The pthread_detach() function shall indicate to the implementation that
storage for the thread thread can be reclaimed when that thread
terminates. If thread has not terminated, pthread_detach() shall
not cause it to terminate. The effect of multiple pthread_detach()
calls on the same target thread is unspecified.
The pthread_join() or pthread_detach() functions should eventually
be called for every thread that is created so that storage associated with the
thread may be reclaimed.
It has been suggested that a "detach" function is not necessary; the
detachstate thread creation attribute is sufficient, since a thread
need never be dynamically detached. However, need arises in at least two
In a cancellation handler for a pthread_join() it is
nearly essential to have a pthread_detach() function in order to
detach the thread on which pthread_join() was waiting. Without it,
it would be necessary to have the handler do another pthread_join()
to attempt to detach the thread, which would both delay the cancellation
processing for an unbounded period and introduce a new call to
pthread_join(), which might itself need a cancellation handler. A
dynamic detach is nearly essential in this case.
In order to detach the "initial thread" (as may
be desirable in processes that set up server threads).
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html