include/lttng/ust-clock.h

   1 #ifndef LTTNG_UST_CLOCK_H
   2 #define LTTNG_UST_CLOCK_H
   3
   4 /*
   5  * Copyright (C) 2014  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; version 2.1 of
  10  * the License.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  20  */
  21
  22 #include <stdint.h>
  23 #include <stddef.h>
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 /*
  30  * Set each callback for the trace clock override, and then enable the
  31  * override. Those functions return negative error values on error, 0 on
  32  * success.
  33  */
  34
  35 /*
  36  * Set clock override read callback. This callback should return the
  37  * current clock time (a 64-bit monotonic counter).
  38  */
  39 int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void));
  40
  41 /*
  42  * Set clock override frequency callback. This callback should return
  43  * the frequency of the clock in cycles per second.
  44  */
  45 int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void));
  46
  47 /*
  48  * Set clock override unique identifier.
  49  * LTTNG_UST_UUID_STR_LEN is the maximum length of uuid string. Includes
  50  * final \0.
  51  */
  52 #define LTTNG_UST_UUID_STR_LEN         37
  53
  54 int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid));
  55
  56 /*
  57  * Set clock override name.
  58  */
  59 int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void));
  60
  61 /*
  62  * Set clock override description.
  63  */
  64 int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void));
  65
  66 /*
  67  * Use the clock override rather than the default clock.
  68  */
  69 int lttng_ust_enable_trace_clock_override(void);
  70
  71 #ifdef __cplusplus
  72 }
  73 #endif
  74
  75 #endif /* LTTNG_UST_CLOCK_H */