commit ffe1f19ca9707f84cb9fdb06209bf36cd8c2ef0a
author Jesse Hall <jessehall@google.com> Fri Mar 22 15:13:48 2013 -0700
committer Jesse Hall <jessehall@google.com> Fri Mar 22 15:27:58 2013 -0700
tree e96e4d9d19a81ec6ee46052e54f3b2fda16465f3
parent 48bc05b56df9919fc39c5f2e3ea6535560eec98f

Fix virtual displays for HWC<=1.1

If we're using a HWC that doesn't support virtual displays, or we have
more virtual displays than HWC supports concurrently, the
VirtualDisplaySurface should simply be a passthrough from source
(GLES) to sink.

This change also tries to distinguish between display types and HWC
display IDs a little better, though there's more to do here. Probably
needs a higher-level rethink; it's too error-prone now.

Bug: 8446838
Change-Id: I708d2cf262ec30177042304f174ca5b8da701df1

services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp

diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index b28500e..d2b3edb 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -21,24 +21,30 @@
 namespace android {
 // ---------------------------------------------------------------------------
 
-VirtualDisplaySurface::VirtualDisplaySurface(HWComposer& hwc, int disp,
+VirtualDisplaySurface::VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
         const sp<IGraphicBufferProducer>& sink, const String8& name)
 :   mHwc(hwc),
-    mDisplayId(disp),
-    mSource(new BufferQueueInterposer(sink, name)),
+    mDisplayId(dispId),
     mName(name)
-{}
+{
+    if (mDisplayId >= 0) {
+        mInterposer = new BufferQueueInterposer(sink, name);
+        mSourceProducer = mInterposer;
+    } else {
+        mSourceProducer = sink;
+    }
+}
 
 VirtualDisplaySurface::~VirtualDisplaySurface() {
     if (mAcquiredBuffer != NULL) {
-        status_t result = mSource->releaseBuffer(Fence::NO_FENCE);
+        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 mSource;
+    return mSourceProducer;
 }
 
 status_t VirtualDisplaySurface::compositionComplete() {
@@ -46,6 +52,9 @@
 }
 
 status_t VirtualDisplaySurface::advanceFrame() {
+    if (mInterposer == NULL)
+        return NO_ERROR;
+
     Mutex::Autolock lock(mMutex);
     status_t result = NO_ERROR;
 
@@ -57,12 +66,12 @@
     }
 
     sp<Fence> fence;
-    result = mSource->acquireBuffer(&mAcquiredBuffer, &fence);
+    result = mInterposer->acquireBuffer(&mAcquiredBuffer, &fence);
     if (result == BufferQueueInterposer::NO_BUFFER_AVAILABLE) {
-        result = mSource->pullEmptyBuffer();
+        result = mInterposer->pullEmptyBuffer();
         if (result != NO_ERROR)
             return result;
-        result = mSource->acquireBuffer(&mAcquiredBuffer, &fence);
+        result = mInterposer->acquireBuffer(&mAcquiredBuffer, &fence);
     }
     if (result != NO_ERROR)
         return result;
@@ -71,6 +80,9 @@
 }
 
 void VirtualDisplaySurface::onFrameCommitted() {
+    if (mInterposer == NULL)
+        return;
+
     Mutex::Autolock lock(mMutex);
     if (mAcquiredBuffer != NULL) {
         // fbFence signals when reads from the framebuffer are finished
@@ -85,7 +97,7 @@
                 String8::format("HWC done: %.21s", mName.string()),
                 fbFence, outFence);
 
-        status_t result = mSource->releaseBuffer(fence);
+        status_t result = mInterposer->releaseBuffer(fence);
         ALOGE_IF(result != NO_ERROR, "VirtualDisplaySurface \"%s\": "
                 "failed to release buffer: %d", mName.string(), result);
         mAcquiredBuffer.clear();

services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h

diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 61bafed..0706e75 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -45,12 +45,18 @@
  * 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.
  */
 class VirtualDisplaySurface : public DisplaySurface {
 public:
-    VirtualDisplaySurface(HWComposer& hwc, int disp,
+    VirtualDisplaySurface(HWComposer& hwc, int32_t dispId,
             const sp<IGraphicBufferProducer>& sink,
             const String8& name);
 
@@ -66,10 +72,14 @@
 
     // immutable after construction
     HWComposer& mHwc;
-    int mDisplayId;
-    sp<BufferQueueInterposer> mSource;
+    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;