bsd/netat/adsp_TimerElem.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * TimerElem.c
  24  *
  25  * From v01.00  04/15/90 mbs
  26  *    Modified for MP, 1996 by Tuyen Nguyen
  27  *   Modified, April 9, 1997 by Tuyen Nguyen for MacOSX.
  28 */
  29
  30 #include <sys/errno.h>
  31 #include <sys/types.h>
  32 #include <sys/param.h>
  33 #include <machine/spl.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/proc.h>
  37 #include <sys/filedesc.h>
  38 #include <sys/fcntl.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/socket.h>
  41
  42 #include <netat/sysglue.h>
  43 #include <netat/appletalk.h>
  44 #include <netat/at_pcb.h>
  45 #include <netat/debug.h>
  46 #include <netat/adsp.h>
  47 #include <netat/adsp_internal.h>
  48
  49
  50 extern  void DoTimerElem();     /* (TimerElemPtr t);
  51                                  * External routine called to
  52                                  * process each one. */
  53
  54 /*
  55  * InsertTimerElem
  56  *
  57  * INPUTS:
  58  *      qhead           Address of ptr to first item in list
  59  *      t               timer element to link in
  60  *      vbl             timer value to use
  61  * OUTPUTS:
  62  *      void
  63  */
  64 void InsertTimerElem(qhead, t, val)
  65     /* (TimerElemPtr *qhead, TimerElemPtr t, word val) */
  66     TimerElemPtr *qhead, t;
  67     int val;
  68 {
  69     TimerElemPtr p;             /* parent pointer */
  70     TimerElemPtr n;             /* current */
  71
  72     if (t->onQ) {
  73         /*
  74                 * someone else beat us to the punch and put this
  75                 * element back on the queue, just return in this case
  76                 */
  77                 return;
  78     }
  79     p = (TimerElemPtr)qhead;
  80
  81     while (n = p->link) {
  82         if (val <= n->timer)    /* Do we go in front of this? */
  83         {
  84             n->timer -= val;    /* Yes, adjust his delta */
  85             break;              /* and go link us in */
  86         }
  87         val -= n->timer;        /* No, subtract off delta from our value */
  88         p = n;
  89     }                           /* while */
  90
  91     /* It must go after item pointed to by p and in front of item
  92      * pointed to by n */
  93
  94     t->onQ = 1; /* we're linked in now */
  95     p->link = t;                /* parent points to us */
  96     t->timer = val;             /* this is our value */
  97     t->link = n;                /* we point to n */
  98
  99 }
 100
 101
 102 /*
 103  * RemoveTimerElem
 104  *
 105  * INPUTS:
 106  *      qhead           Address of ptr to first item in list
 107  *      t               timer element to link in
 108  * OUTPUTS:
 109  *      void
 110  */
 111 void RemoveTimerElem(qhead, t)  /* (TimerElemPtr *qhead, TimerElemPtr t) */
 112     TimerElemPtr *qhead, t;
 113 {
 114     TimerElemPtr p;             /* parent pointer */
 115     TimerElemPtr n;             /* current */
 116
 117     if ( !t->onQ) {
 118         /*
 119                 * someone else beat us to the punch and took this
 120                 * element off of the queue, just return in this case
 121                 */
 122                 return;
 123     }
 124     p = (TimerElemPtr)qhead;
 125
 126     while (n = p->link) /* Get next item in queue */
 127     {
 128         if (n == t)             /* Is it us? */
 129         {
 130             if (p->link = n->link) /* Link our parent to our child */
 131             {
 132                 n->link->timer += t->timer; /* and update child's timer */
 133             }
 134             n->onQ = 0;         /* Not on linked list anymore */
 135             break;
 136         }
 137         p = n;
 138     }                           /* while */
 139
 140 }
 141
 142
 143 /*
 144  * TimerQueueTick
 145  *
 146  * INPUTS:
 147  *      qhead           Address of ptr to first item in list
 148  *
 149  * OUTPUTS:
 150  *      void
 151  */
 152 void TimerQueueTick(qhead)      /* (TimerElemPtr *qhead) */
 153     TimerElemPtr *qhead;
 154 {
 155     TimerElemPtr p;             /* parent pointer */
 156     TimerElemPtr n;             /* current */
 157
 158     p = (TimerElemPtr)qhead;
 159     if (p->link) {              /* Is anything on queue? */
 160         p->link->timer--;       /* Yes, decrement by a tick */
 161         while ((n = p->link) &&
 162                (n->timer == 0)) /* Next guy needs to be serviced */
 163         {
 164                 p->link = n->link;      /* Unlink us */
 165                 n->onQ  = 0;
 166
 167                 DoTimerElem(n);
 168
 169                 p = (TimerElemPtr)qhead;
 170         }                               /* while */
 171     }
 172 }