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 /*
  26  * Set each callback for the trace clock override, and then enable the
  27  * override. Those functions return negative error values on error, 0 on
  28  * success.
  29  */
  30
  31 /*
  32  * Set clock override read callback. This callback should return the
  33  * current clock time (a 64-bit monotonic counter).
  34  */
  35 int lttng_ust_trace_clock_set_read64_cb(uint64_t (*read64)(void));
  36
  37 /*
  38  * Set clock override frequency callback. This callback should return
  39  * the frequency of the clock in cycles per second.
  40  */
  41 int lttng_ust_trace_clock_set_freq_cb(uint64_t (*freq)(void));
  42
  43 /*
  44  * Set clock override unique identifier.
  45  * LTTNG_UST_UUID_STR_LEN is the maximum length of uuid string. Includes
  46  * final \0.
  47  */
  48 #define LTTNG_UST_UUID_STR_LEN         37
  49
  50 int lttng_ust_trace_clock_set_uuid_cb(int (*uuid)(char *uuid));
  51
  52 /*
  53  * Set clock override name.
  54  */
  55 int lttng_ust_trace_clock_set_name_cb(const char *(*name)(void));
  56
  57 /*
  58  * Set clock override description.
  59  */
  60 int lttng_ust_trace_clock_set_description_cb(const char *(*description)(void));
  61
  62 /*
  63  * Use the clock override rather than the default clock.
  64  */
  65 int lttng_ust_enable_trace_clock_override(void);
  66
  67 #endif /* LTTNG_UST_CLOCK_H */