Normal multithreaded applications should not need the predicates from this section because almost any usage of these predicates is unsafe. For example checking the existence of a thread before signalling it is of no use as it may vanish between the two calls. Catching exceptions using catch/3 is the only safe way to deal with thread-existence errors.
These predicates are provided for diagnosis and monitoring tasks. See also section 8.5, describing more high-level primitives.
See also thread_statistics/3 to obtain resource usage information and message_queue_property/2 to get the number of queued messages for a thread.