Ada Programming/Attributes/'Callable
Description edit
X'Callable is an Ada attribute where X is any task object. If the task is completed or has been terminated, this attribute is false. Otherwise, this attribute is true (i.e. the task is callable).
Be warned - calling X'Callable can result in a race condition. X'Callable may be true at the time the attribute value is read, but it may become false at the time action is taken based on the value read. Once X'Callable is false, however, it can be expected to stay false.