OpenSimulator Internals/Reading the Code

Overview

OpenSim is a .NET application. When reading the source, many calls are .NET runtime built-ins, not OpenSim code. Do not chase these into the framework -- they do what they say.

What to Skip

These namespaces are .NET runtime or third-party libraries. Treat them as black boxes.

Namespace / Library	Notes
System.Reflection (Assembly, MethodBase)	Runtime introspection -- finding the current executable, loading plugins dynamically
System.IO (Path, File, FileInfo, StreamReader)	File and path operations
System.Net (ServicePointManager, HttpWebRequest)	HTTP connection management
System.Security.Cryptography.X509Certificates	SSL certificate handling
System.Threading (Thread, Monitor)	Threading primitives
System.Environment	Process exit, environment variables
System.Console	Console output before the OpenSim console is initialised
log4net	Apache logging framework -- not Microsoft, not OpenSim
Nini	.ini file parser, third-party library

What to Follow

These namespaces are OpenSim code.

Namespace	Notes
OpenSim.Framework	Core data structures and interfaces
OpenSim.Framework.Console	OpenSim console infrastructure
OpenSim.Framework.Monitoring	Stats and monitoring
OpenSim.Framework.Servers	Server base classes
OpenSim.Framework.Servers.HttpServer	HTTP server and handler infrastructure
OpenSim.Server.Base	ServerUtils, plugin loading
OpenSim.Server.Handlers	ROBUST HTTP endpoint handlers
OpenSim.Services	Service implementations
OpenSim.Region.CoreModules	Simulator-side modules and connectors

ROBUST Startup Map

Execution entry point for ROBUST.exe:

OpenSimServer.cs
  -- entry point
  -- reads command line, loads connectors, starts HTTP server loop
  |
  HttpServerBase.cs
    -- HTTP server setup
    -- reads [Network] config (port, SSL)
    -- starts HttpServer listener
    |
    ServicesServerBase.cs
      -- config loading (.ini file chain)
      -- loads connector plugins from [ServiceList]
      -- main run loop
      -- clean shutdown handling

Key points:

Config is loaded as a chain: defaults → Robust.ini → any included files. Later files override earlier ones.
Connectors are loaded from [ServiceList] in Robust.ini. Each connector registers its HTTP handlers on startup.
The HTTP server is started before connectors are loaded -- handlers are registered into a running server.
SuppressConsoleCommands = true in [GridService] prevents duplicate console command registration when GridService is loaded both by ROBUST and by a simulator in the same process (standalone mode).

OpenSim.exe Startup Map

Execution entry point for OpenSim.exe (simulator):

OpenSim.cs
  -- entry point
  -- loads region modules, initialises scene
  |
  OpenSimBase.cs
    -- reads OpenSim.ini
    -- loads estate, region, and physics configuration
    -- starts HTTP server for simulator port (default 9000)
    |
    Scene.cs
      -- per-region object: avatars, objects, physics, scripting
      -- holds references to all service connectors via Scene.AssetService, Scene.GridService, etc.