/**
* @file sensor.c
- * @purpose Implementation of sensor thread
+ * @brief Implementation of sensor thread
* TODO: Finalise implementation
*/
-
#include "common.h"
#include "sensor.h"
+#include "options.h"
#include <math.h>
/** Array of sensors, initialised by Sensor_Init **/
static Sensor g_sensors[NUMSENSORS]; //global to this file
+/** Human readable names for the sensors **/
+const char * g_sensor_names[NUMSENSORS] = {
+ "analog_test0", "analog_test1",
+ "analog_fail0", "digital_test0",
+ "digital_test1", "digital_fail0"
+};
+
/**
- * Read a data value from a sensor; block until value is read
- * @param sensor_id - The ID of the sensor
- * @param d - DataPoint to set
- * @returns NULL on error, otherwise d
+ * One off initialisation of *all* sensors
*/
-DataPoint * GetData(int sensor_id, DataPoint * d)
+void Sensor_Init()
{
- // switch based on the sensor_id at the moment for testing;
- // might be able to just directly access ADC from sensor_id?
- //TODO: Implement for real sensors
-
-
- //TODO: We should ensure the time is *never* allowed to change on the server if we use gettimeofday
- // Another way people might think of getting the time is to count CPU cycles with clock()
- // But this will not work because a) CPU clock speed may change on some devices (RPi?) and b) It counts cycles used by all threads
- gettimeofday(&(d->time_stamp), NULL);
-
- switch (sensor_id)
+ for (int i = 0; i < NUMSENSORS; ++i)
{
- case SENSOR_TEST0:
- {
- static int count = 0;
- d->value = count++;
- break;
- }
- case SENSOR_TEST1:
- d->value = (float)(rand() % 100) / 100;
- break;
- default:
- Fatal("Unknown sensor id: %d", sensor_id);
- break;
- }
- usleep(100000); // simulate delay in sensor polling
-
- return d;
+ g_sensors[i].id = i;
+ Data_Init(&(g_sensors[i].data_file));
+ g_sensors[i].record_data = false;
+ }
}
-
/**
- * Destroy a sensor
- * @param s - Sensor to destroy
+ * Start a Sensor recording DataPoints
+ * @param s - The Sensor to start
+ * @param experiment_name - Prepended to DataFile filename
*/
-void Destroy(Sensor * s)
+void Sensor_Start(Sensor * s, const char * experiment_name)
{
- // Maybe move the binary file into long term file storage?
- fclose(s->file);
-}
+ // Set filename
+ char filename[BUFSIZ];
+ if (sprintf(filename, "%s_%d", experiment_name, s->id) >= BUFSIZ)
+ {
+ Fatal("Experiment name \"%s\" too long (>%d)", experiment_name, BUFSIZ);
+ }
+
+ Log(LOGDEBUG, "Sensor %d with DataFile \"%s\"", s->id, filename);
+ // Open DataFile
+ Data_Open(&(s->data_file), filename);
+ s->record_data = true; // Don't forget this!
+ // Create the thread
+ pthread_create(&(s->thread), NULL, Sensor_Loop, (void*)(s));
+}
/**
- * Initialise a sensor
- * @param s - Sensor to initialise
+ * Stop a Sensor from recording DataPoints. Blocks until it has stopped.
