diff --git a/graphics/composer/2.1/IComposer.hal b/graphics/composer/2.1/IComposer.hal
index dd61c11..771fc7d 100644
--- a/graphics/composer/2.1/IComposer.hal
+++ b/graphics/composer/2.1/IComposer.hal
@@ -16,8 +16,7 @@
 
 package android.hardware.graphics.composer@2.1;
 
-import android.hardware.graphics.common@1.0;
-import IComposerCallback;
+import IComposerClient;
 
 interface IComposer {
     /*
@@ -47,210 +46,6 @@
         SKIP_CLIENT_COLOR_TRANSFORM = 2,
     };
 
-    /* Display attributes queryable through getDisplayAttribute. */
-    enum Attribute : int32_t {
-        INVALID = 0,
-
-        /* Dimensions in pixels */
-        WIDTH = 1,
-        HEIGHT = 2,
-
-        /* Vsync period in nanoseconds */
-        VSYNC_PERIOD = 3,
-
-        /*
-         * Dots per thousand inches (DPI * 1000). Scaling by 1000 allows these
-         * numbers to be stored in an int32_t without losing too much
-         * precision. If the DPI for a configuration is unavailable or is
-         * considered unreliable, the device may return UNSUPPORTED instead.
-         */
-        DPI_X = 4,
-        DPI_Y = 5,
-    };
-
-    /* Display requests returned by getDisplayRequests. */
-    enum DisplayRequest : uint32_t {
-        /*
-         * Instructs the client to provide a new client target buffer, even if
-         * no layers are marked for client composition.
-         */
-        FLIP_CLIENT_TARGET = 1 << 0,
-
-        /*
-         * Instructs the client to write the result of client composition
-         * directly into the virtual display output buffer. If any of the
-         * layers are not marked as Composition::CLIENT or the given display
-         * is not a virtual display, this request has no effect.
-         */
-        WRITE_CLIENT_TARGET_TO_OUTPUT = 1 << 1,
-    };
-
-    /* Layer requests returned from getDisplayRequests. */
-    enum LayerRequest : uint32_t {
-        /*
-         * The client should clear its target with transparent pixels where
-         * this layer would be. The client may ignore this request if the
-         * layer must be blended.
-         */
-        CLEAR_CLIENT_TARGET = 1 << 0,
-    };
-
-    /* Power modes for use with setPowerMode. */
-    enum PowerMode : int32_t {
-        /* The display is fully off (blanked). */
-        OFF = 0,
-
-        /*
-         * These are optional low power modes. getDozeSupport may be called to
-         * determine whether a given display supports these modes.
-         */
-
-        /*
-         * The display is turned on and configured in a low power state that
-         * is suitable for presenting ambient information to the user,
-         * possibly with lower fidelity than ON, but with greater efficiency.
-         */
-        DOZE = 1,
-
-        /*
-         * The display is configured as in DOZE but may stop applying display
-         * updates from the client. This is effectively a hint to the device
-         * that drawing to the display has been suspended and that the the
-         * device should remain on in a low power state and continue
-         * displaying its current contents indefinitely until the power mode
-         * changes.
-         *
-         * This mode may also be used as a signal to enable hardware-based
-         * doze functionality. In this case, the device is free to take over
-         * the display and manage it autonomously to implement a low power
-         * always-on display.
-         */
-        DOZE_SUSPEND = 3,
-
-        /* The display is fully on. */
-        ON = 2,
-    };
-
-    /* Vsync values passed to setVsyncEnabled. */
-    enum Vsync : int32_t {
-        INVALID = 0,
-
-        /* Enable vsync. */
-        ENABLE = 1,
-
-        /* Disable vsync. */
-        DISABLE = 2,
-    };
-
-    /* Blend modes, settable per layer. */
-    enum BlendMode : int32_t {
-        INVALID = 0,
-
-        /* colorOut = colorSrc */
-        NONE = 1,
-
-        /* colorOut = colorSrc + colorDst * (1 - alphaSrc) */
-        PREMULTIPLIED = 2,
-
-        /* colorOut = colorSrc * alphaSrc + colorDst * (1 - alphaSrc) */
-        COVERAGE = 3,
-    };
-
-    /* Possible composition types for a given layer. */
-    enum Composition : int32_t {
-        INVALID = 0,
-
-        /*
-         * The client will composite this layer into the client target buffer
-         * (provided to the device through setClientTarget).
