libs/ui: Add support for triple framebuffers

Change-Id: I90dd38deeeda9a3785b87286cc7d252c6f948750

2 files changed, 15 insertions, 8 deletions

diff --git a/include/ui/FramebufferNativeWindow.h b/include/ui/FramebufferNativeWindow.h
index b202b95b1c..8dd21097ad 100644
--- a/include/ui/FramebufferNativeWindow.h
+++ b/include/ui/FramebufferNativeWindow.h
@@ -28,7 +28,8 @@
 #include <ui/ANativeObjectBase.h>
 #include <ui/Rect.h>
 
-#define NUM_FRAME_BUFFERS  2
+#define MIN_NUM_FRAME_BUFFERS  2
+#define MAX_NUM_FRAME_BUFFERS  3
 
 extern "C" EGLNativeWindowType android_createDisplaySurface(void);
 
@@ -74,7 +75,7 @@ private:
     framebuffer_device_t* fbDev;
     alloc_device_t* grDev;
 
-    sp<NativeBuffer> buffers[NUM_FRAME_BUFFERS];
+    sp<NativeBuffer> buffers[MAX_NUM_FRAME_BUFFERS];
     sp<NativeBuffer> front;
     
     mutable Mutex mutex;
diff --git a/libs/ui/FramebufferNativeWindow.cpp b/libs/ui/FramebufferNativeWindow.cpp
index dec99b6c70..a1f204c065 100644
--- a/libs/ui/FramebufferNativeWindow.cpp
+++ b/libs/ui/FramebufferNativeWindow.cpp
@@ -92,8 +92,13 @@ FramebufferNativeWindow::FramebufferNativeWindow()
         mUpdateOnDemand = (fbDev->setUpdateRect != 0);
         
         // initialize the buffer FIFO
-        mNumBuffers = NUM_FRAME_BUFFERS;
-        mNumFreeBuffers = NUM_FRAME_BUFFERS;
+        if(fbDev->numFramebuffers >= MIN_NUM_FRAME_BUFFERS &&
+           fbDev->numFramebuffers <= MAX_NUM_FRAME_BUFFERS){
+            mNumBuffers = fbDev->numFramebuffers;
+        } else {
+            mNumBuffers = MIN_NUM_FRAME_BUFFERS;
+        }
+        mNumFreeBuffers = mNumBuffers;
         mBufferHead = mNumBuffers-1;
 
         /*
@@ -154,10 +159,11 @@ FramebufferNativeWindow::FramebufferNativeWindow()
 FramebufferNativeWindow::~FramebufferNativeWindow() 
 {
     if (grDev) {
-        if (buffers[0] != NULL)
-            grDev->free(grDev, buffers[0]->handle);
-        if (buffers[1] != NULL)
-            grDev->free(grDev, buffers[1]->handle);
+        for(int i = 0; i < mNumBuffers; i++) {
+            if (buffers[i] != NULL) {
+                grDev->free(grDev, buffers[i]->handle);
+            }
+        }
         gralloc_close(grDev);
     }