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(1, &(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         s->averaged_data.time_stamp = 0;
  66         s->averaged_data.value = 0;
  67         return g_num_sensors;
  68 }
  69
  70 /**
  71  * Initialise all sensors used by the program
  72  * TODO: Edit this to add any extra sensors you need
  73  * TODO: Edit the includes as well
  74  */
  75 #include "sensors/resource.h"
  76 #include "sensors/strain.h"
  77 #include "sensors/pressure.h"
  78 void Sensor_Init()
  79 {
  80         //Sensor_Add("cpu_stime", RESOURCE_CPU_SYS, Resource_Read, NULL, NULL, NULL);
  81         //Sensor_Add("cpu_utime", RESOURCE_CPU_USER, Resource_Read, NULL, NULL, NULL);
  82         Sensor_Add("pressure_high0", PRES_HIGH0, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  83         Sensor_Add("pressure_high1", PRES_HIGH1, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  84         Sensor_Add("pressure_low0", PRES_LOW0, Pressure_Read, Pressure_Init, Pressure_Cleanup, NULL);
  85         //Sensor_Add("../testing/count.py", 0, Piped_Read, Piped_Init, Piped_Cleanup, 1e50,-1e50,1e50,-1e50);
  86         Sensor_Add("strain0", STRAIN0, Strain_Read, Strain_Init, Strain_Cleanup, Strain_Sanity);
  87         Sensor_Add("strain1", STRAIN1, Strain_Read, Strain_Init, Strain_Cleanup, Strain_Sanity);
  88         Sensor_Add("strain2", STRAIN2, Strain_Read, Strain_Init, Strain_Cleanup, Strain_Sanity);
  89         Sensor_Add("strain3", STRAIN3, Strain_Read, Strain_Init, Strain_Cleanup, Strain_Sanity);
  90         //Sensor_Add("pressure0", PRESSURE0, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  91         //Sensor_Add("pressure1", PRESSURE1, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  92         //Sensor_Add("pressure_feedback", PRESSURE_FEEDBACK, Pressure_Read, Pressure_Init, 5000,0,5000,0);
  93         //Sensor_Add("enclosure", ENCLOSURE, Enclosure_Read, Enclosure_Init, 1,1,1,1);
  94         //Sensor_Add("dilatometer", DILATOMETER, Dilatometer_Read, Dilatometer_Init, -1,-1,-1,-1);
  95 }
  96
  97 /**
  98  * Cleanup all sensors
  99  */
 100 void Sensor_Cleanup()
 101 {
 102         for (int i = 0; i < g_num_sensors; ++i)
 103         {
 104                 Sensor * s = g_sensors+i;
 105                 if (s->cleanup != NULL)
 106                         s->cleanup(s->user_id);
 107         }
 108         g_num_sensors = 0;
 109 }
 110
 111 /**
 112  * Sets the sensor to the desired control mode. No checks are
 113  * done to see if setting to the desired mode will conflict with
 114  * the current mode - the caller must guarantee this itself.
 115  * @param s The sensor whose mode is to be changed
 116  * @param mode The mode to be changed to
 117  * @param arg An argument specific to the mode to be set.
 118  *            e.g for CONTROL_START it represents the experiment name.
 119  */
 120 void Sensor_SetMode(Sensor * s, ControlModes mode, void * arg)
 121 {
 122         switch(mode)
 123         {
 124                 case CONTROL_START:
 125                         {
 126                                 // Set filename
 127                                 char filename[BUFSIZ];
 128                                 const char *experiment_path = (const char*) arg;
 129                                 int ret;
 130
 131                                 ret = snprintf(filename, BUFSIZ, "%s/sensor_%d", experiment_path, s->id);
 132
 133                                 if (ret >= BUFSIZ)
 134                                 {
 135                                         Fatal("Experiment path \"%s\" too long (%d, limit %d)",
 136                                                         experiment_path, ret, BUFSIZ);
 137                                 }
 138
 139                                 Log(LOGDEBUG, "Sensor %d with DataFile \"%s\"", s->id, filename);
 140                                 // Open DataFile
 141                                 Data_Open(&(s->data_file), filename);
 142                         }
 143                 case CONTROL_RESUME: //Case fallthrough, no break before
 144                         {
 145                                 int ret;
 146                                 s->activated = true; // Don't forget this!
