bsd/netat/adsp_TimerElem.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * TimerElem.c
  32  *
  33  * From v01.00  04/15/90 mbs
  34  *    Modified for MP, 1996 by Tuyen Nguyen
  35  *   Modified, April 9, 1997 by Tuyen Nguyen for MacOSX.
  36 */
  37
  38 #include <sys/errno.h>
  39 #include <sys/types.h>
  40 #include <sys/param.h>
  41 #include <machine/spl.h>
  42 #include <sys/systm.h>
  43 #include <sys/kernel.h>
  44 #include <sys/proc.h>
  45 #include <sys/filedesc.h>
  46 #include <sys/fcntl.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/socket.h>
  49
  50 #include <netat/sysglue.h>
  51 #include <netat/appletalk.h>
  52 #include <netat/at_pcb.h>
  53 #include <netat/debug.h>
  54 #include <netat/adsp.h>
  55 #include <netat/adsp_internal.h>
  56
  57
  58 extern  void DoTimerElem();     /* (TimerElemPtr t);
  59                                  * External routine called to
  60                                  * process each one. */
  61
  62 /*
  63  * InsertTimerElem
  64  *
  65  * INPUTS:
  66  *      qhead           Address of ptr to first item in list
  67  *      t               timer element to link in
  68  *      vbl             timer value to use
  69  * OUTPUTS:
  70  *      void
  71  */
  72 void InsertTimerElem(qhead, t, val)
  73     /* (TimerElemPtr *qhead, TimerElemPtr t, word val) */
  74     TimerElemPtr *qhead, t;
  75     int val;
  76 {
  77     TimerElemPtr p;             /* parent pointer */
  78     TimerElemPtr n;             /* current */
  79
  80     if (t->onQ) {
  81         /*
  82                 * someone else beat us to the punch and put this
  83                 * element back on the queue, just return in this case
  84                 */
  85                 return;
  86     }
  87     p = (TimerElemPtr)qhead;
  88
  89     while (n = p->link) {
  90         if (val <= n->timer)    /* Do we go in front of this? */
  91         {
  92             n->timer -= val;    /* Yes, adjust his delta */
  93             break;              /* and go link us in */
  94         }
  95         val -= n->timer;        /* No, subtract off delta from our value */
  96         p = n;
  97     }                           /* while */
  98
  99     /* It must go after item pointed to by p and in front of item
 100      * pointed to by n */
 101
 102     t->onQ = 1; /* we're linked in now */
 103     p->link = t;                /* parent points to us */
 104     t->timer = val;             /* this is our value */
 105     t->link = n;                /* we point to n */
 106
 107 }
 108
 109
 110 /*
 111  * RemoveTimerElem
 112  *
 113  * INPUTS:
 114  *      qhead           Address of ptr to first item in list
 115  *      t               timer element to link in
 116  * OUTPUTS:
 117  *      void
 118  */
 119 void RemoveTimerElem(qhead, t)  /* (TimerElemPtr *qhead, TimerElemPtr t) */
 120     TimerElemPtr *qhead, t;
 121 {
 122     TimerElemPtr p;             /* parent pointer */
 123     TimerElemPtr n;             /* current */
 124
 125     if ( !t->onQ) {
 126         /*
 127                 * someone else beat us to the punch and took this
 128                 * element off of the queue, just return in this case
 129                 */
 130                 return;
 131     }
 132     p = (TimerElemPtr)qhead;
 133
 134     while (n = p->link) /* Get next item in queue */
 135     {
 136         if (n == t)             /* Is it us? */
 137         {
 138             if (p->link = n->link) /* Link our parent to our child */
 139             {
 140                 n->link->timer += t->timer; /* and update child's timer */
 141             }
 142             n->onQ = 0;         /* Not on linked list anymore */
 143             break;
 144         }
 145         p = n;
 146     }                           /* while */
 147
 148 }
 149
 150
 151 /*
 152  * TimerQueueTick
 153  *
 154  * INPUTS:
 155  *      qhead           Address of ptr to first item in list
 156  *
 157  * OUTPUTS:
 158  *      void
 159  */
 160 void TimerQueueTick(qhead)      /* (TimerElemPtr *qhead) */
 161     TimerElemPtr *qhead;
 162 {
 163     TimerElemPtr p;             /* parent pointer */
 164     TimerElemPtr n;             /* current */
 165
 166     p = (TimerElemPtr)qhead;
 167     if (p->link) {              /* Is anything on queue? */
 168         p->link->timer--;       /* Yes, decrement by a tick */
 169         while ((n = p->link) &&
 170                (n->timer == 0)) /* Next guy needs to be serviced */
 171         {
 172                 p->link = n->link;      /* Unlink us */
 173                 n->onQ  = 0;
 174
 175                 DoTimerElem(n);
 176
 177                 p = (TimerElemPtr)qhead;
 178         }                               /* while */
 179     }
 180 }