Adaptively throttle texture uploads

cc/CCTextureUpdateController.cpp

Index: cc/CCTextureUpdateController.cpp
diff --git a/cc/CCTextureUpdateController.cpp b/cc/CCTextureUpdateController.cpp
index 22207de75f9adf58e4094922578427d865dc25e6..9c0fc5608fc026e74c9a41d73dbbbddb681c855a 100644
--- a/cc/CCTextureUpdateController.cpp
+++ b/cc/CCTextureUpdateController.cpp
@@ -9,12 +9,16 @@
 #include "GraphicsContext3D.h"
 #include "TextureCopier.h"
 #include "TextureUploader.h"
+#include "TraceEvent.h"
+#include <limits>
 #include <wtf/CurrentTime.h>
 
 namespace {
 
-// Number of textures to update with each call to updateMoreTexturesIfEnoughTimeRemaining().
-static const size_t textureUpdatesPerTick = 12;
+static const size_t pixelsPerTexture = 256 * 256;
+
+// Minimum number of textures to update with each call to updateMoreTexturesIfEnoughTimeRemaining().
+static const size_t textureUpdatesPerFullTickMin = 12;
 
 // Measured in seconds.
 static const double textureUpdateTickRate = 0.004;
@@ -29,13 +33,27 @@ static const int textureUploadFlushPeriod = 4;
 
 namespace cc {
 
-size_t CCTextureUpdateController::maxPartialTextureUpdates()
+size_t CCTextureUpdateController::maxPartialUpdatesDefault()
+{
+    return textureUpdatesPerFullTickMin;
+}
+
+size_t CCTextureUpdateController::maxPartialUpdates(TextureUploader* uploader)
+{
+    return maxFullUpdatesPerTick(uploader);
+}
+
+size_t CCTextureUpdateController::maxFullUpdatesPerTick(TextureUploader* uploader)
 {
-    return textureUpdatesPerTick;
+    double texturesPerSecond = uploader->estimatedPixelsPerSecond() / pixelsPerTexture;
+
+    return std::max(textureUpdatesPerFullTickMin,
+                    (size_t) floor(textureUpdateTickRate * texturesPerSecond));
 }
 
 void CCTextureUpdateController::updateTextures(CCResourceProvider* resourceProvider, TextureCopier* copier, TextureUploader* uploader, CCTextureUpdateQueue* queue, size_t count)

[brianderson, 2012/09/18 00:45:52]

The previous patch set had a few bugs that caused back to back flushes, so I
needed to reorganize the logic again.

 {
+    TRACE_EVENT0("cc", "CCTextureUpdateController::updateTextures");
     if (queue->fullUploadSize() || queue->partialUploadSize()) {
         if (uploader->isBusy())
             return;
@@ -43,43 +61,38 @@ void CCTextureUpdateController::updateTextures(CCResourceProvider* resourceProvi
         uploader->beginUploads();
 
         size_t fullUploadCount = 0;
-        while (queue->fullUploadSize() && fullUploadCount < count) {
-            uploader->uploadTexture(resourceProvider, queue->takeFirstFullUpload());
-            fullUploadCount++;
-            if (!(fullUploadCount % textureUploadFlushPeriod))
+        if (queue->fullUploadSize()) {
+            while (queue->fullUploadSize() && fullUploadCount < count) {
+                if (!(fullUploadCount % textureUploadFlushPeriod) && fullUploadCount)
+                    resourceProvider->shallowFlushIfSupported();
+                uploader->uploadTexture(resourceProvider, queue->takeFirstFullUpload());
+                fullUploadCount++;
+            }
+
+            bool cantUpdloadAllPartials = (count - fullUploadCount) < queue->partialUploadSize();
+            if (cantUpdloadAllPartials) {
+                uploader->endUploads();
                 resourceProvider->shallowFlushIfSupported();
+                return;
+            }
         }
 
-        // Make sure there are no dangling uploads without a flush.
-        if (fullUploadCount % textureUploadFlushPeriod)
-            resourceProvider->shallowFlushIfSupported();
-
-        bool moreUploads = queue->fullUploadSize();
-
-        ASSERT(queue->partialUploadSize() <= count);
-        // We need another update batch if the number of updates remaining
-        // in |count| is greater than the remaining partial entries.
-        if ((count - fullUploadCount) < queue->partialUploadSize())
-            moreUploads = true;
-
-        if (moreUploads) {
-            uploader->endUploads();
-            return;
-        }
+        ASSERT(queue->partialUploadSize() <= (count - fullUploadCount));
 
         size_t partialUploadCount = 0;
-        while (queue->partialUploadSize()) {
-            uploader->uploadTexture(resourceProvider, queue->takeFirstPartialUpload());
-            partialUploadCount++;
-            if (!(partialUploadCount % textureUploadFlushPeriod))
+        if (queue->partialUploadSize()) {
+            if (fullUploadCount)
                 resourceProvider->shallowFlushIfSupported();
+            while (queue->partialUploadSize()) {
+                if (!(partialUploadCount % textureUploadFlushPeriod) && partialUploadCount)
+                    resourceProvider->shallowFlushIfSupported();
+                uploader->uploadTexture(resourceProvider, queue->takeFirstPartialUpload());
+                partialUploadCount++;
+            }
         }
 
-        // Make sure there are no dangling partial uploads without a flush.
-        if (partialUploadCount % textureUploadFlushPeriod)
-            resourceProvider->shallowFlushIfSupported();
-
         uploader->endUploads();
+        resourceProvider->shallowFlushIfSupported();
     }
 
     size_t copyCount = 0;
@@ -95,7 +108,7 @@ void CCTextureUpdateController::updateTextures(CCResourceProvider* resourceProvi
         copier->flush();
 }
 
-CCTextureUpdateController::CCTextureUpdateController(CCTextureUpdateControllerClient* client, CCThread* thread, PassOwnPtr<CCTextureUpdateQueue> queue, CCResourceProvider* resourceProvider, TextureCopier* copier, TextureUploader* uploader)
+CCTextureUpdateController::CCTextureUpdateController(CCTextureUpdateControllerClient* client, CCThread* thread, PassOwnPtr<CCTextureUpdateQueue> queue, CCResourceProvider* resourceProvider, TextureCopier* copier, TextureUploader* uploader, size_t maxPartialTextureUpdates)
     : m_client(client)
     , m_timer(adoptPtr(new CCTimer(thread, this)))
     , m_queue(queue)
@@ -103,6 +116,8 @@ CCTextureUpdateController::CCTextureUpdateController(CCTextureUpdateControllerCl
     , m_copier(copier)
     , m_uploader(uploader)
     , m_monotonicTimeLimit(0)
+    , m_textureUpdatesPerTick(maxFullUpdatesPerTick(uploader))
+    , m_maxPartialTextureUpdates(maxPartialTextureUpdates)
     , m_firstUpdateAttempt(true)
 {
 }
@@ -160,7 +175,9 @@ double CCTextureUpdateController::updateMoreTexturesTime() const
 
 size_t CCTextureUpdateController::updateMoreTexturesSize() const
 {
-    return textureUpdatesPerTick;
+    if (m_queue->fullUploadSize() && !m_queue->partialUploadSize())
+        return m_maxPartialTextureUpdates;
+    return m_textureUpdatesPerTick;
 }
 
 bool CCTextureUpdateController::updateMoreTexturesIfEnoughTimeRemaining()