 147
 148                                 // Create the thread
 149                                 ret = pthread_create(&(s->thread), NULL, Sensor_Loop, (void*)(s));
 150                                 if (ret != 0)
 151                                 {
 152                                         Fatal("Failed to create Sensor_Loop for Sensor %d", s->id);
 153                                 }
 154
 155                                 Log(LOGDEBUG, "Resuming sensor %d", s->id);
 156                         }
 157                 break;
 158
 159                 case CONTROL_EMERGENCY:
 160                 case CONTROL_PAUSE:
 161                         s->activated = false;
 162                         pthread_join(s->thread, NULL);
 163                         Log(LOGDEBUG, "Paused sensor %d", s->id);
 164                 break;
 165
 166                 case CONTROL_STOP:
 167                         if (s->activated) //May have been paused before
 168                         {
 169                                 s->activated = false;
 170                                 pthread_join(s->thread, NULL);
 171                         }
 172
 173                         Data_Close(&(s->data_file)); // Close DataFile
 174                         Log(LOGDEBUG, "Stopped sensor %d", s->id);
 175                 break;
 176                 default:
 177                         Fatal("Unknown control mode: %d", mode);
 178         }
 179 }
 180
 181 /**
 182  * Sets all sensors to the desired mode.
 183  * @see Sensor_SetMode for more information.
 184  * @param mode The mode to be changed to
 185  * @param arg An argument specific to the mode to be set.
 186  */
 187 void Sensor_SetModeAll(ControlModes mode, void * arg)
 188 {
 189         if (mode == CONTROL_START)
 190                 Sensor_Init();
 191         for (int i = 0; i < g_num_sensors; i++)
 192                 Sensor_SetMode(&g_sensors[i], mode, arg);
 193         if (mode == CONTROL_STOP)
 194                 Sensor_Cleanup();
 195 }
 196
 197
 198 /**
 199  * Record data from a single Sensor; to be run in a seperate thread
 200  * @param arg - Cast to Sensor* - Sensor that the thread will handle
 201  * @returns NULL (void* required to use the function with pthreads)
 202  */
 203 void * Sensor_Loop(void * arg)
 204 {
 205         Sensor * s = (Sensor*)(arg);
 206         Log(LOGDEBUG, "Sensor %d starts", s->id);
 207
 208         // Until the sensor is stopped, record data points
 209         while (s->activated)
 210         {
 211
 212                 bool success = s->read(s->user_id, &(s->current_data.value));
 213
 214                 struct timespec t;
 215                 clock_gettime(CLOCK_MONOTONIC, &t);
 216                 s->current_data.time_stamp = TIMEVAL_DIFF(t, *Control_GetStartTime());
 217
 218                 if (success)
 219                 {
 220                         if (s->sanity != NULL)
 221                         {
 222                                 if (!s->sanity(s->user_id, s->current_data.value))
 223                                 {
 224                                         Fatal("Sensor %s (%d,%d) reads unsafe value", s->name, s->id, s->user_id);
 225                                 }
 226                         }
 227                         s->averaged_data.time_stamp += s->current_data.time_stamp;
 228                         s->averaged_data.value = s->current_data.value;
 229
 230                         if (++(s->num_read) >= s->averages)
 231                         {
 232                                 s->averaged_data.time_stamp /= s->averages;
 233                                 s->averaged_data.value /= s->averages;
 234                                 Data_Save(&(s->data_file), &(s->averaged_data), 1); // Record it
 235                                 s->num_read = 0;
 236                                 s->averaged_data.time_stamp = 0;
 237                                 s->averaged_data.value = 0;
 238                         }
 239                 }
 240                 else
 241                 {
 242                         // Silence because strain sensors fail ~50% of the time :S
 243                         //Log(LOGWARN, "Failed to read sensor %s (%d,%d)", s->name, s->id,s->user_id);
 244                 }
 245
 246
 247                 clock_nanosleep(CLOCK_MONOTONIC, 0, &(s->sample_time), NULL);
 248
 249         }
 250
 251         // Needed to keep pthreads happy
 252         Log(LOGDEBUG, "Sensor %s (%d,%d) finished", s->name,s->id,s->user_id);
 253         return NULL;
 254 }
 255
 256 /**
 257  * Get a Sensor given its name
 258  * @returns Sensor with the given name, NULL if there isn't one
 259  */
 260 Sensor * Sensor_Identify(const char * name)
 261 {
 262         for (int i = 0; i < g_num_sensors; ++i)
 263         {
 264                 if (strcmp(g_sensors[i].name, name) == 0)
 265                         return &(g_sensors[i]);
 266         }
 267         return NULL;
 268 }
 269
 270 /**
 271  * Helper: Begin sensor response in a given format
 272  * @param context - the FCGIContext
 273  * @param id - ID of sensor
 274  * @param format - Format
 275  */
 276 void Sensor_BeginResponse(FCGIContext * context, Sensor * s, DataFormat format)
 277 {
 278         // Begin response
 279         switch (format)
 280         {
 281                 case JSON:
 282                         FCGI_BeginJSON(context, STATUS_OK);
 283                         FCGI_JSONLong("id", s->id);
 284                         FCGI_JSONLong("user_id", s->user_id); //NOTE: Might not want to expose this?
 285                         FCGI_JSONPair("name", s->name);
 286                         break;
 287                 default:
 288                         FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 289                         break;
 290         }
 291 }
 292
 293 /**
 294  * Helper: End sensor response in a given format
 295  * @param context - the FCGIContext
 296  * @param id - ID of the sensor
 297  * @param format - Format
 298  */
 299 void Sensor_EndResponse(FCGIContext * context, Sensor * s, DataFormat format)
 300 {
 301         // End response
 302         switch (format)
 303         {
 304                 case JSON:
 305                         FCGI_EndJSON();
 306                         break;
 307                 default:
 308                         break;
 309         }
 310 }
 311
 312 /**
 313  * Handle a request to the sensor module
 314  * @param context - The context to work in
 315  * @param params - Parameters passed
 316  */
 317 void Sensor_Handler(FCGIContext *context, char * params)
 318 {
 319         struct timespec now;
 320         clock_gettime(CLOCK_MONOTONIC, &now);
 321         double current_time = TIMEVAL_DIFF(now, *Control_GetStartTime());
 322         int id = 0;
 323         const char * name = "";
 324         double start_time = 0;
 325         double end_time = current_time;
 326         const char * fmt_str;
 327         double sample_s = 0;
 328
 329         // key/value pairs
 330         FCGIValue values[] = {
 331                 {"id", &id, FCGI_INT_T},
 332                 {"name", &name, FCGI_STRING_T},
 333                 {"format", &fmt_str, FCGI_STRING_T},
 334                 {"start_time", &start_time, FCGI_DOUBLE_T},
 335                 {"end_time", &end_time, FCGI_DOUBLE_T},
 336                 {"sample_s", &sample_s, FCGI_DOUBLE_T}
 337         };
 338
 339         // enum to avoid the use of magic numbers
 340         typedef enum {
 341                 ID,
 342                 NAME,
 343                 FORMAT,
 344                 START_TIME,
 345                 END_TIME,
 346                 SAMPLE_S
 347         } SensorParams;
 348
 349         // Fill values appropriately
 350         if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
 351         {
 352                 // Error occured; FCGI_RejectJSON already called
 353                 return;
 354         }
 355
 356         Sensor * s = NULL;
 357         if (FCGI_RECEIVED(values[NAME].flags))
 358         {
 359                 if (FCGI_RECEIVED(values[ID].flags))
 360                 {
 361                         FCGI_RejectJSON(context, "Can't supply both sensor id and name");
 362                         return;
 363                 }
 364                 s = Sensor_Identify(name);
 365                 if (s == NULL)
 366                 {
 367                         FCGI_RejectJSON(context, "Unknown sensor name");
 368                         return;
 369                 }
 370         }
 371         else if (!FCGI_RECEIVED(values[ID].flags))
 372         {
 373                 FCGI_RejectJSON(context, "No sensor id or name supplied");
 374                 return;
 375         }
 376         else if (id < 0 || id >= g_num_sensors)
 377         {
 378                 FCGI_RejectJSON(context, "Invalid sensor id");
 379                 return;
 380         }
 381         else
 382         {
 383                 s = &(g_sensors[id]);
 384         }
 385
 386         // Adjust sample rate if necessary
 387         if (FCGI_RECEIVED(values[SAMPLE_S].flags))
 388         {
 389                 if (sample_s < 0)
 390                 {
 391                         FCGI_RejectJSON(context, "Negative sampling speed!");
 392                         return;
 393                 }
 394                 DOUBLE_TO_TIMEVAL(sample_s, &(s->sample_time));
 395         }
 396
 397
 398         DataFormat format = Data_GetFormat(&(values[FORMAT]));
 399
 400         // Begin response
 401         Sensor_BeginResponse(context, s, format);
 402
 403         // Print Data
 404         Data_Handler(&(s->data_file), &(values[START_TIME]), &(values[END_TIME]), format, current_time);
 405
 406         // Finish response
 407         Sensor_EndResponse(context, s, format);
 408
 409 }
 410
 411 /**
 412  * Get the Name of a Sensor
 413  * @param id - ID number
 414  */
 415 const char * Sensor_GetName(int id)
 416 {
 417         return g_sensors[id].name;
 418 }
 419
 420 DataPoint Sensor_LastData(int id)
 421 {
 422         Sensor * s = &(g_sensors[id]);
 423         return s->current_data;
 424 }
 425
 426