clean-up unneeded code

now that we removed the notion of a "inUse" buffer in surfaceflinger
a lot of code can be simplified / removed.

noteworthy, the whole concept of "unlockClient" wrt. "compositionComplete"
is also gone.

Change-Id: I210413d4c8c0998dae05c8620ebfc895d3e6233d

include/private/surfaceflinger/SharedBufferStack.h

@@ -105,7 +105,7 @@ public:
     volatile int32_t head;      // server's current front buffer
     volatile int32_t available; // number of dequeue-able buffers
     volatile int32_t queued;    // number of buffers waiting for post
-    volatile int32_t inUse;     // buffer currently in use by SF
+    volatile int32_t reserved1;
     volatile status_t status;   // surface's status code
 
     // not part of the conditions
@@ -275,7 +275,6 @@ public:
             int32_t identity);
 
     ssize_t retireAndLock();
-    status_t unlock(int buffer);
     void setStatus(status_t status);
     status_t reallocateAll();
     status_t reallocateAllExcept(int buffer);
@@ -356,12 +355,6 @@ private:
         inline const char* name() const { return "BuffersAvailableCondition"; }
     };
 
-    struct UnlockUpdate : public UpdateBase {
-        const int lockedBuffer;
-        inline UnlockUpdate(SharedBufferBase* sbb, int lockedBuffer);
-        inline ssize_t operator()();
-    };
-
     struct RetireUpdate : public UpdateBase {
         const int numBuffers;
         inline RetireUpdate(SharedBufferBase* sbb, int numBuffers);

libs/surfaceflinger_client/SharedBufferStack.cpp

@@ -58,7 +58,6 @@ SharedBufferStack::SharedBufferStack()
 
 void SharedBufferStack::init(int32_t i)
 {
-    inUse = -2;
     status = NO_ERROR;
     identity = i;
 }
@@ -199,9 +198,9 @@ String8 SharedBufferBase::dump(char const* prefix) const
     SharedBufferStack& stack( *mSharedStack );
     snprintf(buffer, SIZE, 
             "%s[ head=%2d, available=%2d, queued=%2d ] "
-            "reallocMask=%08x, inUse=%2d, identity=%d, status=%d",
+            "reallocMask=%08x, identity=%d, status=%d",
             prefix, stack.head, stack.available, stack.queued,
-            stack.reallocMask, stack.inUse, stack.identity, stack.status);
+            stack.reallocMask, stack.identity, stack.status);
     result.append(buffer);
     result.append("\n");
     return result;
@@ -302,22 +301,6 @@ ssize_t SharedBufferClient::CancelUpdate::operator()() {
     return NO_ERROR;
 }
 
-SharedBufferServer::UnlockUpdate::UnlockUpdate(
-        SharedBufferBase* sbb, int lockedBuffer)
-    : UpdateBase(sbb), lockedBuffer(lockedBuffer) {
-}
-ssize_t SharedBufferServer::UnlockUpdate::operator()() {
-    if (stack.inUse != lockedBuffer) {
-        LOGE("unlocking %d, but currently locked buffer is %d "
-             "(identity=%d, token=%d)",
-                lockedBuffer, stack.inUse,
-                stack.identity, stack.token);
-        return BAD_VALUE;
-    }
-    android_atomic_write(-1, &stack.inUse);
-    return NO_ERROR;
-}
-
 SharedBufferServer::RetireUpdate::RetireUpdate(
         SharedBufferBase* sbb, int numBuffers)
     : UpdateBase(sbb), numBuffers(numBuffers) {
@@ -327,9 +310,6 @@ ssize_t SharedBufferServer::RetireUpdate::operator()() {
     if (uint32_t(head) >= SharedBufferStack::NUM_BUFFER_MAX)
         return BAD_VALUE;
 
-    // Preventively lock the current buffer before updating queued.
-    android_atomic_write(stack.headBuf, &stack.inUse);
-
     // Decrement the number of queued buffers 
     int32_t queued;
     do {
@@ -345,7 +325,6 @@ ssize_t SharedBufferServer::RetireUpdate::operator()() {
     head = (head + 1) % numBuffers;
     const int8_t headBuf = stack.index[head];
     stack.headBuf = headBuf;
-    android_atomic_write(headBuf, &stack.inUse);
 
     // head is only modified here, so we don't need to use cmpxchg
     android_atomic_write(head, &stack.head);
@@ -546,13 +525,6 @@ ssize_t SharedBufferServer::retireAndLock()
     return buf;
 }
 
