diff --git a/include/private/surfaceflinger/LayerState.h b/include/private/surfaceflinger/LayerState.h
index d7fe572..d2fed41 100644
--- a/include/private/surfaceflinger/LayerState.h
+++ b/include/private/surfaceflinger/LayerState.h
@@ -29,6 +29,7 @@
 namespace android {
 
 class Parcel;
+class ISurfaceComposerClient;
 
 struct layer_state_t {
 
@@ -68,6 +69,13 @@
             Region          transparentRegion;
 };
 
+struct ComposerState {
+    sp<ISurfaceComposerClient> client;
+    layer_state_t state;
+    status_t    write(Parcel& output) const;
+    status_t    read(const Parcel& input);
+};
+
 }; // namespace android
 
 #endif // ANDROID_SF_LAYER_STATE_H
diff --git a/include/surfaceflinger/ISurfaceComposer.h b/include/surfaceflinger/ISurfaceComposer.h
index 03fd01b..dba98a3 100644
--- a/include/surfaceflinger/ISurfaceComposer.h
+++ b/include/surfaceflinger/ISurfaceComposer.h
@@ -34,6 +34,7 @@
 // ----------------------------------------------------------------------------
 
 class IMemoryHeap;
+class ComposerState;
 
 class ISurfaceComposer : public IInterface
 {
@@ -105,8 +106,7 @@
     virtual sp<IMemoryHeap> getCblk() const = 0;
 
     /* open/close transactions. requires ACCESS_SURFACE_FLINGER permission */
-    virtual void openGlobalTransaction() = 0;
-    virtual void closeGlobalTransaction() = 0;
+    virtual void setTransactionState(const Vector<ComposerState>& state) = 0;
 
     /* [un]freeze display. requires ACCESS_SURFACE_FLINGER permission */
     virtual status_t freezeDisplay(DisplayID dpy, uint32_t flags) = 0;
@@ -149,8 +149,7 @@
         CREATE_CONNECTION,
         CREATE_GRAPHIC_BUFFER_ALLOC,
         GET_CBLK,
-        OPEN_GLOBAL_TRANSACTION,
-        CLOSE_GLOBAL_TRANSACTION,
+        SET_TRANSACTION_STATE,
         SET_ORIENTATION,
         FREEZE_DISPLAY,
         UNFREEZE_DISPLAY,
diff --git a/include/surfaceflinger/ISurfaceComposerClient.h b/include/surfaceflinger/ISurfaceComposerClient.h
index 2e75a0e..6e9a654 100644
--- a/include/surfaceflinger/ISurfaceComposerClient.h
+++ b/include/surfaceflinger/ISurfaceComposerClient.h
@@ -37,8 +37,6 @@
 
 // ----------------------------------------------------------------------------
 
-class layer_state_t;
-
 class ISurfaceComposerClient : public IInterface
 {
 public:
@@ -69,11 +67,6 @@
      * Requires ACCESS_SURFACE_FLINGER permission
      */
     virtual status_t    destroySurface(SurfaceID sid) = 0;
-
-    /*
-     * Requires ACCESS_SURFACE_FLINGER permission
-     */
-    virtual status_t    setState(int32_t count, const layer_state_t* states) = 0;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/include/surfaceflinger/SurfaceComposerClient.h b/include/surfaceflinger/SurfaceComposerClient.h
index 140b9f8..7fbbfb2 100644
--- a/include/surfaceflinger/SurfaceComposerClient.h
+++ b/include/surfaceflinger/SurfaceComposerClient.h
@@ -37,10 +37,12 @@
 // ---------------------------------------------------------------------------
 
 class DisplayInfo;
+class Composer;
 class IMemoryHeap;
 class ISurfaceComposer;
 class Region;
 class surface_flinger_cblk_t;
+struct layer_state_t;
 
 // ---------------------------------------------------------------------------
 
@@ -59,8 +61,11 @@
 
 // ---------------------------------------------------------------------------
 
+class Composer;
+
 class SurfaceComposerClient : public RefBase
 {
+    friend class Composer;
 public:    
                 SurfaceComposerClient();
     virtual     ~SurfaceComposerClient();
@@ -101,13 +106,7 @@
     // All composer parameters must be changed within a transaction
     // several surfaces can be updated in one transaction, all changes are
     // committed at once when the transaction is closed.
-    // CloseTransaction() usually requires an IPC with the server.
-    
-    //! Open a composer transaction
-    status_t    openTransaction();
-
-    //! commit the transaction
-    status_t    closeTransaction();
+    // closeGlobalTransaction() usually requires an IPC with the server.
 
     //! Open a composer transaction on all active SurfaceComposerClients.
     static void openGlobalTransaction();
@@ -152,19 +151,12 @@
 
 private:
     virtual void onFirstRef();
-    inline layer_state_t*   get_state_l(SurfaceID id);
-    layer_state_t*          lockLayerState(SurfaceID id);
-    inline void             unlockLayerState();
+    Composer& getComposer();
 
-    mutable     Mutex                               mLock;
-                SortedVector<layer_state_t>         mStates;
-                int32_t                             mTransactionOpen;
-                layer_state_t*                      mPrebuiltLayerState;
-
-                // these don't need to be protected because they never change
-                // after assignment
+    mutable     Mutex                       mLock;
                 status_t                    mStatus;
                 sp<ISurfaceComposerClient>  mClient;
+                Composer&                   mComposer;
 };
 
 // ---------------------------------------------------------------------------
diff --git a/include/utils/LinearTransform.h b/include/utils/LinearTransform.h
new file mode 100644
index 0000000..04cb355
--- /dev/null
+++ b/include/utils/LinearTransform.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2011 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 _LIBS_UTILS_LINEAR_TRANSFORM_H
+#define _LIBS_UTILS_LINEAR_TRANSFORM_H
+
+#include <stdint.h>
+
+namespace android {
+
+// LinearTransform defines a structure which hold the definition of a
+// transformation from single dimensional coordinate system A into coordinate
+// system B (and back again).  Values in A and in B are 64 bit, the linear
+// scale factor is expressed as a rational number using two 32 bit values.
+//
+// Specifically, let
+// f(a) = b
+// F(b) = f^-1(b) = a
+// then
+//
+// f(a) = (((a - a_zero) * a_to_b_numer) / a_to_b_denom) + b_zero;
+//
+// and
+//
+// F(b) = (((b - b_zero) * a_to_b_denom) / a_to_b_numer) + a_zero;
+//
+struct LinearTransform {
+  int64_t  a_zero;
+  int64_t  b_zero;
+  int32_t  a_to_b_numer;
+  uint32_t a_to_b_denom;
+
+  // Transform from A->B
+  // Returns true on success, or false in the case of a singularity or an
+  // overflow.
+  bool doForwardTransform(int64_t a_in, int64_t* b_out) const;
+
+  // Transform from B->A
+  // Returns true on success, or false in the case of a singularity or an
+  // overflow.
+  bool doReverseTransform(int64_t b_in, int64_t* a_out) const;
+
+  // Helpers which will reduce the fraction N/D using Euclid's method.
+  template <class T> static void reduce(T* N, T* D);
+  static void reduce(int32_t* N, uint32_t* D);
+};
+
+
+}
+
+#endif  // _LIBS_UTILS_LINEAR_TRANSFORM_H
diff --git a/include/utils/SortedVector.h b/include/utils/SortedVector.h
index 8beec57..0e98aeb 100644
--- a/include/utils/SortedVector.h
+++ b/include/utils/SortedVector.h
@@ -32,6 +32,8 @@
 template <class TYPE>
 class SortedVector : private SortedVectorImpl
 {
+    friend class Vector<TYPE>;
+
 public:
             typedef TYPE    value_type;
     
diff --git a/include/utils/Vector.h b/include/utils/Vector.h
index f1e87e6..b908e2a 100644
--- a/include/utils/Vector.h
+++ b/include/utils/Vector.h
@@ -29,6 +29,9 @@
 
 namespace android {
 
+template <typename TYPE>
+class SortedVector;
+
 /*!
  * The main templated vector class ensuring type safety
  * while making use of VectorImpl.
@@ -47,13 +50,17 @@
     
