CODEWITHSUNDEEP
initializationswiftgrand-central-dispatch
CouchDeveloper
CouchDeveloper

Reputation: 19116

Conundrum with init() and dispatch_sync

In a class, I have the following init() function:

init() {
    let q = 0
    dispatch_sync(queue) {
        self._state = State(q)
    }
}

where _state is an instance of a struct State and queue a global dispatch queue.

I'm using the dispatch_sync call in order to synchronize the potentially concurrently accessed instance of the class.

I'm running in some weird issue, that the compiler is complaining about using the _state variable before it´s being initialized (namely using it in the block, before it is being initialized):

main.swift:363:37: error: variable 'self._state' used before being initialized
    dispatch_sync(s_sync_queue) {
                                ^

However, the sole purpose of using the dispatch queue and the block is to initialize the ivar.

The compiler even states, the code would return without initializing the variable _state:

main.swift:372:5: error: property 'self._state' not initialized
}
^

albeit, clearly, due to dispatch_sync the function init cannot return without leaving the variable _state uninitialized.

So, how could I solve the issue in an efficient manner?

Upvotes: 0

Views: 202

Answers (1)

codester
codester

Reputation: 37189

One option is to declare _state as optional if you can.(If there is no harm to do that)

  var _state:State?

if you make this optional you can use it in dispatch_sync.

Upvotes: 1

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