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_interrupts.h>
  44 #include <rte_alarm.h>
  45 #include <rte_common.h>
  46 #include <rte_per_lcore.h>
  47 #include <rte_eal.h>
  48 #include <rte_launch.h>
  49 #include <rte_lcore.h>
  50 #include <rte_errno.h>
  51 #include <rte_malloc.h>
  52 #include <rte_spinlock.h>
  53 #include <eal_private.h>
  54
  55 #ifndef TFD_NONBLOCK
  56 #include <fcntl.h>
  57 #define TFD_NONBLOCK    O_NONBLOCK
  58 #endif
  59
  60 #define NS_PER_US 1000
  61 #define US_PER_MS 1000
  62 #define MS_PER_S 1000
  63 #define US_PER_S (US_PER_MS * MS_PER_S)
  64
  65 #ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
  66 #define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
  67 #else
  68 #define CLOCK_TYPE_ID CLOCK_MONOTONIC
  69 #endif
  70
  71 struct alarm_entry {
  72         LIST_ENTRY(alarm_entry) next;
  73         struct timeval time;
  74         rte_eal_alarm_callback cb_fn;
  75         void *cb_arg;
  76         volatile uint8_t executing;
  77         volatile pthread_t executing_id;
  78 };
  79
  80 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
  81 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
  82
  83 static struct rte_intr_handle intr_handle = {.fd = -1 };
  84 static int handler_registered = 0;
  85 static void eal_alarm_callback(void *arg);
  86
  87 int
  88 rte_eal_alarm_init(void)
  89 {
  90         intr_handle.type = RTE_INTR_HANDLE_ALARM;
  91         /* create a timerfd file descriptor */
  92         intr_handle.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
  93         if (intr_handle.fd == -1)
  94                 goto error;
  95
  96         return 0;
  97
  98 error:
  99         rte_errno = errno;
 100         return -1;
 101 }
 102
 103 static void
 104 eal_alarm_callback(void *arg __rte_unused)
 105 {
 106         struct timespec now;
 107         struct alarm_entry *ap;
 108
 109         rte_spinlock_lock(&alarm_list_lk);
 110         while ((ap = LIST_FIRST(&alarm_list)) !=NULL &&
 111                         clock_gettime(CLOCK_TYPE_ID, &now) == 0 &&
 112                         (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
 113                                                 (ap->time.tv_usec * NS_PER_US) <= now.tv_nsec))) {
 114                 ap->executing = 1;
 115                 ap->executing_id = pthread_self();
 116                 rte_spinlock_unlock(&alarm_list_lk);
 117
 118                 ap->cb_fn(ap->cb_arg);
 119
 120                 rte_spinlock_lock(&alarm_list_lk);
 121
 122                 LIST_REMOVE(ap, next);
 123                 rte_free(ap);
 124         }
 125
 126         if (!LIST_EMPTY(&alarm_list)) {
 127                 struct itimerspec atime = { .it_interval = { 0, 0 } };
 128
 129                 ap = LIST_FIRST(&alarm_list);
 130                 atime.it_value.tv_sec = ap->time.tv_sec;
 131                 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US;
 132                 /* perform borrow for subtraction if necessary */
 133                 if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US))
 134                         atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US;
 135
 136                 atime.it_value.tv_sec -= now.tv_sec;
 137                 atime.it_value.tv_nsec -= now.tv_nsec;
 138                 timerfd_settime(intr_handle.fd, 0, &atime, NULL);
 139         }
 140         rte_spinlock_unlock(&alarm_list_lk);
 141 }
 142
 143 int
 144 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
 145 {
 146         struct timespec now;
 147         int ret = 0;
 148         struct alarm_entry *ap, *new_alarm;
 149
 150         /* Check parameters, including that us won't cause a uint64_t overflow */
 151         if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
 152                 return -EINVAL;
 153
 154         new_alarm = rte_zmalloc(NULL, sizeof(*new_alarm), 0);
 155         if (new_alarm == NULL)
 156                 return -ENOMEM;
 157
 158         /* use current time to calculate absolute time of alarm */
 159         clock_gettime(CLOCK_TYPE_ID, &now);
 160
 161         new_alarm->cb_fn = cb_fn;
 162         new_alarm->cb_arg = cb_arg;
 163         new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US) + us) % US_PER_S;
 164         new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US) + us) / US_PER_S);
 165
 166         rte_spinlock_lock(&alarm_list_lk);
 167         if (!handler_registered) {
 168                 ret |= rte_intr_callback_register(&intr_handle,
