man3/pthread_sigqueue.3

   1 .\" Copyright (c) 2010 Michael Kerrisk, <mtk.manpages@gmail.com>
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .TH PTHREAD_SIGQUEUE 3 2021-03-22 "Linux man-pages (unreleased)"
   6 .SH NAME
   7 pthread_sigqueue \- queue a signal and data to a thread
   8 .SH LIBRARY
   9 POSIX threads library
  10 .RI ( libpthread ", " \-lpthread )
  11 .SH SYNOPSIS
  12 .nf
  13 .B #include <signal.h>
  14 .B #include <pthread.h>
  15 .PP
  16 .BI "int pthread_sigqueue(pthread_t " thread ", int " sig ,
  17 .BI "                     const union sigval " value );
  18 .fi
  19 .PP
  20 .RS -4
  21 Feature Test Macro Requirements for glibc (see
  22 .BR feature_test_macros (7)):
  23 .RE
  24 .PP
  25 .BR pthread_sigqueue ():
  26 .nf
  27     _GNU_SOURCE
  28 .fi
  29 .SH DESCRIPTION
  30 The
  31 .BR pthread_sigqueue ()
  32 function performs a similar task to
  33 .BR sigqueue (3),
  34 but, rather than sending a signal to a process,
  35 it sends a signal to a thread in the same process as the
  36 calling thread.
  37 .PP
  38 The
  39 .I thread
  40 argument is the ID of a thread in the same process as the caller.
  41 The
  42 .I sig
  43 argument specifies the signal to be sent.
  44 The
  45 .I value
  46 argument specifies data to accompany the signal; see
  47 .BR sigqueue (3)
  48 for details.
  49 .SH RETURN VALUE
  50 On success,
  51 .BR pthread_sigqueue ()
  52 returns 0;
  53 on error, it returns an error number.
  54 .SH ERRORS
  55 .TP
  56 .B EAGAIN
  57 The limit of signals which may be queued has been reached.
  58 (See
  59 .BR signal (7)
  60 for further information.)
  61 .TP
  62 .B EINVAL
  63 .I sig
  64 was invalid.
  65 .TP
  66 .B ENOSYS
  67 .BR pthread_sigqueue ()
  68 is not supported on this system.
  69 .TP
  70 .B ESRCH
  71 .I thread
  72 is not valid.
  73 .SH VERSIONS
  74 The
  75 .BR pthread_sigqueue ()
  76 function first appeared in glibc 2.11.
  77 .SH ATTRIBUTES
  78 For an explanation of the terms used in this section, see
  79 .BR attributes (7).
  80 .ad l
  81 .nh
  82 .TS
  83 allbox;
  84 lbx lb lb
  85 l l l.
  86 Interface       Attribute       Value
  87 T{
  88 .BR pthread_sigqueue ()
  89 T}      Thread safety   MT-Safe
  90 .TE
  91 .hy
  92 .ad
  93 .sp 1
  94 .SH STANDARDS
  95 This function is a GNU extension.
  96 .SH NOTES
  97 The glibc implementation of
  98 .BR pthread_sigqueue ()
  99 gives an error
 100 .RB ( EINVAL )
 101 on attempts to send either of the real-time signals
 102 used internally by the NPTL threading implementation.
 103 See
 104 .BR nptl (7)
 105 for details.
 106 .SH SEE ALSO
 107 .BR rt_tgsigqueueinfo (2),
 108 .BR sigaction (2),
 109 .BR pthread_sigmask (3),
 110 .BR sigqueue (3),
 111 .BR sigwait (3),
 112 .BR pthreads (7),
 113 .BR signal (7)