1 files changed, 10 insertions, 9 deletions
diff --git a/src/com/android/tv/recommendation/ChannelRecord.java b/src/com/android/tv/recommendation/ChannelRecord.java
index 26f0fbf0..c7a7cb37 100644
--- a/src/com/android/tv/recommendation/ChannelRecord.java
+++ b/src/com/android/tv/recommendation/ChannelRecord.java
@@ -17,14 +17,12 @@
 package com.android.tv.recommendation;
 
 import android.content.Context;
+import android.support.annotation.GuardedBy;
 import android.support.annotation.VisibleForTesting;
-
-import com.android.tv.TvApplication;
-import com.android.tv.data.Channel;
+import com.android.tv.TvSingletons;
 import com.android.tv.data.Program;
 import com.android.tv.data.ProgramDataManager;
-import com.android.tv.util.Utils;
-
+import com.android.tv.data.api.Channel;
 import java.util.ArrayDeque;
 import java.util.Deque;
 
@@ -32,7 +30,10 @@ public class ChannelRecord {
     // TODO: decide the value for max history size.
     @VisibleForTesting static final int MAX_HISTORY_SIZE = 100;
     private final Context mContext;
+
+    @GuardedBy("this")
     private final Deque<WatchedProgram> mWatchHistory;
+
     private Program mCurrentProgram;
     private Channel mChannel;
     private long mTotalWatchDurationMs;
@@ -62,7 +63,7 @@ public class ChannelRecord {
         mInputRemoved = removed;
     }
 
-    public long getLastWatchEndTimeMs() {
+    public synchronized long getLastWatchEndTimeMs() {
         WatchedProgram p = mWatchHistory.peekLast();
         return (p == null) ? 0 : p.getWatchEndTimeMs();
     }
@@ -71,7 +72,7 @@ public class ChannelRecord {
         long time = System.currentTimeMillis();
         if (mCurrentProgram == null || mCurrentProgram.getEndTimeUtcMillis() < time) {
             ProgramDataManager manager =
-                    TvApplication.getSingletons(mContext).getProgramDataManager();
+                    TvSingletons.getSingletons(mContext).getProgramDataManager();
             mCurrentProgram = manager.getCurrentProgram(mChannel.getId());
         }
         return mCurrentProgram;
@@ -81,11 +82,11 @@ public class ChannelRecord {
         return mTotalWatchDurationMs;
     }
 
-    public final WatchedProgram[] getWatchHistory() {
+    public final synchronized WatchedProgram[] getWatchHistory() {
         return mWatchHistory.toArray(new WatchedProgram[mWatchHistory.size()]);
     }
 
-    public void logWatchHistory(WatchedProgram p) {
+    public synchronized void logWatchHistory(WatchedProgram p) {
         mWatchHistory.offer(p);
         mTotalWatchDurationMs += p.getWatchedDurationMs();
         if (mWatchHistory.size() > MAX_HISTORY_SIZE) {