mongoose/docs/design-concept/intro.md

title	items
Design Concept	type name file memory-buffers.md type name file event-handler.md type name file events.md type name file conn-flags.md

Mongoose is a multi-protocol networking library that implements non-blocking, asyncronous IO and provides event-based API. It has three basic data structures:

• struct mg_mgr is an event manager that holds all active connections
• struct mg_connection describes a connection
• struct mbuf describes data buffer (received or sent data)

Connections could be either listening, outbound or inbound. Outbound connections are created by mg_connect() call. Listening connections are created by mg_bind() call. Inbound connections are those accepted by a listening connection. Each connection is described by struct mg_connection structure, which has a number of fields like socket, event handler function, send/receive buffer, flags, et cetera.

Mongoose usage pattern is to declare and initialize event manager, create connections and create an event loop by calling mg_mgr_poll() in a loop. mg_mgr_poll() iterates over all sockets, accepts new connections, sends and receives data, closes connections, and calls event handler functions for the respective events.