GetThread is a virtual abstract
TIdThread function that requests a new thread for the thread manager. GetThread is not implemented in
TIdThreadMgr. Descendants of
TIdThreadMgr must implement GetThread to satisfy the requirements for the specific thread manager. GetThread can get a thread instance using
CreateNewThread, re-use a thread from a thread pool, or use another thread creation scheme provided in the
TIdThreadMgr descendant.
GetThread should use the critical section Lock, or other mechanism, to protect the ActiveThreads list while adding the new thread instance.
A thread instance can be freed using ReleaseThread. ReleaseThread is used in TerminateThreads.