Analysis of architecture design of Android operating system

This article mainly introduces the Android operating system architecture design analysis, the Android system architecture is divided into Linux kernel driver, c/C + + framework, Java framework, Java application, this article explains its role, the need for friends can refer to the

have been working on the Android application layer, and have recently begun to study the Android platform, mainly in the Android frameworks layer and the system library layer. Here is my own understanding, comprehension, and hope to share with you.

The Android system architecture is divided into Linux kernel drivers, c/C + + frameworks, Java frameworks, Java applications.

Android Application layer:

The Android application requires Java framework support. Mainly for mobile phone users. The Android application layer is written by Java code and runs in a virtual machine. Virtual machines play a very important role in the Android platform. Virtual machines in the process of executing Java classes, if the Java class needs to communicate with the C/COM + + component, the virtual opportunity loads the C + + component, and then lets the Java function make a smooth call to a function of the C + + component. Java and C/A + + can communicate with each other through a standard JNI interface.

Note: Java classes are run on a virtual machine, and C + + is not performed on a virtual machine. So how do you load C + + component functions?

The answer is: through System.loadlibrary (*.so file name); The entry function is Jni_onload ();

Frameworks Framework layer (Application framework layer):

The Java framework is packaged as a JNI by the C/s + + library. Referred to as Java Native Interface, the Java local interface. A bridge between the application layer and the System library layer. Mainly for mobile phone developers.

C + + framework (System library):

Implement Java framework functionality. The native method in the Java framework is done by C/s + +.

Android driver Bottom (kernel layer):

Finally, drive the hardware completion function.

The system architecture diagram is as follows: