server/sensor.c

   1 /**
   2  * @file sensor.c
   3  * @brief Implementation of sensor thread
   4  * TODO: Finalise implementation
   5  */
   6
   7 #include "common.h"
   8 #include "sensor.h"
   9 #include "options.h"
  10 #include "bbb_pin.h"
  11 #include <math.h>
  12
  13 /** Array of sensors, initialised by Sensor_Init **/
  14 static Sensor g_sensors[SENSORS_MAX];
  15 /** The number of sensors **/
  16 int g_num_sensors = 0;
  17
  18
  19
  20 /**
  21  * Add and initialise a Sensor
  22  * @param name - Human readable name of the sensor
  23  * @param user_id - User identifier
  24  * @param read - Function to call whenever the sensor should be read
  25  * @param init - Function to call to initialise the sensor (may be NULL)
  26  * @param max_error - Maximum error threshold; program will exit if this is exceeded for the sensor reading
  27  * @param min_error - Minimum error threshold; program will exit if the sensor reading falls below this value
  28  * @param max_warn - Maximum warning threshold; program will log warnings if the value exceeds this threshold
  29  * @param min_warn - Minimum warning threshold; program will log warnings if the value falls below this threshold
  30  * @returns Number of actuators added so far
  31  */
  32 int Sensor_Add(const char * name, int user_id, ReadFn read, InitFn init, CleanFn cleanup, SanityFn sanity)
  33 {
  34         if (++g_num_sensors > SENSORS_MAX)
  35         {
  36                 Fatal("Too many sensors; Increase SENSORS_MAX from %d in sensor.h and recompile", SENSORS_MAX);
  37                 // We could design the program to use realloc(3)
  38                 // But since someone who adds a new sensor has to recompile the program anyway...
  39         }
  40         Sensor * s = &(g_sensors[g_num_sensors-1]);
  41
  42         s->id = g_num_sensors-1;
  43         s->user_id = user_id;
  44         Data_Init(&(s->data_file));
  45         s->name = name;
  46         s->read = read; // Set read function
  47         s->init = init; // Set init function
  48
  49         // Start by averaging values taken over a second
  50         DOUBLE_TO_TIMEVAL(1e-4, &(s->sample_time));
  51         s->averages = 1;
  52         s->num_read = 0;
  53
  54         // Set sanity function
  55         s->sanity = sanity;
  56
  57         if (init != NULL)
  58         {
  59                 if (!init(name, user_id))
  60                         Fatal("Couldn't init sensor %s", name);
  61         }
  62
  63         s->current_data.time_stamp = 0;
  64         s->current_data.value = 0;
  65         return g_num_sensors;
  66 }
  67
  68 /**
  69  * Initialise all sensors used by the program
  70  * TODO: Edit this to add any extra sensors you need
  71  * TODO: Edit the includes as well
  72  */
  73 #include "sensors/resource.h"
  74 #include "sensors/strain.h"
  75 #include "sensors/pressure.h"
  76 void Sensor_Init()
  77 {
  78         Sensor_Add("cpu_stime", RESOURCE_CPU_SYS, Resource_Read, NULL, NULL, NULL);
  79         Sensor_Add("cpu_utime", RESOURCE_CPU_USER, Resource_Read, NULL, NULL, NULL);
  80         //Sensor_Add("pressure_high0", PRES_HIGH0, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  81         //Sensor_Add("pressure_high1", PRES_HIGH1, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  82         //Sensor_Add("pressure_low0", PRES_LOW0, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  83         //Sensor_Add("../testing/count.py", 0, Piped_Read, Piped_Init, Piped_Cleanup, 1e50,-1e50,1e50,-1e50);
  84         //Sensor_Add("strain0", STRAIN0, Strain_Read, Strain_Init, 5000,0,5000,0);
  85         //Sensor_Add("strain1", STRAIN1, Strain_Read, Strain_Init, 5000,0,5000,0);
  86         //Sensor_Add("strain2", STRAIN2, Strain_Read, Strain_Init, 5000,0,5000,0);
  87         //Sensor_Add("strain3", STRAIN3, Strain_Read, Strain_Init, 5000,0,5000,0);
  88         //Sensor_Add("pressure0", PRESSURE0, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  89         //Sensor_Add("pressure1", PRESSURE1, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  90         //Sensor_Add("pressure_feedback", PRESSURE_FEEDBACK, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  91         //Sensor_Add("enclosure", ENCLOSURE, Enclosure_Read, Enclosure_Init, 1,1,1,1);
  92         //Sensor_Add("dilatometer", DILATOMETER, Dilatometer_Read, Dilatometer_Init, -1,-1,-1,-1);
  93 }
  94
  95 /**
  96  * Cleanup all sensors
  97  */
  98 void Sensor_Cleanup()
  99 {
 100         for (int i = 0; i < g_num_sensors; ++i)
 101         {
 102                 Sensor * s = g_sensors+i;
 103                 if (s->cleanup != NULL)
 104                         s->cleanup(s->user_id);
 105         }
 106 }
 107
 108 /**
 109  * Sets the sensor to the desired control mode. No checks are
 110  * done to see if setting to the desired mode will conflict with
 111  * the current mode - the caller must guarantee this itself.
 112  * @param s The sensor whose mode is to be changed
 113  * @param mode The mode to be changed to
 114  * @param arg An argument specific to the mode to be set.
 115  *            e.g for CONTROL_START it represents the experiment name.
 116  */
 117 void Sensor_SetMode(Sensor * s, ControlModes mode, void * arg)
 118 {
 119         switch(mode)
 120         {
 121                 case CONTROL_START:
 122                         {
 123                                 // Set filename
 124                                 char filename[BUFSIZ];
 125                                 const char *experiment_path = (const char*) arg;
 126                                 int ret;
 127
 128                                 ret = snprintf(filename, BUFSIZ, "%s/sensor_%d", experiment_path, s->id);
 129
 130                                 if (ret >= BUFSIZ)
 131                                 {
 132                                         Fatal("Experiment path \"%s\" too long (%d, limit %d)",
 133                                                         experiment_path, ret, BUFSIZ);
 134                                 }
 135
 136                                 Log(LOGDEBUG, "Sensor %d with DataFile \"%s\"", s->id, filename);
 137                                 // Open DataFile
 138                                 Data_Open(&(s->data_file), filename);
 139                         }
 140                 case CONTROL_RESUME: //Case fallthrough, no break before
 141                         {
 142                                 int ret;
 143                                 s->activated = true; // Don't forget this!
 144
 145                                 // Create the thread
 146                                 ret = pthread_create(&(s->thread), NULL, Sensor_Loop, (void*)(s));
 147                                 if (ret != 0)
 148                                 {
 149                                         Fatal("Failed to create Sensor_Loop for Sensor %d", s->id);
 150                                 }
 151
 152                                 Log(LOGDEBUG, "Resuming sensor %d", s->id);
 153                         }
 154                 break;
 155
 156                 case CONTROL_EMERGENCY:
 157                 case CONTROL_PAUSE:
 158                         s->activated = false;
 159                         pthread_join(s->thread, NULL);
 160                         Log(LOGDEBUG, "Paused sensor %d", s->id);
 161                 break;
 162
 163                 case CONTROL_STOP:
 164                         if (s->activated) //May have been paused before
 165                         {
 166                                 s->activated = false;
 167                                 pthread_join(s->thread, NULL);
 168                         }
 169
 170                         Data_Close(&(s->data_file)); // Close DataFile
 171                         Log(LOGDEBUG, "Stopped sensor %d", s->id);
 172                 break;
 173                 default:
 174                         Fatal("Unknown control mode: %d", mode);
 175         }
 176 }
 177
 178 /**
 179  * Sets all sensors to the desired mode.
 180  * @see Sensor_SetMode for more information.
