Merge "Remove experimental HWC virtual display support" into jb-mr2-dev

6 files changed, 17 insertions, 490 deletions

diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index f36e1bfb5c..ec296d333f 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -14,7 +14,6 @@ LOCAL_SRC_FILES:= \
     SurfaceFlingerConsumer.cpp \
     SurfaceTextureLayer.cpp \
     Transform.cpp \
-    DisplayHardware/BufferQueueInterposer.cpp \
     DisplayHardware/FramebufferSurface.cpp \
     DisplayHardware/HWComposer.cpp \
     DisplayHardware/PowerHAL.cpp \
diff --git a/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.cpp b/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.cpp
deleted file mode 100644
index 91f9aeabdf..0000000000
--- a/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.cpp
+++ /dev/null
@@ -1,226 +0,0 @@
-/*
- * Copyright 2013 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.
- */
-
-#undef LOG_TAG
-#define LOG_TAG "BQInterposer"
-//#define LOG_NDEBUG 0
-
-#include "BufferQueueInterposer.h"
-
-// ---------------------------------------------------------------------------
-namespace android {
-// ---------------------------------------------------------------------------
-
-#define BQI_LOGV(x, ...) ALOGV("[%s] "x, mName.string(), ##__VA_ARGS__)
-#define BQI_LOGD(x, ...) ALOGD("[%s] "x, mName.string(), ##__VA_ARGS__)
-#define BQI_LOGI(x, ...) ALOGI("[%s] "x, mName.string(), ##__VA_ARGS__)
-#define BQI_LOGW(x, ...) ALOGW("[%s] "x, mName.string(), ##__VA_ARGS__)
-#define BQI_LOGE(x, ...) ALOGE("[%s] "x, mName.string(), ##__VA_ARGS__)
-
-// Get an ID that's unique within this process.
-static int32_t createProcessUniqueId() {
-    static volatile int32_t globalCounter = 0;
-    return android_atomic_inc(&globalCounter);
-}
-
-BufferQueueInterposer::BufferQueueInterposer(
-        const sp<IGraphicBufferProducer>& sink, const String8& name)
-:   mSink(sink),
-    mName(name),
-    mAcquired(false)
-{
-    BQI_LOGV("BufferQueueInterposer sink=%p", sink.get());
-}
-
-BufferQueueInterposer::~BufferQueueInterposer() {
-    Mutex::Autolock lock(mMutex);
-    flushQueuedBuffersLocked();
-    BQI_LOGV("~BufferQueueInterposer");
-}
-
-status_t BufferQueueInterposer::requestBuffer(int slot,
-        sp<GraphicBuffer>* outBuf) {
-    BQI_LOGV("requestBuffer slot=%d", slot);
-    Mutex::Autolock lock(mMutex);
-
-    if (size_t(slot) >= mBuffers.size()) {
-        size_t size = mBuffers.size();
-        mBuffers.insertAt(size, size - slot + 1);
-    }
-    sp<GraphicBuffer>& buf = mBuffers.editItemAt(slot);
-
-    status_t result = mSink->requestBuffer(slot, &buf);
-    *outBuf = buf;
-    return result;
-}
-
-status_t BufferQueueInterposer::setBufferCount(int bufferCount) {
-    BQI_LOGV("setBufferCount count=%d", bufferCount);
-    Mutex::Autolock lock(mMutex);
-
-    bufferCount += 1;
-
-    status_t result = flushQueuedBuffersLocked();
-    if (result != NO_ERROR)
-        return result;
-
-    result = mSink->setBufferCount(bufferCount);
-    if (result != NO_ERROR)
-        return result;
-
-    for (size_t i = 0; i < mBuffers.size(); i++)
-        mBuffers.editItemAt(i).clear();
-    ssize_t n = mBuffers.resize(bufferCount);
-    result = (n < 0) ? n : result;
-
-    return result;
-}
-
-status_t BufferQueueInterposer::dequeueBuffer(int* slot, sp<Fence>* fence,
-            uint32_t w, uint32_t h, uint32_t format, uint32_t usage) {
-    BQI_LOGV("dequeueBuffer %ux%u fmt=%u usage=%#x", w, h, format, usage);
-    return mSink->dequeueBuffer(slot, fence, w, h, format, usage);
-}
-
