BufferQueue improvements and APIs changes

this is the first step of a series of improvements to
BufferQueue. A few things happen in this change:

- setSynchronousMode() goes away as well as the SynchronousModeAllowed flag
- BufferQueue now defaults to (what used to be) synchronous mode
- a new "controlled by app" flag is passed when creating consumers and producers
  those flags are used to put the BufferQueue in a mode where it
  will never block if both flags are set. This is achieved by:
  - returning an error from dequeueBuffer() if it would block
  - making sure a buffer is always available by replacing
    the previous buffer with the new one in queueBuffer()
    (note: this is similar to what asynchrnous mode used to be)

Note: in this change EGL's swap-interval 0 is broken; this will be
fixed in another change.

Change-Id: I691f9507d6e2e158287e3039f2a79a4d4434211d
diff --git a/include/gui/BufferItemConsumer.h b/include/gui/BufferItemConsumer.h
index 0af6f8e..9370e81 100644
--- a/include/gui/BufferItemConsumer.h
+++ b/include/gui/BufferItemConsumer.h
@@ -51,9 +51,11 @@
     // the consumer usage flags passed to the graphics allocator. The
     // bufferCount parameter specifies how many buffers can be locked for user
     // access at the same time.
+    // controlledByApp tells whether this consumer is controlled by the
+    // application.
     BufferItemConsumer(const sp<BufferQueue>& bq, uint32_t consumerUsage,
             int bufferCount = BufferQueue::MIN_UNDEQUEUED_BUFFERS,
-            bool synchronousMode = false);
+            bool controlledByApp = false);
 
     virtual ~BufferItemConsumer();
 
diff --git a/include/gui/BufferQueue.h b/include/gui/BufferQueue.h
index 0143be3..f02e25f 100644
--- a/include/gui/BufferQueue.h
+++ b/include/gui/BufferQueue.h
@@ -97,11 +97,9 @@
 
 
     // BufferQueue manages a pool of gralloc memory slots to be used by
-    // producers and consumers. allowSynchronousMode specifies whether or not
-    // synchronous mode can be enabled by the producer. allocator is used to
-    // allocate all the needed gralloc buffers.
-    BufferQueue(bool allowSynchronousMode = true,
-            const sp<IGraphicBufferAlloc>& allocator = NULL);
+    // producers and consumers. allocator is used to allocate all the
+    // needed gralloc buffers.
+    BufferQueue(const sp<IGraphicBufferAlloc>& allocator = NULL);
     virtual ~BufferQueue();
 
     // Query native window attributes.  The "what" values are enumerated in
@@ -197,15 +195,6 @@
     // will usually be the one obtained from dequeueBuffer.
     virtual void cancelBuffer(int buf, const sp<Fence>& fence);
 
-    // setSynchronousMode sets whether dequeueBuffer is synchronous or
-    // asynchronous. In synchronous mode, dequeueBuffer blocks until
-    // a buffer is available, the currently bound buffer can be dequeued and
-    // queued buffers will be acquired in order.  In asynchronous mode,
-    // a queued buffer may be replaced by a subsequently queued buffer.
-    //
-    // The default mode is asynchronous.
-    virtual status_t setSynchronousMode(bool enabled);
-
     // connect attempts to connect a producer API to the BufferQueue.  This
     // must be called before any other IGraphicBufferProducer methods are
     // called except for getAllocator.  A consumer must already be connected.
@@ -215,7 +204,7 @@
     // it's still connected to a producer).
     //
     // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU).
-    virtual status_t connect(int api, QueueBufferOutput* output);
+    virtual status_t connect(int api, bool producerControlledByApp, QueueBufferOutput* output);
 
     // disconnect attempts to disconnect a producer API from the BufferQueue.
     // Calling this method will cause any subsequent calls to other
@@ -312,9 +301,11 @@
     // consumer may be connected, and when that consumer disconnects the
     // BufferQueue is placed into the "abandoned" state, causing most
     // interactions with the BufferQueue by the producer to fail.
+    // controlledByApp indicates whether the consumer is controlled by
+    // the application.
     //
     // consumer may not be NULL.
-    status_t consumerConnect(const sp<ConsumerListener>& consumer);
+    status_t consumerConnect(const sp<ConsumerListener>& consumer, bool controlledByApp);
 
