bsd/net/devtimer.c

   1 /*
   2  * Copyright (c) 2004,2007-2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_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 License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * devtimer.c
  31  * - timer source based on <kern/thread_call.h>
  32  */
  33
  34 /*
  35  * Modification History:
  36  *
  37  * June 22, 2004        Dieter Siegmund (dieter@apple.com)
  38  * - created
  39  */
  40 #include <sys/param.h>
  41 #include <sys/kernel.h>
  42 #include <sys/malloc.h>
  43 #include <kern/thread_call.h>
  44 #include <net/devtimer.h>
  45 #include <libkern/OSAtomic.h>
  46
  47 #ifdef DEVTIMER_DEBUG
  48 #define _devtimer_printf        printf
  49 #else /* !DEVTIMER_DEBUG */
  50 static __inline__ void
  51 _devtimer_printf(__unused const char * fmt, ...)
  52 {
  53 }
  54 #endif /* !DEVTIMER_DEBUG */
  55
  56 struct devtimer_s {
  57     void *                      dt_callout;
  58     devtimer_timeout_func       dt_timeout_func;
  59     devtimer_process_func       dt_process_func;
  60     void *                      dt_arg0;
  61     void *                      dt_arg1;
  62     void *                      dt_arg2;
  63     int                         dt_generation;
  64     UInt32                      dt_retain_count;
  65 };
  66
  67 #define M_DEVTIMER      M_DEVBUF
  68
  69 static __inline__ void
  70 timeval_add(struct timeval tv1, struct timeval tv2,
  71             struct timeval * result)
  72 {
  73     result->tv_sec = tv1.tv_sec + tv2.tv_sec;
  74     result->tv_usec = tv1.tv_usec + tv2.tv_usec;
  75     if (result->tv_usec > DEVTIMER_USECS_PER_SEC) {
  76         result->tv_usec -= DEVTIMER_USECS_PER_SEC;
  77         result->tv_sec++;
  78     }
  79     return;
  80 }
  81
  82 static __inline__ uint64_t
  83 timeval_to_absolutetime(struct timeval tv)
  84 {
  85     uint64_t    secs;
  86     uint64_t    usecs;
  87
  88     clock_interval_to_absolutetime_interval(tv.tv_sec, NSEC_PER_SEC,
  89                                             &secs);
  90     clock_interval_to_absolutetime_interval(tv.tv_usec, NSEC_PER_USEC,
  91                                             &usecs);
  92     return (secs + usecs);
  93 }
  94
  95
  96 __private_extern__ int
  97 devtimer_valid(devtimer_ref timer)
  98 {
  99     return (timer->dt_callout != NULL);
 100 }
 101
 102 __private_extern__ void
 103 devtimer_retain(devtimer_ref timer)
 104 {
 105     OSIncrementAtomic(&timer->dt_retain_count);
 106     return;
 107 }
 108
 109 __private_extern__ void
 110 devtimer_invalidate(devtimer_ref timer)
 111 {
 112     devtimer_cancel(timer);
 113     timer->dt_arg0 = NULL;
 114     if (timer->dt_callout != NULL) {
 115         thread_call_free(timer->dt_callout);
 116         timer->dt_callout = NULL;
 117     }
 118     return;
 119 }
 120
 121 __private_extern__ void
 122 devtimer_release(devtimer_ref timer)
 123 {
 124     UInt32      old_retain_count;
 125
 126     old_retain_count = OSDecrementAtomic(&timer->dt_retain_count);
 127     switch (old_retain_count) {
 128     case 0:
 129         panic("devtimer_release: retain count is 0\n");
 130         break;
 131     case 1:
 132         devtimer_invalidate(timer);
 133         FREE(timer, M_DEVTIMER);
 134         _devtimer_printf("devtimer: timer released\n");
 135         break;
 136     default:
 137         break;
 138     }
 139     return;
 140 }
 141
 142 static void
 143 devtimer_process(void * param0, void * param1)
 144 {
 145     int                         generation = *(int*)param1;
 146     devtimer_process_func       process_func;
 147     devtimer_timeout_func       timeout_func;
 148     devtimer_ref                timer = (devtimer_ref)param0;
 149
 150     process_func = timer->dt_process_func;
 151     if (process_func != NULL) {
 152         (*process_func)(timer, devtimer_process_func_event_lock);
 153     }
 154     timeout_func = timer->dt_timeout_func;
 155     if (timeout_func != NULL) {
