DispatchQueue

public extension DispatchQueue

  • Executes a block of code, associated with a unique token, only once.

    The code is thread safe and will only execute the block once even in the presence of multithreaded calls.

    Declaration

    Swift

    class func once(token: String = "\(#file).\(#function):\(#line)", block: @escaping @Sendable () -> Void)

    Parameters

    token

    A unique token as key for the block. Use a unique reverse DNS style name such as com.vectorform. or a string representation of a UUID. Defaults to a token created out of the file name, function name and the line number of the method’s call.
    block

    Block to execute once.