lib/librte_eal/linuxapp/eal/eal_alarm.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 #include <stdio.h>
  34 #include <stdint.h>
  35 #include <signal.h>
  36 #include <errno.h>
  37 #include <string.h>
  38 #include <sys/queue.h>
  39 #include <sys/time.h>
  40 #include <sys/timerfd.h>
  41
  42 #include <rte_memory.h>
  43 #include <rte_memzone.h>
  44 #include <rte_interrupts.h>
  45 #include <rte_alarm.h>
  46 #include <rte_common.h>
  47 #include <rte_per_lcore.h>
  48 #include <rte_eal.h>
  49 #include <rte_launch.h>
  50 #include <rte_lcore.h>
  51 #include <rte_errno.h>
  52 #include <rte_malloc.h>
  53 #include <rte_spinlock.h>
  54 #include <eal_private.h>
  55
  56 #ifndef TFD_NONBLOCK
  57 #include <fcntl.h>
  58 #define TFD_NONBLOCK    O_NONBLOCK
  59 #endif
  60
  61 #define NS_PER_US 1000
  62 #define US_PER_MS 1000
  63 #define MS_PER_S 1000
  64 #define US_PER_S (US_PER_MS * MS_PER_S)
  65
  66 #ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
  67 #define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
  68 #else
  69 #define CLOCK_TYPE_ID CLOCK_MONOTONIC
  70 #endif
  71
  72 struct alarm_entry {
  73         LIST_ENTRY(alarm_entry) next;
  74         struct timeval time;
  75         rte_eal_alarm_callback cb_fn;
  76         void *cb_arg;
  77         volatile uint8_t executing;
  78         volatile pthread_t executing_id;
  79 };
  80
  81 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
  82 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
  83
  84 static struct rte_intr_handle intr_handle = {.fd = -1 };
  85 static int handler_registered = 0;
  86 static void eal_alarm_callback(void *arg);
  87
  88 int
  89 rte_eal_alarm_init(void)
  90 {
  91         intr_handle.type = RTE_INTR_HANDLE_ALARM;
  92         /* create a timerfd file descriptor */
  93         intr_handle.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
  94         if (intr_handle.fd == -1)
  95                 goto error;
  96
  97         return 0;
  98
  99 error:
 100         rte_errno = errno;
 101         return -1;
 102 }
 103
 104 static void
 105 eal_alarm_callback(void *arg __rte_unused)
 106 {
 107         struct timespec now;
 108         struct alarm_entry *ap;
 109
 110         rte_spinlock_lock(&alarm_list_lk);
 111         while ((ap = LIST_FIRST(&alarm_list)) !=NULL &&
 112                         clock_gettime(CLOCK_TYPE_ID, &now) == 0 &&
 113                         (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
 114                                                 (ap->time.tv_usec * NS_PER_US) <= now.tv_nsec))) {
 115                 ap->executing = 1;
 116                 ap->executing_id = pthread_self();
 117                 rte_spinlock_unlock(&alarm_list_lk);
 118
 119                 ap->cb_fn(ap->cb_arg);
 120
 121                 rte_spinlock_lock(&alarm_list_lk);
 122
 123                 LIST_REMOVE(ap, next);
 124                 rte_free(ap);
 125         }
 126
 127         if (!LIST_EMPTY(&alarm_list)) {
 128                 struct itimerspec atime = { .it_interval = { 0, 0 } };
 129
 130                 ap = LIST_FIRST(&alarm_list);
 131                 atime.it_value.tv_sec = ap->time.tv_sec;
 132                 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US;
 133                 /* perform borrow for subtraction if necessary */
 134                 if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US))
 135                         atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US;
 136
 137                 atime.it_value.tv_sec -= now.tv_sec;
 138                 atime.it_value.tv_nsec -= now.tv_nsec;
 139                 timerfd_settime(intr_handle.fd, 0, &atime, NULL);
 140         }
 141         rte_spinlock_unlock(&alarm_list_lk);
 142 }
 143
 144 int
 145 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
 146 {
 147         struct timespec now;
 148         int ret = 0;
 149         struct alarm_entry *ap, *new_alarm;
 150
 151         /* Check parameters, including that us won't cause a uint64_t overflow */
 152         if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
 153                 return -EINVAL;
 154
 155         new_alarm = rte_zmalloc(NULL, sizeof(*new_alarm), 0);
 156         if (new_alarm == NULL)
 157                 return -ENOMEM;
 158
 159         /* use current time to calculate absolute time of alarm */
 160         clock_gettime(CLOCK_TYPE_ID, &now);
 161
 162         new_alarm->cb_fn = cb_fn;
 163         new_alarm->cb_arg = cb_arg;
 164         new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US) + us) % US_PER_S;
 165         new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US) + us) / US_PER_S);
 166
