From 7b30e548a58ac96a23033db43c7aac79c86e938c Mon Sep 17 00:00:00 2001
From: Christopher Wiley <wiley@google.com>
Date: Tue, 17 May 2016 13:41:56 -0700
Subject: [PATCH] Clean up class members in Tethering.TetherInterfaceSM

Mark final fields as such.
Group mutex protected fields together with the mutex that protects them.
Always access mutex protected fields under the mutex.

Bug: 28798823
Change-Id: I96cdd5e063babb73e9f124107c5576c47801f34b
Test: Compiles, Wifi tethering continues to work on angler.
---
 .../server/connectivity/Tethering.java        | 48 +++++++++----------
 1 file changed, 23 insertions(+), 25 deletions(-)

diff --git a/services/core/java/com/android/server/connectivity/Tethering.java b/services/core/java/com/android/server/connectivity/Tethering.java
index 7c1973697af72..87dcfd3b5f7be 100644
--- a/services/core/java/com/android/server/connectivity/Tethering.java
+++ b/services/core/java/com/android/server/connectivity/Tethering.java
@@ -264,7 +264,7 @@ public class Tethering extends BaseNetworkObserver {
             TetherInterfaceSM sm = mIfaces.get(iface);
             if (up) {
                 if (sm == null) {
-                    sm = new TetherInterfaceSM(iface, mLooper, usb);
+                    sm = new TetherInterfaceSM(iface, mLooper, usb, mPublicSync);
                     mIfaces.put(iface, sm);
                     sm.start();
                 }
@@ -339,7 +339,7 @@ public class Tethering extends BaseNetworkObserver {
                 if (VDBG) Log.d(TAG, "active iface (" + iface + ") reported as added, ignoring");
                 return;
             }
-            sm = new TetherInterfaceSM(iface, mLooper, usb);
+            sm = new TetherInterfaceSM(iface, mLooper, usb, mPublicSync);
             mIfaces.put(iface, sm);
             sm.start();
         }
@@ -1041,28 +1041,26 @@ public class Tethering extends BaseNetworkObserver {
         // the upstream connection has changed
         static final int CMD_TETHER_CONNECTION_CHANGED   = BASE_IFACE + 12;
 
-        private State mDefaultState;
+        private final State mInitialState;
+        private final State mStartingState;
+        private final State mTetheredState;
+        private final State mUnavailableState;
 
-        private State mInitialState;
-        private State mStartingState;
-        private State mTetheredState;
-
-        private State mUnavailableState;
+        private final boolean mUsb;
+        private final String mIfaceName;
 
+        private final Object mMutex;  // Protects the fields below.
         private boolean mAvailable;
         private boolean mTethered;
-        int mLastError;
+        private int mLastError;
+        private String mMyUpstreamIfaceName;  // may change over time
 
-        String mIfaceName;
-        String mMyUpstreamIfaceName;  // may change over time
-
-        boolean mUsb;
-
-        TetherInterfaceSM(String name, Looper looper, boolean usb) {
+        TetherInterfaceSM(String name, Looper looper, boolean usb, Object mutex) {
             super(name, looper);
             mIfaceName = name;
             mUsb = usb;
             setLastError(ConnectivityManager.TETHER_ERROR_NO_ERROR);
+            mMutex = mutex;
 
             mInitialState = new InitialState();
             addState(mInitialState);
@@ -1085,20 +1083,20 @@ public class Tethering extends BaseNetworkObserver {
             if (current == mStartingState) res += "StartingState";
             if (current == mTetheredState) res += "TetheredState";
             if (current == mUnavailableState) res += "UnavailableState";
-            if (mAvailable) res += " - Available";
-            if (mTethered) res += " - Tethered";
-            res += " - lastError =" + mLastError;
+            if (isAvailable()) res += " - Available";
+            if (isTethered()) res += " - Tethered";
+            res += " - lastError =" + getLastError();
             return res;
         }
 
         public int getLastError() {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 return mLastError;
             }
         }
 
         private void setLastError(int error) {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 mLastError = error;
 
                 if (isErrored()) {
@@ -1112,31 +1110,31 @@ public class Tethering extends BaseNetworkObserver {
         }
 
         public boolean isAvailable() {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 return mAvailable;
             }
         }
 
         private void setAvailable(boolean available) {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 mAvailable = available;
             }
         }
 
         public boolean isTethered() {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 return mTethered;
             }
         }
 
         private void setTethered(boolean tethered) {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 mTethered = tethered;
             }
         }
 
         public boolean isErrored() {
-            synchronized (Tethering.this.mPublicSync) {
+            synchronized (mMutex) {
                 return (mLastError != ConnectivityManager.TETHER_ERROR_NO_ERROR);
             }
         }