man3/pthread_detach.3

   1 .\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk
   2 .\"     <mtk.manpages@gmail.com>
   3 .\"
   4 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   5 .\"
   6 .TH PTHREAD_DETACH 3 2021-03-22 "Linux man-pages (unreleased)" "Linux Programmer's Manual"
   7 .SH NAME
   8 pthread_detach \- detach a thread
   9 .SH LIBRARY
  10 POSIX threads library
  11 .RI ( libpthread ", " \-lpthread )
  12 .SH SYNOPSIS
  13 .nf
  14 .B #include <pthread.h>
  15 .PP
  16 .BI "int pthread_detach(pthread_t " thread );
  17 .fi
  18 .SH DESCRIPTION
  19 The
  20 .BR pthread_detach ()
  21 function marks the thread identified by
  22 .I thread
  23 as detached.
  24 When a detached thread terminates,
  25 its resources are automatically released back to the system without
  26 the need for another thread to join with the terminated thread.
  27 .PP
  28 Attempting to detach an already detached thread results
  29 in unspecified behavior.
  30 .SH RETURN VALUE
  31 On success,
  32 .BR pthread_detach ()
  33 returns 0;
  34 on error, it returns an error number.
  35 .SH ERRORS
  36 .TP
  37 .B EINVAL
  38 .I thread
  39 is not a joinable thread.
  40 .TP
  41 .B ESRCH
  42 No thread with the ID
  43 .I thread
  44 could be found.
  45 .SH ATTRIBUTES
  46 For an explanation of the terms used in this section, see
  47 .BR attributes (7).
  48 .ad l
  49 .nh
  50 .TS
  51 allbox;
  52 lbx lb lb
  53 l l l.
  54 Interface       Attribute       Value
  55 T{
  56 .BR pthread_detach ()
  57 T}      Thread safety   MT-Safe
  58 .TE
  59 .hy
  60 .ad
  61 .sp 1
  62 .SH STANDARDS
  63 POSIX.1-2001, POSIX.1-2008.
  64 .SH NOTES
  65 Once a thread has been detached, it can't be joined with
  66 .BR pthread_join (3)
  67 or be made joinable again.
  68 .PP
  69 A new thread can be created in a detached state using
  70 .BR pthread_attr_setdetachstate (3)
  71 to set the detached attribute of the
  72 .I attr
  73 argument of
  74 .BR pthread_create (3).
  75 .PP
  76 The detached attribute merely determines the behavior of the system
  77 when the thread terminates;
  78 it does not prevent the thread from being terminated
  79 if the process terminates using
  80 .BR exit (3)
  81 (or equivalently, if the main thread returns).
  82 .PP
  83 Either
  84 .BR pthread_join (3)
  85 or
  86 .BR pthread_detach ()
  87 should be called for each thread that an application creates,
  88 so that system resources for the thread can be released.
  89 (But note that the resources of any threads for which one of these
  90 actions has not been done will be freed when the process terminates.)
  91 .SH EXAMPLES
  92 The following statement detaches the calling thread:
  93 .PP
  94 .in +4n
  95 .EX
  96 pthread_detach(pthread_self());
  97 .EE
  98 .in
  99 .SH SEE ALSO
 100 .BR pthread_attr_setdetachstate (3),
 101 .BR pthread_cancel (3),
 102 .BR pthread_create (3),
 103 .BR pthread_exit (3),
 104 .BR pthread_join (3),
 105 .BR pthreads (7)