                             Vector();
                             Vector(const Vector<TYPE>& rhs);
+    explicit                Vector(const SortedVector<TYPE>& rhs);
     virtual                 ~Vector();
 
     /*! copy operator */
             const Vector<TYPE>&     operator = (const Vector<TYPE>& rhs) const;
             Vector<TYPE>&           operator = (const Vector<TYPE>& rhs);    
 
-    /*
+            const Vector<TYPE>&     operator = (const SortedVector<TYPE>& rhs) const;
+            Vector<TYPE>&           operator = (const SortedVector<TYPE>& rhs);
+
+            /*
      * empty the vector
      */
 
@@ -215,6 +222,11 @@
 }
 
 template<class TYPE> inline
+Vector<TYPE>::Vector(const SortedVector<TYPE>& rhs)
+    : VectorImpl(static_cast<const VectorImpl&>(rhs)) {
+}
+
+template<class TYPE> inline
 Vector<TYPE>::~Vector() {
     finish_vector();
 }
@@ -227,6 +239,18 @@
 
 template<class TYPE> inline
 const Vector<TYPE>& Vector<TYPE>::operator = (const Vector<TYPE>& rhs) const {
+    VectorImpl::operator = (static_cast<const VectorImpl&>(rhs));
+    return *this;
+}
+
+template<class TYPE> inline
+Vector<TYPE>& Vector<TYPE>::operator = (const SortedVector<TYPE>& rhs) {
+    VectorImpl::operator = (static_cast<const VectorImpl&>(rhs));
+    return *this;
+}
+
+template<class TYPE> inline
+const Vector<TYPE>& Vector<TYPE>::operator = (const SortedVector<TYPE>& rhs) const {
     VectorImpl::operator = (rhs);
     return *this; 
 }
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 40450a3..c1156d5 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -25,6 +25,8 @@
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 
+#include <private/surfaceflinger/LayerState.h>
+
 #include <surfaceflinger/ISurfaceComposer.h>
 
 #include <ui/DisplayInfo.h>
@@ -74,18 +76,17 @@
         return interface_cast<IMemoryHeap>(reply.readStrongBinder());
     }
 
-    virtual void openGlobalTransaction()
+    virtual void setTransactionState(const Vector<ComposerState>& state)
     {
         Parcel data, reply;
         data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
-        remote()->transact(BnSurfaceComposer::OPEN_GLOBAL_TRANSACTION, data, &reply);
-    }
-
-    virtual void closeGlobalTransaction()
-    {
-        Parcel data, reply;
-        data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
-        remote()->transact(BnSurfaceComposer::CLOSE_GLOBAL_TRANSACTION, data, &reply);
+        Vector<ComposerState>::const_iterator b(state.begin());
+        Vector<ComposerState>::const_iterator e(state.end());
+        data.writeInt32(state.size());
+        for ( ; b != e ; ++b ) {
+            b->write(data);
+        }
+        remote()->transact(BnSurfaceComposer::SET_TRANSACTION_STATE, data, &reply);
     }
 
     virtual status_t freezeDisplay(DisplayID dpy, uint32_t flags)
@@ -218,13 +219,17 @@
             sp<IBinder> b = createGraphicBufferAlloc()->asBinder();
             reply->writeStrongBinder(b);
         } break;
-        case OPEN_GLOBAL_TRANSACTION: {
+        case SET_TRANSACTION_STATE: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
-            openGlobalTransaction();
-        } break;
-        case CLOSE_GLOBAL_TRANSACTION: {
-            CHECK_INTERFACE(ISurfaceComposer, data, reply);
-            closeGlobalTransaction();
+            size_t count = data.readInt32();
+            ComposerState s;
+            Vector<ComposerState> state;
+            state.setCapacity(count);
+            for (size_t i=0 ; i<count ; i++) {
+                s.read(data);
+                state.add(s);
+            }
+            setTransactionState(state);
         } break;
         case SET_ORIENTATION: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
diff --git a/libs/gui/ISurfaceComposerClient.cpp b/libs/gui/ISurfaceComposerClient.cpp
index 8d83392..bc97cac 100644
--- a/libs/gui/ISurfaceComposerClient.cpp
+++ b/libs/gui/ISurfaceComposerClient.cpp
@@ -51,8 +51,7 @@
 
 enum {
     CREATE_SURFACE = IBinder::FIRST_CALL_TRANSACTION,
-    DESTROY_SURFACE,
-    SET_STATE
+    DESTROY_SURFACE
 };
 
 class BpSurfaceComposerClient : public BpInterface<ISurfaceComposerClient>
@@ -92,17 +91,6 @@
         remote()->transact(DESTROY_SURFACE, data, &reply);
         return reply.readInt32();
     }
-
-    virtual status_t setState(int32_t count, const layer_state_t* states)
-    {
-        Parcel data, reply;
-        data.writeInterfaceToken(ISurfaceComposerClient::getInterfaceDescriptor());
-        data.writeInt32(count);
-        for (int i=0 ; i<count ; i++)
-            states[i].write(data);
-        remote()->transact(SET_STATE, data, &reply);
-        return reply.readInt32();
-    }
 };
 
 IMPLEMENT_META_INTERFACE(SurfaceComposerClient, "android.ui.ISurfaceComposerClient");
@@ -133,17 +121,6 @@
             reply->writeInt32( destroySurface( data.readInt32() ) );
             return NO_ERROR;
         } break;
-        case SET_STATE: {
-            CHECK_INTERFACE(ISurfaceComposerClient, data, reply);
-            int32_t count = data.readInt32();
-            layer_state_t* states = new layer_state_t[count];
-            for (int i=0 ; i<count ; i++)
-                states[i].read(data);
-            status_t err = setState(count, states);
-            delete [] states;
-            reply->writeInt32(err);
-            return NO_ERROR;
-        } break;
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 01c4c7e..87901e8 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -17,6 +17,7 @@
 #include <utils/Errors.h>
 #include <binder/Parcel.h>
 #include <private/surfaceflinger/LayerState.h>
+#include <surfaceflinger/ISurfaceComposerClient.h>
 
 namespace android {
 
@@ -58,4 +59,14 @@
     return NO_ERROR;
 }
 
+status_t ComposerState::write(Parcel& output) const {
+    output.writeStrongBinder(client->asBinder());
+    return state.write(output);
+}
+
+status_t ComposerState::read(const Parcel& input) {
+    client = interface_cast<ISurfaceComposerClient>(input.readStrongBinder());
+    return state.read(input);
+}
+
 }; // namespace android
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 1678711..8cead80 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -74,75 +74,52 @@
 