-         *
-         * The device must not request any composition type changes for layers
-         * of this type.
-         */
-        CLIENT = 1,
-
-        /*
-         * The device will handle the composition of this layer through a
-         * hardware overlay or other similar means.
-         *
-         * Upon validateDisplay, the device may request a change from this
-         * type to CLIENT.
-         */
-        DEVICE = 2,
-
-        /*
-         * The device will render this layer using the color set through
-         * setLayerColor. If this functionality is not supported on a layer
-         * that the client sets to SOLID_COLOR, the device must request that
-         * the composition type of that layer is changed to CLIENT upon the
-         * next call to validateDisplay.
-         *
-         * Upon validateDisplay, the device may request a change from this
-         * type to CLIENT.
-         */
-        SOLID_COLOR = 3,
-
-        /*
-         * Similar to DEVICE, but the position of this layer may also be set
-         * asynchronously through setCursorPosition. If this functionality is
-         * not supported on a layer that the client sets to CURSOR, the device
-         * must request that the composition type of that layer is changed to
-         * CLIENT upon the next call to validateDisplay.
-         *
-         * Upon validateDisplay, the device may request a change from this
-         * type to either DEVICE or CLIENT.  Changing to DEVICE will prevent
-         * the use of setCursorPosition but still permit the device to
-         * composite the layer.
-         */
-        CURSOR = 4,
-
-        /*
-         * The device will handle the composition of this layer, as well as
-         * its buffer updates and content synchronization. Only supported on
-         * devices which provide Capability::SIDEBAND_STREAM.
-         *
-         * Upon validateDisplay, the device may request a change from this
-         * type to either DEVICE or CLIENT, but it is unlikely that content
-         * will display correctly in these cases.
-         */
-        SIDEBAND = 5,
-    };
-
-    /* Display types returned by getDisplayType. */
-    enum DisplayType : int32_t {
-        INVALID = 0,
-
-        /*
-         * All physical displays, including both internal displays and
-         * hotpluggable external displays.
-         */
-        PHYSICAL = 1,
-
-        /* Virtual displays created by createVirtualDisplay. */
-        VIRTUAL = 2,
-    };
-
-    struct Rect {
-        int32_t left;
-        int32_t top;
-        int32_t right;
-        int32_t bottom;
-    };
-
-    struct FRect {
-        float left;
-        float top;
-        float right;
-        float bottom;
-    };
-
-    struct Color {
-        uint8_t r;
-        uint8_t g;
-        uint8_t b;
-        uint8_t a;
-    };
-
     /*
      * Provides a list of supported capabilities (as described in the
      * definition of Capability above). This list must not change after
@@ -269,898 +64,14 @@
     dumpDebugInfo() generates (string debugInfo);
 
     /*
-     * Provides a IComposerCallback object for the device to call.
+     * Creates a client of the composer. All resources created by the client
+     * are owned by the client and are only visible to the client.
      *
-     * @param callback is the IComposerCallback object.
-     */
-    registerCallback(IComposerCallback callback);
-
-    /*
-     * Returns the maximum number of virtual displays supported by this device
-     * (which may be 0). The client will not attempt to create more than this
-     * many virtual displays on this device. This number must not change for
-     * the lifetime of the device.
-     */
-    getMaxVirtualDisplayCount() generates (uint32_t count);
-
-    /*
-     * Creates a new virtual display with the given width and height. The
-     * format passed into this function is the default format requested by the
-     * consumer of the virtual display output buffers.
-     *
-     * The display will be assumed to be on from the time the first frame is
-     * presented until the display is destroyed.
-     *
-     * @param width is the width in pixels.
-     * @param height is the height in pixels.
-     * @param formatHint is the default output buffer format selected by
-     *        the consumer.
-     * @return error is NONE upon success. Otherwise,
-     *         UNSUPPORTED when the width or height is too large for the
-     *                     device to be able to create a virtual display.
-     *         NO_RESOURCES when the device is unable to create a new virtual
-     *                      display at this time.
-     * @return display is the newly-created virtual display.
-     * @return format is the format of the buffer the device will produce.
-     */
-    createVirtualDisplay(uint32_t width,
-                         uint32_t height,
-                         PixelFormat formatHint)
-              generates (Error error,
-                         Display display,
-                         PixelFormat format);
-
-    /*
-     * Destroys a virtual display. After this call all resources consumed by
-     * this display may be freed by the device and any operations performed on
-     * this display should fail.
