man3/pthread_detach.3

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.TH PTHREAD_DETACH 3 2017-09-15 "Linux" "Linux Programmer's Manual"
.SH NAME
pthread_detach \- detach a thread
.SH SYNOPSIS
.nf
.B #include <pthread.h>
.PP
.BI "int pthread_detach(pthread_t " thread );
.fi
.PP
Compile and link with \fI\-pthread\fP.
.SH DESCRIPTION
The
.BR pthread_detach ()
function marks the thread identified by
.IR thread
as detached.
When a detached thread terminates,
its resources are automatically released back to the system without
the need for another thread to join with the terminated thread.
.PP
Attempting to detach an already detached thread results
in unspecified behavior.
.SH RETURN VALUE
On success,
.BR pthread_detach ()
returns 0;
on error, it returns an error number.
.SH ERRORS
.TP
.B EINVAL
.I thread
is not a joinable thread.
.TP
.B ESRCH
No thread with the ID
.I thread
could be found.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR pthread_detach ()
T}	Thread safety	MT-Safe
.TE
.sp 1
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
.SH NOTES
Once a thread has been detached, it can't be joined with
.BR pthread_join (3)
or be made joinable again.
.PP
A new thread can be created in a detached state using
.BR pthread_attr_setdetachstate (3)
to set the detached attribute of the
.I attr
argument of
.BR pthread_create (3).
.PP
The detached attribute merely determines the behavior of the system
when the thread terminates;
it does not prevent the thread from being terminated
if the process terminates using
.BR exit (3)
(or equivalently, if the main thread returns).
.PP
Either
.BR pthread_join (3)
or
.BR pthread_detach ()
should be called for each thread that an application creates,
so that system resources for the thread can be released.
(But note that the resources of any threads for which one of these
actions has not been done will be freed when the process terminates.)
.SH EXAMPLE
The following statement detaches the calling thread:
.PP
    pthread_detach(pthread_self());
.SH SEE ALSO
.BR pthread_attr_setdetachstate (3),
.BR pthread_cancel (3),
.BR pthread_create (3),
.BR pthread_exit (3),
.BR pthread_join (3),
.BR pthreads (7)