLUETOOTH_PERM);
     }
 
+    private boolean isBleState(int state) {
+        switch (state) {
+            case BluetoothAdapter.STATE_BLE_ON:
+            case BluetoothAdapter.STATE_BLE_TURNING_ON:
+            case BluetoothAdapter.STATE_BLE_TURNING_OFF:
+                return true;
+        }
+        return false;
+    }
+
     private void bluetoothStateChangeHandler(int prevState, int newState) {
         boolean isStandardBroadcast = true;
         if (prevState == newState) { // No change. Nothing to do.
@@ -2470,8 +2480,15 @@ class BluetoothManagerService extends IBluetoothManager.Stub {
                 sendBluetoothServiceDownCallback();
                 unbindAndFinish();
                 sendBleStateChanged(prevState, newState);
-                // Don't broadcast as it has already been broadcast before
-                isStandardBroadcast = false;
+
+                /* Currently, the OFF intent is broadcasted externally only when we transition
+                 * from TURNING_OFF to BLE_ON state. So if the previous state is a BLE state,
+                 * we are guaranteed that the OFF intent has been broadcasted earlier and we
+                 * can safely skip it.
+                 * Conversely, if the previous state is not a BLE state, it indicates that some
+                 * sort of crash has occurred, moving us directly to STATE_OFF without ever
+                 * passing through BLE_ON. We should broadcast the OFF intent in this case. */
+                isStandardBroadcast = !isBleState(prevState);
 
             } else if (!intermediate_off) {
                 // connect to GattService
@@ -2524,6 +2541,11 @@ class BluetoothManagerService extends IBluetoothManager.Stub {
                 // Show prevState of BLE_ON as OFF to standard users
                 prevState = BluetoothAdapter.STATE_OFF;
             }
+            if (DBG) {
+                Slog.d(TAG,
+                        "Sending State Change: " + BluetoothAdapter.nameForState(prevState) + " > "
+                                + BluetoothAdapter.nameForState(newState));
+            }
             Intent intent = new Intent(BluetoothAdapter.ACTION_STATE_CHANGED);
             intent.putExtra(BluetoothAdapter.EXTRA_PREVIOUS_STATE, prevState);
             intent.putExtra(BluetoothAdapter.EXTRA_STATE, newState);