-     *
-     * @param display is the virtual display to destroy.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when the display handle which was passed in does
-     *                       not refer to a virtual display.
-     */
-    destroyVirtualDisplay(Display display) generates (Error error);
-
-    /*
-     * Accepts the changes required by the device from the previous
-     * validateDisplay call (which may be queried using
-     * getChangedCompositionTypes) and revalidates the display. This function
-     * is equivalent to requesting the changed types from
-     * getChangedCompositionTypes, setting those types on the corresponding
-     * layers, and then calling validateDisplay again.
-     *
-     * After this call it must be valid to present this display. Calling this
-     * after validateDisplay returns 0 changes must succeed with NONE, but
-     * should have no other effect.
+     * There can only be one client at any time.
      *
      * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         NOT_VALIDATED when validateDisplay has not been called.
+     *         NO_RESOURCES when no more client can be created currently.
+     * @return client is the newly created client.
      */
-    acceptDisplayChanges(Display display) generates (Error error);
-
-    /*
-     * Creates a new layer on the given display.
-     *
-     * @param display is the display on which to create the layer.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         NO_RESOURCES when the device was unable to create a layer this
-     *                      time.
-     * @return layer is the handle of the new layer.
-     */
-    createLayer(Display display) generates (Error error, Layer layer);
-
-    /*
-     * Destroys the given layer.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to destroy.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    destroyLayer(Display display, Layer layer) generates (Error error);
-
-    /*
-     * Retrieves which display configuration is currently active.
-     *
-     * If no display configuration is currently active, this function must
-     * return BAD_CONFIG. It is the responsibility of the client to call
-     * setActiveConfig with a valid configuration before attempting to present
-     * anything on the display.
-     *
-     * @param display is the display to which the active config is queried.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_CONFIG when no configuration is currently active.
-     * @return config is the currently active display configuration.
-     */
-    getActiveConfig(Display display) generates (Error error, Config config);
-
-    /*
-     * Retrieves the layers for which the device requires a different
-     * composition type than had been set prior to the last call to
-     * validateDisplay. The client will either update its state with these
-     * types and call acceptDisplayChanges, or will set new types and attempt
-     * to validate the display again.
-     *
-     * The number of changed layers must be the same as the value returned in
-     * numTypes from the last call to validateDisplay.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         NOT_VALIDATED when validateDisplay has not been called.
-     * @return layers is an array of layer handles.
-     * @return types is an array of composition types, each corresponding to
-     *         an element of layers.
-     */
-    getChangedCompositionTypes(Display display)
-                    generates (Error error,
-                               vec<Layer> layers,
-                               vec<Composition> types);
-
-    /*
-     * Returns whether a client target with the given properties can be
-     * handled by the device.
-     *
-     * This function must return true for a client target with width and
-     * height equal to the active display configuration dimensions,
-     * PixelFormat::RGBA_8888, and Dataspace::UNKNOWN. It is not required to
-     * return true for any other configuration.
-     *
-     * @param display is the display to query.
-     * @param width is the client target width in pixels.
-     * @param height is the client target height in pixels.
-     * @param format is the client target format.
-     * @param dataspace is the client target dataspace, as described in
-     *        setLayerDataspace.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         UNSUPPORTED when the given configuration is not supported.
-     */
-    getClientTargetSupport(Display display,
-                           uint32_t width,
-                           uint32_t height,
-                           PixelFormat format,
-                           Dataspace dataspace)
-                generates (Error error);
-
-    /*
-     * Returns the color modes supported on this display.
-     *
-     * All devices must support at least ColorMode::NATIVE.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return modes is an array of color modes.
-     */
-    getColorModes(Display display)
-       generates (Error error,
-                  vec<ColorMode> modes);
-
-    /*
-     * Returns a display attribute value for a particular display
-     * configuration.
-     *
-     * @param display is the display to query.
-     * @param config is the display configuration for which to return
-     *        attribute values.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_CONFIG when config does not name a valid configuration for
-     *                    this display.
-     *         BAD_PARAMETER when attribute is unrecognized.
-     *         UNSUPPORTED when attribute cannot be queried for the config.
-     * @return value is the value of the attribute.
-     */
-    getDisplayAttribute(Display display,
-                        Config config,
-                        Attribute attribute)
-             generates (Error error,
-                        int32_t value);
-
-    /*
-     * Returns handles for all of the valid display configurations on this
-     * display.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return configs is an array of configuration handles.
