1 files changed, 81 insertions, 0 deletions
diff --git a/lib/monotonic.c b/lib/monotonic.c
new file mode 100644
index 0000000..f0aeba6
--- /dev/null
+++ b/lib/monotonic.c
@@ -0,0 +1,81 @@
+/*
+ * Please, don't add this file to libcommon because clock_gettime() requires
+ * -lrt on systems with old libc.
+ *
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ */
+#include <time.h>
+#include <signal.h>
+#ifdef HAVE_SYSINFO
+#include <sys/sysinfo.h>
+#endif
+#include <sys/time.h>
+
+#include "c.h"
+#include "monotonic.h"
+
+int get_boot_time(struct timeval *boot_time)
+{
+#ifdef CLOCK_BOOTTIME
+	struct timespec hires_uptime;
+	struct timeval lores_uptime;
+#endif
+	struct timeval now;
+#ifdef HAVE_SYSINFO
+	struct sysinfo info;
+#endif
+
+	if (gettimeofday(&now, NULL) != 0)
+		return -errno;
+#ifdef CLOCK_BOOTTIME
+	if (clock_gettime(CLOCK_BOOTTIME, &hires_uptime) == 0) {
+		TIMESPEC_TO_TIMEVAL(&lores_uptime, &hires_uptime);
+		timersub(&now, &lores_uptime, boot_time);
+		return 0;
+	}
+#endif
+#ifdef HAVE_SYSINFO
+	/* fallback */
+	if (sysinfo(&info) != 0)
+		return -errno;
+
+	boot_time->tv_sec = now.tv_sec - info.uptime;
+	boot_time->tv_usec = 0;
+	return 0;
+#else
+	return -ENOSYS;
+#endif
+}
+
+time_t get_suspended_time(void)
+{
+#if defined(CLOCK_BOOTTIME) && defined(CLOCK_MONOTONIC)
+	struct timespec boot, mono;
+
+	if (clock_gettime(CLOCK_BOOTTIME, &boot) == 0 &&
+	    clock_gettime(CLOCK_MONOTONIC, &mono) == 0)
+		return boot.tv_sec - mono.tv_sec;
+#endif
+	return 0;
+}
+
+int gettime_monotonic(struct timeval *tv)
+{
+#ifdef CLOCK_MONOTONIC
+	/* Can slew only by ntp and adjtime */
+	int ret;
+	struct timespec ts;
+
+	/* Linux specific, can't slew */
+	if (!(ret = clock_gettime(UL_CLOCK_MONOTONIC, &ts))) {
+		tv->tv_sec = ts.tv_sec;
+		tv->tv_usec = ts.tv_nsec / 1000;
+	}
+	return ret;
+#else
+	return gettimeofday(tv, NULL);
+#endif
+}
+
+