xref: /openbmc/qemu/include/qemu/timed-average.h (revision a53b931645183bd0c15dd19ae0708fc3c81ecf1d)
1 /*
2  * QEMU timed average computation
3  *
4  * Copyright (C) Nodalink, EURL. 2014
5  * Copyright (C) Igalia, S.L. 2015
6  *
7  * Authors:
8  *   Benoît Canet <benoit.canet@nodalink.com>
9  *   Alberto Garcia <berto@igalia.com>
10  *
11  * SPDX-License-Identifier: GPL-2.0-or-later
12  *
13  * This program is free software: you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation, either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
25  */
26 
27 #ifndef TIMED_AVERAGE_H
28 #define TIMED_AVERAGE_H
29 
30 
31 #include "qemu/timer.h"
32 
33 typedef struct TimedAverageWindow TimedAverageWindow;
34 typedef struct TimedAverage TimedAverage;
35 
36 /* All fields of both structures are private */
37 
38 struct TimedAverageWindow {
39     uint64_t      min;             /* minimum value accounted in the window */
40     uint64_t      max;             /* maximum value accounted in the window */
41     uint64_t      sum;             /* sum of all values */
42     uint64_t      count;           /* number of values */
43     int64_t       expiration;      /* the end of the current window in ns */
44 };
45 
46 struct TimedAverage {
47     uint64_t           period;     /* period in nanoseconds */
48     TimedAverageWindow windows[2]; /* two overlapping windows of with
49                                     * an offset of period / 2 between them */
50     unsigned           current;    /* the current window index: it's also the
51                                     * oldest window index */
52     QEMUClockType      clock_type; /* the clock used */
53 };
54 
55 void timed_average_init(TimedAverage *ta, QEMUClockType clock_type,
56                         uint64_t period);
57 
58 void timed_average_account(TimedAverage *ta, uint64_t value);
59 
60 uint64_t timed_average_min(TimedAverage *ta);
61 uint64_t timed_average_avg(TimedAverage *ta);
62 uint64_t timed_average_max(TimedAverage *ta);
63 uint64_t timed_average_sum(TimedAverage *ta, uint64_t *elapsed);
64 
65 #endif
66