-     */
-    getDisplayConfigs(Display display)
-           generates (Error error,
-                      vec<Config> configs);
-
-    /*
-     * Returns a human-readable version of the display's name.
-     *
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return name is the name of the display.
-     */
-    getDisplayName(Display display) generates (Error error, string name);
-
-    /*
-     * Returns the display requests and the layer requests required for the
-     * last validated configuration.
-     *
-     * Display requests provide information about how the client should handle
-     * the client target. Layer requests provide information about how the
-     * client should handle an individual layer.
-     *
-     * The number of layer requests must be equal to the value returned in
-     * numRequests from the last call to validateDisplay.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         NOT_VALIDATED when validateDisplay has not been called.
-     * @return displayRequestMask is the display requests for the current
-     *         validated state.
-     * @return layers is an array of layers which all have at least one
-     *         request.
-     * @return layerRequestMasks is the requests corresponding to each element
-     *         of layers.
-     */
-    getDisplayRequests(Display display)
-            generates (Error error,
-                       uint32_t displayRequestMask,
-                       vec<Layer> layers,
-                       vec<uint32_t> layerRequestMasks);
-
-    /*
-     * Returns whether the given display is a physical or virtual display.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return type is the type of the display.
-     */
-    getDisplayType(Display display) generates (Error error, DisplayType type);
-
-    /*
-     * Returns whether the given display supports PowerMode::DOZE and
-     * PowerMode::DOZE_SUSPEND. DOZE_SUSPEND may not provide any benefit over
-     * DOZE (see the definition of PowerMode for more information), but if
-     * both DOZE and DOZE_SUSPEND are no different from PowerMode::ON, the
-     * device should not claim support.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return support is true only when the display supports doze modes.
-     */
-    getDozeSupport(Display display) generates (Error error, bool support);
-
-    /*
-     * Returns the high dynamic range (HDR) capabilities of the given display,
-     * which are invariant with regard to the active configuration.
-     *
-     * Displays which are not HDR-capable must return no types.
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return types is an array of HDR types, may have 0 elements if the
-     *         display is not HDR-capable.
-     * @return maxLuminance is the desired content maximum luminance for this
-     *         display in cd/m^2.
-     * @return maxAverageLuminance - the desired content maximum frame-average
-     *         luminance for this display in cd/m^2.
-     * @return minLuminance is the desired content minimum luminance for this
-     *         display in cd/m^2.
-     */
-    getHdrCapabilities(Display display)
-            generates (Error error,
-                       vec<Hdr> types,
-                       float maxLuminance,
-                       float maxAverageLuminance,
-                       float minLuminance);
-
-    /*
-     * Retrieves the release fences for device layers on this display which
-     * will receive new buffer contents this frame.
-     *
-     * A release fence is a file descriptor referring to a sync fence object
-     * which will be signaled after the device has finished reading from the
-     * buffer presented in the prior frame. This indicates that it is safe to
-     * start writing to the buffer again. If a given layer's fence is not
-     * returned from this function, it will be assumed that the buffer
-     * presented on the previous frame is ready to be written.
-     *
-     * The fences returned by this function should be unique for each layer
-     * (even if they point to the same underlying sync object).
-     *
-     * @param display is the display to query.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return layers is an array of layer handles.
-     * @return fences is handle that contains an array of sync fence file
-     *         descriptors as described above, each corresponding to an
-     *         element of layers.
-     */
-    getReleaseFences(Display display)
-          generates (Error error,
-                     vec<Layer> layers,
-                     handle releaseFences);
-
-    /*
-     * Presents the current display contents on the screen (or in the case of
-     * virtual displays, into the output buffer).
-     *
-     * Prior to calling this function, the display must be successfully
-     * validated with validateDisplay. Note that setLayerBuffer and
-     * setLayerSurfaceDamage specifically do not count as layer state, so if
-     * there are no other changes to the layer state (or to the buffer's
-     * properties as described in setLayerBuffer), then it is safe to call
-     * this function without first validating the display.
-     *
-     * If this call succeeds, presentFence will be populated with a file
-     * descriptor referring to a present sync fence object. For physical
-     * displays, this fence will be signaled at the vsync when the result of
-     * composition of this frame starts to appear (for video-mode panels) or
-     * starts to transfer to panel memory (for command-mode panels). For
-     * virtual displays, this fence will be signaled when writes to the output
-     * buffer have completed and it is safe to read from it.
