From 9779b221e999583ff89e0dfc40e56398737adbb3 Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Mon, 7 Sep 2009 16:32:45 -0700
Subject: fix [2068105] implement queueBuffer/lockBuffer/dequeueBuffer properly

Rewrote SurfaceFlinger's buffer management from the ground-up.
The design now support an arbitrary number of buffers per surface, however the current implementation is limited to four. Currently only 2 buffers are used in practice.

The main new feature is to be able to dequeue all buffers at once (very important when there are only two).

A client can dequeue all buffers until there are none available, it can lock all buffers except the last one that is used for composition. The client will block then, until a new buffer is enqueued.

The current implementation requires that buffers are locked in the same order they are dequeued and enqueued in the same order they are locked. Only one buffer can be locked at a time.

eg. Allowed sequence:   DQ, DQ, LOCK, Q, LOCK, Q
eg. Forbidden sequence: DQ, DQ, LOCK, LOCK, Q, Q
---
 libs/surfaceflinger/LayerBuffer.cpp | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

(limited to 'libs/surfaceflinger/LayerBuffer.cpp')

diff --git a/libs/surfaceflinger/LayerBuffer.cpp b/libs/surfaceflinger/LayerBuffer.cpp
index 8a55a3f277e4..433b48e1001f 100644
--- a/libs/surfaceflinger/LayerBuffer.cpp
+++ b/libs/surfaceflinger/LayerBuffer.cpp
@@ -28,6 +28,7 @@
 
 #include <hardware/copybit.h>
 
+#include "Buffer.h"
 #include "BufferAllocator.h"
 #include "LayerBuffer.h"
 #include "SurfaceFlinger.h"
@@ -58,7 +59,7 @@ LayerBuffer::~LayerBuffer()
 void LayerBuffer::onFirstRef()
 {
     LayerBaseClient::onFirstRef();
-    mSurface = new SurfaceBuffer(mFlinger, clientIndex(),
+    mSurface = new SurfaceLayerBuffer(mFlinger, clientIndex(),
             const_cast<LayerBuffer *>(this));
 }
 
@@ -181,21 +182,21 @@ sp<LayerBuffer::Source> LayerBuffer::clearSource() {
 }
 
 // ============================================================================
-// LayerBuffer::SurfaceBuffer
+// LayerBuffer::SurfaceLayerBuffer
 // ============================================================================
 
-LayerBuffer::SurfaceBuffer::SurfaceBuffer(const sp<SurfaceFlinger>& flinger,
+LayerBuffer::SurfaceLayerBuffer::SurfaceLayerBuffer(const sp<SurfaceFlinger>& flinger,
         SurfaceID id, const sp<LayerBuffer>& owner)
     : LayerBaseClient::Surface(flinger, id, owner->getIdentity(), owner)
 {
 }
 
-LayerBuffer::SurfaceBuffer::~SurfaceBuffer()
+LayerBuffer::SurfaceLayerBuffer::~SurfaceLayerBuffer()
 {
     unregisterBuffers();
 }
 
-status_t LayerBuffer::SurfaceBuffer::registerBuffers(
+status_t LayerBuffer::SurfaceLayerBuffer::registerBuffers(
         const ISurface::BufferHeap& buffers)
 {
     sp<LayerBuffer> owner(getOwner());
@@ -204,21 +205,21 @@ status_t LayerBuffer::SurfaceBuffer::registerBuffers(
     return NO_INIT;
 }
 
-void LayerBuffer::SurfaceBuffer::postBuffer(ssize_t offset)
+void LayerBuffer::SurfaceLayerBuffer::postBuffer(ssize_t offset)
 {
     sp<LayerBuffer> owner(getOwner());
     if (owner != 0)
         owner->postBuffer(offset);
 }
 
-void LayerBuffer::SurfaceBuffer::unregisterBuffers()
+void LayerBuffer::SurfaceLayerBuffer::unregisterBuffers()
 {
     sp<LayerBuffer> owner(getOwner());
     if (owner != 0)
         owner->unregisterBuffers();
 }
 
-sp<OverlayRef> LayerBuffer::SurfaceBuffer::createOverlay(
+sp<OverlayRef> LayerBuffer::SurfaceLayerBuffer::createOverlay(
         uint32_t w, uint32_t h, int32_t format) {
     sp<OverlayRef> result;
     sp<LayerBuffer> owner(getOwner());
@@ -462,8 +463,8 @@ void LayerBuffer::BufferSource::onDraw(const Region& clip) const
                 const int tmp_h = floorf(src_height * yscale);
                 
                 if (mTempBitmap==0 || 
-                        mTempBitmap->getWidth() < tmp_w || 
-                        mTempBitmap->getHeight() < tmp_h) {
+                        mTempBitmap->getWidth() < size_t(tmp_w) || 
+                        mTempBitmap->getHeight() < size_t(tmp_h)) {
                     mTempBitmap.clear();
                     mTempBitmap = new android::Buffer(
                             tmp_w, tmp_h, src.img.format,
-- 
cgit v1.2.3-59-g8ed1b