 // ---------------------------------------------------------------------------
 
+// NOTE: this is NOT a member function (it's a friend defined with its
+// declaration).
+static inline
+int compare_type( const ComposerState& lhs, const ComposerState& rhs) {
+    if (lhs.client < rhs.client)  return -1;
+    if (lhs.client > rhs.client)  return 1;
+    if (lhs.state.surface < rhs.state.surface)  return -1;
+    if (lhs.state.surface > rhs.state.surface)  return 1;
+    return 0;
+}
+
 class Composer : public Singleton<Composer>
 {
-    Mutex mLock;
-    SortedVector< wp<SurfaceComposerClient> > mActiveConnections;
-    SortedVector<sp<SurfaceComposerClient> > mOpenTransactions;
-
-    Composer() : Singleton<Composer>() {
-    }
-
-    void addClientImpl(const sp<SurfaceComposerClient>& client) {
-        Mutex::Autolock _l(mLock);
-        mActiveConnections.add(client);
-    }
-
-    void removeClientImpl(const sp<SurfaceComposerClient>& client) {
-        Mutex::Autolock _l(mLock);
-        mActiveConnections.remove(client);
-    }
-
-    void openGlobalTransactionImpl()
-    {
-        Mutex::Autolock _l(mLock);
-        if (mOpenTransactions.size()) {
-            LOGE("openGlobalTransaction() called more than once. skipping.");
-            return;
-        }
-        const size_t N = mActiveConnections.size();
-        for (size_t i=0; i<N; i++) {
-            sp<SurfaceComposerClient> client(mActiveConnections[i].promote());
-            if (client != 0 && mOpenTransactions.indexOf(client) < 0) {
-                if (client->openTransaction() == NO_ERROR) {
-                    mOpenTransactions.add(client);
-                } else {
-                    LOGE("openTransaction on client %p failed", client.get());
-                    // let it go, it'll fail later when the user
-                    // tries to do something with the transaction
-                }
-            }
-        }
-    }
-
-    void closeGlobalTransactionImpl()
-    {
-        mLock.lock();
-            SortedVector< sp<SurfaceComposerClient> > clients(mOpenTransactions);
-            mOpenTransactions.clear();
-        mLock.unlock();
-
-        sp<ISurfaceComposer> sm(getComposerService());
-        sm->openGlobalTransaction();
-            const size_t N = clients.size();
-            for (size_t i=0; i<N; i++) {
-                clients[i]->closeTransaction();
-            }
-        sm->closeGlobalTransaction();
-    }
-
     friend class Singleton<Composer>;
 
+    mutable Mutex               mLock;
+    SortedVector<ComposerState> mStates;
+
+    Composer() : Singleton<Composer>() { }
+
+    void closeGlobalTransactionImpl();
+
+    layer_state_t* getLayerStateLocked(
+            const sp<SurfaceComposerClient>& client, SurfaceID id);
+
 public:
-    static void addClient(const sp<SurfaceComposerClient>& client) {
-        Composer::getInstance().addClientImpl(client);
-    }
-    static void removeClient(const sp<SurfaceComposerClient>& client) {
-        Composer::getInstance().removeClientImpl(client);
-    }
-    static void openGlobalTransaction() {
-        Composer::getInstance().openGlobalTransactionImpl();
-    }
+
+    status_t setPosition(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            int32_t x, int32_t y);
+    status_t setSize(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            uint32_t w, uint32_t h);
+    status_t setLayer(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            int32_t z);
+    status_t setFlags(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            uint32_t flags, uint32_t mask);
+    status_t setTransparentRegionHint(
+            const sp<SurfaceComposerClient>& client, SurfaceID id,
+            const Region& transparentRegion);
+    status_t setAlpha(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            float alpha);
+    status_t setMatrix(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            float dsdx, float dtdx, float dsdy, float dtdy);
+    status_t setFreezeTint(
+            const sp<SurfaceComposerClient>& client, SurfaceID id,
+            uint32_t tint);
+
     static void closeGlobalTransaction() {
         Composer::getInstance().closeGlobalTransactionImpl();
     }
@@ -152,69 +129,306 @@
 
 // ---------------------------------------------------------------------------
 
-static inline int compare_type( const layer_state_t& lhs,
-                                const layer_state_t& rhs) {
-    if (lhs.surface < rhs.surface)  return -1;
-    if (lhs.surface > rhs.surface)  return 1;
-    return 0;
+void Composer::closeGlobalTransactionImpl() {
+    sp<ISurfaceComposer> sm(getComposerService());
+
+    Vector<ComposerState> transaction;
+
+    { // scope for the lock
+        Mutex::Autolock _l(mLock);
+        transaction = mStates;
+        mStates.clear();
+    }
+
+   sm->setTransactionState(transaction);
 }
 
+layer_state_t* Composer::getLayerStateLocked(
+        const sp<SurfaceComposerClient>& client, SurfaceID id) {
+
+    ComposerState s;
+    s.client = client->mClient;
+    s.state.surface = id;
+
+    ssize_t index = mStates.indexOf(s);
+    if (index < 0) {
+        // we don't have it, add an initialized layer_state to our list
+        index = mStates.add(s);
+    }
+
+    ComposerState* const out = mStates.editArray();
+    return &(out[index].state);
+}
+
+status_t Composer::setPosition(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, int32_t x, int32_t y) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::ePositionChanged;
+    s->x = x;
+    s->y = y;
+    return NO_ERROR;
+}
+
+status_t Composer::setSize(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, uint32_t w, uint32_t h) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eSizeChanged;
+    s->w = w;
+    s->h = h;
+    return NO_ERROR;
+}
+
+status_t Composer::setLayer(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, int32_t z) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eLayerChanged;
+    s->z = z;
+    return NO_ERROR;
+}
+
+status_t Composer::setFlags(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, uint32_t flags,
+        uint32_t mask) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eVisibilityChanged;
+    s->flags &= ~mask;
+    s->flags |= (flags & mask);
+    s->mask |= mask;
+    return NO_ERROR;
+}
+
+status_t Composer::setTransparentRegionHint(
+        const sp<SurfaceComposerClient>& client, SurfaceID id,
+        const Region& transparentRegion) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eTransparentRegionChanged;
+    s->transparentRegion = transparentRegion;
+    return NO_ERROR;
+}
+
+status_t Composer::setAlpha(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, float alpha) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eAlphaChanged;
+    s->alpha = alpha;
+    return NO_ERROR;
+}
+
+status_t Composer::setMatrix(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, float dsdx, float dtdx,
+        float dsdy, float dtdy) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eMatrixChanged;
+    layer_state_t::matrix22_t matrix;
+    matrix.dsdx = dsdx;
+    matrix.dtdx = dtdx;
+    matrix.dsdy = dsdy;
+    matrix.dtdy = dtdy;
+    s->matrix = matrix;
+    return NO_ERROR;
+}
+
+status_t Composer::setFreezeTint(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, uint32_t tint) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eFreezeTintChanged;
+    s->tint = tint;
+    return NO_ERROR;
+}
+
+// ---------------------------------------------------------------------------
+
 SurfaceComposerClient::SurfaceComposerClient()
-    : mTransactionOpen(0), mPrebuiltLayerState(0), mStatus(NO_INIT)
+    : mStatus(NO_INIT), mComposer(Composer::getInstance())
 {
 }
 