-status_t BufferQueueInterposer::queueBuffer(int slot,
-            const QueueBufferInput& input, QueueBufferOutput* output) {
-    BQI_LOGV("queueBuffer slot=%d", slot);
-    Mutex::Autolock lock(mMutex);
-    mQueue.push(QueuedBuffer(slot, input));
-    *output = mQueueBufferOutput;
-    return NO_ERROR;
-}
-
-void BufferQueueInterposer::cancelBuffer(int slot, const sp<Fence>& fence) {
-    BQI_LOGV("cancelBuffer slot=%d", slot);
-    mSink->cancelBuffer(slot, fence);
-}
-
-int BufferQueueInterposer::query(int what, int* value) {
-    BQI_LOGV("query what=%d", what);
-    return mSink->query(what, value);
-}
-
-status_t BufferQueueInterposer::setSynchronousMode(bool enabled) {
-    BQI_LOGV("setSynchronousMode %s", enabled ? "true" : "false");
-    return mSink->setSynchronousMode(enabled);
-}
-
-status_t BufferQueueInterposer::connect(int api, QueueBufferOutput* output) {
-    BQI_LOGV("connect api=%d", api);
-    Mutex::Autolock lock(mMutex);
-    status_t result = mSink->connect(api, &mQueueBufferOutput);
-    if (result == NO_ERROR) {
-        *output = mQueueBufferOutput;
-    }
-    return result;
-}
-
-status_t BufferQueueInterposer::disconnect(int api) {
-    BQI_LOGV("disconnect: api=%d", api);
-    Mutex::Autolock lock(mMutex);
-    flushQueuedBuffersLocked();
-    return mSink->disconnect(api);
-}
-
-status_t BufferQueueInterposer::pullEmptyBuffer() {
-    status_t result;
-
-    int slot;
-    sp<Fence> fence;
-    result = dequeueBuffer(&slot, &fence, 0, 0, 0, 0);
-    if (result == IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION) {
-        sp<GraphicBuffer> buffer;
-        result = requestBuffer(slot, &buffer);
-    } else if (result != NO_ERROR) {
-        return result;
-    }
-
-    uint32_t w, h, transformHint, numPendingBuffers;
-    mQueueBufferOutput.deflate(&w, &h, &transformHint, &numPendingBuffers);
-
-    IGraphicBufferProducer::QueueBufferInput qbi(0, Rect(w, h),
-            NATIVE_WINDOW_SCALING_MODE_FREEZE, 0, fence);
-    IGraphicBufferProducer::QueueBufferOutput qbo;
-    result = queueBuffer(slot, qbi, &qbo);
-    if (result != NO_ERROR)
-        return result;
-
-    return NO_ERROR;
-}
-
-status_t BufferQueueInterposer::acquireBuffer(sp<GraphicBuffer>* buf,
-        sp<Fence>* fence) {
-    Mutex::Autolock lock(mMutex);
-    if (mQueue.empty()) {
-        BQI_LOGV("acquireBuffer: no buffers available");
-        return NO_BUFFER_AVAILABLE;
-    }
-    if (mAcquired) {
-        BQI_LOGE("acquireBuffer: buffer already acquired");
-        return BUFFER_ALREADY_ACQUIRED;
-    }
-    BQI_LOGV("acquireBuffer: acquiring slot %d", mQueue[0].slot);
-
-    *buf = mBuffers[mQueue[0].slot];
-    *fence = mQueue[0].fence;
-    mAcquired = true;
-    return NO_ERROR;
-}
-
-status_t BufferQueueInterposer::releaseBuffer(const sp<Fence>& fence) {
-    Mutex::Autolock lock(mMutex);
-    if (!mAcquired) {
-        BQI_LOGE("releaseBuffer: releasing a non-acquired buffer");
-        return BUFFER_NOT_ACQUIRED;
-    }
-    BQI_LOGV("releaseBuffer: releasing slot %d to sink", mQueue[0].slot);
-
-    const QueuedBuffer& b = mQueue[0];
-    status_t result = mSink->queueBuffer(b.slot,
-            QueueBufferInput(b.timestamp, b.crop, b.scalingMode,
-                b.transform, b.fence),
-            &mQueueBufferOutput);
-    mQueue.removeAt(0);
-    mAcquired = false;
-
-    return result;
-}
-
-status_t BufferQueueInterposer::flushQueuedBuffersLocked() {
-    if (mAcquired) {
-        BQI_LOGE("flushQueuedBuffersLocked: buffer acquired, can't flush");
