C Modules

We do write complex software, and like everyone doing so, we need a way to structure our source code. Our choice was to go modular. A module is a singleton that defines a feature or a set of related feature and exposes some APIs in order for other modules to access these features. Everything else, including the details of the implementation, is private. Examples of modules are the RPC layer, the threading library, the query engine of a database, the authentication engine, … Then, we can compose the various daemons of our application by including the corresponding modules and their dependencies.

Most modules maintain an internal state and as a consequence they have to be initialized and deinitialized at some point in the lifetime of the program. An internal rule at Intersec is to name the constructor {module}_initialize() and the destructor {module}_shutdown(). Once defined, these functions have to be called and this is where everything become complicated when your program has tens of modules with complex dependencies between them.

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