diff --git a/include/binder/IPCThreadState.h b/include/binder/IPCThreadState.h
index 3378d97..691ba2f 100644
--- a/include/binder/IPCThreadState.h
+++ b/include/binder/IPCThreadState.h
@@ -41,6 +41,7 @@
 
             int                 getCallingPid();
             int                 getCallingUid();
+            int                 getOrigCallingUid();
 
             void                setStrictModePolicy(int32_t policy);
             int32_t             getStrictModePolicy() const;
@@ -116,6 +117,7 @@
             status_t            mLastError;
             pid_t               mCallingPid;
             uid_t               mCallingUid;
+            uid_t               mOrigCallingUid;
             int32_t             mStrictModePolicy;
             int32_t             mLastTransactionBinderFlags;
 };
diff --git a/include/ui/Region.h b/include/ui/Region.h
index 6c9a620..f242f18 100644
--- a/include/ui/Region.h
+++ b/include/ui/Region.h
@@ -55,43 +55,51 @@
             void        set(uint32_t w, uint32_t h);
         
             Region&     orSelf(const Rect& rhs);
+            Region&     xorSelf(const Rect& rhs);
             Region&     andSelf(const Rect& rhs);
             Region&     subtractSelf(const Rect& rhs);
 
             // boolean operators, applied on this
             Region&     orSelf(const Region& rhs);
+            Region&     xorSelf(const Region& rhs);
             Region&     andSelf(const Region& rhs);
             Region&     subtractSelf(const Region& rhs);
 
             // boolean operators
     const   Region      merge(const Rect& rhs) const;
+    const   Region      mergeExclusive(const Rect& rhs) const;
     const   Region      intersect(const Rect& rhs) const;
     const   Region      subtract(const Rect& rhs) const;
 
             // boolean operators
     const   Region      merge(const Region& rhs) const;
+    const   Region      mergeExclusive(const Region& rhs) const;
     const   Region      intersect(const Region& rhs) const;
     const   Region      subtract(const Region& rhs) const;
 
             // these translate rhs first
             Region&     translateSelf(int dx, int dy);
             Region&     orSelf(const Region& rhs, int dx, int dy);
+            Region&     xorSelf(const Region& rhs, int dx, int dy);
             Region&     andSelf(const Region& rhs, int dx, int dy);
             Region&     subtractSelf(const Region& rhs, int dx, int dy);
 
             // these translate rhs first
     const   Region      translate(int dx, int dy) const;
     const   Region      merge(const Region& rhs, int dx, int dy) const;
+    const   Region      mergeExclusive(const Region& rhs, int dx, int dy) const;
     const   Region      intersect(const Region& rhs, int dx, int dy) const;
     const   Region      subtract(const Region& rhs, int dx, int dy) const;
 
     // convenience operators overloads
     inline  const Region      operator | (const Region& rhs) const;
+    inline  const Region      operator ^ (const Region& rhs) const;
     inline  const Region      operator & (const Region& rhs) const;
     inline  const Region      operator - (const Region& rhs) const;
     inline  const Region      operator + (const Point& pt) const;
 
     inline  Region&     operator |= (const Region& rhs);
+    inline  Region&     operator ^= (const Region& rhs);
     inline  Region&     operator &= (const Region& rhs);
     inline  Region&     operator -= (const Region& rhs);
     inline  Region&     operator += (const Point& pt);
@@ -158,6 +166,9 @@
 const Region Region::operator | (const Region& rhs) const {
     return merge(rhs);
 }
+const Region Region::operator ^ (const Region& rhs) const {
+    return mergeExclusive(rhs);
+}
 const Region Region::operator & (const Region& rhs) const {
     return intersect(rhs);
 }
@@ -172,6 +183,9 @@
 Region& Region::operator |= (const Region& rhs) {
     return orSelf(rhs);
 }
+Region& Region::operator ^= (const Region& rhs) {
+    return xorSelf(rhs);
+}
 Region& Region::operator &= (const Region& rhs) {
     return andSelf(rhs);
 }
diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 629b899..b578a6c 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -371,6 +371,11 @@
     return mCallingUid;
 }
 
