Added a DummyConsumer for use with BufferQueue.

The DummyConsumer is a consumer that can connect to BufferQueue
that does nothing.  It is required as BufferQueue checks
if a consumer is connected.  Also fixes a bug where SurfaceTexture
was reusing old texture slots.

Bug: 6172739
Change-Id: I5e7a118dd4d07807ba4c763200242b5ee7d3412b

include/gui/BufferQueue.h

@@ -18,6 +18,7 @@
 #define ANDROID_GUI_BUFFERQUEUE_H
 
 #include <EGL/egl.h>
+#include <EGL/eglext.h>
 
 #include <gui/IGraphicBufferAlloc.h>
 #include <gui/ISurfaceTexture.h>

include/gui/DummyConsumer.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_GUI_DUMMYCONSUMER_H
+#define ANDROID_GUI_DUMMYCONSUMER_H
+
+#include <gui/BufferQueue.h>
+
+namespace android {
+// ----------------------------------------------------------------------------
+
+
+// The DummyConsumer does not keep a reference to BufferQueue
+// unlike SurfaceTexture.  This prevents a circular reference from
+// forming.  The BufferQueue indirectly keeps a DummyConsumer alive
+// through the proxy ConsumerListener.
+class DummyConsumer : public virtual RefBase,
+        protected BufferQueue::ConsumerListener {
+public:
+    DummyConsumer(sp<BufferQueue> bufferQueue);
+    virtual ~DummyConsumer();
+
+protected:
+
+    // Implementation of the BufferQueue::ConsumerListener interface.  These
+    // calls are used to notify the SurfaceTexture of asynchronous events in the
+    // BufferQueue.
+    virtual void onFrameAvailable();
+    virtual void onBuffersReleased();
+
+};
+
+// ----------------------------------------------------------------------------
+}; // namespace android
+
+#endif // ANDROID_GUI_DUMMYCONSUMER_H

libs/gui/Android.mk

@@ -21,6 +21,7 @@ LOCAL_SRC_FILES:= \
 	LayerState.cpp \
 	Surface.cpp \
 	SurfaceComposerClient.cpp \
+	DummyConsumer.cpp
 
 LOCAL_SHARED_LIBRARIES := \
 	libcutils \

libs/gui/DummyConsumer.cpp

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "DummyConsumer"
+// #define LOG_NDEBUG 0
+
+#include <gui/DummyConsumer.h>
+
+#include <utils/Log.h>
+#include <utils/String8.h>
+
+namespace android {
+
+DummyConsumer::DummyConsumer(sp<BufferQueue> bufferQueue) {
+    wp<BufferQueue::ConsumerListener> listener;
+    sp<BufferQueue::ConsumerListener> proxy;
+    listener = static_cast<BufferQueue::ConsumerListener*>(this);
+    proxy = new BufferQueue::ProxyConsumerListener(listener);
+
+    status_t err = bufferQueue->consumerConnect(proxy);
+    if (err != NO_ERROR) {
+        ALOGE("DummyConsumer: error connecting to BufferQueue: %s (%d)",
+                strerror(-err), err);
+    }
+}
+
+DummyConsumer::~DummyConsumer() {
+    ALOGV("~DummyConsumer");
+}
+
+void DummyConsumer::onFrameAvailable() {
+    ALOGV("onFrameAvailable");
+}
+
+void DummyConsumer::onBuffersReleased() {
+    ALOGV("onBuffersReleased");
+}
+
+}; // namespace android

libs/gui/SurfaceTexture.cpp

@@ -575,6 +575,8 @@ void SurfaceTexture::onBuffersReleased() {
             freeBufferLocked(i);
         }
     }
+
+    mCurrentTexture = BufferQueue::INVALID_BUFFER_SLOT;
 }
 
 void SurfaceTexture::dump(String8& result) const