Implemented real time option (activated by define)

Author: f4exb

main.c

@@ -84,6 +84,7 @@ static char args_doc[] = "";
 static struct argp_option options[] = {
     {"verbose",  'v', "VERBOSITY_LEVEL", 0, "Verbosiity level: 0 quiet else verbose level (default : quiet)"},
     {"long-help",  'H', 0, 0, "Print a long help and exit"},
+    {"real-time",  'T', 0, 0, "Engage so called \"real time\" scheduling (defalut 0: no)"},
     {"spi-device",  'd', "SPI_DEVICE", 0, "SPI device, (default : /dev/spidev0.0)"},
     {"modulation",  'M', "MODULATION_SCHEME", 0, "Radio modulation scheme, See long help (-H) option"},
     {"rate",  'R', "DATA_RATE_INDEX", 0, "Data rate index, See long help (-H) option"},
@@ -186,6 +187,7 @@ static void init_args(arguments_t *arguments)
     arguments->tnc_keyup_delay = 10000;
     arguments->tnc_keydown_delay = 0;
     arguments->tnc_switchover_delay = 0;
+    arguments->real_time = 0;
 }
 
 // ------------------------------------------------------------------------------------------------
@@ -214,6 +216,7 @@ static void print_args(arguments_t *arguments)
 {
     fprintf(stderr, "-- options --\n");
     fprintf(stderr, "Verbosity ...........: %d\n", arguments->verbose_level);
+    fprintf(stderr, "Real time ...........: %s\n", (arguments->real_time ? "yes" : "no"));
     fprintf(stderr, "--- radio ---\n");
     fprintf(stderr, "Modulation ..........: %s\n", modulation_names[arguments->modulation]);
     fprintf(stderr, "Rate nominal ........: %d Baud\n", rate_values[arguments->rate]);
@@ -395,6 +398,17 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
                 fprintf(stderr, "Variable length blocks are not allowed (yet?)\n");
             }
             break;
+        // Real time scheduling
+        case 'T':
+            if (ALLOW_REAL_TIME)
+            {
+                arguments->real_time = 1;
+            }
+            else
+            {
+                fprintf(stderr, "Real time scheduling is not allowed\n");
+            }
+            break;
         // Repetition factor
         case 'n':
             arguments->repetition = strtol(arg, &end, 10);

main.h

@@ -5,6 +5,7 @@
 #include <termios.h> 
 
 #define ALLOW_VAR_BLOCKS 0
+#define ALLOW_REAL_TIME  1
 
 typedef enum test_mode_e {
     TEST_NONE = 0,
@@ -97,6 +98,7 @@ typedef struct arguments_s {
     uint32_t     tnc_keyup_delay;      // TNC keyup delay in microseconds
     uint32_t     tnc_keydown_delay;    // TNC keydown delay in microseconds
     uint32_t     tnc_switchover_delay; // TNC Rx/Tx switchover delay in microseconds
+    uint8_t      real_time;            // Engage so called "real time" scheduling
 } arguments_t;
 
 #endif

radio.c

@@ -520,6 +520,21 @@ int init_radio(radio_parms_t *radio_parms, spi_parms_t *spi_parms, arguments_t *
     wiringPiSetup(); // initialize Wiring Pi library and GDOx interrupt routines
     verbprintf(1, "wiringPiSetup done.\n");
 
+    // Switch main thread to real time
+    if (arguments->real_time)
+    {
+        ret = piHiPri(1);
+
+        if (ret == 0)
+        {
+            fprintf(stderr, "RADIO: real time OK\n");
+        }
+        else
+        {
+            perror("RADIO: cannot set in real time");
+        }
+    }
+
     // open SPI link
     PI_CC_SPIParmsDefaults(spi_parms);
     ret = PI_CC_SPISetup(spi_parms, arguments);