Prevent AudioService dead lock issue.

Dead lock sequence:
 1. called onSetA2dpConnectionState()
  1-1. synchronized(mConnectedDevices)
 2. called onServiceDisconnected()
  2-1. synchronized(mA2DPAvrcpLock)
 3. waiting to lock(mConnectedDevices) in onServiceDisconnected()
 4. waiting to lock(mA2DPAvrcpLock) in onSetA2dpConnectionState()

========================================================================================
- watchdog issue
----- pid 3306 at 2014-10-14 16:15:12 -----
Cmd line: system_server

"main" prio=5 tid=1 MONITOR
  - waiting to lock <0x4343e9b0> (a java.util.HashMap) held by tid=46 (AudioService)
      at android.bluetooth.BluetoothA2dp$2.onServiceDisconnected(BluetoothA2dp.java:529)

"AudioService" prio=5 tid=46 MONITOR
      - waiting to lock <0x42ab7a58> (a java.lang.Object) held by tid=1 (main)
========================================================================================

Signed-off-by: Seunghwan Hong <seunghwan.hong@lge.com>

Change-Id: I99e061c07be01aabcd26786ef2ebb71f46717b93

1 files changed, 10 insertions, 9 deletions

diff --git a/media/java/android/media/AudioService.java b/media/java/android/media/AudioService.java
index b0bf4a1..8a78a8f 100644
--- a/media/java/android/media/AudioService.java
+++ b/media/java/android/media/AudioService.java
@@ -508,6 +508,7 @@ public class AudioService extends IAudioService.Stub {
 
     // Reference to BluetoothA2dp to query for AbsoluteVolume.
     private BluetoothA2dp mA2dp;
+    // lock always taken synchronized on mConnectedDevices
     private final Object mA2dpAvrcpLock = new Object();
     // If absolute volume is supported in AVRCP device
     private boolean mAvrcpAbsVolSupported = false;
@@ -2731,12 +2732,12 @@ public class AudioService extends IAudioService.Stub {
             List<BluetoothDevice> deviceList;
             switch(profile) {
             case BluetoothProfile.A2DP:
-                synchronized (mA2dpAvrcpLock) {
-                    mA2dp = (BluetoothA2dp) proxy;
-                    deviceList = mA2dp.getConnectedDevices();
-                    if (deviceList.size() > 0) {
-                        btDevice = deviceList.get(0);
-                        synchronized (mConnectedDevices) {
+                synchronized (mConnectedDevices) {
+                    synchronized (mA2dpAvrcpLock) {
+                        mA2dp = (BluetoothA2dp) proxy;
+                        deviceList = mA2dp.getConnectedDevices();
+                        if (deviceList.size() > 0) {
+                            btDevice = deviceList.get(0);
                             int state = mA2dp.getConnectionState(btDevice);
                             int delay = checkSendBecomingNoisyIntent(
                                                 AudioSystem.DEVICE_OUT_BLUETOOTH_A2DP,
@@ -2831,9 +2832,9 @@ public class AudioService extends IAudioService.Stub {
         public void onServiceDisconnected(int profile) {
             switch(profile) {
             case BluetoothProfile.A2DP:
-                synchronized (mA2dpAvrcpLock) {
-                    mA2dp = null;
-                    synchronized (mConnectedDevices) {
+                synchronized (mConnectedDevices) {
+                    synchronized (mA2dpAvrcpLock) {
+                        mA2dp = null;
                         if (mConnectedDevices.containsKey(AudioSystem.DEVICE_OUT_BLUETOOTH_A2DP)) {
                             makeA2dpDeviceUnavailableNow(
                                     mConnectedDevices.get(AudioSystem.DEVICE_OUT_BLUETOOTH_A2DP));