 156         timer->dt_timeout_func = NULL;
 157         if (timer->dt_generation == generation) {
 158             (*timeout_func)(timer->dt_arg0, timer->dt_arg1, timer->dt_arg2);
 159         }
 160     }
 161     devtimer_release(timer);
 162     if (process_func != NULL) {
 163         (*process_func)(timer, devtimer_process_func_event_unlock);
 164     }
 165     return;
 166 }
 167
 168 __private_extern__ void *
 169 devtimer_arg0(devtimer_ref timer)
 170 {
 171     return (timer->dt_arg0);
 172 }
 173
 174 __private_extern__ devtimer_ref
 175 devtimer_create(devtimer_process_func process_func, void * arg0)
 176 {
 177     devtimer_ref        timer;
 178
 179     timer = _MALLOC(sizeof(*timer), M_DEVTIMER, M_WAITOK | M_ZERO);
 180     if (timer == NULL) {
 181         return (timer);
 182     }
 183     devtimer_retain(timer);
 184     timer->dt_callout = thread_call_allocate(devtimer_process, timer);
 185     if (timer->dt_callout == NULL) {
 186         _devtimer_printf("devtimer: thread_call_allocate failed\n");
 187         devtimer_release(timer);
 188         timer = NULL;
 189     }
 190     timer->dt_process_func = process_func;
 191     timer->dt_arg0 = arg0;
 192     return (timer);
 193 }
 194
 195 __private_extern__ void
 196 devtimer_set_absolute(devtimer_ref timer,
 197                       struct timeval abs_time,
 198                       devtimer_timeout_func timeout_func,
 199                       void * arg1, void * arg2)
 200 {
 201     if (timer->dt_callout == NULL) {
 202         printf("devtimer_set_absolute: uninitialized/freed timer\n");
 203         return;
 204     }
 205     devtimer_cancel(timer);
 206     if (timeout_func == NULL) {
 207         return;
 208     }
 209     timer->dt_timeout_func = timeout_func;
 210     timer->dt_arg1 = arg1;
 211     timer->dt_arg2 = arg2;
 212     _devtimer_printf("devtimer: wakeup time is (%d.%d)\n",
 213                      abs_time.tv_sec, abs_time.tv_usec);
 214     timer->dt_generation++;
 215     devtimer_retain(timer);
 216     thread_call_enter1_delayed(timer->dt_callout,
 217                                &timer->dt_generation,
 218                                timeval_to_absolutetime(abs_time));
 219     return;
 220 }
 221
 222 __private_extern__ void
 223 devtimer_set_relative(devtimer_ref timer,
 224                       struct timeval rel_time,
 225                       devtimer_timeout_func timeout_func,
 226                       void * arg1, void * arg2)
 227 {
 228     struct timeval              abs_time;
 229     struct timeval              current_time;
 230
 231     current_time = devtimer_current_time();
 232     timeval_add(current_time, rel_time, &abs_time);
 233     devtimer_set_absolute(timer, abs_time, timeout_func, arg1, arg2);
 234     return;
 235 }
 236
 237 __private_extern__ void
 238 devtimer_cancel(devtimer_ref timer)
 239 {
 240     if (timer->dt_timeout_func != NULL) {
 241         timer->dt_timeout_func = NULL;
 242         if (timer->dt_callout != NULL) {
 243             _devtimer_printf("devtimer: cancelling timer source\n");
 244             if (thread_call_cancel(timer->dt_callout)) {
 245                 devtimer_release(timer);
 246             }
 247             else {
 248                 _devtimer_printf("devtimer: delayed release\n");
 249             }
 250         }
 251     }
 252     return;
 253 }
 254
 255 __private_extern__ int
 256 devtimer_enabled(devtimer_ref timer)
 257 {
 258     return (timer->dt_timeout_func != NULL);
 259 }
 260
 261 __private_extern__ int32_t
 262 devtimer_current_secs(void)
 263 {
 264     struct timeval      tv;
 265
 266     tv = devtimer_current_time();
 267     return (tv.tv_sec);
 268 }
 269
 270 __private_extern__ struct timeval
 271 devtimer_current_time(void)
 272 {
 273     struct timeval      tv;
 274     clock_sec_t sec;
 275     clock_usec_t usec;
 276
 277     clock_get_system_microtime(&sec, &usec);
 278     tv.tv_sec = sec;
 279     tv.tv_usec = usec;
 280     return (tv);
 281 }