-void SurfaceComposerClient::onFirstRef()
-{
+void SurfaceComposerClient::onFirstRef() {
     sp<ISurfaceComposer> sm(getComposerService());
     if (sm != 0) {
         sp<ISurfaceComposerClient> conn = sm->createConnection();
         if (conn != 0) {
             mClient = conn;
-            Composer::addClient(this);
-            mPrebuiltLayerState = new layer_state_t;
             mStatus = NO_ERROR;
         }
     }
 }
 
-SurfaceComposerClient::~SurfaceComposerClient()
-{
-    delete mPrebuiltLayerState;
+SurfaceComposerClient::~SurfaceComposerClient() {
     dispose();
 }
 
-status_t SurfaceComposerClient::initCheck() const
-{
+status_t SurfaceComposerClient::initCheck() const {
     return mStatus;
 }
 
-sp<IBinder> SurfaceComposerClient::connection() const
-{
+sp<IBinder> SurfaceComposerClient::connection() const {
     return (mClient != 0) ? mClient->asBinder() : 0;
 }
 
 status_t SurfaceComposerClient::linkToComposerDeath(
         const sp<IBinder::DeathRecipient>& recipient,
-        void* cookie, uint32_t flags)
-{
+        void* cookie, uint32_t flags) {
     sp<ISurfaceComposer> sm(getComposerService());
     return sm->asBinder()->linkToDeath(recipient, cookie, flags);
 }
 
-void SurfaceComposerClient::dispose()
-{
+void SurfaceComposerClient::dispose() {
     // this can be called more than once.
     sp<ISurfaceComposerClient> client;
     Mutex::Autolock _lm(mLock);
     if (mClient != 0) {
-        Composer::removeClient(this);
         client = mClient; // hold ref while lock is held
         mClient.clear();
     }
     mStatus = NO_INIT;
 }
 
+sp<SurfaceControl> SurfaceComposerClient::createSurface(
+        DisplayID display,
+        uint32_t w,
+        uint32_t h,
+        PixelFormat format,
+        uint32_t flags)
+{
+    String8 name;
+    const size_t SIZE = 128;
+    char buffer[SIZE];
+    snprintf(buffer, SIZE, "<pid_%d>", getpid());
+    name.append(buffer);
+
+    return SurfaceComposerClient::createSurface(name, display,
+            w, h, format, flags);
+}
+
+sp<SurfaceControl> SurfaceComposerClient::createSurface(
+        const String8& name,
+        DisplayID display,
+        uint32_t w,
+        uint32_t h,
+        PixelFormat format,
+        uint32_t flags)
+{
+    sp<SurfaceControl> result;
+    if (mStatus == NO_ERROR) {
+        ISurfaceComposerClient::surface_data_t data;
+        sp<ISurface> surface = mClient->createSurface(&data, name,
+                display, w, h, format, flags);
+        if (surface != 0) {
+            result = new SurfaceControl(this, surface, data, w, h, format, flags);
+        }
+    }
+    return result;
+}
+
+status_t SurfaceComposerClient::destroySurface(SurfaceID sid) {
+    if (mStatus != NO_ERROR)
+        return mStatus;
+    status_t err = mClient->destroySurface(sid);
+    return err;
+}
+
+inline Composer& SurfaceComposerClient::getComposer() {
+    return mComposer;
+}
+
+// ----------------------------------------------------------------------------
+
+void SurfaceComposerClient::openGlobalTransaction() {
+    // Currently a no-op
+}
+
+void SurfaceComposerClient::closeGlobalTransaction() {
+    Composer::closeGlobalTransaction();
+}
+
+// ----------------------------------------------------------------------------
+
+status_t SurfaceComposerClient::setFreezeTint(SurfaceID id, uint32_t tint) {
+    return getComposer().setFreezeTint(this, id, tint);
+}
+
+status_t SurfaceComposerClient::setPosition(SurfaceID id, int32_t x, int32_t y) {
+    return getComposer().setPosition(this, id, x, y);
+}
+
+status_t SurfaceComposerClient::setSize(SurfaceID id, uint32_t w, uint32_t h) {
+    return getComposer().setSize(this, id, w, h);
+}
+
+status_t SurfaceComposerClient::setLayer(SurfaceID id, int32_t z) {
+    return getComposer().setLayer(this, id, z);
+}
+
+status_t SurfaceComposerClient::hide(SurfaceID id) {
+    return getComposer().setFlags(this, id,
+            ISurfaceComposer::eLayerHidden,
+            ISurfaceComposer::eLayerHidden);
+}
+
+status_t SurfaceComposerClient::show(SurfaceID id, int32_t) {
+    return getComposer().setFlags(this, id,
+            0,
+            ISurfaceComposer::eLayerHidden);
+}
+
+status_t SurfaceComposerClient::freeze(SurfaceID id) {
+    return getComposer().setFlags(this, id,
+            ISurfaceComposer::eLayerFrozen,
+            ISurfaceComposer::eLayerFrozen);
+}
+
+status_t SurfaceComposerClient::unfreeze(SurfaceID id) {
+    return getComposer().setFlags(this, id,
+            0,
+            ISurfaceComposer::eLayerFrozen);
+}
+
+status_t SurfaceComposerClient::setFlags(SurfaceID id, uint32_t flags,
+        uint32_t mask) {
+    return getComposer().setFlags(this, id, flags, mask);
+}
+
+status_t SurfaceComposerClient::setTransparentRegionHint(SurfaceID id,
+        const Region& transparentRegion) {
+    return getComposer().setTransparentRegionHint(this, id, transparentRegion);
+}
+
+status_t SurfaceComposerClient::setAlpha(SurfaceID id, float alpha) {
+    return getComposer().setAlpha(this, id, alpha);
+}
+
+status_t SurfaceComposerClient::setMatrix(SurfaceID id, float dsdx, float dtdx,
+        float dsdy, float dtdy) {
+    return getComposer().setMatrix(this, id, dsdx, dtdx, dsdy, dtdy);
+}
+
+// ----------------------------------------------------------------------------
+
 status_t SurfaceComposerClient::getDisplayInfo(
         DisplayID dpy, DisplayInfo* info)
 {
@@ -273,70 +487,7 @@
     return n;
 }
 