-     *
-     * @param display is the display to present.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         NO_RESOURCES when no valid output buffer has been set for a
-     *                      virtual display.
-     *         NOT_VALIDATED when validateDisplay has not successfully been
-     *                       called for this display.
-     * @return presentFence is a sync fence file descriptor as described
-     *         above.
-     */
-    presentDisplay(Display display)
-        generates (Error error,
-                   handle presentFence);
-
-    /*
-     * Sets the active configuration for this display. Upon returning, the
-     * given display configuration should be active and remain so until either
-     * this function is called again or the display is disconnected.
-     *
-     * @param display is the display to which the active config is set.
-     * @param config is the new display configuration.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_CONFIG when the configuration handle passed in is not valid
-     *                    for this display.
-     */
-    setActiveConfig(Display display, Config config) generates (Error error);
-
-    /*
-     * Sets the buffer handle which will receive the output of client
-     * composition.  Layers marked as Composition::CLIENT will be composited
-     * into this buffer prior to the call to presentDisplay, and layers not
-     * marked as Composition::CLIENT should be composited with this buffer by
-     * the device.
-     *
-     * The buffer handle provided may be empty if no layers are being
-     * composited by the client. This must not result in an error (unless an
-     * invalid display handle is also provided).
-     *
-     * Also provides a file descriptor referring to an acquire sync fence
-     * object, which will be signaled when it is safe to read from the client
-     * target buffer.  If it is already safe to read from this buffer, an
-     * empty handle may be passed instead.
-     *
-     * For more about dataspaces, see setLayerDataspace.
-     *
-     * The damage parameter describes a surface damage region as defined in
-     * the description of setLayerSurfaceDamage.
-     *
-     * Will be called before presentDisplay if any of the layers are marked as
-     * Composition::CLIENT. If no layers are so marked, then it is not
-     * necessary to call this function. It is not necessary to call
-     * validateDisplay after changing the target through this function.
-     *
-     * @param display is the display to which the client target is set.
-     * @param target is the new target buffer.
-     * @param acquireFence is a sync fence file descriptor as described above.
-     * @param dataspace is the dataspace of the buffer, as described in
-     *        setLayerDataspace.
-     * @param damage is the surface damage region.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when the new target handle was invalid.
-     */
-    setClientTarget(Display display,
-                    handle target,
-                    handle acquireFence,
-                    Dataspace dataspace,
-                    vec<Rect> damage)
-         generates (Error error);
-
-    /*
-     * Sets the color mode of the given display.
-     *
-     * Upon returning from this function, the color mode change must have
-     * fully taken effect.
-     *
-     * All devices must support at least ColorMode::NATIVE, and displays are
-     * assumed to be in this mode upon hotplug.
-     *
-     * @param display is the display to which the color mode is set.
-     * @param mode is the mode to set to.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when mode is not a valid color mode.
-     *         UNSUPPORTED when mode is not supported on this display.
-     */
-    setColorMode(Display display, ColorMode mode) generates (Error error);
-
-    /*
-     * Sets a color transform which will be applied after composition.
-     *
-     * If hint is not ColorTransform::ARBITRARY, then the device may use the
-     * hint to apply the desired color transform instead of using the color
-     * matrix directly.
-     *
-     * If the device is not capable of either using the hint or the matrix to
-     * apply the desired color transform, it should force all layers to client
-     * composition during validateDisplay.
-     *
-     * If Capability::SKIP_CLIENT_COLOR_TRANSFORM is present, then the client
-     * will never apply the color transform during client composition, even if
-     * all layers are being composed by the client.
-     *
-     * The matrix provided is an affine color transformation of the following
-     * form:
-     *
-     * |r.r r.g r.b 0|
-     * |g.r g.g g.b 0|
-     * |b.r b.g b.b 0|
-     * |Tr  Tg  Tb  1|
-     *
-     * This matrix will be provided in row-major form:
-     *
-     * {r.r, r.g, r.b, 0, g.r, ...}.
-     *
-     * Given a matrix of this form and an input color [R_in, G_in, B_in], the
-     * output color [R_out, G_out, B_out] will be:
-     *
-     * R_out = R_in * r.r + G_in * g.r + B_in * b.r + Tr
-     * G_out = R_in * r.g + G_in * g.g + B_in * b.g + Tg
-     * B_out = R_in * r.b + G_in * g.b + B_in * b.b + Tb
-     *
-     * @param display is the display to which the color transform is set.
