OpenSim.Region.ScriptEngine.DotNetEngine

DotNetEngine

Namespace: OpenSim.Region.ScriptEngine.DotNetEngine

DotNetEngine is a ScriptEngine that executes LSL scripts contained within objects.
Core development blog: [1]

To look at the LSL command implementation status, go to LSL Status.

How it works

• Create instance of ScriptEngine(scene).
  
• ScriptEngine will create instances of:
  

EventManager
EventQueueManager
ScriptManager
AppDomainManager
LSLLongCmdHandler

• EventManager will hook up all necessary events. (all possible script events, script rez, script derez, etc)
  
• When events are received, they are processed inside EventManager.
  

For example:
Event for loading a script will be processed and EventManager will tell ScriptManager to load the script.
Event such as touch_start is received in EventManager then sent to EventQueueManager that will tell SCriptManager to execute the touch_start function in the script.

Note! If event is for a particular object, EventQueueManager will queue event for all scripts inside that object.

• If it is a script rez then OpenSim.Region.ScriptEngine.DotNetEngine.Compiler.LSL will compile the script to .Net Assembly.
  
• This assembly is loaded into an AppDomain created by AppDomainManager.
  
• EventQueueManager has a separate thread running to process its event queue. Events are actually functions inside the script .dll that is called "<state>_event_<event_name>" for example "default_event_touch_start". State is read from a global variable in the script .dll.
  
• Some commands requires more time before returning, processing these is done in LSLLongCmdHandler.
  
• Every script receives a private instance of LSL_BuiltIn_Commands. This is their only way of manipulating anything outside themselves.
  

Places to extend script support

• LSL_BuiltIn_Commands.cs

These are the functions script can use to manipulate the scene. Commonly known as ll-functions. They are LSL functions such as llSay, llWhisper, etc. LSL Status contains up to date status on what functions have been implemented. Anyone who wants to contribute can implement a command and put a patch on the [http://www.opensimulator.org/mantis bug tracker}.

• EventManager.cs

This is where events are coming from server and being queued for scripts. All 16 or so LSL events needs to be implemented here.

This image is a bit (not much) outdated, but gives you an idea of the path script events/functions go through.