Obtains the data associated with the specified thread-specific
    data key.

1 - C Binding

    #include <tis.h>

    void *
    tis_getspecific (
                pthread_key_t   key);

2 - Arguments

 key

    Identifies a value returned by a call to tis_key_create().
    This routine returns the data value associated with the thread-
    specific data key.

3 - Description

    This routine returns the value currently bound to the specified
    thread-specific data key.

    This routine can be called from a data destructor function.

    When threads are present, the data and keys are thread specific;
    they enable a library to maintain context on a per-thread basis.

4 - Return Values

    No errors are returned. This routine returns the data value
    associated with the specified thread-specific data key key. If
    no data value is associated with key, or if key is not defined,
    then a NULL value is returned.

5 - Associated Routines

       tis_key_create()
       tis_key_delete()
       tis_setspecific()