+ * @param s - The Sensor to stop
*/
-void Init(Sensor * s, int id)
+void Sensor_Stop(Sensor * s)
{
- s->write_index = 0;
- s->read_offset = 0;
- s->id = id;
-
- #define FILENAMESIZE 3
- char filename[FILENAMESIZE];
- if (s->id >= pow(10, FILENAMESIZE))
+ // Stop
+ if (s->record_data)
{
- Fatal("Too many sensors! FILENAMESIZE is %d; increase it and recompile.", FILENAMESIZE);
+ s->record_data = false;
+ pthread_join(s->thread, NULL); // Wait for thread to exit
+ Data_Close(&(s->data_file)); // Close DataFile
+ s->newest_data.time_stamp = 0;
+ s->newest_data.value = 0;
}
+}
- pthread_mutex_init(&(s->mutex), NULL);
-
- sprintf(filename, "%d", s->id);
- unlink(filename); //TODO: Move old files somewhere
-
- s->file = fopen(filename, "a+b"); // open binary file
- Log(LOGDEBUG, "Initialised sensor %d; binary file is \"%s\"", id, filename);
+/**
+ * Stop all Sensors
+ */
+void Sensor_StopAll()
+{
+ for (int i = 0; i < NUMSENSORS; ++i)
+ Sensor_Stop(g_sensors+i);
}
+/**
+ * Start all Sensors
+ */
+void Sensor_StartAll(const char * experiment_name)
+{
+ for (int i = 0; i < NUMSENSORS; ++i)
+ Sensor_Start(g_sensors+i, experiment_name);
+}
+/**
+ * Checks the sensor data for unsafe or unexpected results
+ * @param sensor_id - The ID of the sensor
+ * @param value - The value from the sensor to test
+ */
+void Sensor_CheckData(SensorId id, double value)
+{
+ switch (sensor_id)
+ {
+ case ANALOG_FAIL0:
+ {
+ if( value > ANALOG_FAIL0_SAFETY || value < ANALOG_FAIL0_MIN_SAFETY)
+ {
+ Log(LOGERR, "Sensor analog_fail0 is above or below its safety value of %d or %d\n", ANALOG_FAIL0_SAFETY, ANALOG_FAIL0_MIN_SAFETY);
+ //new function that stops actuators?
+ }
+ else if( value > ANALOG_FAIL0_WARN || value < ANALOG_FAIL0_MIN_WARN)
+ {
+ Log(LOGWARN, "Sensor analog_test0 is above or below its warning value of %d or %d\n", ANALOG_FAIL0_WARN, ANALOG_FAIL0_MIN_WARN);
+ }
+ break;
+ }
+ case DIGITAL_FAIL0:
+ {
+ if( value != 0 && value != 1)
+ {
+ Log(LOGERR, "Sensor digital_fail0 is not 0 or 1\n");
+ }
+ break;
+ }
+ default:
+ {
+ //So it doesn't complain about the missing cases - in practice we will need all sensors to be checked as above, no need to include a default as we should only pass valid sensor_id's; unless for some reason we have a sensor we don't need to check (but then why would you pass to this function in the first place :P)
+ }
+ }
+}
/**
- * Run the main sensor polling loop
- * @param arg - Cast to Sensor* - Sensor that the thread will handle
- * @returns NULL (void* required to use the function with pthreads)
+ * Read a DataPoint from a Sensor; block until value is read
+ * @param id - The ID of the sensor
+ * @param d - DataPoint to set
+ * @returns True if the DataPoint was different from the most recently recorded.
*/
-void * Sensor_Main(void * arg)
+bool Sensor_Read(Sensor * s, DataPoint * d)
{
- Sensor * s = (Sensor*)(arg);
+
+ // Set time stamp
+ struct timeval t;
+ gettimeofday(&t, NULL);
+ d->time_stamp = TIMEVAL_DIFF(t, g_options.start_time);
- while (Thread_Runstate() == RUNNING) //TODO: Exit condition
+ // Read value based on Sensor Id
+ switch (s->id)
{
- // The sensor will write data to a buffer until it is full
- // Then it will open a file and dump the buffer to the end of it.
