commit d1def087b15801002d0dad243841bda08886547d
author Etan Cohen <etancohen@google.com> Sun Sep 29 10:02:14 2019 -0700
committer Etan Cohen <etancohen@google.com> Fri Oct 04 16:15:39 2019 +0000
tree 68007367faef0b8284918b6e511664b60114d726
parent 7957387b5d459386191cf45ca90e45446ed13f93

Add synchroniztaion to prevent concurrent modification exception

Fix unsynchronized concurrent use.

Bug: 141503388
Test: atest com.android.server.wifi.HalDeviceManagerTest
Change-Id: Ibe3ffccfca4d175e3f6eb57b202ae0d76d5f33ef
(cherry picked from commit 175e0b8a9bbaf173d02bde574de5c22f82617f51)

service/java/com/android/server/wifi/HalDeviceManager.java

diff --git a/service/java/com/android/server/wifi/HalDeviceManager.java b/service/java/com/android/server/wifi/HalDeviceManager.java
index d2ad47f..e10234f 100644
--- a/service/java/com/android/server/wifi/HalDeviceManager.java
+++ b/service/java/com/android/server/wifi/HalDeviceManager.java
@@ -1723,9 +1723,11 @@
             int requestedIfaceType, WifiIfaceInfo[][] currentIfaces, int numNecessaryInterfaces) {
         // rule 0: check for any low priority interfaces
         int numAvailableLowPriorityInterfaces = 0;
-        for (InterfaceCacheEntry entry : mInterfaceInfoCache.values()) {
-            if (entry.type == existingIfaceType && entry.isLowPriority) {
-                numAvailableLowPriorityInterfaces++;
+        synchronized (mLock) {
+            for (InterfaceCacheEntry entry : mInterfaceInfoCache.values()) {
+                if (entry.type == existingIfaceType && entry.isLowPriority) {
+                    numAvailableLowPriorityInterfaces++;
+                }
             }
         }
         if (numAvailableLowPriorityInterfaces >= numNecessaryInterfaces) {
@@ -1780,8 +1782,10 @@
         LongSparseArray<WifiIfaceInfo> orderedListLowPriority = new LongSparseArray<>();
         LongSparseArray<WifiIfaceInfo> orderedList = new LongSparseArray<>();
         for (WifiIfaceInfo info : interfaces) {
-            InterfaceCacheEntry cacheEntry = mInterfaceInfoCache.get(
-                    Pair.create(info.name, getType(info.iface)));
+            InterfaceCacheEntry cacheEntry;
+            synchronized (mLock) {
+                cacheEntry = mInterfaceInfoCache.get(Pair.create(info.name, getType(info.iface)));
+            }
             if (cacheEntry == null) {
                 Log.e(TAG,
                         "selectInterfacesToDelete: can't find cache entry with name=" + info.name);