/* ptclear.c - _ptclear */

#include 

/*------------------------------------------------------------------------
 *  _ptclear  -  Used by ptdelete and ptreset to clear or reset a port
 *                 (internal function assumes interrupts disabled and
 *                 arguments have been checked for validity)
 *------------------------------------------------------------------------
 */
void    _ptclear(
          struct ptentry *ptptr,        /* Table entry to clear         */
          uint16       newstate,        /* New state for port           */
          int32        (*dispose)(int32)/* Disposal function to call    */
         )
{
        struct  ptnode  *walk;          /* Pointer to walk message list */

        /* Place port in limbo state while waiting processes are freed */

        ptptr->ptstate = PT_LIMBO;

        ptptr->ptseq++;                 /* Reset accession number       */
        walk = ptptr->pthead;           /* First item on msg list       */

        if ( walk != NULL ) {           /* If message list nonempty     */

                /* Walk message list and dispose of each message */

                for( ; walk!=NULL ; walk=walk->ptnext) {
                        (*dispose)( walk->ptmsg );
                }

                /* Link entire message list into the free list */

                (ptptr->pttail)->ptnext = ptfree;
                ptfree = ptptr->pthead;
        }

        if (newstate == PT_ALLOC) {
                ptptr->pttail = ptptr->pthead = NULL;
                semreset(ptptr->ptssem, ptptr->ptmaxcnt);
                semreset(ptptr->ptrsem, 0);
        } else {
                semdelete(ptptr->ptssem);
                semdelete(ptptr->ptrsem);
        }
        ptptr->ptstate = newstate;
        return;
}