iphone - Crash with CALayer, memory problem -

my hotpaw2 solution incremental drawing problem. alas, discovered issue solution implemented it. reveals memory-induced crash when press botton @ bottom of iphone suspend app , restart it. (i can run app indefinitely long don't this). crash occurs @ indicated line below, occurs in foobar, subclass of uiview:

- (void)drawrect:(cgrect)rect { cgcontextref ctx = uigraphicsgetcurrentcontext();  // @@crash here: program received signal exc_bad_access  [backinglayer renderincontext:ctx];     // render backing layer current context [self randomrectangle: ctx];  } 

in interface of foobar have declared backing layer instance variable:

@private  nstimer* timer; calayer *backinglayer; 

in implementation of foobar, backinglayer occurs once more, in initwithframe, in following paragraph:

    backinglayer = self.layer;      // [backinglayer retain];     // set color space , background color     cgcolorspaceref colorspace = cgcolorspacecreatedevicergb();     cgfloat components[4] = {0.0f, 0.0f, 0.0f, 1.0f};     cgcolorref bgcolor = cgcolorcreate(colorspace, components);     backinglayer.backgroundcolor = bgcolor;     cgcolorrelease(bgcolor);     cgcolorspacerelease(colorspace); 

i should there nstimer timer defined in initwithframe fires off tick method below 12 times second:

- (void)tick {     // tell view needs re-draw      if (running) {  // go!        //  nslog(@"framerate: %2.1f, framecount: %d", framerate, framecount);         [self setneedsdisplay];         framecount++;     }  } 

i've run instruments on app. no memory leaks detected. when run allocations , (a) suspend app physical button, (b) touch app icon make run again, see huge cluster of allocations (~2 gb) --- , crash.

-- jim

see last comment, should have put here. fixed setting bool running false when app enters inactive state, resetting true when becomes active once again.