How can I optimize Lua.IsTrue() on Update()?

[vcesauron]

Disclaimer: I am still a beginner at profiling code, so pardon me if I say anything stupid xD

Our game is suffering from intermittent freezes every other couple of seconds. After taking a look at the CPU Profiler and the Call Stack, blocks of GC.Alloc() and GC.Collect() caused by Lua.IsTrue(string) seem like the "culprit".

Screenshots

gc1.png (114.55 KiB) Viewed 394 times

gc2.png (194.01 KiB) Viewed 394 times

gc3.png (278.19 KiB) Viewed 394 times

The game relies on checking for many Lua conditions several times per frame, and the way I do it currently is calling Lua.IsTrue(condition) every time I need to check the value of condition.

I created some sort of manager to limit the number of calls to this function per frame since many of those aren't frame-critic, and I did reduce the number of calls per frame from +20 to 5 (a value chosen by me), but it still keeps causing freezes.

How can I keep checking for Lua conditions while avoiding the freezes?

[Tony Li]

Hi,

Avoid checking Lua.IsTrue() continually on Update().

If you're checking Lua.IsTrue() on Update(), you're using polling. It's much more efficient to make your code event-driven.

For example, if you want to know when a variable "X" exceeds 10, write a C# method IncrementX(), like:

Code: Select all

public void IncrementX()
{
    int x = DialogueLua.GetVariable("X").asInt;
    x++;
    DialogueLua.SetVariable("X", x);
    if (x >= 10)
    {
        // Invoke some event here
    }
}

You can call that method in a C# script or in Lua (e.g., in a conversation node's Script field) by registering it with Lua.

For another example of event-driven checking, examine the "Shoot 5 Enemies" quest in DemoScene2. The Enemies' IncrementOnDestroy components increment a variable and then invoke an OnIncrement() UnityEvent. The scene only checks if the variable is >= 5 in this OnIncrement() event. It doesn't check every frame.

If that's not possible, switch the Dialogue System to use NLua.

[vcesauron]

I'm gonna try the event-driven approach first.
Because I'm using booleans, most of the checks are Variable["X"] == true, but I'll try to apply the same logic.

If it doesn't work, I'll try NLua.

Thanks for the quick response!

[Tony Li]

Glad to help!