Shrink the transfer queue by default

This change can save 1.25MB per process if the app is using webview.

Change-Id: I32b691f15fa7d395e546963fa64e2fd269a89be9

4 files changed, 33 insertions, 19 deletions

diff --git a/Source/WebCore/platform/graphics/android/TilesManager.cpp b/Source/WebCore/platform/graphics/android/TilesManager.cpp
index 082f0bc..7fe856b 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.cpp
+++ b/Source/WebCore/platform/graphics/android/TilesManager.cpp
@@ -106,6 +106,7 @@ TilesManager::TilesManager()
     , m_useMinimalMemory(true)
     , m_useDoubleBuffering(true)
     , m_treeUpdates(0)
+    , m_queue(0)
     , m_drawGLCount(1)
     , m_lastTimeLayersUsed(0)
     , m_hasLayerTextures(false)
@@ -427,6 +428,14 @@ void TilesManager::setMaxLayerTextureCount(int max)
     m_hasLayerTextures = true;
 }
 
+TransferQueue* TilesManager::transferQueue()
+{
+    // To minimize the memory usage, transfer queue can be set to minimal size
+    // if required.
+    if (!m_queue)
+        m_queue = new TransferQueue(m_useMinimalMemory);
+    return m_queue;
+}
 
 float TilesManager::tileWidth()
 {
diff --git a/Source/WebCore/platform/graphics/android/TilesManager.h b/Source/WebCore/platform/graphics/android/TilesManager.h
index 855994d..b670055 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.h
+++ b/Source/WebCore/platform/graphics/android/TilesManager.h
@@ -82,7 +82,7 @@ public:
     void addPaintedSurface(PaintedSurface* surface);
 
     ShaderProgram* shader() { return &m_shader; }
-    TransferQueue* transferQueue() { return &m_queue; }
+    TransferQueue* transferQueue();
     VideoLayerManager* videoLayerManager() { return &m_videoLayerManager; }
 
     void gatherLayerTextures();
@@ -254,7 +254,7 @@ private:
     static TilesManager* gInstance;
 
     ShaderProgram m_shader;
-    TransferQueue m_queue;
+    TransferQueue* m_queue;
 
     VideoLayerManager m_videoLayerManager;
 
diff --git a/Source/WebCore/platform/graphics/android/TransferQueue.cpp b/Source/WebCore/platform/graphics/android/TransferQueue.cpp
index e97e1a1..ddd1c20 100644
--- a/Source/WebCore/platform/graphics/android/TransferQueue.cpp
+++ b/Source/WebCore/platform/graphics/android/TransferQueue.cpp
@@ -50,7 +50,10 @@
 
 #endif // DEBUG
 
-#define ST_BUFFER_NUMBER 6
+// For simple webView usage, MINIMAL_SIZE is recommended for memory saving.
+// In browser case, EFFICIENT_SIZE is preferred.
+#define MINIMAL_SIZE 1
+#define EFFICIENT_SIZE 6
 
 // Set this to 1 if we would like to take the new GpuUpload approach which
 // relied on the glCopyTexSubImage2D instead of a glDraw call
@@ -58,7 +61,7 @@
 
 namespace WebCore {
 
-TransferQueue::TransferQueue()
+TransferQueue::TransferQueue(bool useMinimalMem)
     : m_eglSurface(EGL_NO_SURFACE)
     , m_transferQueueIndex(0)
     , m_fboID(0)
@@ -69,10 +72,9 @@ TransferQueue::TransferQueue()
     , m_currentUploadType(DEFAULT_UPLOAD_TYPE)
 {
     memset(&m_GLStateBeforeBlit, 0, sizeof(m_GLStateBeforeBlit));
-
-    m_emptyItemCount = ST_BUFFER_NUMBER;
-
-    m_transferQueue = new TileTransferData[ST_BUFFER_NUMBER];
+    m_transferQueueSize = useMinimalMem ? MINIMAL_SIZE : EFFICIENT_SIZE;
+    m_emptyItemCount = m_transferQueueSize;
+    m_transferQueue = new TileTransferData[m_transferQueueSize];
 }
 
 TransferQueue::~TransferQueue()
@@ -117,7 +119,7 @@ void TransferQueue::initGLResources(int width, int height)
         int extraBuffersNeeded = 0;
         m_ANW->query(m_ANW.get(), NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS,
                      &extraBuffersNeeded);
-        m_sharedSurfaceTexture->setBufferCount(ST_BUFFER_NUMBER + extraBuffersNeeded);
+        m_sharedSurfaceTexture->setBufferCount(m_transferQueueSize + extraBuffersNeeded);
 
         int result = native_window_set_buffers_geometry(m_ANW.get(),
                 width, height, HAL_PIXEL_FORMAT_RGBA_8888);
@@ -323,7 +325,7 @@ void TransferQueue::emptyQueue()
 // Must be called within a m_transferQueueItemLocks.
 void TransferQueue::setPendingDiscard()
 {
-    for (int i = 0 ; i < ST_BUFFER_NUMBER; i++)
+    for (int i = 0 ; i < m_transferQueueSize; i++)
         if (m_transferQueue[i].status == pendingBlit)
             m_transferQueue[i].status = pendingDiscard;
 
