exc_bad_access on [NSDate timeIntervalSinceReferenceDate]

问题

I'm getting weird behavior out of [NSDate timeIntervalSinceReferenceDate].

I have the following function:

-(void) insertRow{
NSTimeInterval timeNow = [NSDate timeIntervalSinceReferenceDate];
if (timeNow - secondsSinceTableViewScroll <0.5){
    [self insertRow];
    return;
}

NSIndexSet *indexSet = [NSIndexSet indexSetWithIndex:[self.itemsToFollow count] - 1];
[self.tableView insertSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];
}

which is a callback from an ASIHTTPRequest requestFinished.If I put a breakpoint in the code, it works fine. If I just try to run the code, I get an exc_bad_access on the line:

NSTimeInterval timeNow = [NSDate timeIntervalSinceReferenceDate];

secondsSinceTableViewScroll is an ivar declared in the header and set like this:

 secondsSinceTableViewScroll = [NSDate timeIntervalSinceReferenceDate];

Any ideas why I'm getting the exc_bad_access when there is no breakpoint?

Thanks

Only thing I could find

I was checking the time like this:

-(void) insertRow{
end = [NSDate timeIntervalSinceReferenceDate];
if(end-start < 0.05){
    [self insertRow];
    return;
}

NSIndexSet *indexSet = [NSIndexSet indexSetWithIndex:[self.itemsToFollow count] - 1];
[self.tableView insertSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];
}

I'm sure somewhere it says you can't have back to back calls of timeIntervalSinceReferenceDate and that's why it was crashing (this kind of recursive loop was a pretty bad idea anyways).

So use a while loop, or better yet an NSTimer.

Thanks for the help though

回答1:

Change

[self insertRow];

[self performSelector:@selector(insertRow) withObject:nil afterDelay:0];

回答2:

Your symptom suggests you're actually crashing on another thread. Do you have other threads running? Check the backtraces for all your threads. The above is on the main thread, correct?

EDIT: You're recursing too quickly and overflowing your stack. Half a second of "as fast as you can call yourself" is going to overflow your stack very quickly.

来源：https://stackoverflow.com/questions/7852865/exc-bad-access-on-nsdate-timeintervalsincereferencedate

标签

ios

nsdate

exc-bad-access