A better WAR of driver issue by using GPU fence

bug:5270526
Change-Id: I790a3fc995edc73192b2bcb24eaa29e99434f2fb

3 files changed, 39 insertions, 13 deletions

diff --git a/Source/WebCore/platform/graphics/android/BaseTileTexture.h b/Source/WebCore/platform/graphics/android/BaseTileTexture.h
index 0f694a5..d2560dd 100644
--- a/Source/WebCore/platform/graphics/android/BaseTileTexture.h
+++ b/Source/WebCore/platform/graphics/android/BaseTileTexture.h
@@ -83,6 +83,7 @@ public:
     TileTransferData()
     : status(emptyItem)
     , savedBaseTilePtr(0)
+    , m_syncKHR(EGL_NO_SYNC_KHR)
     {
     }
     TransferItemStatus status;
@@ -91,6 +92,14 @@ public:
 #if DEBUG_TRANSFER_USING_CPU_UPLOAD
     SkBitmap bitmap;
 #endif
+    // Sync object for GPU fence, this is the only the info passed from UI
+    // thread to Tex Gen thread. The reason of having this is due to the
+    // missing sync mechanism on Surface Texture on some vendor. b/5122031.
+    // Bascially the idea is that when UI thread utilize one buffer from
+    // the surface texture, we'll need to kick off the GPU commands, and only
+    // when those particular commands finish, we could write into this buffer
+    // again in Tex Gen thread.
+    EGLSyncKHR m_syncKHR;
 };
 
 // DoubleBufferedTexture using a SkBitmap as backing mechanism
diff --git a/Source/WebCore/platform/graphics/android/TransferQueue.cpp b/Source/WebCore/platform/graphics/android/TransferQueue.cpp
index 50502f6..df9aede 100644
--- a/Source/WebCore/platform/graphics/android/TransferQueue.cpp
+++ b/Source/WebCore/platform/graphics/android/TransferQueue.cpp
@@ -34,9 +34,11 @@
 #include <gui/SurfaceTexture.h>
 #include <gui/SurfaceTextureClient.h>
 
-#ifdef DEBUG
 #include <cutils/log.h>
 #include <wtf/text/CString.h>
+#define XLOGC(...) android_printLog(ANDROID_LOG_DEBUG, "TransferQueue", __VA_ARGS__)
+
+#ifdef DEBUG
 
 #undef XLOG
 #define XLOG(...) android_printLog(ANDROID_LOG_DEBUG, "TransferQueue", __VA_ARGS__)
@@ -64,10 +66,6 @@ TransferQueue::TransferQueue()
     m_emptyItemCount = ST_BUFFER_NUMBER;
 
     m_transferQueue = new TileTransferData[ST_BUFFER_NUMBER];
-    for (int i = 0; i < ST_BUFFER_NUMBER; i++) {
-        m_transferQueue[i].savedBaseTilePtr = 0;
-        m_transferQueue[i].status = emptyItem;
-    }
 }
 
 TransferQueue::~TransferQueue()
@@ -132,7 +130,9 @@ bool TransferQueue::checkObsolete(int index)
     return false;
 }
 
-void TransferQueue::blitTileFromQueue(GLuint fboID, BaseTileTexture* destTex, GLuint srcTexId, GLenum srcTexTarget)
+void TransferQueue::blitTileFromQueue(GLuint fboID, BaseTileTexture* destTex,
+                                      GLuint srcTexId, GLenum srcTexTarget,
+                                      int index)
 {
     // guarantee that we have a texture to blit into
     destTex->requireTexture();
@@ -158,14 +158,23 @@ void TransferQueue::blitTileFromQueue(GLuint fboID, BaseTileTexture* destTex, GL
     TilesManager::instance()->shader()->drawQuad(rect, srcTexId, 1.0,
                        srcTexTarget);
 
+    // To workaround a sync issue on some platforms, we should insert the sync
+    // here while in the current FBO.
+    // This will essentially kick off the GPU command buffer, and the Tex Gen
+    // thread will then have to wait for this buffer to finish before writing
+    // into the same memory.
+    EGLDisplay dpy = eglGetCurrentDisplay();
+    if (m_transferQueue[index].m_syncKHR != EGL_NO_SYNC_KHR)
+        eglDestroySyncKHR(dpy, m_transferQueue[index].m_syncKHR);
+    m_transferQueue[index].m_syncKHR = eglCreateSyncKHR(eglGetCurrentDisplay(),
+                                                        EGL_SYNC_FENCE_KHR,
+                                                        0);
+    if (m_transferQueue[index].m_syncKHR == EGL_NO_SYNC_KHR)
+        XLOGC("ERROR: eglClientWaitSyncKHR return error");
+
     // Clean up FBO setup.
     glBindFramebuffer(GL_FRAMEBUFFER, 0); // rebind the standard FBO
 
-    // Add a sync point here to WAR a driver bug.
-    glViewport(0, 0, 0, 0);
-    TilesManager::instance()->shader()->drawQuad(rect, destTex->m_ownTextureId,
-                                                 1.0, GL_TEXTURE_2D);
-
     GLUtils::checkGlError("copy the surface texture into the normal one");
 }
 
@@ -198,6 +207,12 @@ bool TransferQueue::readyForUpdate()
     if (!getHasGLContext())
         return false;
 
+    // Check the GPU fence
+    eglClientWaitSyncKHR(eglGetCurrentDisplay(),
+                         m_transferQueue[getNextTransferQueueIndex()].m_syncKHR,
+                         EGL_SYNC_FLUSH_COMMANDS_BIT_KHR,
+                         EGL_FOREVER_KHR);
+
     return true;
 }
 
@@ -270,7 +285,8 @@ void TransferQueue::updateDirtyBaseTiles()
 #else
             blitTileFromQueue(m_fboID, destTexture,
                               m_sharedSurfaceTextureId,
-                              m_sharedSurfaceTexture->getCurrentTextureTarget());
+                              m_sharedSurfaceTexture->getCurrentTextureTarget(),
+                              index);
 #endif
 
             // After the base tile copied into the GL texture, we need to
diff --git a/Source/WebCore/platform/graphics/android/TransferQueue.h b/Source/WebCore/platform/graphics/android/TransferQueue.h
index 291215c..dbe29f8 100644
--- a/Source/WebCore/platform/graphics/android/TransferQueue.h
+++ b/Source/WebCore/platform/graphics/android/TransferQueue.h
@@ -95,7 +95,8 @@ private:
     void cleanupTransportQueue();
 
     void blitTileFromQueue(GLuint fboID, BaseTileTexture* destTex,
-                           GLuint srcTexId, GLenum srcTexTarget);
+                           GLuint srcTexId, GLenum srcTexTarget,
+                           int index);
 
     // Note that the m_transferQueueIndex only changed in the TexGen thread
     // where we are going to move on to update the next item in the queue.