checkpoint

timer.c

@@ -0,0 +1,69 @@
+#define _POSIX_C_SOURCE 200809l
+
+#include <time.h>
+
+#include "timer.h"
+
+const clockid_t CLOCK_ID = CLOCK_PROCESS_CPUTIME_ID;
+
+struct _timer {
+	struct timespec start, stop;
+	struct timespec times[TIMER_MAX_PARTIAL];
+} timer = {0};
+
+int timer_start(void) { return clock_gettime(CLOCK_ID, &timer.start); }
+
+int timer_reset(void)
+{
+	timer = (struct _timer) {0};
+	return 0;
+}
+
+int timer_stop(void) { return clock_gettime(CLOCK_ID, &timer.stop); }
+
+// partial clocks also update the stop time
+int timer_partial(int idx)
+{
+	if (idx > TIMER_MAX_PARTIAL || idx < 0) {
+		return -1;
+	}
+	clock_gettime(CLOCK_ID, &timer.stop);
+	return clock_gettime(CLOCK_ID, &(timer.times[idx]));
+}
+
+size_t timer_get_us(int idx)
+{
+	if (idx > TIMER_MAX_PARTIAL) {
+		return -1;
+	}
+
+	struct timespec ts = {0};
+	if (idx < 0) {
+		ts = timer.stop;
+	} else {
+		ts = timer.times[idx];
+	}
+	ts.tv_sec -= timer.start.tv_sec;
+	ts.tv_nsec -= timer.start.tv_nsec;
+
+	// FIXME: check overflow
+	return (ts.tv_nsec / 1000) + (ts.tv_sec * 1000000);
+}
+
+double timer_get_sec(int idx)
+{
+	if (idx > TIMER_MAX_PARTIAL) {
+		return -1;
+	}
+
+	struct timespec ts = {0};
+	if (idx < 0) {
+		ts = timer.stop;
+	} else {
+		ts = timer.times[idx];
+	}
+	ts.tv_sec -= timer.start.tv_sec;
+	ts.tv_nsec -= timer.start.tv_nsec;
+
+	return (double)ts.tv_sec + ((double)ts.tv_nsec / 1e9);
+}