Break on EXC_BAD_ACCESS in XCode?
- by jasonh
I'm new to iPhone development and XCode in general and have no idea how to begin troubleshooting an EXC_BAD_ACCESS signal. How can I get XCode to break at the exact line that is causing the error?
I can't seem to get XCode to stop on the line causing the problem, but I do see the following lines in my debug console:
Sun Oct 25 15:12:14 jasonsmacbook
TestProject[1289] :
CGContextSetStrokeColorWithColor:
invalid context
Sun Oct 25 15:12:14 jasonsmacbook
TestProject[1289] :
CGContextSetLineWidth: invalid context
Sun Oct 25 15:12:14 jasonsmacbook
TestProject[1289] :
CGContextAddPath: invalid context
Sun Oct 25 15:12:14 jasonsmacbook
TestProject[1289] :
CGContextDrawPath: invalid context
2009-10-25 15:12:14.680
LanderTest[1289:207] *** -[CFArray
objectAtIndex:]: message sent to
deallocated instance 0x3c4e610
Now, I am attempting to draw to the context I retrieve from UIGraphicsGetCurrentContext() and pass to the object that I want to draw with.
Further trial and error debugging and I found that an NSMutableArray I have a property for on my class was a zombie. I went into the init function for the class and here's the code I was using:
if ((self = [super init])) {
NSMutableArray *array = [NSMutableArray array];
self.terrainBlocks = array;
[array release];
}
return self;
}
I removed the [array release] line and it no longer gives me the EXC_BAD_ACCESS signal, but I'm now confused about why this works. I thought that when I used the property, it automatically retained it for me, and thus I should release it from within init so that I don't have a leak. I'm thoroughly confused about how this works and all the guides and Stackoverflow questions I've read only confuse me more about how to set properties within my init method. There seems to be no consensus as to which way is the best.
