ios - raywenderlich tutorial - simple iphone game - part2 -

I'm using the other part, and I'm confused about the implementation of the ccTouchesEnded method This is where 'shooting' is applied: player (a cannon) changes in the touched direction, and the projectile shot happens. The part which is ambiguous to me is: _nextProjectile is being released, while it may still be in use (below the code - _nextProjectile runAction ). Can you please tell why is it safe to release the object at this point?

  - (zero) CCTE attracted: (NSSET *) touches the event: (UEVENT *) Event {[_player runAction: [CCSequence Actions: [CCRotateTo actionWithDuration: rotateDuration angle: cocosAngle], [ CCCallBlock ActionWishblock: ^ {// OK to add now - Rotation is finished! [Self combine: _nextProjectile]; [_projectiles addObject: _nextProjectile]; Release [_nextProjectile release]; _nextProjectile = Zero; }], Zero]]; // Proseclose at the actual endpoint [_nextProjectile runAction: [CCSequence actions: [CCMoveTo proceedings: realMoveDuration status: realDest], [CCCallBlockN operationWishblock: ^ (CCNode * node) {[_projectiles removal object: node]; [Node removal head and chinup: yes]; }], Zero]]; }    
 
 
 before  ccTouchesEnded: withEvent:  you increase Keep the number of  _nextProjectile  on this line:  
  _nextProjectile = [[CCSprite spriteWithFile: @ "projectile2.png"];];   
 Then at some point you have to reduce the calculation to keep the memory leak to stop. In other words: You are responsible for continuing it. This is where this line is coming:  
  [_ nextProjectile release];   
 Why is it safe to issue it at that time? The code snippets in your question are actions in the sequence of both verbs.  
  [_ player runAction: [CCSequence actions: ...]];   
 Performing an action on an object increases the number of keep on that object. This means that the action takes up the object itself and another reference to  _nextProjectile  is that the order of verbs is executed before the action is actually executed, so the action object is already made to  _nextProjectile < / Strong> therefore it is actually safe to release it in any one verb. They were waiting for issuing  _nextProjectile  until these lines were passed:  
  [self addChild: _nextProjectile]; [_projectiles addObject: _nextProjectile];   
 A release before these lines probably (I have not seen any other code from  ccTouchesEnded: withEvent: ) resulted in an EXC_BAD_ACCESS runtime error.  
 Here's some more information about maintaining: