blob: bf11b11632b7464bb454d4e02a17bfe92a47d5d4 (
plain) (
blame)
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
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/*
* Copyright (c) 2014, 2018 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/test-info.h>
#include <rtems.h>
#include <rtems/test.h>
#include <rtems/score/threadimpl.h>
static uint_fast32_t estimate_busy_loop_maximum( void )
{
uint_fast32_t units = 0;
uint_fast32_t initial = rtems_clock_get_ticks_since_boot();
while ( initial == rtems_clock_get_ticks_since_boot() ) {
++units;
}
return units;
}
static uint_fast32_t wait_for_tick_change( void )
{
uint_fast32_t initial = rtems_clock_get_ticks_since_boot();
uint_fast32_t now;
do {
now = rtems_clock_get_ticks_since_boot();
} while ( now == initial );
return now;
}
uint_fast32_t rtems_test_get_one_tick_busy_count( void )
{
uint_fast32_t last;
uint_fast32_t now;
uint_fast32_t a;
uint_fast32_t b;
uint_fast32_t m;
/* Choose a lower bound */
a = 1;
/* Estimate an upper bound */
wait_for_tick_change();
b = 2 * estimate_busy_loop_maximum();
while ( true ) {
last = wait_for_tick_change();
T_busy( b );
now = rtems_clock_get_ticks_since_boot();
if ( now != last ) {
break;
}
b *= 2;
last = now;
}
/* Find a good value */
do {
m = ( a + b ) / 2;
last = wait_for_tick_change();
T_busy( m );
now = rtems_clock_get_ticks_since_boot();
if ( now != last ) {
b = m;
} else {
a = m;
}
} while ( b - a > 1 );
return m;
}
void rtems_test_busy_cpu_usage( time_t seconds, long nanoseconds )
{
Thread_Control *executing;
Timestamp_Control busy;
Timestamp_Control start;
Timestamp_Control now;
executing = _Thread_Get_executing();
_Thread_Get_CPU_time_used( executing, &start );
_Timestamp_Set( &busy, seconds, nanoseconds );
do {
_Thread_Get_CPU_time_used( executing, &now );
} while ( now - start < busy );
}
|