- // Rinse and repeat
-
- // The reason I've added the buffer is because locks are expensive
- // But maybe it's better to just write data straight to the file
- // I'd like to do some tests by changing SENSOR_DATABUFSIZ
+ case ANALOG_TEST0:
+ d->value = (double)(rand() % 100) / 100;
+ break;
- while (s->write_index < SENSOR_DATABUFSIZ)
+ case ANALOG_TEST1:
{
- DataPoint * d = &(s->buffer[s->write_index]);
- if (GetData(s->id, d) == NULL)
- {
- Fatal("Error collecting data");
- }
- s->write_index += 1;
+ static int count = 0;
+ d->value = count++;
+ break;
}
+ case ANALOG_FAIL0:
+ d->value = (double)(rand() % 6) * -( rand() % 2) / ( rand() % 100 + 1);
+ //Gives a value between -5 and 5
+ CheckSensor(sensor_id, d->value);
+ break;
+ case DIGITAL_TEST0:
+ d->value = t.tv_sec % 2;
+ break;
+ case DIGITAL_TEST1:
+ d->value = (t.tv_sec+1)%2;
+ break;
+ case DIGITAL_FAIL0:
+ if( rand() % 100 > 98)
+ d->value = 2;
+ d->value = rand() % 2;
+ //Gives 0 or 1 or a 2 every 1/100 times
+ CheckSensor(sensor_id, d->value);
+ break;
+ default:
+ Fatal("Unknown sensor id: %d", s->id);
+ break;
+ }
+ usleep(100000); // simulate delay in sensor polling
- //Log(LOGDEBUG, "Filled buffer");
-
- // CRITICAL SECTION (no threads should be able to read/write the file at the same time)
- pthread_mutex_lock(&(s->mutex));
- //TODO: Valgrind complains about this fseek: "Syscall param write(buf) points to uninitialised byte(s)"
- // Not sure why, but we should find out and fix it.
- fseek(s->file, 0, SEEK_END);
- int amount_written = fwrite(s->buffer, sizeof(DataPoint), SENSOR_DATABUFSIZ, s->file);
- if (amount_written != SENSOR_DATABUFSIZ)
- {
- Fatal("Wrote %d data points and expected to write %d to \"%s\" - %s", amount_written, SENSOR_DATABUFSIZ, strerror(errno));
- }
- //Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
- pthread_mutex_unlock(&(s->mutex));
- // End of critical section
+ // Perform sanity check based on Sensor's ID and the DataPoint
+ Sensor_CheckData(s->id, d);
- s->write_index = 0; // reset position in buffer
-
+ // Update latest DataPoint if necessary
+ bool result = (d->value != s->newest_data.value);
+ if (result)
+ {
+ s->newest_data.time_stamp = d->time_stamp;
+ s->newest_data.value = d->value;
}
- Log(LOGDEBUG, "Thread for sensor %d exits", s->id);
- return NULL;
+ return result;
}
/**
- * Fill buffer with most recent sensor data
- * @param s - Sensor to use
- * @param buffer - Buffer to fill
- * @param bufsiz - Size of buffer to fill
- * @returns The number of DataPoints actually read
+ * Record data from a single Sensor; to be run in a seperate thread
+ * @param arg - Cast to Sensor* - Sensor that the thread will handle
+ * @returns NULL (void* required to use the function with pthreads)
*/
-int Sensor_Query(Sensor * s, DataPoint * buffer, int bufsiz)
+void * Sensor_Loop(void * arg)
{
- int amount_read = 0;
- //CRITICAL SECTION (Don't access file while sensor thread is writing to it!)
