#include <sys/time.h>
#include <stdint.h>
#include <stddef.h>
+#include <stdio.h>
+#include "lttng-ust-uuid.h"
/* TRACE CLOCK */
}
static __inline__
-const char *trace_clock_uuid(void)
+int trace_clock_uuid(char *uuid)
{
- return "CLOCK_MONOTONIC";
+ 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, LTTNG_UST_UUID_STR_LEN - 1, fp);
+ if (len < LTTNG_UST_UUID_STR_LEN - 1) {
+ ret = -EINVAL;
+ goto end;
+ }
+ uuid[LTTNG_UST_UUID_STR_LEN - 1] = '\0';
+end:
+ fclose(fp);
+ return ret;
}
#endif /* _UST_CLOCK_H */