 167         rte_spinlock_lock(&alarm_list_lk);
 168         if (!handler_registered) {
 169                 ret |= rte_intr_callback_register(&intr_handle,
 170                                 eal_alarm_callback, NULL);
 171                 handler_registered = (ret == 0) ? 1 : 0;
 172         }
 173
 174         if (LIST_EMPTY(&alarm_list))
 175                 LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
 176         else {
 177                 LIST_FOREACH(ap, &alarm_list, next) {
 178                         if (ap->time.tv_sec > new_alarm->time.tv_sec ||
 179                                         (ap->time.tv_sec == new_alarm->time.tv_sec &&
 180                                                         ap->time.tv_usec > new_alarm->time.tv_usec)){
 181                                 LIST_INSERT_BEFORE(ap, new_alarm, next);
 182                                 break;
 183                         }
 184                         if (LIST_NEXT(ap, next) == NULL) {
 185                                 LIST_INSERT_AFTER(ap, new_alarm, next);
 186                                 break;
 187                         }
 188                 }
 189         }
 190
 191         if (LIST_FIRST(&alarm_list) == new_alarm) {
 192                 struct itimerspec alarm_time = {
 193                         .it_interval = {0, 0},
 194                         .it_value = {
 195                                 .tv_sec = us / US_PER_S,
 196                                 .tv_nsec = (us % US_PER_S) * NS_PER_US,
 197                         },
 198                 };
 199                 ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL);
 200         }
 201         rte_spinlock_unlock(&alarm_list_lk);
 202
 203         return ret;
 204 }
 205
 206 int
 207 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
 208 {
 209         struct alarm_entry *ap, *ap_prev;
 210         int count = 0;
 211         int err = 0;
 212         int executing;
 213
 214         if (!cb_fn) {
 215                 rte_errno = EINVAL;
 216                 return -1;
 217         }
 218
 219         do {
 220                 executing = 0;
 221                 rte_spinlock_lock(&alarm_list_lk);
 222                 /* remove any matches at the start of the list */
 223                 while ((ap = LIST_FIRST(&alarm_list)) != NULL &&
 224                                 cb_fn == ap->cb_fn &&
 225                                 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 226
 227                         if (ap->executing == 0) {
 228                                 LIST_REMOVE(ap, next);
 229                                 rte_free(ap);
 230                                 count++;
 231                         } else {
 232                                 /* If calling from other context, mark that alarm is executing
 233                                  * so loop can spin till it finish. Otherwise we are trying to
 234                                  * cancel our self - mark it by EINPROGRESS */
 235                                 if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 236                                         executing++;
 237                                 else
 238                                         err = EINPROGRESS;
 239
 240                                 break;
 241                         }
 242                 }
 243                 ap_prev = ap;
 244
 245                 /* now go through list, removing entries not at start */
 246                 LIST_FOREACH(ap, &alarm_list, next) {
 247                         /* this won't be true first time through */
 248                         if (cb_fn == ap->cb_fn &&
 249                                         (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 250
 251                                 if (ap->executing == 0) {
 252                                         LIST_REMOVE(ap, next);
 253                                         rte_free(ap);
 254                                         count++;
 255                                         ap = ap_prev;
 256                                 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 257                                         executing++;
 258                                 else
 259                                         err = EINPROGRESS;
 260                         }
 261                         ap_prev = ap;
 262                 }
 263                 rte_spinlock_unlock(&alarm_list_lk);
 264         } while (executing != 0);
 265
 266         if (count == 0 && err == 0)
 267                 rte_errno = ENOENT;
 268         else if (err)
 269                 rte_errno = err;
 270
 271         return count;
 272 }