DispatchQueue

class DispatchQueue : DispatchObject
  • once(token:block:)

    Executes a block of code, associated with a unique token, only once. The code is thread safe and will only execute the code once even in the presence of multithreaded calls.

    Declaration

    Swift

    public class func once(token: String, block: () -> Void)
    Parameters
    token

    A unique name.
    block

    Block to execute once.