- pthread_mutex_lock(&(s->mutex));
-
- fseek(s->file, -bufsiz*sizeof(DataPoint), SEEK_END);
- amount_read = fread(buffer, sizeof(DataPoint), bufsiz, s->file);
- //Log(LOGDEBUG, "Read %d data points", amount_read);
- pthread_mutex_unlock(&(s->mutex));
- return amount_read;
+ Sensor * s = (Sensor*)(arg);
+ Log(LOGDEBUG, "Sensor %d starts", s->id);
+
+ // Until the sensor is stopped, record data points
+ while (s->record_data)
+ {
+ DataPoint d;
+ //Log(LOGDEBUG, "Sensor %d reads data [%f,%f]", s->id, d.time_stamp, d.value);
+ if (Sensor_Read(s, &d)) // If new DataPoint is read:
+ {
+ //Log(LOGDEBUG, "Sensor %d saves data [%f,%f]", s->id, d.time_stamp, d.value);
+ Data_Save(&(s->data_file), &d, 1); // Record it
+ }
+ }
+
+ // Needed to keep pthreads happy
+
+ Log(LOGDEBUG, "Sensor %d finished", s->id);
+ return NULL;
}
/**
return NULL;
}
// Bounds check
- if (id < 0 || id > NUMSENSORS)
+ if (id < 0 || id >= NUMSENSORS)
return NULL;
+
+ Log(LOGDEBUG, "Sensor \"%s\" identified", g_sensor_names[id]);
return g_sensors+id;
}
/**
- * Handle a request to the sensor module
- * @param context - The context to work in
- * @param params - Parameters passed
+ * Helper: Begin sensor response in a given format
+ * @param context - the FCGIContext
+ * @param id - ID of sensor
+ * @param format - Format
*/
-void Sensor_Handler(FCGIContext *context, char * params)
+void Sensor_BeginResponse(FCGIContext * context, SensorId id, DataFormat format)
{
- DataPoint buffer[SENSOR_QUERYBUFSIZ];
- StatusCodes status = STATUS_OK;
- const char * key; const char * value;
-
- Sensor * sensor = NULL;
-
- while ((params = FCGI_KeyPair(params, &key, &value)) != NULL)
+ // Begin response
+ switch (format)
{
- Log(LOGDEBUG, "Got key=%s and value=%s", key, value);
- if (strcmp(key, "id") == 0)
- {
- if (sensor != NULL)
- {
- Log(LOGERR, "Only one sensor id should be specified");
- status = STATUS_ERROR;
- break;
- }
- if (*value == '\0')
- {
- Log(LOGERR, "No id specified.");
- status = STATUS_ERROR;
- break;
- }
-
- sensor = Sensor_Identify(value);
- if (sensor == NULL)
- {
- Log(LOGERR, "Invalid sensor id: %s", value);
- status = STATUS_ERROR;
- break;
- }
- }
- else
- {
- Log(LOGERR, "Unknown key \"%s\" (value = %s)", key, value);
- status = STATUS_ERROR;
+ case JSON:
+ FCGI_BeginJSON(context, STATUS_OK);
+ FCGI_JSONLong("id", id);
+ FCGI_JSONKey("data");
+ break;
+ default:
+ FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
break;
- }
- }
-
- if (status != STATUS_ERROR && sensor == NULL)
- {
- Log(LOGERR, "No valid sensor id given");
- status = STATUS_ERROR;
- }
-
- if (status == STATUS_ERROR)
- {
- FCGI_RejectJSON(context);
- }
- else
- {
-
- FCGI_BeginJSON(context, status);
- FCGI_JSONPair(key, value); // should spit back sensor ID
- //Log(LOGDEBUG, "Call Sensor_Query...");
- int amount_read = Sensor_Query(sensor, buffer, SENSOR_QUERYBUFSIZ);
- //Log(LOGDEBUG, "Read %d DataPoints", amount_read);
- //Log(LOGDEBUG, "Produce JSON response");
- FCGI_JSONKey("data");
- FCGI_JSONValue("[");
- for (int i = 0; i < amount_read; ++i)
- {
- //TODO: Consider; is it better to give both tv_sec and tv_usec to the client seperately, instead of combining here?
- //NOTE: Must always use doubles; floats get rounded!