-     * @param matrix is a 4x4 transform matrix (16 floats) as described above.
-     * @param hint is a hint value which may be used instead of the given
-     *        matrix unless it is ColorTransform::ARBITRARY.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when hint is not a valid color transform hint.
-     */
-    setColorTransform(Display display,
-                      vec<float> matrix,
-                      ColorTransform hint)
-           generates (Error error);
-
-    /*
-     * Sets the output buffer for a virtual display. That is, the buffer to
-     * which the composition result will be written.
-     *
-     * Also provides a file descriptor referring to a release sync fence
-     * object, which will be signaled when it is safe to write to the output
-     * buffer. If it is already safe to write to the output buffer, an empty
-     * handle may be passed instead.
-     *
-     * Must be called at least once before presentDisplay, but does not have
-     * any interaction with layer state or display validation.
-     *
-     * @param display is the virtual display to which the output buffer is
-     *        set.
-     * @param buffer is the new output buffer.
-     * @param releaseFence is a sync fence file descriptor as described above.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when the new output buffer handle was invalid.
-     *         UNSUPPORTED when display does not refer to a virtual display.
-     */
-    setOutputBuffer(Display display,
-                    handle buffer,
-                    handle releaseFence)
-         generates (Error error);
-
-    /*
-     * Sets the power mode of the given display. The transition must be
-     * complete when this function returns. It is valid to call this function
-     * multiple times with the same power mode.
-     *
-     * All displays must support PowerMode::ON and PowerMode::OFF.  Whether a
-     * display supports PowerMode::DOZE or PowerMode::DOZE_SUSPEND may be
-     * queried using getDozeSupport.
-     *
-     * @param display is the display to which the power mode is set.
-     * @param mode is the new power mode.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when mode was not a valid power mode.
-     *         UNSUPPORTED when mode is not supported on this display.
-     */
-    setPowerMode(Display display, PowerMode mode) generates (Error error);
-
-    /*
-     * Enables or disables the vsync signal for the given display. Virtual
-     * displays never generate vsync callbacks, and any attempt to enable
-     * vsync for a virtual display though this function must succeed and have
-     * no other effect.
-     *
-     * @param display is the display to which the vsync mode is set.
-     * @param enabled indicates whether to enable or disable vsync
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_PARAMETER when enabled was an invalid value.
-     */
-    setVsyncEnabled(Display display, Vsync enabled) generates (Error error);
-
-    /*
-     * Instructs the device to inspect all of the layer state and determine if
-     * there are any composition type changes necessary before presenting the
-     * display. Permitted changes are described in the definition of
-     * Composition above.
-     *
-     * Also returns the number of layer requests required by the given layer
-     * configuration.
-     *
-     * @param display is the display to validate.
-     * @return error is NONE or HAS_CHANGES upon success.
-     *         NONE when no changes are necessary and it is safe to present
-     *              the display using the current layer state.
-     *         HAS_CHANGES when composition type changes are needed.
-     *         Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     * @return numTypes is the number of composition type changes required by
-     *         the device; if greater than 0, the client must either set and
-     *         validate new types, or call acceptDisplayChanges to accept the
-     *         changes returned by getChangedCompositionTypes. It must be the
-     *         same as the number of changes returned by
-     *         getChangedCompositionTypes (see the declaration of that
-     *         function for more information).
-     * @return numRequests is the number of layer requests required by this
-     *         layer configuration. It must be equal to the number of layer
-     *         requests returned by getDisplayRequests (see the declaration of
-     *         that function for more information).
-     */
-    validateDisplay(Display display)
-         generates (Error error,
-                    uint32_t numTypes,
-                    uint32_t numRequests);
-
-    /*
-     * Layer Functions
-     *
-     * These are functions which operate on layers, but which do not modify
-     * state that must be validated before use. See also 'Layer State
-     * Functions' below.
-     */
-
-    /*
-     * Asynchronously sets the position of a cursor layer.
-     *
-     * Prior to validateDisplay, a layer may be marked as Composition::CURSOR.
-     * If validation succeeds (i.e., the device does not request a composition
-     * change for that layer), then once a buffer has been set for the layer
-     * and it has been presented, its position may be set by this function at
-     * any time between presentDisplay and any subsequent validateDisplay
-     * calls for this display.
