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 == 0)
  54                 pthread_detach(info->id);
  55         else
  56                 info->id = -1;
  57
  58         return ret;
  59 }
  60
  61 void task_stop(struct task_info *info)
  62 {
  63         if (!info)
  64                 return;
  65
  66         if (info->periodic.timer_fd)
  67                 close(info->periodic.timer_fd);
  68
  69         if (info->id > 0)
  70                 pthread_cancel(info->id);
  71
  72         if (info->postfn)
  73                 info->postfn(info->private_data);
  74 }
  75
  76 void task_deinit(struct task_info *info)
  77 {
  78         if (!info)
  79                 return;
  80
  81         free(info);
  82 }
  83
  84 int task_period_start(struct task_info *info, unsigned int period_ms)
  85 {
  86         unsigned int ns;
  87         unsigned int sec;
  88         struct itimerspec itval;
  89
  90         if (!info)
  91                 return -1;
  92
  93         info->periodic.timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
  94         if (info->periodic.timer_fd == -1)
  95                 return info->periodic.timer_fd;
  96
  97         info->periodic.wakeups_missed = 0;
  98
  99         sec = period_ms / 1000;
 100         ns = (period_ms - (sec * 1000)) * 1000;
 101         itval.it_interval.tv_sec = sec;
 102         itval.it_interval.tv_nsec = ns;
 103         itval.it_value.tv_sec = sec;
 104         itval.it_value.tv_nsec = ns;
 105
 106         return timerfd_settime(info->periodic.timer_fd, 0, &itval, NULL);
 107 };
 108
 109 void task_period_wait(struct task_info *info)
 110 {
 111         unsigned long long missed;
 112         int ret;
 113
 114         if (!info)
 115                 return;
 116
 117         ret = read(info->periodic.timer_fd, &missed, sizeof (missed));
 118         if (ret == -1)
 119                 return;
 120
 121         if (missed > 0)
 122                 info->periodic.wakeups_missed += (missed - 1);
 123 }
 124
 125 void task_period_stop(struct task_info *info)
 126 {
 127         if (!info)
 128                 return;
 129
 130         if (info->periodic.timer_fd) {
 131                 timerfd_settime(info->periodic.timer_fd, 0, NULL, NULL);
 132                 close(info->periodic.timer_fd);
 133         }
 134 }