     // consumerDisconnect disconnects a consumer from the BufferQueue. All
     // buffers will be freed and the BufferQueue is placed in the "abandoned"
@@ -347,10 +338,6 @@
     // fail if a producer is connected to the BufferQueue.
     status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers);
 
-    // isSynchronousMode returns whether the BufferQueue is currently in
-    // synchronous mode.
-    bool isSynchronousMode() const;
-
     // setConsumerName sets the name used in logging
     void setConsumerName(const String8& name);
 
@@ -568,13 +555,18 @@
     // to NULL and is written by consumerConnect and consumerDisconnect.
     sp<ConsumerListener> mConsumerListener;
 
+    // mConsumerControlledByApp whether the connected consumer is controlled by the
+    // application.
+    bool mConsumerControlledByApp;
+
+    // mDequeueBufferCannotBlock whether dequeueBuffer() isn't allowed to block.
+    // this flag is set durring connect() when both consumer and producer are controlled
+    // by the application.
+    bool mDequeueBufferCannotBlock;
+
     // mSynchronousMode whether we're in synchronous mode or not
     bool mSynchronousMode;
 
-    // mAllowSynchronousMode whether we allow synchronous mode or not.  Set
-    // when the BufferQueue is created (by the consumer).
-    const bool mAllowSynchronousMode;
-
     // mConnectedApi indicates the producer API that is currently connected
     // to this BufferQueue.  It defaults to NO_CONNECTED_API (= 0), and gets
     // updated by the connect and disconnect methods.
diff --git a/include/gui/ConsumerBase.h b/include/gui/ConsumerBase.h
index 42b84cc..7b58bc5 100644
--- a/include/gui/ConsumerBase.h
+++ b/include/gui/ConsumerBase.h
@@ -87,7 +87,9 @@
 
     // ConsumerBase constructs a new ConsumerBase object to consume image
     // buffers from the given BufferQueue.
-    ConsumerBase(const sp<BufferQueue> &bufferQueue);
+    // The controlledByApp flag indicates that this consumer is under the application's
+    // control.
+    ConsumerBase(const sp<BufferQueue> &bufferQueue, bool controlledByApp = false);
 
     // onLastStrongRef gets called by RefBase just before the dtor of the most
     // derived class.  It is used to clean up the buffers so that ConsumerBase
diff --git a/include/gui/CpuConsumer.h b/include/gui/CpuConsumer.h
index 5f1e369..2890350 100644
--- a/include/gui/CpuConsumer.h
+++ b/include/gui/CpuConsumer.h
@@ -67,7 +67,7 @@
     // Create a new CPU consumer. The maxLockedBuffers parameter specifies
     // how many buffers can be locked for user access at the same time.
     CpuConsumer(const sp<BufferQueue>& bq,
-            uint32_t maxLockedBuffers, bool synchronousMode = true);
+            uint32_t maxLockedBuffers, bool controlledByApp = false);
 
     virtual ~CpuConsumer();
 
diff --git a/include/gui/DummyConsumer.h b/include/gui/DummyConsumer.h
deleted file mode 100644
index 08e8ec8..0000000
--- a/include/gui/DummyConsumer.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * 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 GLConsumer.  This prevents a circular reference from
-// forming without having to use a ProxyConsumerListener
-class DummyConsumer : public BufferQueue::ConsumerListener {
-public:
-    DummyConsumer();
-    virtual ~DummyConsumer();
-protected:
-
-    // Implementation of the BufferQueue::ConsumerListener interface.  These
-    // calls are used to notify the GLConsumer of asynchronous events in the
-    // BufferQueue.
-    virtual void onFrameAvailable();
-    virtual void onBuffersReleased();
-
-};
-
-// ----------------------------------------------------------------------------
-}; // namespace android
-
-#endif // ANDROID_GUI_DUMMYCONSUMER_H
diff --git a/include/gui/GLConsumer.h b/include/gui/GLConsumer.h
index 65544bd..1df5b42 100644
--- a/include/gui/GLConsumer.h
+++ b/include/gui/GLConsumer.h
@@ -87,7 +87,7 @@
     // requirement that either of these methods be called.
     GLConsumer(const sp<BufferQueue>& bq,
             GLuint tex, GLenum texTarget = GL_TEXTURE_EXTERNAL_OES,
-            bool useFenceSync = true);
+            bool useFenceSync = true, bool isControlledByApp = false);
 
