.\"	$OpenBSD: getthrid.2,v 1.2 2014/08/31 06:41:23 jmc Exp $
.\"	$NetBSD: getpid.2,v 1.5 1995/02/27 12:33:12 cgd Exp $
.\"
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.\"     @(#)getpid.2	8.1 (Berkeley) 6/4/93
.\"
.Dd $Mdocdate: August 31 2014 $
.Dt GETTHRID 2
.Os
.Sh NAME
.Nm getthrid
.Nd get thread identifier
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft pid_t
.Fn getthrid void
.Sh DESCRIPTION
.Nm
returns the thread ID of the calling thread.
This is used in the implementation of the thread library
.Pq Fl lpthread
and can appear in the output of system utilities such as
.Xr ps 1
and
.Xr kdump 1 .
.Pp
Thread IDs are not a stable interface and should not be used directly
by applications except for correlation with system utility output.
Applications should use the
.Vt pthread_t
values from
.Xr pthread_self 3
and
.Xr pthread_create 3
to identify threads within the process itself.
.Sh RETURN VALUES
This function is always successful, and no return value is
reserved to indicate an error.
.Sh SEE ALSO
.Xr __tfork 2 ,
.Xr getpid 2 ,
.Xr pthread_create 3 ,
.Xr pthread_self 3
.Sh STANDARDS
The
.Nm
syscall is specific to
.Ox
and should not be used in portable applications.
.Sh HISTORY
The
.Nm
syscall appeared in
.Ox 3.9 .