Android CS architecture based on Asynchronous dual-screen modification record of android2.3

Reprinted please indicate the source of this article: http://www.cnblogs.com/xl19862005

Author: xandy

CS architecture for Android

Before that, it is necessary to clarify the concepts listed in table 1 in tables.

Isurface	Defines the basic surface interface for GUI system client (application) and server (surfaceflinger) Interaction
Bpsurface	An isurface derived class that provides an interface for the server to call the client function.
Bnsurface	Another derived class of isurface that provides interfaces for the client to call the server function. After the server receives a call request from the client (through bnsurface), such as registerbuffer and postbuffer, bnsuerface: ontransact is triggered.
Surface	(The private class of layerbaseclient) is the derived class of bnsurface.
Surfacebuffer	(Surfacebuffer's private class) is the derived class of surface.
Isurfacecomposer	Defines basic interfaces for client-to-server interaction
Bpsurfacecomposer	Is a derived class that provides an interface for the server to call the client function.
Bnsurfacecomposer	Is a derived class that provides the interface client to call the server function. Surfaceflinger class derived from bnsurfacecomposer
Surfacecomposerclient	Directly used by the client. The isurface (bnsurface), isurfacecomposer (bnsurfacecomposer), and isurfaceflingerclient interfaces are called to interact with the server.
Bclient	Derived from isurfaceflingerclient (bnsurfaceflingerclient), call the createsurface of the server to create a surface. Each surface corresponds to a layer.
Egldisplay	ID or handle displayed by the System
Eglsurface	System window or framebuffer handle
Eglconfig	EGL configuration of Surface
Eglcontext	OpenGL ES graphics up and down files
Nativedisplaytype	Native system display type
Nativewindowtype	Native System window cache type
Nativepixmaptype	Native system framebuffer
Egl_native_window_t	Defines a local window class. This class provides all the descriptions of the local window and all the methods used to operate the local window in EGL (OpenGL ES and the interface of the local GUI system ).

-Table 1-Surface Related Concepts

When designing Android, Google's Gui adopts the CS architecture. It can be understood that each newly created surface (the client side is the surface, which corresponds to the layer of the Service side one by one) is a client, the service end is mainly surfaceflinger, which will independently generate a libsurfaceflinger. so library, connect to it through the service name surfaceflinger on the client side, and then use IPC (binder) to set the content of the surface, for example, buffers, format, width, and height are sent to the service. Then, the content of the corresponding surface is calculated, cut, arranged, and output in the threadloop of surfaceflinger, it involves EGL (OpenGL ES) plotting and buffer management.

The CS architecture of the android GUI system 1 shows the correspondingProgramAs shown in process 2, this part of content is included in the frameworks package, where JNI serves as a bridge between the C and C ++ layers and the Java layer.

-Figure 1-CS architecture