-sp<SurfaceControl> SurfaceComposerClient::createSurface(
-        DisplayID display,
-        uint32_t w,
-        uint32_t h,
-        PixelFormat format,
-        uint32_t flags)
-{
-    String8 name;
-    const size_t SIZE = 128;
-    char buffer[SIZE];
-    snprintf(buffer, SIZE, "<pid_%d>", getpid());
-    name.append(buffer);
-
-    return SurfaceComposerClient::createSurface(name, display,
-            w, h, format, flags);
-}
-
-sp<SurfaceControl> SurfaceComposerClient::createSurface(
-        const String8& name,
-        DisplayID display,
-        uint32_t w,
-        uint32_t h,
-        PixelFormat format,
-        uint32_t flags)
-{
-    sp<SurfaceControl> result;
-    if (mStatus == NO_ERROR) {
-        ISurfaceComposerClient::surface_data_t data;
-        sp<ISurface> surface = mClient->createSurface(&data, name,
-                display, w, h, format, flags);
-        if (surface != 0) {
-            result = new SurfaceControl(this, surface, data, w, h, format, flags);
-        }
-    }
-    return result;
-}
-
-status_t SurfaceComposerClient::destroySurface(SurfaceID sid)
-{
-    if (mStatus != NO_ERROR)
-        return mStatus;
-
-    // it's okay to destroy a surface while a transaction is open,
-    // (transactions really are a client-side concept)
-    // however, this indicates probably a misuse of the API or a bug
-    // in the client code.
-    LOGW_IF(mTransactionOpen,
-         "Destroying surface while a transaction is open. "
-         "Client %p: destroying surface %d, mTransactionOpen=%d",
-         this, sid, mTransactionOpen);
-
-    status_t err = mClient->destroySurface(sid);
-    return err;
-}
-
-void SurfaceComposerClient::openGlobalTransaction()
-{
-    Composer::openGlobalTransaction();
-}
-
-void SurfaceComposerClient::closeGlobalTransaction()
-{
-    Composer::closeGlobalTransaction();
-}
+// ----------------------------------------------------------------------------
 
 status_t SurfaceComposerClient::freezeDisplay(DisplayID dpy, uint32_t flags)
 {
@@ -350,199 +501,13 @@
     return sm->unfreezeDisplay(dpy, flags);
 }
 
-int SurfaceComposerClient::setOrientation(DisplayID dpy, 
+int SurfaceComposerClient::setOrientation(DisplayID dpy,
         int orientation, uint32_t flags)
 {
     sp<ISurfaceComposer> sm(getComposerService());
     return sm->setOrientation(dpy, orientation, flags);
 }
 
-status_t SurfaceComposerClient::openTransaction()
-{
-    if (mStatus != NO_ERROR)
-        return mStatus;
-    Mutex::Autolock _l(mLock);
-    mTransactionOpen++;
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::closeTransaction()
-{
-    if (mStatus != NO_ERROR)
-        return mStatus;
-
-    Mutex::Autolock _l(mLock);
-    if (mTransactionOpen <= 0) {
-        LOGE(   "closeTransaction (client %p, mTransactionOpen=%d) "
-                "called more times than openTransaction()",
-                this, mTransactionOpen);
-        return INVALID_OPERATION;
-    }
-
-    if (mTransactionOpen >= 2) {
-        mTransactionOpen--;
-        return NO_ERROR;
-    }
-
-    mTransactionOpen = 0;
-    const ssize_t count = mStates.size();
-    if (count) {
-        mClient->setState(count, mStates.array());
-        mStates.clear();
-    }
-    return NO_ERROR;
-}
-
-layer_state_t* SurfaceComposerClient::get_state_l(SurfaceID index)
-{
-    // API usage error, do nothing.
-    if (mTransactionOpen<=0) {
-        LOGE("Not in transaction (client=%p, SurfaceID=%d, mTransactionOpen=%d",
-                this, int(index), mTransactionOpen);
-        return 0;
-    }
-
-    // use mPrebuiltLayerState just to find out if we already have it
-    layer_state_t& dummy(*mPrebuiltLayerState);
-    dummy.surface = index;
-    ssize_t i = mStates.indexOf(dummy);
-    if (i < 0) {
-        // we don't have it, add an initialized layer_state to our list
-        i = mStates.add(dummy);
-    }
-    return mStates.editArray() + i;
-}
-
-layer_state_t* SurfaceComposerClient::lockLayerState(SurfaceID id)
-{
-    layer_state_t* s;
-    mLock.lock();
-    s = get_state_l(id);
-    if (!s) mLock.unlock();
-    return s;
-}
-
-void SurfaceComposerClient::unlockLayerState()
-{
-    mLock.unlock();
-}
-
-status_t SurfaceComposerClient::setPosition(SurfaceID id, int32_t x, int32_t y)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::ePositionChanged;
-    s->x = x;
-    s->y = y;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setSize(SurfaceID id, uint32_t w, uint32_t h)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eSizeChanged;
-    s->w = w;
-    s->h = h;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setLayer(SurfaceID id, int32_t z)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eLayerChanged;
-    s->z = z;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::hide(SurfaceID id)
-{
-    return setFlags(id, ISurfaceComposer::eLayerHidden,
-            ISurfaceComposer::eLayerHidden);
-}
-
-status_t SurfaceComposerClient::show(SurfaceID id, int32_t)
-{
-    return setFlags(id, 0, ISurfaceComposer::eLayerHidden);
-}
-
-status_t SurfaceComposerClient::freeze(SurfaceID id)
-{
-    return setFlags(id, ISurfaceComposer::eLayerFrozen,
-            ISurfaceComposer::eLayerFrozen);
-}
-
-status_t SurfaceComposerClient::unfreeze(SurfaceID id)
-{
-    return setFlags(id, 0, ISurfaceComposer::eLayerFrozen);
-}
-
-status_t SurfaceComposerClient::setFlags(SurfaceID id,
-        uint32_t flags, uint32_t mask)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eVisibilityChanged;
-    s->flags &= ~mask;
-    s->flags |= (flags & mask);
-    s->mask |= mask;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setTransparentRegionHint(
-        SurfaceID id, const Region& transparentRegion)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eTransparentRegionChanged;
-    s->transparentRegion = transparentRegion;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setAlpha(SurfaceID id, float alpha)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eAlphaChanged;
-    s->alpha = alpha;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setMatrix(
-        SurfaceID id,
-        float dsdx, float dtdx,
-        float dsdy, float dtdy )
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eMatrixChanged;
-    layer_state_t::matrix22_t matrix;
-    matrix.dsdx = dsdx;
-    matrix.dtdx = dtdx;
-    matrix.dsdy = dsdy;
-    matrix.dtdy = dtdy;
-    s->matrix = matrix;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
-status_t SurfaceComposerClient::setFreezeTint(SurfaceID id, uint32_t tint)
-{
-    layer_state_t* s = lockLayerState(id);
-    if (!s) return BAD_INDEX;
-    s->what |= ISurfaceComposer::eFreezeTintChanged;
-    s->tint = tint;
-    unlockLayerState();
-    return NO_ERROR;
-}
-
 // ----------------------------------------------------------------------------
 
 ScreenshotClient::ScreenshotClient()
diff --git a/libs/gui/tests/SurfaceTexture_test.cpp b/libs/gui/tests/SurfaceTexture_test.cpp
index dfa9211..c06400e 100644
--- a/libs/gui/tests/SurfaceTexture_test.cpp
+++ b/libs/gui/tests/SurfaceTexture_test.cpp
@@ -84,10 +84,10 @@
             ASSERT_TRUE(mSurfaceControl != NULL);
             ASSERT_TRUE(mSurfaceControl->isValid());
 