@@ -376,7 +378,7 @@ void TransferQueue::updateDirtyBaseTiles()
     const int nextItemIndex = getNextTransferQueueIndex();
     int index = nextItemIndex;
     bool usedFboForUpload = false;
-    for (int k = 0; k < ST_BUFFER_NUMBER ; k++) {
+    for (int k = 0; k < m_transferQueueSize ; k++) {
         if (m_transferQueue[index].status == pendingBlit) {
             bool obsoleteBaseTile = checkObsolete(&m_transferQueue[index]);
             // Save the needed info, update the Surf Tex, clean up the item in
@@ -399,7 +401,7 @@ void TransferQueue::updateDirtyBaseTiles()
             m_transferQueue[index].status = emptyItem;
             if (obsoleteBaseTile) {
                 XLOG("Warning: the texture is obsolete for this baseTile");
-                index = (index + 1) % ST_BUFFER_NUMBER;
+                index = (index + 1) % m_transferQueueSize;
                 continue;
             }
 
@@ -436,7 +438,7 @@ void TransferQueue::updateDirtyBaseTiles()
                  destTexture,
                  destTexture->m_ownTextureId);
         }
-        index = (index + 1) % ST_BUFFER_NUMBER;
+        index = (index + 1) % m_transferQueueSize;
     }
 
     // Clean up FBO setup. Doing this for both CPU/GPU upload can make the
@@ -448,7 +450,7 @@ void TransferQueue::updateDirtyBaseTiles()
         GLUtils::checkGlError("updateDirtyBaseTiles");
     }
 
-    m_emptyItemCount = ST_BUFFER_NUMBER;
+    m_emptyItemCount = m_transferQueueSize;
     m_transferQueueItemCond.signal();
 }
 
@@ -571,7 +573,7 @@ void TransferQueue::addItemInTransferQueue(const TileRenderInfo* renderInfo,
                                            TextureUploadType type,
                                            const SkBitmap* bitmap)
 {
-    m_transferQueueIndex = (m_transferQueueIndex + 1) % ST_BUFFER_NUMBER;
+    m_transferQueueIndex = (m_transferQueueIndex + 1) % m_transferQueueSize;
 
     int index = m_transferQueueIndex;
     if (m_transferQueue[index].savedBaseTilePtr
@@ -613,7 +615,7 @@ void TransferQueue::cleanupPendingDiscard()
 {
     int index = getNextTransferQueueIndex();
 
-    for (int i = 0 ; i < ST_BUFFER_NUMBER; i++) {
+    for (int i = 0 ; i < m_transferQueueSize; i++) {
         if (m_transferQueue[index].status == pendingDiscard) {
             // No matter what the current upload type is, as long as there has
             // been a Surf Tex enqueue operation, this updateTexImage need to
@@ -639,7 +641,7 @@ void TransferQueue::cleanupPendingDiscard()
             m_transferQueue[index].savedBaseTileTexturePtr = 0;
             m_transferQueue[index].status = emptyItem;
         }
-        index = (index + 1) % ST_BUFFER_NUMBER;
+        index = (index + 1) % m_transferQueueSize;
     }
 }
 
@@ -688,7 +690,7 @@ void TransferQueue::restoreGLState()
 
 int TransferQueue::getNextTransferQueueIndex()
 {
-    return (m_transferQueueIndex + 1) % ST_BUFFER_NUMBER;
+    return (m_transferQueueIndex + 1) % m_transferQueueSize;
 }
 
 } // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/android/TransferQueue.h b/Source/WebCore/platform/graphics/android/TransferQueue.h
index ec3e5e2..5dd2e0a 100644
--- a/Source/WebCore/platform/graphics/android/TransferQueue.h
+++ b/Source/WebCore/platform/graphics/android/TransferQueue.h
@@ -108,7 +108,7 @@ public:
 
 class TransferQueue {
 public:
-    TransferQueue();
+    TransferQueue(bool useMinimalMem);
     ~TransferQueue();
 
     // This will be called by the browser through nativeSetProperty
@@ -220,6 +220,9 @@ private:
     // resource limited. To get better performance, it is better to separate
     // the pure color tile into another queue.
     WTF::Vector<TileTransferData> m_pureColorTileQueue;
+
+    // The number of items transfer queue can buffer up.
+    int m_transferQueueSize;
 };
 
 } // namespace WebCore