Move liblttng-ust to 'src/lib/'

[lttng-ust.git] / src / lib / lttng-ust / clock.h

diff --git a/src/lib/lttng-ust/clock.h b/src/lib/lttng-ust/clock.h
new file mode 100644 (file)
index 0000000..203cce0
--- /dev/null
+++ b/src/lib/lttng-ust/clock.h
@@ -0,0 +1,62 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2010 Pierre-Marc Fournier
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _UST_CLOCK_H
+#define _UST_CLOCK_H
+
+#include <time.h>
+#include <sys/time.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <urcu/system.h>
+#include <urcu/arch.h>
+#include <lttng/ust-clock.h>
+
+#include "lttng-ust-uuid.h"
+
+struct lttng_ust_trace_clock {
+       uint64_t (*read64)(void);
+       uint64_t (*freq)(void);
+       int (*uuid)(char *uuid);
+       const char *(*name)(void);
+       const char *(*description)(void);
+};
+
+extern struct lttng_ust_trace_clock *lttng_ust_trace_clock
+       __attribute__((visibility("hidden")));
+
+void lttng_ust_clock_init(void);
+
+/* Use the kernel MONOTONIC clock. */
+
+static __inline__
+uint64_t trace_clock_read64_monotonic(void)
+{
+       struct timespec ts;
+
+       if (caa_unlikely(clock_gettime(CLOCK_MONOTONIC, &ts))) {
+               ts.tv_sec = 0;
+               ts.tv_nsec = 0;
+       }
+       return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
+}
+
+static __inline__
+uint64_t trace_clock_read64(void)
+{
+       struct lttng_ust_trace_clock *ltc = CMM_LOAD_SHARED(lttng_ust_trace_clock);
+
+       if (caa_likely(!ltc)) {
+               return trace_clock_read64_monotonic();
+       } else {
+               cmm_read_barrier_depends();     /* load ltc before content */
+               return ltc->read64();
+       }
+}
+
+#endif /* _UST_CLOCK_H */