From: Michel Pollet <buserror@gmail.com>
Date: Wed, 10 Jan 2018 09:10:29 +0000 (+0000)
Subject: Clean up that CLOCK mess
X-Git-Tag: v1.6~2
X-Git-Url: https://git.htl-mechatronik.at/public/?a=commitdiff_plain;h=518c3746fd032147bef5cbb5d6461c8628faa30a;p=sx%2Fsimavr.git

Clean up that CLOCK mess

Generalized getting a time stamp related to the simulation. Make it
really portable.

Signed-off-by: Michel Pollet <buserror@gmail.com>
---

diff --git a/simavr/sim/sim_avr.c b/simavr/sim/sim_avr.c
index 6106df6..1878b41 100644
--- a/simavr/sim/sim_avr.c
+++ b/simavr/sim/sim_avr.c
@@ -71,6 +71,26 @@ avr_global_logger_get(void)
 	return _avr_global_logger;
 }
 
+uint64_t
+avr_get_time_stamp(
+		avr_t * avr )
+{
+	uint64_t stamp;
+#ifndef CLOCK_MONOTONIC_RAW
+	/* CLOCK_MONOTONIC_RAW isn't portable, here is the POSIX alternative.
+	 * Only downside is that it will drift if the system clock changes */
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	stamp = (((uint64_t)tv.tv_sec) * 1E9) + (tv.tv_usec * 1000);
+#else
+	struct timespec tp;
+	clock_gettime(CLOCK_MONOTONIC_RAW, &tp);
+	stamp = (tp.tv_sec * 1E9) + tp.tv_nsec;
+#endif
+	if (!avr->time_base)
+		avr->time_base = stamp;
+	return stamp - avr->time_base;
+}
 
 int
 avr_init(
@@ -149,10 +169,6 @@ avr_reset(
 		avr->sreg[i] = 0;
 	avr_interrupt_reset(avr);
 	avr_cycle_timer_reset(avr);
-	/* Take simulation start time */
-	struct timespec tp;
-	clock_gettime(CLOCK_MONOTONIC_RAW, &tp);
-	avr->sim_start_time_ns = tp.tv_sec*1E9+tp.tv_nsec;
 	if (avr->reset)
 		avr->reset(avr);
 	avr_io_t * port = avr->io_port;
@@ -327,17 +343,12 @@ avr_callback_sleep_raw(
 		avr_t *avr,
 		avr_cycle_count_t how_long)
 {
-	struct timespec tp;
-
 	/* figure out how long we should wait to match the sleep deadline */
 	uint64_t deadline_ns = avr_cycles_to_nsec(avr, avr->cycle + how_long);
-	clock_gettime(CLOCK_MONOTONIC_RAW, &tp);
-	uint64_t runtime_ns = (tp.tv_sec*1E9+tp.tv_nsec) - avr->sim_start_time_ns;
-	if (runtime_ns >= deadline_ns) {
+	uint64_t runtime_ns = avr_get_time_stamp(avr);
+	if (runtime_ns >= deadline_ns)
 		return;
-	}
-
-	uint64_t sleep_us = (deadline_ns - runtime_ns)/1000;
+	uint64_t sleep_us = (deadline_ns - runtime_ns) / 1000;
 	usleep(sleep_us);
 	return;
 }
diff --git a/simavr/sim/sim_avr.h b/simavr/sim/sim_avr.h
index 92459dc..3553976 100644
--- a/simavr/sim/sim_avr.h
+++ b/simavr/sim/sim_avr.h
@@ -201,7 +201,7 @@ typedef struct avr_t {
 	 * is passed on to the operating system.
 	 */
 	uint32_t 			sleep_usec;
-	uint64_t			sim_start_time_ns;
+	uint64_t			time_base;	// for avr_get_time_stamp()
 
 	// called at init time
 	void (*init)(struct avr_t * avr);
@@ -476,6 +476,10 @@ uint32_t
 avr_pending_sleep_usec(
 		avr_t * avr,
 		avr_cycle_count_t howLong);
+/* Return the number of 'real time' spent since sim started, in uS */
+uint64_t
+avr_get_time_stamp(
+		avr_t * avr );
 
 #ifdef __cplusplus
 };