-status_t SharedBufferServer::unlock(int buf)
-{
-    UnlockUpdate update(this, buf);
-    status_t err = updateCondition( update );
-    return err;
-}
-
 void SharedBufferServer::setStatus(status_t status)
 {
     if (status < NO_ERROR) {
@@ -694,12 +666,6 @@ status_t SharedBufferServer::shrink(int newNumBuffers)
     stack.head = 0;
     stack.headBuf = 0;
 
-    // If one of the buffers is in use it must be the head buffer, which we are
-    // renaming to buffer 0.
-    if (stack.inUse > 0) {
-        stack.inUse = 0;
-    }
-
     // Free the buffers from the end of the list that are no longer needed.
     for (int i = newNumBuffers; i < mNumBuffers; i++) {
         mBufferList.remove(i);

services/surfaceflinger/Layer.cpp

@@ -691,22 +691,6 @@ void Layer::unlockPageFlip(
     }
 }
 
-void Layer::finishPageFlip()
-{
-    ClientRef::Access sharedClient(mUserClientRef);
-    SharedBufferServer* lcblk(sharedClient.get());
-    if (lcblk) {
-        int buf = mBufferManager.getActiveBufferIndex();
-        if (buf >= 0) {
-            status_t err = lcblk->unlock( buf );
-            LOGE_IF(err!=NO_ERROR,
-                    "layer %p, buffer=%d wasn't locked!",
-                    this, buf);
-        }
-    }
-}
-
-
 void Layer::dump(String8& result, char* buffer, size_t SIZE) const
 {
     LayerBaseClient::dump(result, buffer, SIZE);

services/surfaceflinger/Layer.h

@@ -75,7 +75,6 @@ public:
     virtual uint32_t doTransaction(uint32_t transactionFlags);
     virtual void lockPageFlip(bool& recomputeVisibleRegions);
     virtual void unlockPageFlip(const Transform& planeTransform, Region& outDirtyRegion);
-    virtual void finishPageFlip();
     virtual bool needsBlending() const      { return mNeedsBlending; }
     virtual bool needsDithering() const     { return mNeedsDithering; }
     virtual bool needsFiltering() const;

services/surfaceflinger/LayerBase.cpp

@@ -273,10 +273,6 @@ void LayerBase::unlockPageFlip(
     }
 }
 
-void LayerBase::finishPageFlip()
-{
-}
-
 void LayerBase::invalidate()
 {
     if ((android_atomic_or(1, &mInvalidate)&1) == 0) {

services/surfaceflinger/LayerBase.h

@@ -173,11 +173,6 @@ public:
      */
     virtual void unlockPageFlip(const Transform& planeTransform, Region& outDirtyRegion);
     
-    /**
-     * finishPageFlip - called after all surfaces have drawn.
-     */
-    virtual void finishPageFlip();
-    
     /**
      * needsBlending - true if this surface needs blending
      */

services/surfaceflinger/SurfaceFlinger.cpp

@@ -394,14 +394,10 @@ bool SurfaceFlinger::threadLoop()
         logger.log(GraphicLog::SF_SWAP_BUFFERS, index);
         postFramebuffer();
 
-        logger.log(GraphicLog::SF_UNLOCK_CLIENTS, index);
-        unlockClients();
-
         logger.log(GraphicLog::SF_REPAINT_DONE, index);
     } else {
         // pretend we did the post
         hw.compositionComplete();
-        unlockClients();
         usleep(16667); // 60 fps period
     }
     return true;
@@ -920,17 +916,6 @@ void SurfaceFlinger::composeSurfaces(const Region& dirty)
     }
 }
 
-void SurfaceFlinger::unlockClients()
-{
-    const LayerVector& drawingLayers(mDrawingState.layersSortedByZ);
-    const size_t count = drawingLayers.size();
-    sp<LayerBase> const* const layers = drawingLayers.array();
-    for (size_t i=0 ; i<count ; ++i) {
-        const sp<LayerBase>& layer = layers[i];
-        layer->finishPageFlip();
-    }
-}
-
 void SurfaceFlinger::debugFlashRegions()
 {
     const DisplayHardware& hw(graphicPlane(0).displayHardware());

services/surfaceflinger/SurfaceFlinger.h

@@ -314,7 +314,6 @@ private:
             void        handleRepaint();
             void        postFramebuffer();
             void        composeSurfaces(const Region& dirty);
-            void        unlockClients();
 
 
             ssize_t     addClientLayer(const sp<Client>& client,