thr_getspecific(3thread)
thr_getspecific --
get thread-specific data
Synopsis
cc [options] -Kthread file
#include <thread.h>
int thr_getspecific(thread_key_t key, void **value);
Description
thr_getspecific obtains the value
currently bound to the specified key on behalf of the calling thread.
Parameters
key-
key whose value is to be returned
value-
pointer to a location in which thr_getspecific will
store the value associated by the calling thread with the
specified key.
key parameter
key is a key obtained with a previous
call to
thr_keycreate(3thread).
The effect of calling thr_getspecific with a key
value not obtained with thr_keycreate
or after key has been deleted with thr_keydelete
is undefined.
value parameter
If a value is bound to the specified key by the calling thread,
that value is placed in the location pointed to by value.
If no value is bound to the specified key for the calling
thread, the location pointed to by value is set to NULL.
Usage
thr_getspecific is not guaranteed to detect an invalid key.
If thr_getspecific returns 0 and sets the location pointed
to by value to NULL, either no value is currently
bound to key, the value bound to key is NULL,
or key is invalid.
In this case, the caller can determine whether key is invalid
by calling
thr_setspecific(key, NULL)
to get the applicable error number.
Return values
thr_getspecific returns zero for success and an error number
for failure as described below.
Errors
If any of the following conditions is detected, thr_getspecific
returns the corresponding value and the contents of the location
pointed to by value are unchanged:
EINVAL-
key is not a valid key
References
Intro(3thread),
thr_keycreate(3thread),
thr_keydelete(3thread),
thr_setspecific(3thread)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004