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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
.TH "PTHREAD_DETACH" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" pthread_detach
.SH NAME
pthread_detach \- detach a thread
.SH SYNOPSIS
.LP
\fB#include <pthread.h>
.br
.sp
int pthread_detach(pthread_t\fP \fIthread\fP\fB); \fP
\fB
.br
\fP
.SH DESCRIPTION
.LP
The \fIpthread_detach\fP() function shall indicate to the implementation
that storage for the thread \fIthread\fP can be
reclaimed when that thread terminates. If \fIthread\fP has not terminated,
\fIpthread_detach\fP() shall not cause it to
terminate. The effect of multiple \fIpthread_detach\fP() calls on
the same target thread is unspecified.
.SH RETURN VALUE
.LP
If the call succeeds, \fIpthread_detach\fP() shall return 0; otherwise,
an error number shall be returned to indicate the
error.
.SH ERRORS
.LP
The \fIpthread_detach\fP() function shall fail if:
.TP 7
.B EINVAL
The implementation has detected that the value specified by \fIthread\fP
does not refer to a joinable thread.
.TP 7
.B ESRCH
No thread could be found corresponding to that specified by the given
thread ID.
.sp
.LP
The \fIpthread_detach\fP() function shall not return an error code
of [EINTR].
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
None.
.SH RATIONALE
.LP
The \fIpthread_join\fP() or \fIpthread_detach\fP() functions should
eventually be
called for every thread that is created so that storage associated
with the thread may be reclaimed.
.LP
It has been suggested that a "detach" function is not necessary; the
\fIdetachstate\fP thread creation attribute is
sufficient, since a thread need never be dynamically detached. However,
need arises in at least two cases:
.IP " 1." 4
In a cancellation handler for a \fIpthread_join\fP() it is nearly
essential to
have a \fIpthread_detach\fP() function in order to detach the thread
on which \fIpthread_join\fP() was waiting. Without it, it would be
necessary to have the handler do
another \fIpthread_join\fP() to attempt to detach the thread, which
would both delay
the cancellation processing for an unbounded period and introduce
a new call to \fIpthread_join\fP(), which might itself need a cancellation
handler. A dynamic detach is
nearly essential in this case.
.LP
.IP " 2." 4
In order to detach the "initial thread" (as may be desirable in processes
that set up server threads).
.LP
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIpthread_join\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
\fI<pthread.h>\fP
.SH 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 .
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