-        return INVALID_OPERATION;
-    }
-
-    status_t result = NO_ERROR;
-    for (size_t i = 0; i < mQueue.size(); i++) {
-        const QueuedBuffer& b = mQueue[i];
-        BQI_LOGV("flushing queued slot %d to sink", b.slot);
-        status_t err = mSink->queueBuffer(b.slot,
-                QueueBufferInput(b.timestamp, b.crop, b.scalingMode,
-                    b.transform, b.fence),
-                &mQueueBufferOutput);
-        if (err != NO_ERROR && result == NO_ERROR) // latch first error
-            result = err;
-    }
-    mQueue.clear();
-    return result;
-}
-
-// ---------------------------------------------------------------------------
-} // namespace android
-// ---------------------------------------------------------------------------
diff --git a/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.h b/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.h
deleted file mode 100644
index 7e84e973d6..0000000000
--- a/services/surfaceflinger/DisplayHardware/BufferQueueInterposer.h
+++ /dev/null
@@ -1,152 +0,0 @@
-/*
- * Copyright 2013 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_SF_BUFFERQUEUEINTERPOSER_H
-#define ANDROID_SF_BUFFERQUEUEINTERPOSER_H
-
-#include <gui/IGraphicBufferProducer.h>
-#include <utils/Mutex.h>
-#include <utils/Vector.h>
-
-// ---------------------------------------------------------------------------
-namespace android {
-// ---------------------------------------------------------------------------
-
-// BufferQueueInterposers introduce an extra stage between a buffer producer
-// (the source) and a buffer consumer (the sink), which communicate via the
-// IGraphicBufferProducer interface. It is designed to be as transparent as
-// possible to both endpoints, so that they can work the same whether an
-// interposer is present or not.
-//
-// When the interpose is present, the source queues buffers to the
-// IGraphicBufferProducer implemented by BufferQueueInterposer. A client of
-// the BufferQueueInterposer can acquire each buffer in turn and read or
-// modify it, releasing the buffer when finished. When the buffer is released,
-// the BufferQueueInterposer queues it to the original IGraphicBufferProducer
-// interface representing the sink.
-//
-// A BufferQueueInterposer can be used to do additional rendering to a buffer
-// before it is consumed -- essentially pipelining two producers. As an
-// example, SurfaceFlinger uses this to implement mixed GLES and HWC
-// compositing to the same buffer for virtual displays. If it used two separate
-// buffer queues, then in GLES-only or mixed GLES+HWC compositing, the HWC
-// would have to copy the GLES output buffer to the HWC output buffer, using
-// more bandwidth than having HWC do additional composition "in place" on the
-// GLES output buffer.
-//
-// The goal for this class is to be usable in a variety of situations and be
-// part of libgui. But both the interface and implementation need some
-// iteration before then, so for now it should only be used by
-// VirtualDisplaySurface, which is why it's currently in SurfaceFlinger.
-//
-// Some of the problems that still need to be solved are:
-//
-// - Refactor the interposer interface along with BufferQueue and ConsumerBase,
-//   so that there is a common interface for the consumer end of a queue. The
-//   existing interfaces have some problems when the implementation isn't the
-//   final consumer.
-//
-// - The client of the interposer may need one or more buffers in addition to
-//   those used by the source and sink. IGraphicBufferProducer will probably
