Plugin Profiler

This plugin adds lua profiling functionality to DCSServerBot.

You can choose from two different profilers:

Chrome
Callgrind

Both profilers have pros and cons. Please refer to the respective documentation of these profilers.

[!WARNING] Profiling can be extremely heavy and will most likely slow down your DCS World server.
Please do not use it in production or only for a short period of time!

Configuration

As Profiler is an optional plugin, you need to activate it in main.yaml first like so:

opt_plugins:
  - profiler

The plugin itself is configured with a file named config/plugins/profiler.yaml. You’ll find a sample in ./samples:

DCS.dcsserver_release:
  profiler: chrome        # one of chrome, callgrind
  attach_on_launch: true  # attach the profiler on mission launch (default: true)
  verbose: true           # Enable verbose profiling (default: false). This will slow down even more! 

If the profiler is not attached on mission launch, you can attach the profiler manually with the below-mentioned Discord commands.

[!NOTE] If the profiler is attached on mission start, it only profiles lua calls and does not call a GC before capturing the heap size. If the profiler is attached manually, lua and C calls will be captured and a GC will be called before the heap size is captured. Attaching the profiler manually is much more expensive than doing it for the whole mission, but you get much better information out of it. Also, the file sizes will vary dramatically.

Discord Commands

Evaluating Results

Chrome Profiler

The chrome profiler generates a file “profile.json” in your Saved Games<instance>\Logs directory. You can load this file either into the Chrome DevTools (CTRL+SHIFT+I in your Chrome browser) Performance tab, or you can use other third-party tools to analyze the trace. Two options are Perfetto UI or speedscope.

Callgrind

Callgrind generates a file named callgrind.out. You can load this file into Valgrind or (K)Cachegrind. Both tools are Linux tools, which means that you either need a Linux (virtual) system at hand or you can use WSL to install the respective tool.

[!IMPORTANT] This plugin is experimental and may yield misleading or incorrect results. I have made a lot of efforts to refine it, but further adjustments and possibly significant modifications are required for accurate outcomes. It’s also possible that this approach won’t be compatible with DCS World due to inherent limitations within the software itself.