The journal
149 articles on building software and understanding how it works.
Some LL commands, like llSetTimerEvent and llHTTPRequest, don't return immediately — they come back later as events. LSLLongCmdHandler is a new class with a dedicated thread that keeps track of these long-running requests.
Script events now execute multithreaded — one object at a time, so multicore CPUs finally get used — plus cached event binding to avoid reflection on every call.
.NET cannot unload an assembly, only a whole AppDomain — so scripts get an AppDomainManager that pools scripts into domains and recycles domains as scripts die.
Proof in pixels: a screenshot of llSay() running for real.
Charles Krinkle contributed the interface and empty prototypes for all the LL builtin functions, so the compiler can now be tested against all kinds of scripts without erroring out. Thanks dude!
ScriptEngine is now implemented in OpenSim: a default script in every object, a touch_start event, and llSay writing to the server console. Now the 350+ builtin ll-functions can be implemented and tested in-world.
Quick status: the LSL-to-C# translator is close to complete, the compiler and script manager work, and what remains is the builtin commands and events.
Want to help with OpenSim scripting? LSL_BaseClass.cs contains a pile of empty llFunctions that all need implementing — here is how to get started.
Instead of compiling LSL directly, I first translate it to C# — simpler for other OpenSim developers to contribute to, and the same translator can double as a learning tool for people moving from LSL to C#. Written in less than a day with regex and a couple of passes.
After a meeting with Babbage Linden it is clear compilation moves to the server, and the LSO bytecode path goes away. So I'm changing course: a server-side LSL compiler working from the script text instead.
The full event pipeline works end to end: pressing a button in the test app sends an event through the ScriptEngine, into the queue, and out to the correct compiled script. Screenshot included.
The plan for the first simple version of script support: a simplified event queue with a custom threadpool, one shared AppDomain, and a basic LSL compiler that others can extend while I keep working on the core.
Builtin commands are easy — incoming events need planning. An EventHandler translates OpenSim happenings into LSL-compatible events, and an Event Queue Manager executes them on a separate thread so the server never blocks.
The architecture for OpenSim script support: a dynamically loaded ScriptEngine assembly that hooks the server's events, a compiler that turns LSL into .NET assemblies, and the loading pipeline between them.
Static and global variables, push/pop and simple scripts with math and llSay now work, and the internal state is ready for serializing so a running script can be moved between servers. Next up: local variables, custom functions, states and jumps.