-//   need to change to allow the producer to specify how many buffers it needs
-//   to dequeue at a time, and then the interposer can add its requirements to
-//   those of the source.
-//
-// - Abandoning, disconnecting, and connecting need to pass through somehow.
-//   There needs to be a way to tell the interposer client to release its
-//   buffer immediately so it can be queued/released, e.g. when the source
-//   calls disconnect().
-//
-// - Right now the source->BQI queue is synchronous even if the BQI->sink queue
-//   is asynchronous. Need to figure out how asynchronous should behave and
-//   implement that.
-
-class BufferQueueInterposer : public BnGraphicBufferProducer {
-public:
-    BufferQueueInterposer(const sp<IGraphicBufferProducer>& sink,
-            const String8& name);
-
-    //
-    // IGraphicBufferProducer interface
-    //
-    virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* outBuf);
-    virtual status_t setBufferCount(int bufferCount);
-    virtual status_t dequeueBuffer(int* slot, sp<Fence>* fence,
-            uint32_t w, uint32_t h, uint32_t format, uint32_t usage);
-    virtual status_t queueBuffer(int slot,
-            const QueueBufferInput& input, QueueBufferOutput* output);
-    virtual void cancelBuffer(int slot, const sp<Fence>& fence);
-    virtual int query(int what, int* value);
-    virtual status_t setSynchronousMode(bool enabled);
-    virtual status_t connect(int api, QueueBufferOutput* output);
-    virtual status_t disconnect(int api);
-
-    //
-    // Interposer interface
-    //
-
-    enum {
-        NO_BUFFER_AVAILABLE = 2,    // matches BufferQueue
-        BUFFER_NOT_ACQUIRED,
-        BUFFER_ALREADY_ACQUIRED,
-    };
-
-    // Acquire the oldest queued buffer. If no buffers are pending, returns
-    // NO_BUFFER_AVAILABLE. If a buffer is currently acquired, returns
-    // BUFFER_ALREADY_ACQUIRED.
-    status_t acquireBuffer(sp<GraphicBuffer>* buf, sp<Fence>* fence);
-
-    // Release the currently acquired buffer, queueing it to the sink. If the
-    // current buffer hasn't been acquired, returns BUFFER_NOT_ACQUIRED.
-    status_t releaseBuffer(const sp<Fence>& fence);
-
-    // pullEmptyBuffer dequeues a buffer from the sink, then immediately
-    // queues it to the interposer. This makes a buffer available for the
-    // client to acquire even if the source hasn't queued one.
-    status_t pullEmptyBuffer();
-
-private:
-    struct QueuedBuffer {
-        QueuedBuffer(): slot(-1) {}
-        QueuedBuffer(int slot, const QueueBufferInput& qbi): slot(slot) {
-            qbi.deflate(&timestamp, &crop, &scalingMode, &transform, &fence);
-        }
-        int slot;
-        int64_t timestamp;
-        Rect crop;
-        int scalingMode;
-        uint32_t transform;
-        sp<Fence> fence;
-    };
-
-    virtual ~BufferQueueInterposer();
-    status_t flushQueuedBuffersLocked();
-
-    const sp<IGraphicBufferProducer> mSink;
-    String8 mName;
-
-    Mutex mMutex;
-    Vector<sp<GraphicBuffer> > mBuffers;
-    Vector<QueuedBuffer> mQueue;
-    bool mAcquired;
-    QueueBufferOutput mQueueBufferOutput;
-};
-
-// ---------------------------------------------------------------------------
-} // namespace android
-// ---------------------------------------------------------------------------
-
-#endif // ANDROID_SF_BUFFERQUEUEINTERPOSER_H
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 3f00f073f7..f0f7463920 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -50,6 +50,10 @@
 