+int IPCThreadState::getOrigCallingUid()
+{
+    return mOrigCallingUid;
+}
+
 int64_t IPCThreadState::clearCallingIdentity()
 {
     int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
@@ -641,6 +646,7 @@
 {
     pthread_setspecific(gTLS, this);
     clearCaller();
+    mOrigCallingUid = mCallingUid;
     mIn.setDataCapacity(256);
     mOut.setDataCapacity(256);
 }
@@ -987,6 +993,7 @@
             
             mCallingPid = tr.sender_pid;
             mCallingUid = tr.sender_euid;
+            mOrigCallingUid = tr.sender_euid;
             
             int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
             if (gDisableBackgroundScheduling) {
@@ -1045,6 +1052,7 @@
             
             mCallingPid = origPid;
             mCallingUid = origUid;
+            mOrigCallingUid = origUid;
 
             IF_LOG_TRANSACTIONS() {
                 TextOutput::Bundle _b(alog);
diff --git a/libs/gui/BitTube.cpp b/libs/gui/BitTube.cpp
index 785da39..55f4178 100644
--- a/libs/gui/BitTube.cpp
+++ b/libs/gui/BitTube.cpp
@@ -17,8 +17,9 @@
 #include <stdint.h>
 #include <sys/types.h>
 
-#include <unistd.h>
 #include <fcntl.h>
+#include <signal.h>
+#include <unistd.h>
 
 #include <utils/Errors.h>
 
@@ -38,6 +39,8 @@
         mSendFd = fds[1];
         fcntl(mReceiveFd, F_SETFL, O_NONBLOCK);
         fcntl(mSendFd, F_SETFL, O_NONBLOCK);
+        // ignore SIGPIPE, we handle write errors through EPIPE instead
+        signal(SIGPIPE, SIG_IGN);
     } else {
         mReceiveFd = -errno;
         ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd));
diff --git a/libs/ui/Region.cpp b/libs/ui/Region.cpp
index 8cd047a..6e2e731 100644
--- a/libs/ui/Region.cpp
+++ b/libs/ui/Region.cpp
@@ -126,6 +126,9 @@
 Region& Region::orSelf(const Rect& r) {
     return operationSelf(r, op_or);
 }
+Region& Region::xorSelf(const Rect& r) {
+    return operationSelf(r, op_xor);
+}
 Region& Region::andSelf(const Rect& r) {
     return operationSelf(r, op_and);
 }
@@ -143,6 +146,9 @@
 Region& Region::orSelf(const Region& rhs) {
     return operationSelf(rhs, op_or);
 }
+Region& Region::xorSelf(const Region& rhs) {
+    return operationSelf(rhs, op_xor);
+}
 Region& Region::andSelf(const Region& rhs) {
     return operationSelf(rhs, op_and);
 }
@@ -165,6 +171,9 @@
 const Region Region::merge(const Rect& rhs) const {
     return operation(rhs, op_or);
 }
+const Region Region::mergeExclusive(const Rect& rhs) const {
+    return operation(rhs, op_xor);
+}
 const Region Region::intersect(const Rect& rhs) const {
     return operation(rhs, op_and);
 }
@@ -182,6 +191,9 @@
 const Region Region::merge(const Region& rhs) const {
     return operation(rhs, op_or);
 }
+const Region Region::mergeExclusive(const Region& rhs) const {
+    return operation(rhs, op_xor);
+}
 const Region Region::intersect(const Region& rhs) const {
     return operation(rhs, op_and);
 }
@@ -205,6 +217,9 @@
 Region& Region::orSelf(const Region& rhs, int dx, int dy) {
     return operationSelf(rhs, dx, dy, op_or);
 }
+Region& Region::xorSelf(const Region& rhs, int dx, int dy) {
+    return operationSelf(rhs, dx, dy, op_xor);
+}
 Region& Region::andSelf(const Region& rhs, int dx, int dy) {
     return operationSelf(rhs, dx, dy, op_and);
 }
@@ -222,6 +237,9 @@
 const Region Region::merge(const Region& rhs, int dx, int dy) const {
     return operation(rhs, dx, dy, op_or);
 }
+const Region Region::mergeExclusive(const Region& rhs, int dx, int dy) const {
+    return operation(rhs, dx, dy, op_xor);
+}
 const Region Region::intersect(const Region& rhs, int dx, int dy) const {
     return operation(rhs, dx, dy, op_and);
 }
@@ -421,6 +439,7 @@
     SkRegion::Op sk_op;
     switch (op) {
         case op_or: sk_op = SkRegion::kUnion_Op; name="OR"; break;
+        case op_xor: sk_op = SkRegion::kUnion_XOR; name="XOR"; break;
         case op_and: sk_op = SkRegion::kIntersect_Op; name="AND"; break;
         case op_nand: sk_op = SkRegion::kDifference_Op; name="NAND"; break;
     }
diff --git a/opengl/libs/EGL/egl_display.cpp b/opengl/libs/EGL/egl_display.cpp
index 5cf5236..6b2ae51 100644
--- a/opengl/libs/EGL/egl_display.cpp
+++ b/opengl/libs/EGL/egl_display.cpp
@@ -345,42 +345,73 @@
 void egl_display_t::loseCurrent(egl_context_t * cur_c)
 {
     if (cur_c) {
-        egl_surface_t * cur_r = get_surface(cur_c->read);
-        egl_surface_t * cur_d = get_surface(cur_c->draw);
+        egl_display_t* display = cur_c->getDisplay();
+        if (display) {
+            display->loseCurrentImpl(cur_c);
+        }
+    }
+}
 