-     *
-     * Once validateDisplay is called, this function will not be called again
-     * until the validate/present sequence is completed.
-     *
-     * May be called from any thread so long as it is not interleaved with the
-     * validate/present sequence as described above.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the position is set.
-     * @param x is the new x coordinate (in pixels from the left of the
-     *        screen).
-     * @param y is the new y coordinate (in pixels from the top of the
-     *        screen).
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when the layer is invalid or is not currently marked
-     *                   as Composition::CURSOR.
-     *         NOT_VALIDATED when the device is currently in the middle of the
-     *                       validate/present sequence.
-     */
-    setCursorPosition(Display display,
-                      Layer layer,
-                      int32_t x,
-                      int32_t y)
-           generates (Error error);
-
-    /*
-     * Sets the buffer handle to be displayed for this layer. If the buffer
-     * properties set at allocation time (width, height, format, and usage)
-     * have not changed since the previous frame, it is not necessary to call
-     * validateDisplay before calling presentDisplay unless new state needs to
-     * be validated in the interim.
-     *
-     * Also provides a file descriptor referring to an acquire sync fence
-     * object, which will be signaled when it is safe to read from the given
-     * buffer. If it is already safe to read from the buffer, an empty handle
-     * may be passed instead.
-     *
-     * This function must return NONE and have no other effect if called for a
-     * layer with a composition type of Composition::SOLID_COLOR (because it
-     * has no buffer) or Composition::SIDEBAND or Composition::CLIENT (because
-     * synchronization and buffer updates for these layers are handled
-     * elsewhere).
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the buffer is set.
-     * @param buffer is the buffer handle to set.
-     * @param acquireFence is a sync fence file descriptor as described above.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     *         BAD_PARAMETER when the buffer handle passed in was invalid.
-     */
-    setLayerBuffer(Display display,
-                   Layer layer,
-                   handle buffer,
-                   handle acquireFence)
-        generates (Error error);
-
-    /*
-     * Provides the region of the source buffer which has been modified since
-     * the last frame. This region does not need to be validated before
-     * calling presentDisplay.
-     *
-     * Once set through this function, the damage region remains the same
-     * until a subsequent call to this function.
-     *
-     * If damage is non-empty, then it may be assumed that any portion of the
-     * source buffer not covered by one of the rects has not been modified
-     * this frame. If damage is empty, then the whole source buffer must be
-     * treated as if it has been modified.
-     *
-     * If the layer's contents are not modified relative to the prior frame,
-     * damage will contain exactly one empty rect([0, 0, 0, 0]).
-     *
-     * The damage rects are relative to the pre-transformed buffer, and their
-     * origin is the top-left corner. They will not exceed the dimensions of
-     * the latched buffer.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the damage region is set.
-     * @param damage is the new surface damage region.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerSurfaceDamage(Display display,
-                          Layer layer,
-                          vec<Rect> damage)
-               generates (Error error);
-
-    /*
-     * Layer State Functions
-     *
-     * These functions modify the state of a given layer. They do not take
-     * effect until the display configuration is successfully validated with
-     * validateDisplay and the display contents are presented with
-     * presentDisplay.
-     */
-
-    /*
-     * Sets the blend mode of the given layer.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the blend mode is set.
-     * @param mode is the new blend mode.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     *         BAD_PARAMETER when an invalid blend mode was passed in.
-     */
-    setLayerBlendMode(Display display,
-                      Layer layer,
-                      BlendMode mode)
-           generates (Error error);
-
-    /*
-     * Sets the color of the given layer. If the composition type of the layer
-     * is not Composition::SOLID_COLOR, this call must succeed and have no
-     * other effect.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the blend mode is set.
-     * @param color is the new color.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerColor(Display display,
-                  Layer layer,
-                  Color color)
-       generates (Error error);
-
-    /*
-     * Sets the desired composition type of the given layer. During
-     * validateDisplay, the device may request changes to the composition
-     * types of any of the layers as described in the definition of
-     * Composition above.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the blend mode is set.
-     * @param type is the new composition type.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     *         BAD_PARAMETER when an invalid composition type was passed in.
-     *         UNSUPPORTED when a valid composition type was passed in, but it
-     *                     is not supported by this device.
