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_name = (const char*) arg;
 126
 127                                 if (snprintf(filename, BUFSIZ, "%s_%d", experiment_name, s->id) >= BUFSIZ)
 128                                 {
 129                                         Fatal("Experiment name \"%s\" too long (>%d)", experiment_name, BUFSIZ);
 130                                 }
 131
 132                                 Log(LOGDEBUG, "Sensor %d with DataFile \"%s\"", s->id, filename);
 133                                 // Open DataFile
 134                                 Data_Open(&(s->data_file), filename);
 135                         }
 136                 case CONTROL_RESUME: //Case fallthrough, no break before
 137                         {
 138                                 int ret;
 139                                 s->activated = true; // Don't forget this!
 140
 141                                 // Create the thread
 142                                 ret = pthread_create(&(s->thread), NULL, Sensor_Loop, (void*)(s));
 143                                 if (ret != 0)
 144                                 {
 145                                         Fatal("Failed to create Sensor_Loop for Sensor %d", s->id);
 146                                 }
 147
 148                                 Log(LOGDEBUG, "Resuming sensor %d", s->id);
 149                         }
 150                 break;
 151
 152                 case CONTROL_EMERGENCY:
 153                 case CONTROL_PAUSE:
 154                         s->activated = false;
 155                         pthread_join(s->thread, NULL);
 156                         Log(LOGDEBUG, "Paused sensor %d", s->id);
 157                 break;
 158
 159                 case CONTROL_STOP:
 160                         if (s->activated) //May have been paused before
 161                         {
 162                                 s->activated = false;
 163                                 pthread_join(s->thread, NULL);
 164                         }
 165
 166                         Data_Close(&(s->data_file)); // Close DataFile
 167                         Log(LOGDEBUG, "Stopped sensor %d", s->id);
 168                 break;
 169                 default:
 170                         Fatal("Unknown control mode: %d", mode);
 171         }
 172 }
 173
 174 /**
 175  * Sets all sensors to the desired mode.
 176  * @see Sensor_SetMode for more information.
 177  * @param mode The mode to be changed to
 178  * @param arg An argument specific to the mode to be set.
 179  */
 180 void Sensor_SetModeAll(ControlModes mode, void * arg)
 181 {
 182         for (int i = 0; i < g_num_sensors; i++)
 183                 Sensor_SetMode(&g_sensors[i], mode, arg);
 184 }
 185
 186
 187 /**
 188  * Record data from a single Sensor; to be run in a seperate thread
 189  * @param arg - Cast to Sensor* - Sensor that the thread will handle
 190  * @returns NULL (void* required to use the function with pthreads)
 191  */
 192 void * Sensor_Loop(void * arg)
 193 {
 194         Sensor * s = (Sensor*)(arg);
 195         Log(LOGDEBUG, "Sensor %d starts", s->id);
 196
 197         // Until the sensor is stopped, record data points
 198         while (s->activated)
 199         {
 200                 DataPoint d;
 201                 d.value = 0;
 202                 bool success = s->read(s->user_id, &(d.value));
 203
 204                 struct timespec t;
 205                 clock_gettime(CLOCK_MONOTONIC, &t);
 206                 d.time_stamp = TIMEVAL_DIFF(t, *Control_GetStartTime());
 207
 208                 if (success)
 209                 {
 210                         if (s->sanity != NULL)
 211                         {
 212                                 if (!s->sanity(s->user_id, d.value))
 213                                 {
 214                                         Fatal("Sensor %s (%d,%d) reads unsafe value", s->name, s->id, s->user_id);
 215                                 }
 216                         }
 217                         s->current_data.time_stamp += d.time_stamp;
 218                         s->current_data.value += d.value;
 219
 220                         if (++(s->num_read) >= s->averages)
 221                         {
 222                                 s->current_data.time_stamp /= s->averages;
 223                                 s->current_data.value /= s->averages;
 224                                 Data_Save(&(s->data_file), &(s->current_data), 1); // Record it
 225                                 s->num_read = 0;
 226                                 s->current_data.time_stamp = 0;
 227                                 s->current_data.value = 0;
 228                         }
 229                 }
 230                 else
 231                         Log(LOGWARN, "Failed to read sensor %s (%d,%d)", s->name, s->id,s->user_id);
 232
 233
 234                 clock_nanosleep(CLOCK_MONOTONIC, 0, &(s->sample_time), NULL);
 235
 236         }
 237
 238         // Needed to keep pthreads happy
 239         Log(LOGDEBUG, "Sensor %s (%d,%d) finished", s->name,s->id,s->user_id);
 240         return NULL;
 241 }
 242
 243 /**
 244  * Get a Sensor given its name
 245  * @returns Sensor with the given name, NULL if there isn't one
 246  */
 247 Sensor * Sensor_Identify(const char * name)
 248 {
 249         for (int i = 0; i < g_num_sensors; ++i)
 250         {
 251                 if (strcmp(g_sensors[i].name, name) == 0)
 252                         return &(g_sensors[i]);
 253         }
 254         return NULL;
 255 }
 256
 257 /**
 258  * Helper: Begin sensor response in a given format
 259  * @param context - the FCGIContext
 260  * @param id - ID of sensor
 261  * @param format - Format
 262  */
 263 void Sensor_BeginResponse(FCGIContext * context, Sensor * s, DataFormat format)
 264 {
 265         // Begin response
 266         switch (format)
 267         {
 268                 case JSON:
 269                         FCGI_BeginJSON(context, STATUS_OK);
 270                         FCGI_JSONLong("id", s->id);
 271                         FCGI_JSONLong("user_id", s->user_id); //NOTE: Might not want to expose this?
 272                         FCGI_JSONPair("name", s->name);
 273                         break;
 274                 default:
 275                         FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 276                         break;
 277         }
 278 }
 279
 280 /**
 281  * Helper: End sensor response in a given format
 282  * @param context - the FCGIContext
 283  * @param id - ID of the sensor
 284  * @param format - Format
 285  */
 286 void Sensor_EndResponse(FCGIContext * context, Sensor * s, DataFormat format)
 287 {
 288         // End response
 289         switch (format)
 290         {
 291                 case JSON:
 292                         FCGI_EndJSON();
 293                         break;
 294                 default:
 295                         break;
 296         }
 297 }
 298
 299 /**
 300  * Handle a request to the sensor module
 301  * @param context - The context to work in
 302  * @param params - Parameters passed
 303  */
 304 void Sensor_Handler(FCGIContext *context, char * params)
 305 {
 306         struct timespec now;
 307         clock_gettime(CLOCK_MONOTONIC, &now);
 308         double current_time = TIMEVAL_DIFF(now, *Control_GetStartTime());
 309
 310         int id = 0;
 311         const char * name = "";
 312         double start_time = 0;
 313         double end_time = current_time;
 314         const char * fmt_str;
 315         double sample_s = 0;
 316
 317         // key/value pairs
 318         FCGIValue values[] = {
 319                 {"id", &id, FCGI_INT_T},
 320                 {"name", &name, FCGI_STRING_T},
 321                 {"format", &fmt_str, FCGI_STRING_T},
 322                 {"start_time", &start_time, FCGI_DOUBLE_T},
 323                 {"end_time", &end_time, FCGI_DOUBLE_T},
 324                 {"sample_s", &sample_s, FCGI_DOUBLE_T}
 325         };
 326
 327         // enum to avoid the use of magic numbers
 328         typedef enum {
 329                 ID,
 330                 NAME,
 331                 FORMAT,
 332                 START_TIME,
 333                 END_TIME,
 334                 SAMPLE_S
 335         } SensorParams;
 336
 337         // Fill values appropriately
 338         if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
 339         {
 340                 // Error occured; FCGI_RejectJSON already called
 341                 return;
 342         }
 343
 344         Sensor * s = NULL;
 345         if (FCGI_RECEIVED(values[NAME].flags))
 346         {
 347                 if (FCGI_RECEIVED(values[ID].flags))
 348                 {
 349                         FCGI_RejectJSON(context, "Can't supply both sensor id and name");
 350                         return;
 351                 }
 352                 s = Sensor_Identify(name);
 353                 if (s == NULL)
 354                 {
 355                         FCGI_RejectJSON(context, "Unknown sensor name");
 356                         return;
 357                 }
 358         }
 359         else if (!FCGI_RECEIVED(values[ID].flags))
 360         {
 361                 FCGI_RejectJSON(context, "No sensor id or name supplied");
 362                 return;
 363         }
 364         else if (id < 0 || id >= g_num_sensors)
 365         {
 366                 FCGI_RejectJSON(context, "Invalid sensor id");
 367                 return;
 368         }
 369         else
 370         {
 371                 s = &(g_sensors[id]);
 372         }
 373
 374         // Adjust sample rate if necessary
 375         if (FCGI_RECEIVED(values[SAMPLE_S].flags))
 376         {
 377                 if (sample_s < 0)
 378                 {
 379                         FCGI_RejectJSON(context, "Negative sampling speed!");
 380                         return;
 381                 }
 382                 DOUBLE_TO_TIMEVAL(sample_s, &(s->sample_time));
 383         }
 384
 385
 386         DataFormat format = Data_GetFormat(&(values[FORMAT]));
 387
 388         // Begin response
 389         Sensor_BeginResponse(context, s, format);
 390
 391         // Print Data
 392         Data_Handler(&(s->data_file), &(values[START_TIME]), &(values[END_TIME]), format, current_time);
 393
 394         // Finish response
 395         Sensor_EndResponse(context, s, format);
 396
 397 }
 398
 399 /**
 400  * Get the Name of a Sensor
 401  * @param id - ID number
 402  */
 403 const char * Sensor_GetName(int id)
 404 {
 405         return g_sensors[id].name;
 406 }
 407
 408
 409