add enable-use-system-time param to switch.conf.xml use at your own risk, someone with windows could verify it works ok

src/include/private/switch_core_pvt.h

@@ -213,6 +213,8 @@ typedef enum {
 
 struct switch_runtime {
 	switch_time_t initiated;
+	switch_time_t mono_initiated;
+	switch_time_t mono_reference;
 	switch_time_t reference;
 	int64_t offset;
 	switch_event_t *global_vars;

src/include/switch_core.h

@@ -2107,6 +2107,7 @@ SWITCH_DECLARE(void *) switch_loadable_module_create_interface(switch_loadable_m
  \return the current epoch time in microseconds
 */
 SWITCH_DECLARE(switch_time_t) switch_micro_time_now(void);
+SWITCH_DECLARE(switch_time_t) switch_mono_micro_time_now(void);
 SWITCH_DECLARE(void) switch_core_memory_reclaim(void);
 SWITCH_DECLARE(void) switch_core_memory_reclaim_events(void);
 SWITCH_DECLARE(void) switch_core_memory_reclaim_logger(void);
@@ -2130,6 +2131,7 @@ SWITCH_DECLARE(void) switch_time_set_timerfd(switch_bool_t enable);
 SWITCH_DECLARE(void) switch_time_set_nanosleep(switch_bool_t enable);
 SWITCH_DECLARE(void) switch_time_set_matrix(switch_bool_t enable);
 SWITCH_DECLARE(void) switch_time_set_cond_yield(switch_bool_t enable);
+SWITCH_DECLARE(void) switch_time_set_use_system_time(switch_bool_t enable);
 SWITCH_DECLARE(uint32_t) switch_core_min_dtmf_duration(uint32_t duration);
 SWITCH_DECLARE(uint32_t) switch_core_max_dtmf_duration(uint32_t duration);
 SWITCH_DECLARE(double) switch_core_min_idle_cpu(double new_limit);

src/switch_core.c

@@ -1560,6 +1560,7 @@ SWITCH_DECLARE(switch_status_t) switch_core_init(switch_core_flag_t flags, switc
 
 	runtime.running = 1;
 	runtime.initiated = switch_time_now();
+	runtime.mono_initiated = switch_mono_micro_time_now();
 	
 	switch_scheduler_add_task(switch_epoch_time_now(NULL), heartbeat_callback, "heartbeat", "core", 0, NULL, SSHF_NONE | SSHF_NO_DEL);
 
@@ -1779,6 +1780,8 @@ static void switch_load_core_config(const char *file)
 					if (tmp > 0) {
 						switch_core_default_dtmf_duration((uint32_t) tmp);
 					}
+				} else if (!strcasecmp(var, "enable-use-system-time")) {
+					switch_time_set_use_system_time(switch_true(val));
 				} else if (!strcasecmp(var, "enable-monotonic-timing")) {
 					switch_time_set_monotonic(switch_true(val));
 				} else if (!strcasecmp(var, "enable-softtimer-timerfd")) {
@@ -1990,7 +1993,7 @@ SWITCH_DECLARE(void) switch_core_measure_time(switch_time_t total_ms, switch_cor
 
 SWITCH_DECLARE(switch_time_t) switch_core_uptime(void)
 {
-	return switch_micro_time_now() - runtime.initiated;
+	return switch_mono_micro_time_now() - runtime.mono_initiated;
 }
 
 

src/switch_time.c

@@ -70,6 +70,9 @@ static int MONO = 1;
 static int MONO = 0;
 #endif
 
+
+static int SYSTEM_TIME = 0;
+
 /* clock_nanosleep works badly on some kernels but really well on others.
    timerfd seems to work well as long as it exists so if you have timerfd we'll also enable clock_nanosleep by default.
 */
@@ -140,6 +143,8 @@ typedef struct timer_matrix timer_matrix_t;
 
 static timer_matrix_t TIMER_MATRIX[MAX_ELEMENTS + 1];
 
+static switch_time_t time_now(int64_t offset);
+
 SWITCH_DECLARE(void) switch_os_yield(void)
 {
 #if defined(WIN32)
@@ -313,6 +318,11 @@ SWITCH_DECLARE(switch_time_t) switch_micro_time_now(void)
 	return (globals.RUNNING == 1 && runtime.timestamp) ? runtime.timestamp : switch_time_now();
 }
 
+SWITCH_DECLARE(switch_time_t) switch_mono_micro_time_now(void)
+{
+	return time_now(-1);
+}
+
 
 SWITCH_DECLARE(time_t) switch_epoch_time_now(time_t *t)
 {
@@ -334,6 +344,12 @@ SWITCH_DECLARE(void) switch_time_set_monotonic(switch_bool_t enable)
 }
 
 
+SWITCH_DECLARE(void) switch_time_set_use_system_time(switch_bool_t enable)
+{
+	SYSTEM_TIME = enable;
+}
+
+
 SWITCH_DECLARE(void) switch_time_set_timerfd(switch_bool_t enable)
 {
 #if defined(HAVE_TIMERFD_CREATE)
@@ -376,9 +392,15 @@ static switch_time_t time_now(int64_t offset)
 	if (MONO) {
 #ifndef WIN32
 		struct timespec ts;
-		clock_gettime(CLOCK_MONOTONIC, &ts);
+		clock_gettime(offset ? CLOCK_MONOTONIC : CLOCK_REALTIME, &ts);
+		if (offset < 0) offset = 0;
 		now = ts.tv_sec * APR_USEC_PER_SEC + (ts.tv_nsec / 1000) + offset;
 #else
+		if (offset == 0) {
+			return switch_time_now();
+		} else if (offset < 0) offset = 0;
+		
+
 		if (win32_use_qpc) {
 			/* Use QueryPerformanceCounter */
 			uint64_t count = 0;
@@ -431,10 +453,22 @@ SWITCH_DECLARE(void) switch_time_sync(void)
 
 	runtime.reference = switch_time_now();
 
-	runtime.offset = runtime.reference - time_now(0);
-	runtime.reference = time_now(runtime.offset);
+	if (SYSTEM_TIME) {
+		runtime.reference = time_now(0);
+		runtime.mono_reference = time_now(-1);
+		runtime.offset = 0;
+	} else {
+		runtime.offset = runtime.reference - time_now(0);
+		runtime.reference = time_now(runtime.offset);
+	}
+
+
 	if (runtime.reference - last_time > 1000000 || last_time == 0) {
-		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Clock synchronized to system time.\n");
+		if (SYSTEM_TIME) {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Clock is already configured to always report system time.\n");
+		} else {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Clock synchronized to system time.\n");
+		}
 	}
 	last_time = runtime.reference;