-        // by construction, these are either 0 or valid (possibly terminated)
-        // it should be impossible for these to be invalid
-        ContextRef _cur_c(cur_c);
-        SurfaceRef _cur_r(cur_r);
-        SurfaceRef _cur_d(cur_d);
+void egl_display_t::loseCurrentImpl(egl_context_t * cur_c)
+{
+    // by construction, these are either 0 or valid (possibly terminated)
+    // it should be impossible for these to be invalid
+    ContextRef _cur_c(cur_c);
+    SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
+    SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);
 
+    { // scope for the lock
+        Mutex::Autolock _l(lock);
         cur_c->onLooseCurrent();
 
-        _cur_c.release();
-        _cur_r.release();
-        _cur_d.release();
     }
+
+    // This cannot be called with the lock held because it might end-up
+    // calling back into EGL (in particular when a surface is destroyed
+    // it calls ANativeWindow::disconnect
+    _cur_c.release();
+    _cur_r.release();
+    _cur_d.release();
 }
 
 EGLBoolean egl_display_t::makeCurrent(egl_context_t* c, egl_context_t* cur_c,
         EGLSurface draw, EGLSurface read, EGLContext ctx,
         EGLSurface impl_draw, EGLSurface impl_read, EGLContext impl_ctx)
 {
-    Mutex::Autolock _l(lock);
     EGLBoolean result;
-    if (c) {
-        result = c->cnx->egl.eglMakeCurrent(
-                disp[c->impl].dpy, impl_draw, impl_read, impl_ctx);
-    } else {
-        result = cur_c->cnx->egl.eglMakeCurrent(
-                disp[cur_c->impl].dpy, impl_draw, impl_read, impl_ctx);
-    }
-    if (result == EGL_TRUE) {
-        loseCurrent(cur_c);
+
+    // by construction, these are either 0 or valid (possibly terminated)
+    // it should be impossible for these to be invalid
+    ContextRef _cur_c(cur_c);
+    SurfaceRef _cur_r(cur_c ? get_surface(cur_c->read) : NULL);
+    SurfaceRef _cur_d(cur_c ? get_surface(cur_c->draw) : NULL);
+
+    { // scope for the lock
+        Mutex::Autolock _l(lock);
         if (c) {
-            c->onMakeCurrent(draw, read);
+            result = c->cnx->egl.eglMakeCurrent(
+                    disp[c->impl].dpy, impl_draw, impl_read, impl_ctx);
+            if (result == EGL_TRUE) {
+                c->onMakeCurrent(draw, read);
+            }
+        } else {
+            result = cur_c->cnx->egl.eglMakeCurrent(
+                    disp[cur_c->impl].dpy, impl_draw, impl_read, impl_ctx);
+            if (result == EGL_TRUE) {
+                cur_c->onLooseCurrent();
+            }
         }
     }
+
+    if (result == EGL_TRUE) {
+        // This cannot be called with the lock held because it might end-up
+        // calling back into EGL (in particular when a surface is destroyed
+        // it calls ANativeWindow::disconnect
+        _cur_c.release();
+        _cur_r.release();
+        _cur_d.release();
+    }
+
     return result;
 }
 
diff --git a/opengl/libs/EGL/egl_display.h b/opengl/libs/EGL/egl_display.h
index 4479e00..f3c4ddf 100644
--- a/opengl/libs/EGL/egl_display.h
+++ b/opengl/libs/EGL/egl_display.h
@@ -64,6 +64,7 @@
 class EGLAPI egl_display_t { // marked as EGLAPI for testing purposes
     static egl_display_t sDisplay[NUM_DISPLAYS];
     EGLDisplay getDisplay(EGLNativeDisplayType display);
+    void loseCurrentImpl(egl_context_t * cur_c);
 
