timeout.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License.
   5  *
   6  *   This program is distributed in the hope that it will be useful,
   7  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  *   GNU General Public License for more details.
  10  *
  11  *   You should have received a copy of the GNU General Public License
  12  *   along with this program; if not, write to the Free Software
  13  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  14  *
  15  *   Copyright (C) 2020 embedd.ch
  16  *   Copyright (C) 2020 Felix Fietkau <nbd@nbd.name>
  17  *   Copyright (C) 2020 John Crispin <john@phrozen.org>
  18  */
  19
  20 #include <string.h>
  21
  22 #include <libubox/utils.h>
  23
  24 #include "timeout.h"
  25
  26 static int usteer_timeout_cmp(const void *k1, const void *k2, void *ptr)
  27 {
  28         uint32_t ref = (uint32_t) (intptr_t) ptr;
  29         int32_t t1 = (uint32_t) (intptr_t) k1 - ref;
  30         int32_t t2 = (uint32_t) (intptr_t) k2 - ref;
  31
  32         if (t1 < t2)
  33                 return -1;
  34         else if (t1 > t2)
  35                 return 1;
  36         else
  37                 return 0;
  38 }
  39
  40 static int32_t usteer_timeout_delta(struct usteer_timeout *t, uint32_t time)
  41 {
  42         uint32_t val = (uint32_t) (intptr_t) t->node.key;
  43         return val - time;
  44 }
  45
  46 static void usteer_timeout_recalc(struct usteer_timeout_queue *q, uint32_t time)
  47 {
  48         struct usteer_timeout *t;
  49         int32_t delta;
  50
  51         if (avl_is_empty(&q->tree)) {
  52                 uloop_timeout_cancel(&q->timeout);
  53                 return;
  54         }
  55
  56         t = avl_first_element(&q->tree, t, node);
  57
  58         delta = usteer_timeout_delta(t, time);
  59         if (delta < 1)
  60                 delta = 1;
  61
  62         uloop_timeout_set(&q->timeout, delta);
  63 }
  64
  65 static uint32_t ampgr_timeout_current_time(void)
  66 {
  67         struct timespec ts;
  68         uint32_t val;
  69
  70         clock_gettime(CLOCK_MONOTONIC, &ts);
  71         val = ts.tv_sec * 1000;
  72         val += ts.tv_nsec / 1000000;
  73
  74         return val;
  75 }
  76
  77 static void usteer_timeout_cb(struct uloop_timeout *timeout)
  78 {
  79         struct usteer_timeout_queue *q;
  80         struct usteer_timeout *t, *tmp;
  81         bool found;
  82         uint32_t time;
  83
  84         q = container_of(timeout, struct usteer_timeout_queue, timeout);
  85         do {
  86                 found = false;
  87                 time = ampgr_timeout_current_time();
  88
  89                 avl_for_each_element_safe(&q->tree, t, node, tmp) {
  90                         if (usteer_timeout_delta(t, time) > 0)
  91                                 break;
  92
  93                         usteer_timeout_cancel(q, t);
  94                         if (q->cb)
  95                                 q->cb(q, t);
  96                         found = true;
  97                 }
  98         } while (found);
  99
 100         usteer_timeout_recalc(q, time);
 101 }
 102
 103
 104 void usteer_timeout_init(struct usteer_timeout_queue *q)
 105 {
 106         avl_init(&q->tree, usteer_timeout_cmp, true, NULL);
 107         q->timeout.cb = usteer_timeout_cb;
 108 }
 109
 110 static void __usteer_timeout_cancel(struct usteer_timeout_queue *q,
 111                                    struct usteer_timeout *t)
 112 {
 113         avl_delete(&q->tree, &t->node);
 114 }
 115
 116 void usteer_timeout_set(struct usteer_timeout_queue *q, struct usteer_timeout *t,
 117                        int msecs)
 118 {
 119         uint32_t time = ampgr_timeout_current_time();
 120         uint32_t val = time + msecs;
 121         bool recalc = false;
 122
 123         q->tree.cmp_ptr = (void *) (intptr_t) time;
 124         if (usteer_timeout_isset(t)) {
 125                 if (avl_is_first(&q->tree, &t->node))
 126                         recalc = true;
 127
 128                 __usteer_timeout_cancel(q, t);
 129         }
 130
 131         t->node.key = (void *) (intptr_t) val;
 132         avl_insert(&q->tree, &t->node);
 133         if (avl_is_first(&q->tree, &t->node))
 134                 recalc = true;
 135
 136         if (recalc)
 137                 usteer_timeout_recalc(q, time);
 138 }
 139
 140 void usteer_timeout_cancel(struct usteer_timeout_queue *q,
 141                           struct usteer_timeout *t)
 142 {
 143         if (!usteer_timeout_isset(t))
 144                 return;
 145
 146         __usteer_timeout_cancel(q, t);
 147         memset(&t->node.list, 0, sizeof(t->node.list));
 148 }
 149
 150 void usteer_timeout_flush(struct usteer_timeout_queue *q)
 151 {
 152         struct usteer_timeout *t, *tmp;
 153
 154         uloop_timeout_cancel(&q->timeout);
 155         avl_remove_all_elements(&q->tree, t, node, tmp) {
 156                 memset(&t->node.list, 0, sizeof(t->node.list));
 157                 if (q->cb)
 158                         q->cb(q, t);
 159         }
 160 }