X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Fclock.h;h=e9407f2608cd154ee3c602411868bedcc90b91e3;hb=f41a6b5f307db311352f79d35f0656959db60891;hp=a0bf24991c2e43654463ddfb4b41244a04dbb7c0;hpb=08ba2503b86d1506117c077c99eb1c38973a48f3;p=lttng-ust.git

diff --git a/src/common/clock.h b/src/common/clock.h
index a0bf2499..e9407f26 100644
--- a/src/common/clock.h
+++ b/src/common/clock.h
@@ -7,9 +7,56 @@
 #ifndef _UST_COMMON_CLOCK_H
 #define _UST_COMMON_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>
+
+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);
+};
+
 /*
- * Part of the private ABI between liblttng-ust and liblttng-ust-ctl.
+ * The trace clock is a public symbol of liblttng-ust-common accessed by other
+ * libraries through the trace_clock_read64 static inline function. It is
+ * initialised in the liblttng-ust-common constructor.
  */
-void lttng_ust_clock_init(void);
+extern struct lttng_ust_trace_clock *lttng_ust_trace_clock;
+
+/* 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_COMMON_CLOCK_H */