-            ASSERT_EQ(NO_ERROR, mComposerClient->openTransaction());
+            SurfaceComposerClient::openGlobalTransaction();
             ASSERT_EQ(NO_ERROR, mSurfaceControl->setLayer(0x7FFFFFFF));
             ASSERT_EQ(NO_ERROR, mSurfaceControl->show());
-            ASSERT_EQ(NO_ERROR, mComposerClient->closeTransaction());
+            SurfaceComposerClient::closeGlobalTransaction();
 
             sp<ANativeWindow> window = mSurfaceControl->getSurface();
             mEglSurface = eglCreateWindowSurface(mEglDisplay, mGlConfig,
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 35c8640..450cdf1 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -36,10 +36,10 @@
         ASSERT_TRUE(mSurfaceControl != NULL);
         ASSERT_TRUE(mSurfaceControl->isValid());
 
-        ASSERT_EQ(NO_ERROR, mComposerClient->openTransaction());
+        SurfaceComposerClient::openGlobalTransaction();
         ASSERT_EQ(NO_ERROR, mSurfaceControl->setLayer(30000));
         ASSERT_EQ(NO_ERROR, mSurfaceControl->show());
-        ASSERT_EQ(NO_ERROR, mComposerClient->closeTransaction());
+        SurfaceComposerClient::closeGlobalTransaction();
 
         mSurface = mSurfaceControl->getSurface();
         ASSERT_TRUE(mSurface != NULL);
diff --git a/libs/utils/Android.mk b/libs/utils/Android.mk
index 093189c..774e8c9 100644
--- a/libs/utils/Android.mk
+++ b/libs/utils/Android.mk
@@ -27,6 +27,7 @@
 	Debug.cpp \
 	FileMap.cpp \
 	Flattenable.cpp \
+	LinearTransform.cpp \
 	ObbFile.cpp \
 	Pool.cpp \
 	PropertyMap.cpp \
diff --git a/libs/utils/LinearTransform.cpp b/libs/utils/LinearTransform.cpp
new file mode 100644
index 0000000..d752415
--- /dev/null
+++ b/libs/utils/LinearTransform.cpp
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+#define __STDC_LIMIT_MACROS
+
+#include <assert.h>
+#include <stdint.h>
+
+#include <utils/LinearTransform.h>
+
+namespace android {
+
+template<class T> static inline T ABS(T x) { return (x < 0) ? -x : x; }
+
+// Static math methods involving linear transformations
+static bool scale_u64_to_u64(
+        uint64_t val,
+        uint32_t N,
+        uint32_t D,
+        uint64_t* res,
+        bool round_up_not_down) {
+    uint64_t tmp1, tmp2;
+    uint32_t r;
+
+    assert(res);
+    assert(D);
+
+    // Let U32(X) denote a uint32_t containing the upper 32 bits of a 64 bit
+    // integer X.
+    // Let L32(X) denote a uint32_t containing the lower 32 bits of a 64 bit
+    // integer X.
+    // Let X[A, B] with A <= B denote bits A through B of the integer X.
+    // Let (A | B) denote the concatination of two 32 bit ints, A and B.
+    // IOW X = (A | B) => U32(X) == A && L32(X) == B
+    //
+    // compute M = val * N (a 96 bit int)
+    // ---------------------------------
+    // tmp2 = U32(val) * N (a 64 bit int)
+    // tmp1 = L32(val) * N (a 64 bit int)
+    // which means
+    // M = val * N = (tmp2 << 32) + tmp1
+    tmp2 = (val >> 32) * N;
+    tmp1 = (val & UINT32_MAX) * N;
+
+    // compute M[32, 95]
+    // tmp2 = tmp2 + U32(tmp1)
+    //      = (U32(val) * N) + U32(L32(val) * N)
+    //      = M[32, 95]
+    tmp2 += tmp1 >> 32;
+
+    // if M[64, 95] >= D, then M/D has bits > 63 set and we have
+    // an overflow.
+    if ((tmp2 >> 32) >= D) {
+        *res = UINT64_MAX;
+        return false;
+    }
+
+    // Divide.  Going in we know
+    // tmp2 = M[32, 95]
+    // U32(tmp2) < D
+    r = tmp2 % D;
+    tmp2 /= D;
+
+    // At this point
+    // tmp1      = L32(val) * N
+    // tmp2      = M[32, 95] / D
+    //           = (M / D)[32, 95]
+    // r         = M[32, 95] % D
+    // U32(tmp2) = 0
+    //
+    // compute tmp1 = (r | M[0, 31])
+    tmp1 = (tmp1 & UINT32_MAX) | ((uint64_t)r << 32);
+
+    // Divide again.  Keep the remainder around in order to round properly.
+    r = tmp1 % D;
+    tmp1 /= D;
+
+    // At this point
+    // tmp2      = (M / D)[32, 95]
+    // tmp1      = (M / D)[ 0, 31]
+    // r         =  M % D
+    // U32(tmp1) = 0
+    // U32(tmp2) = 0
+
+    // Pack the result and deal with the round-up case (As well as the
+    // remote possiblility over overflow in such a case).
+    *res = (tmp2 << 32) | tmp1;
+    if (r && round_up_not_down) {
+        ++(*res);
+        if (!(*res)) {
+            *res = UINT64_MAX;
+            return false;
+        }
+    }
+
+    return true;
+}
+
+static bool linear_transform_s64_to_s64(
+        int64_t  val,
+        int64_t  basis1,
+        int32_t  N,
+        uint32_t D,
+        int64_t  basis2,
+        int64_t* out) {
+    uint64_t scaled, res;
+    uint64_t abs_val;
+    bool is_neg;
+
+    if (!out)
+        return false;
+
+    // Compute abs(val - basis_64). Keep track of whether or not this delta
+    // will be negative after the scale opertaion.
+    if (val < basis1) {
+        is_neg = true;
+        abs_val = basis1 - val;
+    } else {
+        is_neg = false;
+        abs_val = val - basis1;
+    }
+
+    if (N < 0)
+        is_neg = !is_neg;
+
+    if (!scale_u64_to_u64(abs_val,
+                          ABS(N),
+                          D,
+                          &scaled,
+                          is_neg))
+        return false; // overflow/undeflow
+
+    // if scaled is >= 0x8000<etc>, then we are going to overflow or
+    // underflow unless ABS(basis2) is large enough to pull us back into the
+    // non-overflow/underflow region.
+    if (scaled & INT64_MIN) {
+        if (is_neg && (basis2 < 0))
+            return false; // certain underflow
+
+        if (!is_neg && (basis2 >= 0))
+            return false; // certain overflow
+
+        if (ABS(basis2) <= static_cast<int64_t>(scaled & INT64_MAX))
+            return false; // not enough
+
+        // Looks like we are OK
+        *out = (is_neg ? (-scaled) : scaled) + basis2;
+    } else {
+        // Scaled fits within signed bounds, so we just need to check for
+        // over/underflow for two signed integers.  Basically, if both scaled
+        // and basis2 have the same sign bit, and the result has a different
+        // sign bit, then we have under/overflow.  An easy way to compute this
+        // is
+        // (scaled_signbit XNOR basis_signbit) &&
+        // (scaled_signbit XOR res_signbit)
+        // ==
+        // (scaled_signbit XOR basis_signbit XOR 1) &&
+        // (scaled_signbit XOR res_signbit)
+
+        if (is_neg)
+            scaled = -scaled;
+        res = scaled + basis2;
+
+        if ((scaled ^ basis2 ^ INT64_MIN) & (scaled ^ res) & INT64_MIN)
+            return false;
+
+        *out = res;
+    }
+
+    return true;
+}
+
+bool LinearTransform::doForwardTransform(int64_t a_in, int64_t* b_out) const {
+    if (0 == a_to_b_denom)
+        return false;
+
+    return linear_transform_s64_to_s64(a_in,
+                                       a_zero,
+                                       a_to_b_numer,
+                                       a_to_b_denom,
+                                       b_zero,
+                                       b_out);
+}
+
+bool LinearTransform::doReverseTransform(int64_t b_in, int64_t* a_out) const {
+    if (0 == a_to_b_numer)
+        return false;
+
+    return linear_transform_s64_to_s64(b_in,
+                                       b_zero,
+                                       a_to_b_denom,
+                                       a_to_b_numer,
+                                       a_zero,
+                                       a_out);
+}
+
+template <class T> void LinearTransform::reduce(T* N, T* D) {
+    T a, b;
+    if (!N || !D || !(*D)) {
+        assert(false);
+        return;
+    }
+
+    a = *N;
+    b = *D;
+
+    if (a == 0) {
+        *D = 1;
+        return;
+    }
+
+    // This implements Euclid's method to find GCD.
+    if (a < b) {
+        T tmp = a;
+        a = b;
+        b = tmp;
+    }
+
+    while (1) {
+        // a is now the greater of the two.
+        const T remainder = a % b;
+        if (remainder == 0) {
+            *N /= b;
+            *D /= b;
+            return;
+        }
+        // by swapping remainder and b, we are guaranteeing that a is
+        // still the greater of the two upon entrance to the loop.
+        a = b;
+        b = remainder;
+    }
+};
+
+template void LinearTransform::reduce<uint64_t>(uint64_t* N, uint64_t* D);
+template void LinearTransform::reduce<uint32_t>(uint32_t* N, uint32_t* D);
+
+void LinearTransform::reduce(int32_t* N, uint32_t* D) {
+    if (N && D && *D) {
+        if (*N < 0) {
+            *N = -(*N);
+            reduce(reinterpret_cast<uint32_t*>(N), D);
+            *N = -(*N);
+        } else {
+            reduce(reinterpret_cast<uint32_t*>(N), D);
+        }
+    }
+}
+
+}  // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index f0b19f2..1c57bc1 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -78,7 +78,6 @@
 SurfaceFlinger::SurfaceFlinger()
     :   BnSurfaceComposer(), Thread(false),
         mTransactionFlags(0),
-        mTransactionCount(0),
         mResizeTransationPending(false),
         mLayersRemoved(false),
         mBootTime(systemTime()),
@@ -385,13 +384,11 @@
         handleConsoleEvents();
     }
 
