bsd/netat/adsp_TimerElem.c

   1 /*
   2  * Copyright (c) 2006 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 atlock_t adsptmr_lock;
  58
  59 extern  void DoTimerElem();     /* (TimerElemPtr t);
  60                                  * External routine called to
  61                                  * process each one. */
  62
  63 /*
  64  * InsertTimerElem
  65  *
  66  * INPUTS:
  67  *      qhead           Address of ptr to first item in list
  68  *      t               timer element to link in
  69  *      vbl             timer value to use
  70  * OUTPUTS:
  71  *      void
  72  */
  73 void InsertTimerElem(qhead, t, val)
  74     /* (TimerElemPtr *qhead, TimerElemPtr t, word val) */
  75     TimerElemPtr *qhead, t;
  76     int val;
  77 {
  78     TimerElemPtr p;             /* parent pointer */
  79     TimerElemPtr n;             /* current */
  80     int s;
  81
  82     ATDISABLE(s, adsptmr_lock);
  83
  84     if (t->onQ) {
  85         /*
  86          * someone else beat us to the punch and put this
  87          * element back on the queue, just return in this case
  88          */
  89         ATENABLE(s, adsptmr_lock);
  90         return;
  91     }
  92     p = (TimerElemPtr)qhead;
  93
  94     while (n = p->link) {
  95         if (val <= n->timer)    /* Do we go in front of this? */
  96         {
  97             n->timer -= val;    /* Yes, adjust his delta */
  98             break;              /* and go link us in */
  99         }
 100         val -= n->timer;        /* No, subtract off delta from our value */
 101         p = n;
 102     }                           /* while */
 103
 104     /* It must go after item pointed to by p and in front of item
 105      * pointed to by n */
 106
 107     t->onQ = 1; /* we're linked in now */
 108     p->link = t;                /* parent points to us */
 109     t->timer = val;             /* this is our value */
 110     t->link = n;                /* we point to n */
 111
 112     ATENABLE(s, adsptmr_lock);
 113 }
 114
 115
 116 /*
 117  * RemoveTimerElem
 118  *
 119  * INPUTS:
 120  *      qhead           Address of ptr to first item in list
 121  *      t               timer element to link in
 122  * OUTPUTS:
 123  *      void
 124  */
 125 void RemoveTimerElem(qhead, t)  /* (TimerElemPtr *qhead, TimerElemPtr t) */
 126     TimerElemPtr *qhead, t;
 127 {
 128     TimerElemPtr p;             /* parent pointer */
 129     TimerElemPtr n;             /* current */
 130     int s;
 131
 132     ATDISABLE(s, adsptmr_lock);
 133
 134     if ( !t->onQ) {
 135         /*
 136          * someone else beat us to the punch and took this
 137          * element off of the queue, just return in this case
 138          */
 139         ATENABLE(s, adsptmr_lock);
 140         return;
 141     }
 142     p = (TimerElemPtr)qhead;
 143
 144     while (n = p->link) /* Get next item in queue */
 145     {
 146         if (n == t)             /* Is it us? */
 147         {
 148             if (p->link = n->link) /* Link our parent to our child */
 149             {
 150                 n->link->timer += t->timer; /* and update child's timer */
 151             }
 152             n->onQ = 0;         /* Not on linked list anymore */
 153             break;
 154         }
 155         p = n;
 156     }                           /* while */
 157
 158     ATENABLE(s, adsptmr_lock);
 159 }
 160
 161
 162 /*
 163  * TimerQueueTick
 164  *
 165  * INPUTS:
 166  *      qhead           Address of ptr to first item in list
 167  *
 168  * OUTPUTS:
 169  *      void
 170  */
 171 void TimerQueueTick(qhead)      /* (TimerElemPtr *qhead) */
 172     TimerElemPtr *qhead;
 173 {
 174     TimerElemPtr p;             /* parent pointer */
 175     TimerElemPtr n;             /* current */
 176     int s;
 177
 178     ATDISABLE(s, adsptmr_lock);
 179
 180     p = (TimerElemPtr)qhead;
 181     if (p->link)                /* Is anything on queue? */
 182         p->link->timer--;       /* Yes, decrement by a tick */
 183     else
 184         goto done;              /* No, we're outta' here */
 185
 186     while ((n = p->link) &&
 187            (n->timer == 0)) /* Next guy needs to be serviced */
 188     {
 189         p->link = n->link;      /* Unlink us */
 190         n->onQ  = 0;
 191
 192         ATENABLE(s, adsptmr_lock);
 193         DoTimerElem(n);
 194         ATDISABLE(s, adsptmr_lock);
 195
 196         p = (TimerElemPtr)qhead;
 197     }                           /* while */
 198
 199 done:
 200     ATENABLE(s, adsptmr_lock);
 201 }