1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
/* Copyright (c) 2017 Red Hat, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef STOPWATCH_H
#define STOPWATCH_H 1
#include <stdbool.h>
enum stopwatch_units {
SW_MS,
SW_US,
SW_NS,
};
struct stopwatch_stats {
unsigned long long count; /* Total number of samples. */
enum stopwatch_units unit; /* Unit of following values. */
unsigned long long max; /* Maximum value. */
unsigned long long min; /* Minimum value. */
double pctl_95; /* 95th percentile. */
double ewma_50; /* Exponentially weighted moving average
(alpha 0.50). */
double ewma_1; /* Exponentially weighted moving average
(alpha 0.01). */
};
/* Create a new stopwatch.
* The "units" are not used for any calculations but are printed when
* statistics are requested.
*/
void stopwatch_create(const char *name, enum stopwatch_units units);
/* Start a stopwatch. */
void stopwatch_start(const char *name, unsigned long long ts);
/* Stop a stopwatch. The elapsed time will be used for updating statistics
* for this stopwatch.
*/
void stopwatch_stop(const char *name, unsigned long long ts);
/* Retrieve statistics calculated from collected samples */
bool stopwatch_get_stats(const char *name, struct stopwatch_stats *stats);
/* Block until all enqueued samples have been processed. */
void stopwatch_sync(void);
#endif /* stopwatch.h */
|
