PTHREAD_DETACH(P) POSIX Programmer's Manual PTHREAD_DETACH(P)
pthread_detach - detach a thread
int pthread_detach(pthread_t thread);
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.
If the call succeeds, pthread_detach() shall return 0; otherwise, an error number shall be
returned to indicate the error.
The pthread_detach() function shall fail if:
EINVAL The implementation has detected that the value specified by thread does not refer
to a joinable thread.
ESRCH No thread could be found corresponding to that specified by the given thread ID.
The pthread_detach() function shall not return an error code of [EINTR].
The following sections are informative.
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. How-
ever, need arises in at least two cases:
1. 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 cancella-
tion 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.
2. In order to detach the "initial thread" (as may be desirable in processes that set up
pthread_join() , the Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h>
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 PTHREAD_DETACH(P)