-    if (LIKELY(mTransactionCount == 0)) {
-        // if we're in a global transaction, don't do anything.
-        const uint32_t mask = eTransactionNeeded | eTraversalNeeded;
-        uint32_t transactionFlags = peekTransactionFlags(mask);
-        if (LIKELY(transactionFlags)) {
-            handleTransaction(transactionFlags);
-        }
+    // if we're in a global transaction, don't do anything.
+    const uint32_t mask = eTransactionNeeded | eTraversalNeeded;
+    uint32_t transactionFlags = peekTransactionFlags(mask);
+    if (UNLIKELY(transactionFlags)) {
+        handleTransaction(transactionFlags);
     }
 
     // post surfaces (if needed)
@@ -1176,28 +1173,33 @@
     return old;
 }
 
-void SurfaceFlinger::openGlobalTransaction()
-{
-    android_atomic_inc(&mTransactionCount);
-}
 
-void SurfaceFlinger::closeGlobalTransaction()
-{
-    if (android_atomic_dec(&mTransactionCount) == 1) {
-        signalEvent();
+void SurfaceFlinger::setTransactionState(const Vector<ComposerState>& state) {
+    Mutex::Autolock _l(mStateLock);
 
-        // if there is a transaction with a resize, wait for it to
-        // take effect before returning.
-        Mutex::Autolock _l(mStateLock);
-        while (mResizeTransationPending) {
-            status_t err = mTransactionCV.waitRelative(mStateLock, s2ns(5));
-            if (CC_UNLIKELY(err != NO_ERROR)) {
-                // just in case something goes wrong in SF, return to the
-                // called after a few seconds.
-                LOGW_IF(err == TIMED_OUT, "closeGlobalTransaction timed out!");
-                mResizeTransationPending = false;
-                break;
-            }
+    uint32_t flags = 0;
+    const size_t count = state.size();
+    for (size_t i=0 ; i<count ; i++) {
+        const ComposerState& s(state[i]);
+        sp<Client> client( static_cast<Client *>(s.client.get()) );
+        flags |= setClientStateLocked(client, s.state);
+    }
+    if (flags) {
+        setTransactionFlags(flags);
+    }
+
+    signalEvent();
+
+    // if there is a transaction with a resize, wait for it to
+    // take effect before returning.
+    while (mResizeTransationPending) {
+        status_t err = mTransactionCV.waitRelative(mStateLock, s2ns(5));
+        if (CC_UNLIKELY(err != NO_ERROR)) {
+            // just in case something goes wrong in SF, return to the
+            // called after a few seconds.
+            LOGW_IF(err == TIMED_OUT, "closeGlobalTransaction timed out!");
+            mResizeTransationPending = false;
+            break;
         }
     }
 }
@@ -1393,60 +1395,52 @@
     return err;
 }
 
