Cocos2d App is Freezing

I'm creating a game app using cocos2d Chipmunk. The app is working normally but after 30 to 40 seconds the app become开发者_开发技巧s unresponsive(app freezes) without any error log. Can any tell me why this is happening and how to overcome this problem. Please tell me the code also.

Thanks in advance..

i got the solution. i was using timers but was not unscheduling them that's why app was freezing. now it is working fine after unscheduling that timers.