Question

I am working on multithreaded code. Data access is locked in several sections via “NSLock” objects. I want to ensure that some methods which are called within these sections check if their appropriate lock was aquired.

Something like:

assert([myLock isSet] == YES);

I can’t find something like “isSet” in NSLock. Any ideas how to ensure a lock is set?

Thanks!

Answer 1

How are you acquiring the lock? If you’re calling lock, then the fact that you’re even running afterwards should guarantee you’ve acquired it. If you call lockBeforeDate, the return value tells you.

If you want to test from elsewhere, you could do

if ( [myLock tryLock] )
{
    // oops, lock was not previously acquired!
    ...
    [myLock unlock];
}
else
{
    // yep, lock was already acquired
}

However, in general this seems like a questionable thing to want to do. You should do the locking where it’s needed and trust it to work rather than trying to oversee it from the outside.