| PTHREAD_GETSPECIFIC(3) | Library Functions Manual | PTHREAD_GETSPECIFIC(3) |
pthread_getspecific,
pthread_setspecific —
thread-specific data value
POSIX Threads Library (libpthread, -lpthread)
#include
<pthread.h>
void *
pthread_getspecific(pthread_key_t
key);
int
pthread_setspecific(pthread_key_t
key, const void
*value);
The
pthread_getspecific()
function returns the value currently bound to the specified
key on behalf of the calling thread. Conversely, the
pthread_setspecific() function associates a
thread-specific value with a key obtained via a
previous call to
pthread_key_create(3).
Different threads have different values bound to each key. These values are
typically pointers to blocks of dynamically allocated memory that have been
reserved for use by the calling thread.
Undefined behavior may follow if either
function is called with a key value not obtained from
pthread_key_create(3),
or if the call is made after key has been deleted with
pthread_key_delete(3).
It is possible to call either function from a thread-specific data
destructor function. Note however that this is not well defined for the
pthread_setspecific()
function; lost storage or infinite loops may occur.
The pthread_getspecific() function will
return the thread-specific data value associated with the given
key. If no thread-specific data value is associated
with key, then the value NULL
is returned. If successful, the
pthread_setspecific() function will return zero.
Otherwise an error number will be returned to indicate the error.
No errors are defined for either function.
These functions conform to IEEE Std 1003.1-2001 (“POSIX.1”).
| July 9, 2010 | NetBSD 11.0 |