 namespace android {
 
+// This is not a real HWC version. It's used for in-development features that
+// haven't been committed to a specific real HWC version.
+#define HWC_DEVICE_API_VERSION_1_EXP HARDWARE_DEVICE_API_VERSION_2(1, 0xFF, HWC_HEADER_VERSION)
+
 #define MIN_HWC_HEADER_VERSION HWC_HEADER_VERSION
 
 #define NUM_PHYSICAL_DISPLAYS HWC_NUM_DISPLAY_TYPES
@@ -152,8 +156,8 @@ HWComposer::HWComposer(
 
         // the number of displays we actually have depends on the
         // hw composer version
-        if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_2)) {
-            // 1.2 adds support for virtual displays
+        if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_EXP)) {
+            // 1.?? adds support for virtual displays
             mNumDisplays = MAX_DISPLAYS;
         } else if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_1)) {
             // 1.1 adds support for multiple displays
@@ -581,7 +585,7 @@ status_t HWComposer::prepare() {
         }
         mLists[i] = disp.list;
         if (mLists[i]) {
-            if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_2)) {
+            if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_EXP)) {
                 mLists[i]->outbuf = NULL;
                 mLists[i]->outbufAcquireFenceFd = -1;
             } else if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_1)) {
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index 7e14d955a7..2838b23031 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -15,7 +15,9 @@
  */
 
 #include "VirtualDisplaySurface.h"
-#include "HWComposer.h"
+
+#include <cutils/log.h>
+#include <gui/IGraphicBufferProducer.h>
 
 // ---------------------------------------------------------------------------
 namespace android {
@@ -23,28 +25,16 @@ namespace android {
 
 VirtualDisplaySurface::VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
         const sp<IGraphicBufferProducer>& sink, const String8& name)
-:   mHwc(hwc),
-    mDisplayId(dispId),
-    mName(name)
+:   mSink(sink)
 {
-    if (mDisplayId >= 0) {
-        mInterposer = new BufferQueueInterposer(sink, name);
-        mSourceProducer = mInterposer;
-    } else {
-        mSourceProducer = sink;
-    }
+    LOG_ALWAYS_FATAL_IF(dispId >= 0);
 }
 
 VirtualDisplaySurface::~VirtualDisplaySurface() {
-    if (mAcquiredBuffer != NULL) {
-        status_t result = mInterposer->releaseBuffer(Fence::NO_FENCE);
-        ALOGE_IF(result != NO_ERROR, "VirtualDisplaySurface \"%s\": "
-                "failed to release buffer: %d", mName.string(), result);
-    }
 }
 
 sp<IGraphicBufferProducer> VirtualDisplaySurface::getIGraphicBufferProducer() const {
-    return mSourceProducer;
+    return mSink;
 }
 
 status_t VirtualDisplaySurface::compositionComplete() {
@@ -52,60 +42,10 @@ status_t VirtualDisplaySurface::compositionComplete() {
 }
 
 status_t VirtualDisplaySurface::advanceFrame() {
-    if (mInterposer == NULL)
-        return NO_ERROR;
-
-    Mutex::Autolock lock(mMutex);
-    status_t result = NO_ERROR;
-
-    if (mAcquiredBuffer != NULL) {
-        ALOGE("VirtualDisplaySurface \"%s\": "
-                "advanceFrame called twice without onFrameCommitted",
-                mName.string());
-        return INVALID_OPERATION;
-    }
-
-    sp<Fence> fence;
-    result = mInterposer->acquireBuffer(&mAcquiredBuffer, &fence);
-    if (result == BufferQueueInterposer::NO_BUFFER_AVAILABLE) {
-        result = mInterposer->pullEmptyBuffer();
-        if (result != NO_ERROR)
-            return result;
-        result = mInterposer->acquireBuffer(&mAcquiredBuffer, &fence);
-    }
-    if (result != NO_ERROR)
-        return result;
-
-    result = mHwc.fbPost(mDisplayId, fence, mAcquiredBuffer);
-    if (result == NO_ERROR) {
-        result = mHwc.setOutputBuffer(mDisplayId, fence, mAcquiredBuffer);
-    }
-    return result;
+    return NO_ERROR;
 }
 