 public:
     enum {
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 8b4c074..42e280f 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -32,6 +32,7 @@
 endif
 ifeq ($(TARGET_BOARD_PLATFORM), omap4)
 	LOCAL_CFLAGS += -DHAS_CONTEXT_PRIORITY
+	LOCAL_CFLAGS += -DUSE_TRIPLE_BUFFERING
 endif
 ifeq ($(TARGET_BOARD_PLATFORM), s5pc110)
 	LOCAL_CFLAGS += -DHAS_CONTEXT_PRIORITY -DNEVER_DEFAULT_TO_ASYNC_MODE
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp
index 09f1906..69f1aca 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.cpp
@@ -43,14 +43,6 @@
 DisplayHardwareBase::DisplayEventThread::~DisplayEventThread() {
 }
 
-void DisplayHardwareBase::DisplayEventThread::onFirstRef() {
-    if (initCheck() == NO_ERROR) {
-        run("DisplayEventThread", PRIORITY_URGENT_DISPLAY);
-    } else {
-        ALOGW("/sys/power/wait_for_fb_{wake|sleep} don't exist");
-    }
-}
-
 status_t DisplayHardwareBase::DisplayEventThread::initCheck() const {
     return ((access(kSleepFileName, R_OK) == 0 &&
             access(kWakeFileName, R_OK) == 0)) ? NO_ERROR : NO_INIT;
@@ -120,6 +112,14 @@
     mDisplayEventThread = new DisplayEventThread(flinger);
 }
 
+void DisplayHardwareBase::startSleepManagement() const {
+    if (mDisplayEventThread->initCheck() == NO_ERROR) {
+        mDisplayEventThread->run("DisplayEventThread", PRIORITY_URGENT_DISPLAY);
+    } else {
+        ALOGW("/sys/power/wait_for_fb_{wake|sleep} don't exist");
+    }
+}
+
 DisplayHardwareBase::~DisplayHardwareBase() {
     // request exit
     mDisplayEventThread->requestExitAndWait();
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
index 91ea602..fba211b 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
@@ -35,6 +35,8 @@
 
     ~DisplayHardwareBase();
 
+    void startSleepManagement() const;
+
     // console management
     void releaseScreen() const;
     void acquireScreen() const;
@@ -52,7 +54,6 @@
     public:
         DisplayEventThread(const sp<SurfaceFlinger>& flinger);
         virtual ~DisplayEventThread();
-        virtual void onFirstRef();
         virtual bool threadLoop();
         status_t releaseScreen() const;
         status_t initCheck() const;
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 64f72d5..3e6b872 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -98,7 +98,12 @@
     mSurfaceTexture = new SurfaceTextureLayer(mTextureName, this);
     mSurfaceTexture->setFrameAvailableListener(new FrameQueuedListener(this));
     mSurfaceTexture->setSynchronousMode(true);
+#ifdef USE_TRIPLE_BUFFERING
+#warning "using triple buffering"
+    mSurfaceTexture->setBufferCountServer(3);
+#else
     mSurfaceTexture->setBufferCountServer(2);
+#endif
 }
 
 Layer::~Layer()
diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index 44aafdf..e764001 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -458,16 +458,21 @@
 void LayerBase::dump(String8& result, char* buffer, size_t SIZE) const
 {
     const Layer::State& s(drawingState());
+
+    snprintf(buffer, SIZE,
+            "+ %s %p (%s)\n",
+            getTypeId(), this, getName().string());
+    result.append(buffer);
+
     s.transparentRegion.dump(result, "transparentRegion");
     transparentRegionScreen.dump(result, "transparentRegionScreen");
     visibleRegionScreen.dump(result, "visibleRegionScreen");
+
     snprintf(buffer, SIZE,
-            "+ %s %p (%s)\n"
             "      "
             "z=%9d, pos=(%g,%g), size=(%4d,%4d), "
             "isOpaque=%1d, needsDithering=%1d, invalidate=%1d, "
             "alpha=0x%02x, flags=0x%08x, tr=[%.2f, %.2f][%.2f, %.2f]\n",
-            getTypeId(), this, getName().string(),
             s.z, s.transform.tx(), s.transform.ty(), s.w, s.h,
             isOpaque(), needsDithering(), contentDirty,
             s.alpha, s.flags,
diff --git a/services/surfaceflinger/MessageQueue.cpp b/services/surfaceflinger/MessageQueue.cpp
index 1ff3567..290fff4 100644
--- a/services/surfaceflinger/MessageQueue.cpp
+++ b/services/surfaceflinger/MessageQueue.cpp
@@ -133,7 +133,8 @@
 }
 
 void MessageQueue::invalidate() {
-    mHandler->signalInvalidate();
+//    mHandler->signalInvalidate();
+    mEvents->requestNextVsync();
 }
 
 void MessageQueue::refresh() {
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 870235b..40717f4 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -300,6 +300,7 @@
     // start the EventThread
     mEventThread = new EventThread(this);
     mEventQueue.setEventThread(mEventThread);
+    hw.startSleepManagement();
 