 169                                 eal_alarm_callback, NULL);
 170                 handler_registered = (ret == 0) ? 1 : 0;
 171         }
 172
 173         if (LIST_EMPTY(&alarm_list))
 174                 LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
 175         else {
 176                 LIST_FOREACH(ap, &alarm_list, next) {
 177                         if (ap->time.tv_sec > new_alarm->time.tv_sec ||
 178                                         (ap->time.tv_sec == new_alarm->time.tv_sec &&
 179                                                         ap->time.tv_usec > new_alarm->time.tv_usec)){
 180                                 LIST_INSERT_BEFORE(ap, new_alarm, next);
 181                                 break;
 182                         }
 183                         if (LIST_NEXT(ap, next) == NULL) {
 184                                 LIST_INSERT_AFTER(ap, new_alarm, next);
 185                                 break;
 186                         }
 187                 }
 188         }
 189
 190         if (LIST_FIRST(&alarm_list) == new_alarm) {
 191                 struct itimerspec alarm_time = {
 192                         .it_interval = {0, 0},
 193                         .it_value = {
 194                                 .tv_sec = us / US_PER_S,
 195                                 .tv_nsec = (us % US_PER_S) * NS_PER_US,
 196                         },
 197                 };
 198                 ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL);
 199         }
 200         rte_spinlock_unlock(&alarm_list_lk);
 201
 202         return ret;
 203 }
 204
 205 int
 206 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
 207 {
 208         struct alarm_entry *ap, *ap_prev;
 209         int count = 0;
 210         int err = 0;
 211         int executing;
 212
 213         if (!cb_fn) {
 214                 rte_errno = EINVAL;
 215                 return -1;
 216         }
 217
 218         do {
 219                 executing = 0;
 220                 rte_spinlock_lock(&alarm_list_lk);
 221                 /* remove any matches at the start of the list */
 222                 while ((ap = LIST_FIRST(&alarm_list)) != NULL &&
 223                                 cb_fn == ap->cb_fn &&
 224                                 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 225
 226                         if (ap->executing == 0) {
 227                                 LIST_REMOVE(ap, next);
 228                                 rte_free(ap);
 229                                 count++;
 230                         } else {
 231                                 /* If calling from other context, mark that alarm is executing
 232                                  * so loop can spin till it finish. Otherwise we are trying to
 233                                  * cancel our self - mark it by EINPROGRESS */
 234                                 if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 235                                         executing++;
 236                                 else
 237                                         err = EINPROGRESS;
 238
 239                                 break;
 240                         }
 241                 }
 242                 ap_prev = ap;
 243
 244                 /* now go through list, removing entries not at start */
 245                 LIST_FOREACH(ap, &alarm_list, next) {
 246                         /* this won't be true first time through */
 247                         if (cb_fn == ap->cb_fn &&
 248                                         (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 249
 250                                 if (ap->executing == 0) {
 251                                         LIST_REMOVE(ap, next);
 252                                         rte_free(ap);
 253                                         count++;
 254                                         ap = ap_prev;
 255                                 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 256                                         executing++;
 257                                 else
 258                                         err = EINPROGRESS;
 259                         }
 260                         ap_prev = ap;
 261                 }
 262                 rte_spinlock_unlock(&alarm_list_lk);
 263         } while (executing != 0);
 264
 265         if (count == 0 && err == 0)
 266                 rte_errno = ENOENT;
 267         else if (err)
 268                 rte_errno = err;
 269
 270         return count;
 271 }