lib/babeltrace/ctf-writer/clock.h

   1 #ifndef BABELTRACE_CTF_WRITER_CLOCK_H
   2 #define BABELTRACE_CTF_WRITER_CLOCK_H
   3
   4 /*
   5  * BabelTrace - CTF Writer: Clock
   6  *
   7  * Copyright 2013 EfficiOS Inc.
   8  *
   9  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  *
  29  * The Common Trace Format (CTF) Specification is available at
  30  * http://www.efficios.com/ctf
  31  */
  32
  33 #include <stdint.h>
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 struct bt_ctf_clock;
  40
  41 /*
  42  * bt_ctf_clock_create: create a clock.
  43  *
  44  * Allocate a new clock setting its reference count to 1.
  45  *
  46  * @param name Name of the clock (will be copied).
  47  *
  48  * Returns an allocated clock on success, NULL on error.
  49  */
  50 extern struct bt_ctf_clock *bt_ctf_clock_create(const char *name);
  51
  52 /*
  53  * bt_ctf_clock_set_description: set a clock's description.
  54  *
  55  * Set the clock's description. The description appears in the clock's TSDL
  56  * meta-data.
  57  *
  58  * @param clock Clock instance.
  59  * @param desc Description of the clock.
  60  *
  61  * Returns 0 on success, a negative value on error.
  62  */
  63 extern int bt_ctf_clock_set_description(struct bt_ctf_clock *clock,
  64                 const char *desc);
  65
  66 /*
  67  * bt_ctf_clock_set_frequency: set a clock's frequency.
  68  *
  69  * Set the clock's frequency (Hz).
  70  *
  71  * @param clock Clock instance.
  72  * @param freq Clock's frequency in Hz, defaults to 1 000 000 000 Hz (1ns).
  73  *
  74  * Returns 0 on success, a negative value on error.
  75  */
  76 extern int bt_ctf_clock_set_frequency(struct bt_ctf_clock *clock,
  77                 uint64_t freq);
  78
  79 /*
  80  * bt_ctf_clock_set_precision: set a clock's precision.
  81  *
  82  * Set the clock's precision.
  83  *
  84  * @param clock Clock instance.
  85  * @param precision Clock's precision in clock ticks, defaults to 1.
  86  *
  87  * Returns 0 on success, a negative value on error.
  88  */
  89 extern int bt_ctf_clock_set_precision(struct bt_ctf_clock *clock,
  90                 uint64_t precision);
  91
  92 /*
  93  * bt_ctf_clock_set_offset_s: set a clock's offset in seconds.
  94  *
  95  * Set the clock's offset in seconds from POSIX.1 Epoch, 1970-01-01,
  96  * defaults to 0.
  97  *
  98  * @param clock Clock instance.
  99  * @param offset_s Clock's offset in seconds, defaults to 0.
 100  *
 101  * Returns 0 on success, a negative value on error.
 102  */
 103 extern int bt_ctf_clock_set_offset_s(struct bt_ctf_clock *clock,
 104                 uint64_t offset_s);
 105
 106
 107 /*
 108  * bt_ctf_clock_set_offset: set a clock's offset in ticks.
 109  *
 110  * Set the clock's offset in ticks from Epoch + offset_s.
 111  *
 112  * @param clock Clock instance.
 113  * @param offset Clock's offset in ticks from Epoch + offset_s, defaults to 0.
 114  *
 115  * Returns 0 on success, a negative value on error.
 116  */
 117 extern int bt_ctf_clock_set_offset(struct bt_ctf_clock *clock,
 118                 uint64_t offset);
 119
 120 /*
 121  * bt_ctf_clock_set_is_absolute: set a clock's absolute attribute.
 122  *
 123  * A clock is absolute if the clock is a global reference across the trace's
 124  * other clocks.
 125  *
 126  * @param clock Clock instance.
 127  * @param is_absolute Clock's absolute attribute, defaults to FALSE.
 128  *
 129  * Returns 0 on success, a negative value on error.
 130  */
 131 extern int bt_ctf_clock_set_is_absolute(struct bt_ctf_clock *clock,
 132                 int is_absolute);
 133
 134 /*
 135  * bt_ctf_clock_set_time: set a clock's current time value.
 136  *
 137  * Set the current time in nanoseconds since the clock's origin (offset and
 138  * offset_s attributes). The clock's value will be sampled as events are
 139  * appended to a stream.
 140  *
 141  * Returns 0 on success, a negative value on error.
 142  */
 143 extern int bt_ctf_clock_set_time(struct bt_ctf_clock *clock, uint64_t time);
 144
 145 /*
 146  * bt_ctf_clock_get and bt_ctf_clock_put: increment and decrement the
 147  * refcount of the clock
 148  *
 149  * These functions ensure that the clock won't be destroyed when it
 150  * is in use. The same number of get and put (plus one extra put to
 151  * release the initial reference done at creation) has to be done to
 152  * destroy a clock.
 153  *
 154  * When the clock refcount is decremented to 0 by a bt_ctf_clock_put,
 155  * the clock is freed.
 156  *
 157  * @param clock Clock instance.
 158  */
 159 extern void bt_ctf_clock_get(struct bt_ctf_clock *clock);
 160 extern void bt_ctf_clock_put(struct bt_ctf_clock *clock);
 161
 162 #ifdef __cplusplus
 163 }
 164 #endif
 165
 166 #endif /* BABELTRACE_CTF_WRITER_CLOCK_H */