include/lttng/ust-clock.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2014  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  */
   6
   7 #ifndef LTTNG_UST_CLOCK_H
   8 #define LTTNG_UST_CLOCK_H
   9
  10 #include <stdint.h>
  11 #include <stddef.h>
  12
  13 /*
  14  * Set each callback for the trace clock override, and then enable the
  15  * override. Those functions return negative error values on error, 0 on
  16  * success.
  17  */
  18
  19 /*
  20  * Set clock override read callback. This callback should return the
  21  * current clock time (a 64-bit monotonic counter).
  22  */
  23 int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void));
  24
  25 /*
  26  * Set clock override frequency callback. This callback should return
  27  * the frequency of the clock in cycles per second.
  28  */
  29 int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void));
  30
  31 /*
  32  * Set clock override unique identifier.
  33  * LTTNG_UST_UUID_STR_LEN is the maximum length of uuid string. Includes
  34  * final \0.
  35  */
  36 #define LTTNG_UST_UUID_STR_LEN         37
  37
  38 int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid));
  39
  40 /*
  41  * Set clock override name.
  42  */
  43 int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void));
  44
  45 /*
  46  * Set clock override description.
  47  */
  48 int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void));
  49
  50 /*
  51  * Use the clock override rather than the default clock.
  52  */
  53 int lttng_ust_enable_trace_clock_override(void);
  54
  55 #endif /* LTTNG_UST_CLOCK_H */