Use gettimeofday for z_time functions

include/zenoh-pico/system/platform/freertos_plus_tcp.h

@@ -14,6 +14,8 @@
 #ifndef ZENOH_PICO_SYSTEM_FREERTOS_PLUS_TCP_TYPES_H
 #define ZENOH_PICO_SYSTEM_FREERTOS_PLUS_TCP_TYPES_H
 
+#include <time.h>
+
 #include "FreeRTOS.h"
 #include "FreeRTOS_IP.h"
 #include "semphr.h"
@@ -54,7 +56,7 @@ typedef void *_z_condvar_t;
 #endif  // Z_MULTI_THREAD == 1
 
 typedef TickType_t z_clock_t;
-typedef TickType_t z_time_t;
+typedef struct timeval z_time_t;
 
 typedef struct {
     union {

src/system/freertos_plus_tcp/system.c

@@ -17,6 +17,7 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/time.h>
 
 #include "FreeRTOS_IP.h"
 #include "zenoh-pico/config.h"
@@ -193,31 +194,62 @@ z_result_t z_sleep_s(size_t time) {
 }
 
 /*------------------ Clock ------------------*/
-z_clock_t z_clock_now(void) { return z_time_now(); }
+z_clock_t z_clock_now(void) { return xTaskGetTickCount(); }
 
 unsigned long z_clock_elapsed_us(z_clock_t *instant) { return z_clock_elapsed_ms(instant) * 1000; }
 
-unsigned long z_clock_elapsed_ms(z_clock_t *instant) { return z_time_elapsed_ms(instant); }
+unsigned long z_clock_elapsed_ms(z_clock_t *instant) {
+    z_clock_t now = z_clock_now();
+
+    unsigned long elapsed = (now - *instant) * portTICK_PERIOD_MS;
+    return elapsed;
+}
 
 unsigned long z_clock_elapsed_s(z_clock_t *instant) { return z_clock_elapsed_ms(instant) / 1000; }
 
 /*------------------ Time ------------------*/
-z_time_t z_time_now(void) { return xTaskGetTickCount(); }
+z_time_t z_time_now(void) {
+    z_time_t now;
+    gettimeofday(&now, NULL);
+    return now;
+}
 
 const char *z_time_now_as_str(char *const buf, unsigned long buflen) {
-    snprintf(buf, buflen, "%u", z_time_now());
+    z_time_t tv = z_time_now();
+    struct tm ts;
+    ts = *localtime(&tv.tv_sec);
+    strftime(buf, buflen, "%Y-%m-%dT%H:%M:%SZ", &ts);
     return buf;
 }
 
-unsigned long z_time_elapsed_us(z_time_t *time) { return z_time_elapsed_ms(time) * 1000; }
+unsigned long z_time_elapsed_us(z_time_t *time) {
+    z_time_t now;
+    gettimeofday(&now, NULL);
+
+    unsigned long elapsed = (unsigned long)(1000000 * (now.tv_sec - time->tv_sec) + (now.tv_usec - time->tv_usec));
+    return elapsed;
+}
 
 unsigned long z_time_elapsed_ms(z_time_t *time) {
-    z_time_t now = z_time_now();
+    z_time_t now;
+    gettimeofday(&now, NULL);
 
-    unsigned long elapsed = (now - *time) * portTICK_PERIOD_MS;
+    unsigned long elapsed = (unsigned long)(1000 * (now.tv_sec - time->tv_sec) + (now.tv_usec - time->tv_usec) / 1000);
     return elapsed;
 }
 
-unsigned long z_time_elapsed_s(z_time_t *time) { return z_time_elapsed_ms(time) / 1000; }
+unsigned long z_time_elapsed_s(z_time_t *time) {
+    z_time_t now;
+    gettimeofday(&now, NULL);
 
-z_result_t _z_get_time_since_epoch(_z_time_since_epoch *t) { return -1; }
+    unsigned long elapsed = (unsigned long)(now.tv_sec - time->tv_sec);
+    return elapsed;
+}
+
+z_result_t _z_get_time_since_epoch(_z_time_since_epoch *t) {
+    z_time_t now;
+    gettimeofday(&now, NULL);
+    t->secs = (uint32_t)now.tv_sec;
+    t->nanos = (uint32_t)now.tv_usec * 1000;
+    return 0;
+}