Delete : how to be sure there is no memory leak?

Question

Here is my code, I wonder if the delete is good enough to destroy an object and that there is no memory leak :

class Shoot extends MovableObject{
constructor(){
    super();
    this.speed = 2;
    this.geometry = new THREE.CircleGeometry(0.5);
    this.material = new THREE.MeshBasicMaterial({ color: 0xffffff });
    this.mesh = new THREE.Mesh(this.geometry, this.material);
}

setRotation(rotation){
    this.mesh.rotation.set(rotation.x, rotation.y, rotation.z);
}

setPosition(position){
    this.mesh.position.set(position.x, position.y, position.z);
}

}

Later i've got this function, listShoot is the only place I have Shoot instances :

var position;
listShoot.forEach(function(shoot, i, list){
    position = shoot.getMesh().getWorldPosition();
    if(/*i want to destroy my shoot*/){
        list.splice(i, 1);
        scene.remove(shoot.getMesh()); // This is ThreeJS
        delete shoot;
        console.log("shoot destroyed");
    }
});

Although there is an answer here that has been accepted, there are extra things you may want to consider if you are using three.js. Search stack for something like "three.js delete object" — 2pha, Jun 09 '16 at 13:53

score 0 · Accepted Answer · edited May 23 '17 at 11:58

Although I can't give you a complete answer, I do know that you can't delete variables which are part of a closure.

var myfunc = function(a, b, c) {
  console.log(a,b,c);
  delete b;
  console.log(a,b,c);
}; 

myfunc(1,2,3);

The above code will output the following:

1 2 3
1 2 3

As for garbage collection in closures have a look at this related question.

You can always assign undefined to the variable.

var myfunc = function(a, b, c) {
  console.log(a,b,c);
  b = undefined;
  console.log(a,b,c);
}; 

myfunc(1,2,3);

Which outputs:

1 2 3
1 undefined 3

score 0 · Answer 2 · answered Jun 09 '16 at 10:23

0

I think you just should null the shoot variable, to lose the link. Like this:

shoot = null;
console.log("shoot destroyed");

answered Jun 09 '16 at 10:23

Telman

1,444
1
9
12

Delete : how to be sure there is no memory leak?

2 Answers2