Seeker memory leak

General
1

We’re seeing the Seeker stay in memory when destroyed, not 100% sure why that is, but we’ve worked around the issue for now by using AstarPath.StartPath instead of seeker-per-object

Here’s code to reproduce the issue:

using System;
using System.Collections;
using Pathfinding;
using UnityEngine;
using Random = UnityEngine.Random;

public class Test : MonoBehaviour {
    public int TargetCount = 10000;
    public int PerSecond = 100;
    public int CurrentCount;

    public int CompletedCount;

    // Update is called once per frame
    void Update() {
        if (CurrentCount >= TargetCount) {
            return;
        }

        for (int i = 0; i < Mathf.CeilToInt(PerSecond * Time.deltaTime); i++) {
            StartCoroutine(Seek(i));
            CurrentCount++;
            if (CurrentCount == TargetCount) {
                break;
            }
        }
    }

    IEnumerator Seek(int i) {
        var go = new GameObject($"Seeker #{i}");
        var seeker = go.AddComponent<Seeker>();
        var modifier = go.AddComponent<RaycastModifier>();
        modifier.useRaycasting = false;
        modifier.useGraphRaycasting = true;

        bool done = false;

        void Callback(Path path) {
            seeker.pathCallback -= Callback;
            done = true;
        }

        seeker.pathCallback = Callback;
        // wait a frame to give everything time to call Start and such
        yield return null;
        // path to somewhere random
        var start = transform.position;
        var dest = start + new Vector3(Random.Range(-10.0f, 10.0f), 0, Random.Range(-10.0f, 10.0f));
        seeker.StartPath(start, dest);
        // and then wait for the path to be done
        while (!done) {
            yield return null;
        }

        yield return null;
        // destroy the seeker gameobject
        Destroy(go);
        CompletedCount++;
        if (CompletedCount == TargetCount) {
            yield return null;
            // for good measure, just run the gc here to prove we are in fact leaking and
            // not just waiting for gc to run
            GC.Collect();
            yield return null;
            for (int j = 0; j < 10; j++) {
                Debug.LogError("DONE!");
            }
        }
    }
}

When then taking a snapshot of the project via the memory profiler package you should see seekers and related objects hanging around: https://share.dl.je/2020/11/2020-11-06_12-24-20_6AOtHhNVbU.png

This was tested in a build, so it’s not just a unity editor quirk