Lesson 61 +10 XP

C# Job System & Burst Compiler

To maximize game performance, Unity provides the Data-Oriented Technology Stack (DOTS), which includes the C# Job System and the Burst Compiler.

C# Job System

Normally, Unity scripts run on a single thread (the main thread). The C# Job System allows you to write safe, multithreaded code that takes advantage of multi-core CPUs.

It prevents race conditions (two threads writing to the same memory at once) through safety checks.
Jobs only work with value types (structs and native containers, not class references).

IJobParallelFor is a common job interface used to compute math over large arrays of data:

using Unity.Jobs;
using Unity.Collections;

public struct MovementJob : IJobParallelFor
{
    public NativeArray<Vector3> positions;
    public NativeArray<Vector3> velocities;
    public float deltaTime;

    public void Execute(int index)
    {
        positions[index] += velocities[index] * deltaTime;
    }
}

The Burst Compiler

The Burst Compiler is a highly optimized compiler technology that translates C# job code into optimized machine code.

It uses LLVM to optimize instructions for target platforms.
Simply add the [BurstCompile] attribute above your job struct to enable it, resulting in massive speed gains.

TL;DR

C# Job System compiles multithreaded operations safely.
Jobs work only with value types and native collections (like NativeArray).
The Burst Compiler uses LLVM to optimize job code for specific CPU architectures.
Add [BurstCompile] to job structs to enable compiler optimization.

C# Job System & Burst Compiler