 void VirtualDisplaySurface::onFrameCommitted() {
-    if (mInterposer == NULL)
-        return;
-
-    Mutex::Autolock lock(mMutex);
-    if (mAcquiredBuffer != NULL) {
-        // fbFence signals when reads from the framebuffer are finished
-        // outFence signals when writes to the output buffer are finished
-        // It's unlikely that there will be an implementation where fbFence
-        // signals after outFence (in fact they'll typically be the same
-        // sync_pt), but just to be pedantic we merge them so the sink will
-        // be sure to wait until both are complete.
-        sp<Fence> fbFence = mHwc.getAndResetReleaseFence(mDisplayId);
-        sp<Fence> outFence = mHwc.getLastRetireFence(mDisplayId);
-        sp<Fence> fence = Fence::merge(
-                String8::format("HWC done: %.21s", mName.string()),
-                fbFence, outFence);
-
-        status_t result = mInterposer->releaseBuffer(fence);
-        ALOGE_IF(result != NO_ERROR, "VirtualDisplaySurface \"%s\": "
-                "failed to release buffer: %d", mName.string(), result);
-        mAcquiredBuffer.clear();
-    }
 }
 
 void VirtualDisplaySurface::dump(String8& result) const {
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 0706e75660..f321795763 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -17,7 +17,6 @@
 #ifndef ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H
 #define ANDROID_SF_VIRTUAL_DISPLAY_SURFACE_H
 
-#include "BufferQueueInterposer.h"
 #include "DisplaySurface.h"
 
 // ---------------------------------------------------------------------------
@@ -26,33 +25,8 @@ namespace android {
 
 class HWComposer;
 
-/* This DisplaySurface implementation uses a BufferQueueInterposer to pass
- * partially- or fully-composited buffers from the OpenGL ES driver to
- * HWComposer to use as the output buffer for virtual displays. Allowing HWC
- * to compose into the same buffer that contains GLES results saves bandwidth
- * compared to having two separate BufferQueues for frames with at least some
- * GLES composition.
- *
- * The alternative would be to have two complete BufferQueues, one from GLES
- * to HWC and one from HWC to the virtual display sink (e.g. video encoder).
- * For GLES-only frames, the same bandwidth saving could be achieved if buffers
- * could be acquired from the GLES->HWC queue and inserted into the HWC->sink
- * queue. That would be complicated and doesn't help the mixed GLES+HWC case.
- *
- * On frames with no GLES composition, the VirtualDisplaySurface dequeues a
- * buffer directly from the sink IGraphicBufferProducer and passes it to HWC,
- * bypassing the GLES driver. This is only guaranteed to work if
- * eglSwapBuffers doesn't immediately dequeue a buffer for the next frame,
- * since we can't rely on being able to dequeue more than one buffer at a time.
- *
- * This class also has a passthrough mode, where it doesn't use a
- * BufferQueueInterposer and never sends buffers to HWC. Instead, OpenGL ES
- * output buffers are queued directly to the virtual display sink; this class
- * is inactive after construction. This mode is used when the HWC doesn't
- * support compositing for virtual displays.
- *
- * TODO(jessehall): Add a libgui test that ensures that EGL/GLES do lazy
- * dequeBuffers; we've wanted to require that for other reasons anyway.
+/* This DisplaySurface implementation is a stub used for developing HWC
+ * virtual display support. It is currently just a passthrough.
  */
 class VirtualDisplaySurface : public DisplaySurface {
 public:
@@ -70,19 +44,7 @@ public:
 private:
     virtual ~VirtualDisplaySurface();
 
-    // immutable after construction
-    HWComposer& mHwc;
-    int32_t mDisplayId;
-    String8 mName;
-
-    // with HWC support, both of these point to the same object.
-    // otherwise, mInterposer is NULL and mSourceProducer is the sink.
-    sp<BufferQueueInterposer> mInterposer;
-    sp<IGraphicBufferProducer> mSourceProducer;
-
-    // mutable, must be synchronized with mMutex
-    Mutex mMutex;
-    sp<GraphicBuffer> mAcquiredBuffer;
+    sp<IGraphicBufferProducer> mSink;
 };
 
 // ---------------------------------------------------------------------------