The
pthread_getspecific()
function returns the value currently bound to the specified
key
on behalf of the calling thread.
The effect of calling
pthread_getspecific()
with a
key
value not obtained from
pthread_key_create()
or after
key
has been deleted with
pthread_key_delete()
is undefined.
The
pthread_getspecific()
function may be called from a thread-specific data destructor function.
A call to
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
pthread_setspecific().