Fix triple buffer update bug

bug:11140550

Change-Id: I530bf8b071c7336eb7a20293d6c9c2f5360df47e

1 files changed, 6 insertions, 0 deletions

diff --git a/src/com/android/gallery3d/filtershow/pipeline/SharedPreset.java b/src/com/android/gallery3d/filtershow/pipeline/SharedPreset.java
index 3f850fed2..334361263 100644
--- a/src/com/android/gallery3d/filtershow/pipeline/SharedPreset.java
+++ b/src/com/android/gallery3d/filtershow/pipeline/SharedPreset.java
@@ -21,6 +21,7 @@ public class SharedPreset {
     private volatile ImagePreset mProducerPreset = null;
     private volatile ImagePreset mConsumerPreset = null;
     private volatile ImagePreset mIntermediatePreset = null;
+    private volatile boolean mHasNewContent = false;
 
     public synchronized void enqueuePreset(ImagePreset preset) {
         if (mProducerPreset == null || (!mProducerPreset.same(preset))) {
@@ -31,12 +32,17 @@ public class SharedPreset {
         ImagePreset temp = mIntermediatePreset;
         mIntermediatePreset = mProducerPreset;
         mProducerPreset = temp;
+        mHasNewContent = true;
     }
 
     public synchronized ImagePreset dequeuePreset() {
+        if (!mHasNewContent) {
+            return mConsumerPreset;
+        }
         ImagePreset temp = mConsumerPreset;
         mConsumerPreset = mIntermediatePreset;
         mIntermediatePreset = temp;
+        mHasNewContent = false;
         return mConsumerPreset;
     }
 }