Question

I want to write a C++ program that plays MP3. Among available MP3 decoding libraries, I chose mpg123.

I noticed that, besides being able to link against libmpg123 and make the necessary function calls in my code, the library includes a back-end/front-end interface that enables me to communicate with it’s executable, and thus not having to include it’s code in my program.

What are the advantages of writing a front-end rather than simply linking against the library?

Answer 1

Most of the advantages comes from process separation between your executable and the library executable:

• Increased safety & security: if the library is crashing, this will not crash your application.
• Implicit multi-processing: since both are running on separate processes, this is almost for free.
• Predisposition to networking: if communication between processes is done with pipes or stdin/stdout, you can easily forward them to sockets and run your executable on a separate machine.
• Language neutral: you can use whatever programming language you want.

Of course, there is a performance penalty by using an external communication channel. But the benefits of having such decoupling can be quite impressive.