lwp/q.c

   1 /*
   2  * Emulate the vax instructions for queue insertion and deletion, somewhat.
   3  * A std_queue structure is defined here and used by these routines.  These
   4  * routines use caddr_ts so they can operate on any structure.  The std_queue
   5  * structure is used rather than proc structures so that when the proc struct
   6  * changes only process management code breaks.  The ideal solution would be
   7  * to define a std_queue as a global type which is part of all the structures
   8  * which are manipulated by these routines.  This would involve considerable
   9  * effort...
  10  */
  11
  12 #ifdef HAVE_CONFIG_H
  13 #include <config.h>
  14 RCSID("$Id$") ;
  15 #endif
  16
  17 #include <stdio.h>
  18 #include <sys/types.h>
  19 #include <sys/time.h>
  20 #ifdef HAVE_SYS_CDEFS_H
  21 #include <sys/cdefs.h>
  22 #endif
  23 #include <utime.h>
  24
  25 #include "q.h"
  26
  27 /* Ansified, made more readable, and mayby fixed /lha */
  28
  29 struct std_queue {
  30         struct std_queue *q_link;
  31         struct std_queue *q_rlink;
  32 } ;
  33
  34 void lwp_insque(void *elementp, void *quep)
  35 {
  36     struct std_queue *que = (struct std_queue *) quep ;
  37     struct std_queue *element = (struct std_queue *) elementp ;
  38
  39     element->q_link = que->q_link;
  40     element->q_rlink = que;
  41
  42     que->q_link->q_rlink = element;
  43     que->q_link = element;
  44 }
  45
  46 void lwp_remque(void *elementp)
  47 {
  48     struct std_queue *element = (struct std_queue *) elementp ;
  49
  50     element->q_link->q_rlink = element->q_rlink;
  51     element->q_rlink->q_link = element->q_link;
  52
  53     element->q_rlink = element->q_link = (struct std_queue *) 0;
  54 }
  55