     // updateTexImage acquires the most recently queued buffer, and sets the
     // image contents of the target texture to it.
@@ -177,10 +177,6 @@
     // current texture buffer.
     status_t doGLFenceWait() const;
 
-    // isSynchronousMode returns whether the GLConsumer is currently in
-    // synchronous mode.
-    bool isSynchronousMode() const;
-
     // set the name of the GLConsumer that will be used to identify it in
     // log messages.
     void setName(const String8& name);
@@ -190,7 +186,6 @@
     status_t setDefaultBufferFormat(uint32_t defaultFormat);
     status_t setConsumerUsageBits(uint32_t usage);
     status_t setTransformHint(uint32_t hint);
-    virtual status_t setSynchronousMode(bool enabled);
 
     // getBufferQueue returns the BufferQueue object to which this
     // GLConsumer is connected.
diff --git a/include/gui/IGraphicBufferProducer.h b/include/gui/IGraphicBufferProducer.h
index 29c7ff3..af5fcfc 100644
--- a/include/gui/IGraphicBufferProducer.h
+++ b/include/gui/IGraphicBufferProducer.h
@@ -171,13 +171,6 @@
     // 'what' tokens allowed are that of android_natives.h
     virtual int query(int what, int* value) = 0;
 
-    // setSynchronousMode set whether dequeueBuffer is synchronous or
-    // asynchronous. In synchronous mode, dequeueBuffer blocks until
-    // a buffer is available, the currently bound buffer can be dequeued and
-    // queued buffers will be retired in order.
-    // The default mode is asynchronous.
-    virtual status_t setSynchronousMode(bool enabled) = 0;
-
     // connect attempts to connect a client API to the IGraphicBufferProducer.
     // This must be called before any other IGraphicBufferProducer methods are
     // called except for getAllocator.
@@ -188,7 +181,7 @@
     // outWidth, outHeight and outTransform are filled with the default width
     // and height of the window and current transform applied to buffers,
     // respectively.
-    virtual status_t connect(int api, QueueBufferOutput* output) = 0;
+    virtual status_t connect(int api, bool producerControlledByApp, QueueBufferOutput* output) = 0;
 
     // disconnect attempts to disconnect a client API from the
     // IGraphicBufferProducer.  Calling this method will cause any subsequent
diff --git a/include/gui/Surface.h b/include/gui/Surface.h
index c25847c..6f12e77 100644
--- a/include/gui/Surface.h
+++ b/include/gui/Surface.h
@@ -61,8 +61,11 @@
      * However, once a Surface is connected, it'll prevent other Surfaces
      * referring to the same IGraphicBufferProducer to become connected and
      * therefore prevent them to be used as actual producers of buffers.
+     *
+     * the controlledByApp flag indicates that this Surface (producer) is
+     * controlled by the application. This flag is used at connect time.
      */
-    Surface(const sp<IGraphicBufferProducer>& bufferProducer);
+    Surface(const sp<IGraphicBufferProducer>& bufferProducer, bool controlledByApp = false);
 
     /* getIGraphicBufferProducer() returns the IGraphicBufferProducer this
      * Surface was created with. Usually it's an error to use the
@@ -228,6 +231,10 @@
     // window. this is only a hint, actual transform may differ.
     uint32_t mTransformHint;
 
+    // mProducerControlledByApp whether this buffer producer is controlled
+    // by the application
+    bool mProducerControlledByApp;
+
     // mConsumerRunningBehind whether the consumer is running more than
     // one buffer behind the producer.
     mutable bool mConsumerRunningBehind;