 181  * @param mode The mode to be changed to
 182  * @param arg An argument specific to the mode to be set.
 183  */
 184 void Sensor_SetModeAll(ControlModes mode, void * arg)
 185 {
 186         for (int i = 0; i < g_num_sensors; i++)
 187                 Sensor_SetMode(&g_sensors[i], mode, arg);
 188 }
 189
 190
 191 /**
 192  * Record data from a single Sensor; to be run in a seperate thread
 193  * @param arg - Cast to Sensor* - Sensor that the thread will handle
 194  * @returns NULL (void* required to use the function with pthreads)
 195  */
 196 void * Sensor_Loop(void * arg)
 197 {
 198         Sensor * s = (Sensor*)(arg);
 199         Log(LOGDEBUG, "Sensor %d starts", s->id);
 200
 201         // Until the sensor is stopped, record data points
 202         while (s->activated)
 203         {
 204                 DataPoint d;
 205                 d.value = 0;
 206                 bool success = s->read(s->user_id, &(d.value));
 207
 208                 struct timespec t;
 209                 clock_gettime(CLOCK_MONOTONIC, &t);
 210                 d.time_stamp = TIMEVAL_DIFF(t, *Control_GetStartTime());
 211
 212                 if (success)
 213                 {
 214                         if (s->sanity != NULL)
 215                         {
 216                                 if (!s->sanity(s->user_id, d.value))
 217                                 {
 218                                         Fatal("Sensor %s (%d,%d) reads unsafe value", s->name, s->id, s->user_id);
 219                                 }
 220                         }
 221                         s->current_data.time_stamp += d.time_stamp;
 222                         s->current_data.value += d.value;
 223
 224                         if (++(s->num_read) >= s->averages)
 225                         {
 226                                 s->current_data.time_stamp /= s->averages;
 227                                 s->current_data.value /= s->averages;
 228                                 Data_Save(&(s->data_file), &(s->current_data), 1); // Record it
 229                                 s->num_read = 0;
 230                                 s->current_data.time_stamp = 0;
 231                                 s->current_data.value = 0;
 232                         }
 233                 }
 234                 else
 235                         Log(LOGWARN, "Failed to read sensor %s (%d,%d)", s->name, s->id,s->user_id);
 236
 237
 238                 clock_nanosleep(CLOCK_MONOTONIC, 0, &(s->sample_time), NULL);
 239
 240         }
 241
 242         // Needed to keep pthreads happy
 243         Log(LOGDEBUG, "Sensor %s (%d,%d) finished", s->name,s->id,s->user_id);
 244         return NULL;
 245 }
 246
 247 /**
 248  * Get a Sensor given its name
 249  * @returns Sensor with the given name, NULL if there isn't one
 250  */
 251 Sensor * Sensor_Identify(const char * name)
 252 {
 253         for (int i = 0; i < g_num_sensors; ++i)
 254         {
 255                 if (strcmp(g_sensors[i].name, name) == 0)
 256                         return &(g_sensors[i]);
 257         }
 258         return NULL;
 259 }
 260
 261 /**
 262  * Helper: Begin sensor response in a given format
 263  * @param context - the FCGIContext
 264  * @param id - ID of sensor
 265  * @param format - Format
 266  */
 267 void Sensor_BeginResponse(FCGIContext * context, Sensor * s, DataFormat format)
 268 {
 269         // Begin response
 270         switch (format)
 271         {
 272                 case JSON:
