Android Binder Framework

In the Linux OS, there are several techniques to achieve IPC (Inter-process communication) like files, sockets, signals, pipes, message queues, semaphores, shared memory, etc. However, Android’s modified Linux kernel comes with a binder framework which enables an RPC (remote procedure call) mechanism between the client and server processes, where the client process can execute remote methods in the server process as if they were executed locally. So data can be passed to the remote method calls and results can be returned to the client calling thread. It appears as if the thread from the client process jumps into another (remote) process and starts executing in there (known as Thread Migration).

What is Binder?

An IPC/component system for developing object-oriented OS services

• A kernel driver to facilitate inter-process communication.
• Lightweight RPC (Remote Procedure Communication) mechanism.
• Per-process thread pool for processing requests.
• Synchronous communication b/w processes
• Not yet another object-oriented kernel.
• Instead, an object-oriented operating system environment that works on traditional kernels, like Linux!
• Essential to Android!
• Comes from OpenBinder:-