NAME
pthread_detach - detach a thread
SYNOPSIS
#include <pthread.h>
int pthread_detach(pthread_t thread);
DESCRIPTION
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.
RETURN VALUE
If the call succeeds, pthread_detach() shall return 0; otherwise, an
error number shall be returned to indicate the error.
ERRORS
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.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
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 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
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.
2. In order to detach the "initial thread" (as may be desirable in
processes that set up server threads).
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_join() , the Base Definitions volume of IEEE Std 1003.1-2001,
<pthread.h>
COPYRIGHT
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 .