 273                         FCGI_BeginJSON(context, STATUS_OK);
 274                         FCGI_JSONLong("id", s->id);
 275                         FCGI_JSONLong("user_id", s->user_id); //NOTE: Might not want to expose this?
 276                         FCGI_JSONPair("name", s->name);
 277                         break;
 278                 default:
 279                         FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 280                         break;
 281         }
 282 }
 283
 284 /**
 285  * Helper: End sensor response in a given format
 286  * @param context - the FCGIContext
 287  * @param id - ID of the sensor
 288  * @param format - Format
 289  */
 290 void Sensor_EndResponse(FCGIContext * context, Sensor * s, DataFormat format)
 291 {
 292         // End response
 293         switch (format)
 294         {
 295                 case JSON:
 296                         FCGI_EndJSON();
 297                         break;
 298                 default:
 299                         break;
 300         }
 301 }
 302
 303 /**
 304  * Handle a request to the sensor module
 305  * @param context - The context to work in
 306  * @param params - Parameters passed
 307  */
 308 void Sensor_Handler(FCGIContext *context, char * params)
 309 {
 310         struct timespec now;
 311         clock_gettime(CLOCK_MONOTONIC, &now);
 312         double current_time = TIMEVAL_DIFF(now, *Control_GetStartTime());
 313         int id = 0;
 314         const char * name = "";
 315         double start_time = 0;
 316         double end_time = current_time;
 317         const char * fmt_str;
 318         double sample_s = 0;
 319
 320         // key/value pairs
 321         FCGIValue values[] = {
 322                 {"id", &id, FCGI_INT_T},
 323                 {"name", &name, FCGI_STRING_T},
 324                 {"format", &fmt_str, FCGI_STRING_T},
 325                 {"start_time", &start_time, FCGI_DOUBLE_T},
 326                 {"end_time", &end_time, FCGI_DOUBLE_T},
 327                 {"sample_s", &sample_s, FCGI_DOUBLE_T}
 328         };
 329
 330         // enum to avoid the use of magic numbers
 331         typedef enum {
 332                 ID,
 333                 NAME,
 334                 FORMAT,
 335                 START_TIME,
 336                 END_TIME,
 337                 SAMPLE_S
 338         } SensorParams;
 339
 340         // Fill values appropriately
 341         if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
 342         {
 343                 // Error occured; FCGI_RejectJSON already called
 344                 return;
 345         }
 346
 347         Sensor * s = NULL;
 348         if (FCGI_RECEIVED(values[NAME].flags))
 349         {
 350                 if (FCGI_RECEIVED(values[ID].flags))
 351                 {
 352                         FCGI_RejectJSON(context, "Can't supply both sensor id and name");
 353                         return;
 354                 }
 355                 s = Sensor_Identify(name);
 356                 if (s == NULL)
 357                 {
 358                         FCGI_RejectJSON(context, "Unknown sensor name");
 359                         return;
 360                 }
 361         }
 362         else if (!FCGI_RECEIVED(values[ID].flags))
 363         {
 364                 FCGI_RejectJSON(context, "No sensor id or name supplied");
 365                 return;
 366         }
 367         else if (id < 0 || id >= g_num_sensors)
 368         {
 369                 FCGI_RejectJSON(context, "Invalid sensor id");
 370                 return;
 371         }
 372         else
 373         {
 374                 s = &(g_sensors[id]);
 375         }
 376
 377         // Adjust sample rate if necessary
 378         if (FCGI_RECEIVED(values[SAMPLE_S].flags))
 379         {
 380                 if (sample_s < 0)
 381                 {
 382                         FCGI_RejectJSON(context, "Negative sampling speed!");
 383                         return;
 384                 }
 385                 DOUBLE_TO_TIMEVAL(sample_s, &(s->sample_time));
 386         }
 387
 388
 389         DataFormat format = Data_GetFormat(&(values[FORMAT]));
 390
 391         // Begin response
 392         Sensor_BeginResponse(context, s, format);
 393
 394         // Print Data
 395         Data_Handler(&(s->data_file), &(values[START_TIME]), &(values[END_TIME]), format, current_time);
 396
 397         // Finish response
 398         Sensor_EndResponse(context, s, format);
 399
 400 }
 401
 402 /**
 403  * Get the Name of a Sensor
 404  * @param id - ID number
 405  */
 406 const char * Sensor_GetName(int id)
 407 {
 408         return g_sensors[id].name;
 409 }
 410
 411
 412