What is SKSpinLockSync in Sprite Kit and how do I fix it

Question

I am receiving a bug report with the following stack trace and I have no idea what the problem is. I\'ve seen suggestions that this could be caused by having an emitter\'s

Answer 1

I had the same problem and I found that when I call

NSString *p = [[NSBundle mainBundle] pathForResource:name ofType:@"sks"];  
SKEmitterNode *e = [NSKeyedUnarchiver unarchiveObjectWithFile:p];  

many times, it will randomly crash the app with the same crash log

SKSpinLockSync(int*, void ()() block_pointer) + 36  
-[SKTexture loadImageData] + 252  
-[SKTexture size] + 44  
SKCEmitterSprite::update(double) + 2928  

I think this is Sprite Kit problem and hope Apple will fix this soon

My solution is : don't call unarchiveObjectWithFile everytime

unarchiveObjectWithFile may relate to IO and this may crash if you do that too often like every frame in your game, or the problem come from SKTexture cache system has problem when it need texture data and call loadImageData in non-thread safe.

So I reuse SKEmitterNode with copy, here is my function

// Emitter Pool
- (SKEmitterNode*)getEmitter:(NSString*)name {
    if(!mDictEmitter)
        self.mDictEmitter = [NSMutableDictionary new];
    SKEmitterNode *e = [mDictEmitter objectForKey:name];
    if(!e){
        NSString *p = [[NSBundle mainBundle] pathForResource:name ofType:@"sks"];
        e = [NSKeyedUnarchiver unarchiveObjectWithFile:p];
        [mDictEmitter setObject:e forKey:name];
    }
    return [e copy];
}