l4/pkg/ferret/examples/monitors/merge_mon/poll.c

   1 /**
   2  * \file   ferret/examples/merge_mon/poll.c
   3  * \brief  polls for outstanding sensors
   4  *
   5  * \date   2007-11-27
   6  * \author Ronald Aigner  <ra3@os.inf.tu-dresden.de>
   7  */
   8 /*
   9  * (c) 2007-2009 Technische Universität Dresden
  10  * This file is part of TUD:OS and distributed under the terms of the
  11  * GNU General Public License 2.
  12  * Please see the COPYING-GPL-2 file for details.
  13  */
  14
  15 #include <stdio.h>
  16
  17 #include <l4/sys/cache.h>
  18 #include <l4/util/util.h>
  19
  20 #include <l4/ferret/monitor.h>
  21 #include <l4/ferret/comm.h>
  22 #include <l4/ferret/sensors/list_consumer.h>
  23 //#include <l4/ferret/sensors/tbuf_consumer.h>
  24
  25 #include "poll.h"
  26 #include "main.h"
  27
  28 static void polling_thread(void* arg)
  29 {
  30     int searching = 1;
  31     int i, ret;
  32     uint16_t type;
  33
  34     while (searching)
  35     {
  36         l4_sleep(1000);
  37         searching = 0;
  38
  39         for (i = 0; i < sensor_count; i++)
  40         {
  41             if (sensors[i].open)
  42                 continue;
  43
  44                         l4_cap_idx_t srv = lookup_sensordir();
  45
  46             searching = 1;
  47             ret = ferret_att(srv, sensors[i].major, sensors[i].minor,
  48                              sensors[i].instance, sensors[i].sensor);
  49             if (ret)
  50             {
  51                 if (verbose)
  52                 {
  53                     printf("Still could not attach to %hu:%hu:%hu, retrying!\n",
  54                            sensors[i].major, sensors[i].minor,
  55                            sensors[i].instance);
  56                 }
  57                 continue;
  58             }
  59
  60             // this looks a bit racy ...
  61             sensors[i].copied    = 0;
  62             sensors[i].last_lost = 0;
  63             sensors[i].last_ts   = 0;
  64
  65             type = ((ferret_common_t *)(sensors[i].sensor))->type;
  66             if (type != FERRET_LIST && type != FERRET_TBUF)
  67             {
  68                 printf("Found wrong sensor type (%d): %hu!\n", i, type);
  69             }
  70
  71             if (verbose)
  72             {
  73                 printf("Attached to %hu:%hu:%hu.\n",
  74                        sensors[i].major, sensors[i].minor,
  75                        sensors[i].instance);
  76             }
  77
  78             __asm__ __volatile__("": : :"memory");  // barrier
  79             sensors[i].open = 1;
  80         }
  81     }
  82 }
  83
  84 void poll_sensors(void)
  85 {
  86     l4thread_create_named(polling_thread, ".poll", 0, L4THREAD_CREATE_ASYNC);
  87 }