-status_t SurfaceFlinger::setClientState(
+uint32_t SurfaceFlinger::setClientStateLocked(
         const sp<Client>& client,
-        int32_t count,
-        const layer_state_t* states)
+        const layer_state_t& s)
 {
-    Mutex::Autolock _l(mStateLock);
     uint32_t flags = 0;
-    for (int i=0 ; i<count ; i++) {
-        const layer_state_t& s(states[i]);
-        sp<LayerBaseClient> layer(client->getLayerUser(s.surface));
-        if (layer != 0) {
-            const uint32_t what = s.what;
-            if (what & ePositionChanged) {
-                if (layer->setPosition(s.x, s.y))
-                    flags |= eTraversalNeeded;
-            }
-            if (what & eLayerChanged) {
-                ssize_t idx = mCurrentState.layersSortedByZ.indexOf(layer);
-                if (layer->setLayer(s.z)) {
-                    mCurrentState.layersSortedByZ.removeAt(idx);
-                    mCurrentState.layersSortedByZ.add(layer);
-                    // we need traversal (state changed)
-                    // AND transaction (list changed)
-                    flags |= eTransactionNeeded|eTraversalNeeded;
-                }
-            }
-            if (what & eSizeChanged) {
-                if (layer->setSize(s.w, s.h)) {
-                    flags |= eTraversalNeeded;
-                    mResizeTransationPending = true;
-                }
-            }
-            if (what & eAlphaChanged) {
-                if (layer->setAlpha(uint8_t(255.0f*s.alpha+0.5f)))
-                    flags |= eTraversalNeeded;
-            }
-            if (what & eMatrixChanged) {
-                if (layer->setMatrix(s.matrix))
-                    flags |= eTraversalNeeded;
-            }
-            if (what & eTransparentRegionChanged) {
-                if (layer->setTransparentRegionHint(s.transparentRegion))
-                    flags |= eTraversalNeeded;
-            }
-            if (what & eVisibilityChanged) {
-                if (layer->setFlags(s.flags, s.mask))
-                    flags |= eTraversalNeeded;
+    sp<LayerBaseClient> layer(client->getLayerUser(s.surface));
+    if (layer != 0) {
+        const uint32_t what = s.what;
+        if (what & ePositionChanged) {
+            if (layer->setPosition(s.x, s.y))
+                flags |= eTraversalNeeded;
+        }
+        if (what & eLayerChanged) {
+            ssize_t idx = mCurrentState.layersSortedByZ.indexOf(layer);
+            if (layer->setLayer(s.z)) {
+                mCurrentState.layersSortedByZ.removeAt(idx);
+                mCurrentState.layersSortedByZ.add(layer);
+                // we need traversal (state changed)
+                // AND transaction (list changed)
+                flags |= eTransactionNeeded|eTraversalNeeded;
             }
         }
+        if (what & eSizeChanged) {
+            if (layer->setSize(s.w, s.h)) {
+                flags |= eTraversalNeeded;
+                mResizeTransationPending = true;
+            }
+        }
+        if (what & eAlphaChanged) {
+            if (layer->setAlpha(uint8_t(255.0f*s.alpha+0.5f)))
+                flags |= eTraversalNeeded;
+        }
+        if (what & eMatrixChanged) {
+            if (layer->setMatrix(s.matrix))
+                flags |= eTraversalNeeded;
+        }
+        if (what & eTransparentRegionChanged) {
+            if (layer->setTransparentRegionHint(s.transparentRegion))
+                flags |= eTraversalNeeded;
+        }
+        if (what & eVisibilityChanged) {
+            if (layer->setFlags(s.flags, s.mask))
+                flags |= eTraversalNeeded;
+        }
     }
-    if (flags) {
-        setTransactionFlags(flags);
-    }
-    return NO_ERROR;
+    return flags;
 }
 
 void SurfaceFlinger::screenReleased(int dpy)
@@ -1588,8 +1582,7 @@
 {
     switch (code) {
         case CREATE_CONNECTION:
-        case OPEN_GLOBAL_TRANSACTION:
-        case CLOSE_GLOBAL_TRANSACTION:
+        case SET_TRANSACTION_STATE:
         case SET_ORIENTATION:
         case FREEZE_DISPLAY:
         case UNFREEZE_DISPLAY:
@@ -2469,9 +2462,6 @@
 status_t Client::destroySurface(SurfaceID sid) {
     return mFlinger->removeSurface(this, sid);
 }
-status_t Client::setState(int32_t count, const layer_state_t* states) {
-    return mFlinger->setClientState(this, count, states);
-}
 
 // ---------------------------------------------------------------------------
 
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 45f80ae..b49fa36 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -70,14 +70,12 @@
     sp<LayerBaseClient> getLayerUser(int32_t i) const;
 
 private:
-
     // ISurfaceComposerClient interface
     virtual sp<ISurface> createSurface(
             surface_data_t* params, const String8& name,
             DisplayID display, uint32_t w, uint32_t h,PixelFormat format,
             uint32_t flags);
     virtual status_t destroySurface(SurfaceID surfaceId);
-    virtual status_t setState(int32_t count, const layer_state_t* states);
     virtual status_t onTransact(
         uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags);
 
@@ -168,8 +166,7 @@
     virtual sp<IGraphicBufferAlloc>     createGraphicBufferAlloc();
     virtual sp<IMemoryHeap>             getCblk() const;
     virtual void                        bootFinished();
-    virtual void                        openGlobalTransaction();
-    virtual void                        closeGlobalTransaction();
+    virtual void                        setTransactionState(const Vector<ComposerState>& state);
     virtual status_t                    freezeDisplay(DisplayID dpy, uint32_t flags);
     virtual status_t                    unfreezeDisplay(DisplayID dpy, uint32_t flags);
     virtual int                         setOrientation(DisplayID dpy, int orientation, uint32_t flags);
@@ -220,8 +217,7 @@
 
     status_t removeSurface(const sp<Client>& client, SurfaceID sid);
     status_t destroySurface(const wp<LayerBaseClient>& layer);
-    status_t setClientState(const sp<Client>& client,
-            int32_t count, const layer_state_t* states);
+    uint32_t setClientStateLocked(const sp<Client>& client, const layer_state_t& s);
 
     class LayerVector : public SortedVector< sp<LayerBase> > {
     public:
@@ -337,7 +333,6 @@
     mutable     Mutex                   mStateLock;
                 State                   mCurrentState;
     volatile    int32_t                 mTransactionFlags;
-    volatile    int32_t                 mTransactionCount;
                 Condition               mTransactionCV;
                 SortedVector< sp<LayerBase> > mLayerPurgatory;
                 bool                    mResizeTransationPending;
diff --git a/services/surfaceflinger/tests/resize/resize.cpp b/services/surfaceflinger/tests/resize/resize.cpp
index 18c54b3..56b2a8f 100644
--- a/services/surfaceflinger/tests/resize/resize.cpp
+++ b/services/surfaceflinger/tests/resize/resize.cpp
@@ -43,9 +43,9 @@
             PIXEL_FORMAT_RGB_565);
 
 
-    client->openTransaction();
+    SurfaceComposerClient::openGlobalTransaction();
     surface->setLayer(100000);
-    client->closeTransaction();
+    SurfaceComposerClient::closeGlobalTransaction();
 
     Surface::SurfaceInfo info;
     surface->lock(&info);
@@ -57,9 +57,9 @@
     android_memset16((uint16_t*)info.bits, 0x07E0, bpr*info.h);
     surface->unlockAndPost();
 
-    client->openTransaction();
+    SurfaceComposerClient::openGlobalTransaction();
     surface->setSize(320, 240);
-    client->closeTransaction();
+    SurfaceComposerClient::closeGlobalTransaction();
 
     
     IPCThreadState::self()->joinThreadPool();
diff --git a/services/surfaceflinger/tests/surface/surface.cpp b/services/surfaceflinger/tests/surface/surface.cpp
index 5265f91..8e1c3fe 100644
--- a/services/surfaceflinger/tests/surface/surface.cpp
+++ b/services/surfaceflinger/tests/surface/surface.cpp
@@ -39,9 +39,9 @@
     
     sp<SurfaceControl> surfaceControl = client->createSurface(
             getpid(), 0, 160, 240, PIXEL_FORMAT_RGB_565);
-    client->openTransaction();
+    SurfaceComposerClient::openGlobalTransaction();
     surfaceControl->setLayer(100000);
-    client->closeTransaction();
+    SurfaceComposerClient::closeGlobalTransaction();
 
     // pretend it went cross-process
     Parcel parcel;