objective-cmultithreadingwatchos-2nsthreadwkinterfacetable

EXC_BAD_ACCESS while [WKInterfaceTable setNumberOfRows:withRowType]

I wanna to update table from a background thread using this part of the code

 __block typeof(self.tableB) self_tableB = self.tableB;
    [lwc setBaseControllerCallback:^(int ndx) {
        __block typeof(ndx) ndx_t = ndx;
        [[NSOperationQueue mainQueue] addOperationWithBlock:^{
            [self_tableB setNumberOfRows: 0 withRowType:TABLEELEMENT];
            [self_tableB setNumberOfRows: ndx_t withRowType:TABLEELEMENT];
        }];

    }];

where

^(int ndx) {
//...
}

is a block called from background thread (NSThread) and lwc - is an instance of my custom background thread class.

To clear this method is called like with: //code inside thread if (handlerBase_inner) { handlerBase_inner(ndx++); }

So, at [self_tableB setNumberOfRows: ndx_t withRowType:TABLEELEMENT]; I can see EXC_BAD_ACCESS. Why? What is the

Solution

  • I worry about self_tableB. I'm not sure that you want a strong reference to it, artificially keeping it alive might cause it to have a dangling pointer back to its delegate.

    __block __weak typeof(self.tableB) self_tableB = self.tableB;

    Adding a weak annotation might to the trick.