Move UST registry into sessiond and implement notifiers

[lttng-tools.git] / src / bin / lttng-sessiond / ust-clock.h

diff --git a/src/bin/lttng-sessiond/ust-clock.h b/src/bin/lttng-sessiond/ust-clock.h
new file mode 100644 (file)
index 0000000..7d9c99a
--- /dev/null
+++ b/src/bin/lttng-sessiond/ust-clock.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2010  Pierre-Marc Fournier
+ * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1 of
+ * the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#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 <errno.h>
+
+#include <common/compat/uuid.h>
+
+/* TRACE CLOCK */
+
+/*
+ * Currently using the kernel MONOTONIC clock, waiting for kernel-side
+ * LTTng to implement mmap'd trace clock.
+ */
+
+/* Choosing correct trace clock */
+
+static __inline__
+uint64_t trace_clock_read64(void)
+{
+       struct timespec ts;
+
+       clock_gettime(CLOCK_MONOTONIC, &ts);
+       return ((uint64_t) ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
+}
+
+static __inline__
+uint64_t trace_clock_freq(void)
+{
+       return 1000000000ULL;
+}
+
+static __inline__
+int trace_clock_uuid(char *uuid)
+{
+       int ret = 0;
+       size_t len;
+       FILE *fp;
+
+       /*
+        * boot_id needs to be read once before being used concurrently
+        * to deal with a Linux kernel race. A fix is proposed for
+        * upstream, but the work-around is needed for older kernels.
+        */
+       fp = fopen("/proc/sys/kernel/random/boot_id", "r");
+       if (!fp) {
+               return -ENOENT;
+       }
+       len = fread(uuid, 1, UUID_STR_LEN - 1, fp);
+       if (len < UUID_STR_LEN - 1) {
+               ret = -EINVAL;
+               goto end;
+       }
+       uuid[UUID_STR_LEN - 1] = '\0';
+end:
+       fclose(fp);
+       return ret;
+}
+
+#endif /* _UST_CLOCK_H */