Ugly as hell workaround for UIWebView crashing on non-main thread dealloc (inside a UIView)

gistfile1.m

- (void)dealloc {
    webView_.delegate = nil; // delegate is self here, so first set to nil before call stopLoading.
    [webView_ stopLoading];
    
    // UIWebView must be released in the main thread, or we get:
    // Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
    // This is less evil than the proposed http://stackoverflow.com/questions/945082/uiwebview-in-multithread-viewcontroller
    // Calling removeFromSuperview in a dealloc is ugly and evil, but else UIView has a strong reference to UIWebView and our main-release call would be irrelevant.
    if (![NSThread isMainThread]) {
        [webView_ performSelectorOnMainThread:@selector(removeFromSuperview) withObject:nil waitUntilDone:YES];        
    }

    [webView_ performSelectorOnMainThread:@selector(release) withObject:nil waitUntilDone:YES];
    [super dealloc];
}

@NSElvis - if i call stopLoading first, couldn't this maybe lead to calling one of my delegate methods within the dealloc? (if the dealloc is on another thread and then context switches...)?

After @anlumo1 'es suggestion, performSelectorOnMainThread immediately calls release if already on main thread, when waitUntilDone is set to YES. (http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/nsobject_Class/Reference/Reference.html)

Still unsure about that removeFromSuperview.

Also - how would I solve this in ARC?

On ARC: maybe settings webView_ to nil in main thread will just work? Something like

dispatch_sync(dispatch_get_main_queue(), ^() {
        webView_ = nil;
    });

@insanehunter problem is that the block will hold a strong reference to it, so in the end webView will get deallocated in the thread the block was created. (i tried that at first)

Oh, that's really tricky then.

__block variables are not retained, so probably this code should work?

__block id this = self;
dispatch_sync(dispatch_get_main_queue(), ^() {
      this.webView_ = nil;
  });

Anyway, I should go and read on blocks and GCD.

__block will be retained under ARC - Apple changed this behavior. I could use __weak, but that's more overhead, and I'm not sure what other implications this might would have. (or __unsafe_unretained combined with a CFRetain/CFRelease? feels very hacky...)

Super thanks man.. You saved my a**..