.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
.\" All rights reserved.
.\"
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.\"	This product includes software developed by John Birrell.
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.\"    may be used to endorse or promote products derived from this software
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.\" $FreeBSD: head/share/man/man3/pthread_getspecific.3 283093 2015-05-19 02:24:55Z pkelsey $
.\"
.Dd April 4, 1996
.Dt PTHREAD_GETSPECIFIC 3
.Os
.Sh NAME
.Nm pthread_getspecific
.Nd get a thread-specific data value
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft void *
.Fn pthread_getspecific "pthread_key_t key"
.Sh DESCRIPTION
The
.Fn pthread_getspecific
function returns the value currently bound to the specified
.Fa key
on behalf of the calling thread.
.Pp
The effect of calling
.Fn pthread_getspecific
with a
.Fa key
value not obtained from
.Fn pthread_key_create
or after
.Fa key
has been deleted with
.Fn pthread_key_delete
is undefined.
.Pp
The
.Fn pthread_getspecific
function may be called from a thread-specific data destructor function.
A call to
.Fn pthread_getspecific
for the thread-specific data key being destroyed returns the value NULL,
unless the value is changed (after the destructor starts) by a call to
.Fn pthread_setspecific .
.Sh RETURN VALUES
The
.Fn pthread_getspecific
function will return the thread-specific data value associated with the given
.Fa key .
If no thread-specific data value is associated with
.Fa key ,
then the value NULL is returned.
.Sh ERRORS
None.
.Sh SEE ALSO
.Xr pthread_key_create 3 ,
.Xr pthread_key_delete 3 ,
.Xr pthread_setspecific 3
.Sh STANDARDS
The
.Fn pthread_getspecific
function conforms to
.St -p1003.1-96 .