     /*
      *  We're now ready to accept clients...
@@ -403,7 +404,8 @@
 void SurfaceFlinger::onMessageReceived(int32_t what)
 {
     switch (what) {
-        case MessageQueue::INVALIDATE: {
+        case MessageQueue::REFRESH: {
+//        case MessageQueue::INVALIDATE: {
             // check for transactions
             if (CC_UNLIKELY(mConsoleSignals)) {
                 handleConsoleEvents();
@@ -419,42 +421,47 @@
             // post surfaces (if needed)
             handlePageFlip();
 
-            if (!mDirtyRegion.isEmpty()) {
-                signalRefresh();
-            }
-        } break;
+//            signalRefresh();
+//
+//        } break;
+//
+//        case MessageQueue::REFRESH: {
 
-        case MessageQueue::REFRESH: {
-            if (!mDirtyRegion.isEmpty()) {
-                // NOTE: it is mandatory to call hw.compositionComplete()
-                // after handleRefresh()
-                handleRefresh();
+            handleRefresh();
 
-                const DisplayHardware& hw(graphicPlane(0).displayHardware());
-                if (CC_UNLIKELY(mHwWorkListDirty)) {
-                    // build the h/w work list
-                    handleWorkList();
-                }
-                if (CC_LIKELY(hw.canDraw())) {
-                    // repaint the framebuffer (if needed)
-                    handleRepaint();
-                    // inform the h/w that we're done compositing
-                    hw.compositionComplete();
-                    postFramebuffer();
-                } else {
-                    // pretend we did the post
-                    hw.compositionComplete();
-                }
+            const DisplayHardware& hw(graphicPlane(0).displayHardware());
+
+//            if (mDirtyRegion.isEmpty()) {
+//                return;
+//            }
+
+            if (CC_UNLIKELY(mHwWorkListDirty)) {
+                // build the h/w work list
+                handleWorkList();
             }
+
+            if (CC_LIKELY(hw.canDraw())) {
+                // repaint the framebuffer (if needed)
+                handleRepaint();
+                // inform the h/w that we're done compositing
+                hw.compositionComplete();
+                postFramebuffer();
+            } else {
+                // pretend we did the post
+                hw.compositionComplete();
+            }
+
         } break;
     }
 }
 
 void SurfaceFlinger::postFramebuffer()
 {
-    // this should never happen. we do the flip anyways so we don't
-    // risk to cause a deadlock with hwc
-    ALOGW_IF(mSwapRegion.isEmpty(), "mSwapRegion is empty");
+    // mSwapRegion can be empty here is some cases, for instance if a hidden
+    // or fully transparent window is updating.
+    // in that case, we need to flip anyways to not risk a deadlock with
+    // h/w composer.
+
     const DisplayHardware& hw(graphicPlane(0).displayHardware());
     const nsecs_t now = systemTime();
     mDebugInSwapBuffers = now;
@@ -1651,11 +1658,13 @@
     snprintf(buffer, SIZE,
             "  last eglSwapBuffers() time: %f us\n"
             "  last transaction time     : %f us\n"
+            "  transaction-flags         : %08x\n"
             "  refresh-rate              : %f fps\n"
             "  x-dpi                     : %f\n"
             "  y-dpi                     : %f\n",
             mLastSwapBufferTime/1000.0,
             mLastTransactionTime/1000.0,
+            mTransactionFlags,
             hw.getRefreshRate(),
             hw.getDpiX(),
             hw.getDpiY());
@@ -1784,6 +1793,7 @@
                 reply->writeInt32(0);
                 reply->writeInt32(mDebugRegion);
                 reply->writeInt32(mDebugBackground);
+                reply->writeInt32(mDebugDisableHWC);
                 return NO_ERROR;
             case 1013: {
                 Mutex::Autolock _l(mStateLock);