program crashes when removing shapes in spacemanager - cocos2d

i am using spacemanager with chipmunk physics for my game. What i am trying to do is hit a ball to a pillar and make the ball disappear. i am recreating the ball in different location so the user can hit another pillar. i have the ball shape and ball sprite as member variable.

Here is the code for creating ball, pillar shapes etc.

   ball = [smgr addCircleAt:cpv(1000,10) mass:0.5 radius:35];
ball->collision_type = kBallCollisionType;

ballSprite = [cpCCSprite spriteWithShape:ball file:@"head.png"];
//[ballSprite autoFreeShape];
[self addChild:ballSprite];
ballSprite.spaceManager = smgr;
//ballSprite.ignoreRotation = NO;

cpShape *dome = [smgr addRectAt:cpv(400,500) mass:1 width:400 height:100 rotation:0];
dome->collision_type = kRectCollisionType;
cpCCSprite *dome1 = [cpCCSprite spriteWithShape:dome file:@"001.png"];
[self addChild:dome1];
dome1.spaceManager = smgr;

cpShape *pillarone = [smgr addRectAt:cpv(300,300) mass:1 width:45 height:194 rotation:0开发者_JS百科];
pillarone->collision_type = kRectCollisionType;
cpCCSprite *pillar1 = [cpCCSprite spriteWithShape:pillarone file:@"004.png"];
[self addChild:pillar1];

pillar1.spaceManager = smgr;

cpShape *pillartwo = [smgr addRectAt:cpv(500,300) mass:1 width:45 height:194 rotation:0];
pillartwo->collision_type = kRectCollisionType;
cpCCSprite *pillar2 = [cpCCSprite spriteWithShape:pillartwo file:@"004.png"];
[self addChild:pillar2];

pillar2.spaceManager = smgr;


cpShape *staticground = [smgr addRectAt:cpv(510,25) mass:1 width:0 height:0 rotation:0];
cpCCSprite *staticground1 = [cpCCSprite spriteWithShape:staticground file:@"grass1-1024.png"];
[self addChild:staticground1 z:1 tag:0];


[smgr addCollisionCallbackBetweenType:kRectCollisionType 
                            otherType:kBallCollisionType 
                               target:self 
                             selector:@selector(handleCollisionWithFragmentingRect:arbiter:space:)];

AND HERE IS THE CODE FOR COLLISION HANDLING.

- (void) handleCollisionWithFragmentingRect:(CollisionMoment)moment arbiter:(cpArbiter*)arb space:(cpSpace*)space{  
if (moment == COLLISION_POSTSOLVE)
{
    [self removeChild:ball->data cleanup:YES];
    [smgr removeAndFreeShape:ball];

    ball = [smgr addCircleAt:cpv(1000,10) mass:0.5 radius:35];
    ball->collision_type = kBallCollisionType;
    ballSprite = [cpCCSprite spriteWithShape:ball file:@"head.png"];
    [self addChild:ballSprite];
    ballSprite.spaceManager = smgr;
}

}

When the first ball hits the pillar it disappears fine. but for the second and some times third ball i pick and hit the pillar it crashes with error as follows.

Chipmunk warning: Cannot remove a constraint that was not added to the space. (Removed twice maybe?)
Failed condition: cpArrayContains(space->constraints, constraint)

i am not sure where i went wrong, can anyone help please.

Thanks.

I think you need to add teh ball to be removed to a "garbage" array, and not remove it on the handleCollisionWithFragmentingRect function. For all safety measures, include the

- (void) update : (ccTime) dt
{
    for (cpShape *shape in _garbage)
    {
        // Remove shape
        [self removeChild:shape->data cleanup:YES];
        [smgr removeAndFreeShape:shape];

        // Add new ball
        ball = [smgr addCircleAt:cpv(1000,10) mass:0.5 radius:35];
        ball->collision_type = kBallCollisionType;
        ballSprite = [cpCCSprite spriteWithShape:ball file:@"head.png"];
        [self addChild:ballSprite];
        ballSprite.spaceManager = smgr;
    }
    ...

}

And then you would change the handle function to this:

- (void) handleCollisionWithFragmentingRect:(CollisionMoment)moment arbiter:(cpArbiter*)arb space:(cpSpace*)space
{  
    if (moment == COLLISION_POSTSOLVE)
    {
        // SHOULDNT BE A DIRECT REFERENCE TO MEMBER VARIABLE BALL. 
        // SHOULD BE ADDED FROM INFORMATION WITHIN THE PARAMETERS OF THIS FUNCTION.
        _garbage.addObject(ball);
    }
}