task-utils.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public
   4  * License v2 as published by the Free Software Foundation.
   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 GNU
   9  * General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public
  12  * License along with this program; if not, write to the
  13  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14  * Boston, MA 021110-1307, USA.
  15  */
  16
  17 #include <pthread.h>
  18 #include <sys/timerfd.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22
  23 #include "task-utils.h"
  24
  25 struct task_info *task_init(void *(*threadfn)(void *), int (*postfn)(void *),
  26                             void *thread_private)
  27 {
  28         struct task_info *info = calloc(1, sizeof(struct task_info));
  29
  30         if (!info)
  31                 return NULL;
  32
  33         info->private_data = thread_private;
  34         info->threadfn = threadfn;
  35         info->postfn = postfn;
  36
  37         return info;
  38 }
  39
  40 int task_start(struct task_info *info)
  41 {
  42         int ret;
  43
  44         if (!info)
  45                 return -1;
  46
  47         if (!info->threadfn)
  48                 return -1;
  49
  50         ret = pthread_create(&info->id, NULL, info->threadfn,
  51                              info->private_data);
  52
  53         if (ret)
  54                 info->id = 0;
  55
  56         return ret;
  57 }
  58
  59 void task_stop(struct task_info *info)
  60 {
  61         if (!info)
  62                 return;
  63
  64         if (info->id > 0) {
  65                 pthread_cancel(info->id);
  66                 pthread_join(info->id, NULL);
  67                 info->id = 0;
  68         }
  69
  70         if (info->periodic.timer_fd) {
  71                 close(info->periodic.timer_fd);
  72                 info->periodic.timer_fd = 0;
  73         }
  74
  75         if (info->postfn)
  76                 info->postfn(info->private_data);
  77 }
  78
  79 void task_deinit(struct task_info *info)
  80 {
  81         if (!info)
  82                 return;
  83
  84         free(info);
  85 }
  86
  87 int task_period_start(struct task_info *info, unsigned int period_ms)
  88 {
  89         unsigned int ns;
  90         unsigned int sec;
  91         struct itimerspec itval;
  92
  93         if (!info)
  94                 return -1;
  95
  96         info->periodic.timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
  97         if (info->periodic.timer_fd == -1) {
  98                 info->periodic.timer_fd = 0;
  99                 return info->periodic.timer_fd;
 100         }
 101
 102         info->periodic.wakeups_missed = 0;
 103
 104         sec = period_ms / 1000;
 105         ns = (period_ms - (sec * 1000)) * 1000;
 106         itval.it_interval.tv_sec = sec;
 107         itval.it_interval.tv_nsec = ns;
 108         itval.it_value.tv_sec = sec;
 109         itval.it_value.tv_nsec = ns;
 110
 111         return timerfd_settime(info->periodic.timer_fd, 0, &itval, NULL);
 112 };
 113
 114 void task_period_wait(struct task_info *info)
 115 {
 116         unsigned long long missed;
 117         int ret;
 118
 119         if (!info)
 120                 return;
 121
 122         ret = read(info->periodic.timer_fd, &missed, sizeof (missed));
 123         if (ret == -1)
 124                 return;
 125
 126         if (missed > 0)
 127                 info->periodic.wakeups_missed += (missed - 1);
 128 }
 129
 130 void task_period_stop(struct task_info *info)
 131 {
 132         if (!info)
 133                 return;
 134
 135         if (info->periodic.timer_fd) {
 136                 timerfd_settime(info->periodic.timer_fd, 0, NULL, NULL);
 137                 close(info->periodic.timer_fd);
 138                 info->periodic.timer_fd = -1;
 139         }
 140 }