- double time = buffer[i].time_stamp.tv_sec + 1e-6*(buffer[i].time_stamp.tv_usec);
- FCGI_JSONValue("[%f, %f]", time, buffer[i].value);
- if (i+1 < amount_read)
- FCGI_JSONValue(",");
- }
- FCGI_JSONValue("]");
- //Log(LOGDEBUG, "Done producing JSON response");
- FCGI_EndJSON();
}
}
/**
- * Setup Sensors, start Sensor polling thread(s)
+ * Helper: End sensor response in a given format
+ * @param context - the FCGIContext
+ * @param id - ID of the sensor
+ * @param format - Format
*/
-void Sensor_Spawn()
+void Sensor_EndResponse(FCGIContext * context, SensorId id, DataFormat format)
{
- // start sensor threads
- for (int i = 0; i < NUMSENSORS; ++i)
+ // End response
+ switch (format)
{
- Init(g_sensors+i, i);
- pthread_create(&(g_sensors[i].thread), NULL, Sensor_Main, (void*)(g_sensors+i));
+ case JSON:
+ FCGI_EndJSON();
+ break;
+ default:
+ break;
}
}
/**
- * Quit Sensor loops
+ * Handle a request to the sensor module
+ * @param context - The context to work in
+ * @param params - Parameters passed
*/
-void Sensor_Join()
+void Sensor_Handler(FCGIContext *context, char * params)
{
- if (!Thread_Runstate())
+ struct timeval now;
+ gettimeofday(&now, NULL);
+ double current_time = TIMEVAL_DIFF(now, g_options.start_time);
+
+ int id = 0;
+ double start_time = 0;
+ double end_time = current_time;
+ const char * fmt_str;
+
+ // key/value pairs
+ FCGIValue values[] = {
+ {"id", &id, FCGI_REQUIRED(FCGI_INT_T)},
+ {"format", &fmt_str, FCGI_STRING_T},
+ {"start_time", &start_time, FCGI_DOUBLE_T},
+ {"end_time", &end_time, FCGI_DOUBLE_T},
+ };
+
+ // enum to avoid the use of magic numbers
+ typedef enum {
+ ID,
+ FORMAT,
+ START_TIME,
+ END_TIME,
+ } SensorParams;
+
+ // Fill values appropriately
+ if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
{
- Fatal("This function should not be called before Thread_QuitProgram");
+ // Error occured; FCGI_RejectJSON already called
+ return;
}
- for (int i = 0; i < NUMSENSORS; ++i)
+ else if (id < 0 || id >= NUMSENSORS)
+ {
+ FCGI_RejectJSON(context, "Invalid sensor id specified");
+ return;
+ }
+
+ // Get Sensor and format
+ Sensor * s = g_sensors+id;
+ DataFormat format = JSON;
+
+ // Check if format type was specified
+ if (FCGI_RECEIVED(values[FORMAT].flags))
{
- pthread_join(g_sensors[i].thread, NULL);
- Destroy(g_sensors+i);
+ if (strcmp(fmt_str, "json") == 0)
+ format = JSON;
+ else if (strcmp(fmt_str, "tsv") == 0)
+ format = TSV;
+ else
+ {
+ FCGI_RejectJSON(context, "Unknown format type specified.");
+ return;
+ }
}
+
+ // Begin response
+ Sensor_BeginResponse(context, id, format);
+
+ // If a time was specified
+ if (FCGI_RECEIVED(values[START_TIME].flags) || FCGI_RECEIVED(values[END_TIME].flags))
+ {
+ // Wrap times relative to the current time
+ if (start_time < 0)
+ start_time += current_time;
+ if (end_time < 0)
+ end_time += current_time;
+
+ // Print points by time range
+ Data_PrintByTimes(&(s->data_file), start_time, end_time, format);
+ }
+ else // No time was specified; just return a recent set of points
+ {
+ pthread_mutex_lock(&(s->data_file.mutex));
+ int start_index = s->data_file.num_points-DATA_BUFSIZ;
+ int end_index = s->data_file.num_points;
+ pthread_mutex_unlock(&(s->data_file.mutex));
+
+ // Bounds check
+ if (start_index < 0)
+ start_index = 0;
+ if (end_index < 0)
+ end_index = 0;
+
+ // Print points by indexes
+ Log(LOGDEBUG, "Sensor %d file \"%s\" indexes %d->%d", s->id, s->data_file.filename, start_index, end_index);
+ Data_PrintByIndexes(&(s->data_file), start_index, end_index, format);
+ }
+
+ // Finish response
+ Sensor_EndResponse(context, id, format);
+
}
+
+
+