-     */
-    setLayerCompositionType(Display display,
-                            Layer layer,
-                            Composition type)
-                 generates (Error error);
-
-    /*
-     * Sets the dataspace that the current buffer on this layer is in.
-     *
-     * The dataspace provides more information about how to interpret the
-     * buffer contents, such as the encoding standard and color transform.
-     *
-     * See the values of Dataspace for more information.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the dataspace is set.
-     * @param dataspace is the new dataspace.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerDataspace(Display display,
-                      Layer layer,
-                      Dataspace dataspace)
-           generates (Error error);
-
-    /*
-     * Sets the display frame (the portion of the display covered by a layer)
-     * of the given layer. This frame will not exceed the display dimensions.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the frame is set.
-     * @param frame is the new display frame.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerDisplayFrame(Display display,
-                         Layer layer,
-                         Rect frame)
-              generates (Error error);
-
-    /*
-     * Sets an alpha value (a floating point value in the range [0.0, 1.0])
-     * which will be applied to the whole layer. It can be conceptualized as a
-     * preprocessing step which applies the following function:
-     *   if (blendMode == BlendMode::PREMULTIPLIED)
-     *       out.rgb = in.rgb * planeAlpha
-     *   out.a = in.a * planeAlpha
-     *
-     * If the device does not support this operation on a layer which is
-     * marked Composition::DEVICE, it must request a composition type change
-     * to Composition::CLIENT upon the next validateDisplay call.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the plane alpha is set.
-     * @param alpha is the plane alpha value to apply.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerPlaneAlpha(Display display,
-                       Layer layer,
-                       float alpha)
-            generates (Error error);
-
-    /*
-     * Sets the sideband stream for this layer. If the composition type of the
-     * given layer is not Composition::SIDEBAND, this call must succeed and
-     * have no other effect.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the sideband stream is set.
-     * @param stream is the new sideband stream.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     *         BAD_PARAMETER when an invalid sideband stream was passed in.
-     */
-    setLayerSidebandStream(Display display,
-                           Layer layer,
-                           handle stream)
-                generates (Error error);
-
-    /*
-     * Sets the source crop (the portion of the source buffer which will fill
-     * the display frame) of the given layer. This crop rectangle will not
-     * exceed the dimensions of the latched buffer.
-     *
-     * If the device is not capable of supporting a true float source crop
-     * (i.e., it will truncate or round the floats to integers), it should set
-     * this layer to Composition::CLIENT when crop is non-integral for the
-     * most accurate rendering.
-     *
-     * If the device cannot support float source crops, but still wants to
-     * handle the layer, it should use the following code (or similar) to
-     * convert to an integer crop:
-     *   intCrop.left = (int) ceilf(crop.left);
-     *   intCrop.top = (int) ceilf(crop.top);
-     *   intCrop.right = (int) floorf(crop.right);
-     *   intCrop.bottom = (int) floorf(crop.bottom);
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the source crop is set.
-     * @param crop is the new source crop.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerSourceCrop(Display display,
-                       Layer layer,
-                       FRect crop)
-            generates (Error error);
-
-    /*
-     * Sets the transform (rotation/flip) of the given layer.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the transform is set.
-     * @param transform is the new transform.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     *         BAD_PARAMETER when an invalid transform was passed in.
-     */
-    setLayerTransform(Display display,
-                      Layer layer,
-                      Transform transform)
-           generates (Error error);
-
-    /*
-     * Specifies the portion of the layer that is visible, including portions
-     * under translucent areas of other layers. The region is in screen space,
-     * and will not exceed the dimensions of the screen.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the visible region is set.
-     * @param visible is the new visible region, in screen space.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerVisibleRegion(Display display,
-                          Layer layer,
-                          vec<Rect> visible)
-               generates (Error error);
-
-    /*
-     * Sets the desired Z order (height) of the given layer. A layer with a
-     * greater Z value occludes a layer with a lesser Z value.
-     *
-     * @param display is the display on which the layer was created.
-     * @param layer is the layer to which the Z order is set.
-     * @param z is the new Z order.
-     * @return error is NONE upon success. Otherwise,
-     *         BAD_DISPLAY when an invalid display handle was passed in.
-     *         BAD_LAYER when an invalid layer handle was passed in.
-     */
-    setLayerZOrder(Display display,
-                   Layer layer,
-                   uint32_t z)
-        generates (Error error);
+    createClient() generates (Error error, IComposerClient client);
 };