1/*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include <time.h>
17#include <threads.h>
18#include "test.h"
19
20#define ms (1000.0)
21#define us (1000000)
22#define ns (1000000000L)
23
24double ustimer(struct timespec tss, struct timespec tse)
25{
26    double sd = difftime(tse.tv_sec, tss.tv_sec);
27    long nsd = tse.tv_nsec - tss.tv_nsec;
28    if (nsd < 0) {
29        return us * (sd - 1) + (ns + nsd) / ms;
30    } else {
31        return us * (sd) + nsd / ms;
32    }
33}
34
35void yieldfunc(void)
36{
37    struct timespec tss, tse;
38    timespec_get(&tss, TIME_UTC);
39    do {
40        thrd_yield();
41        timespec_get(&tse, TIME_UTC);
42    } while (ustimer(tss, tse) < 100.0);
43}
44
45/**
46 * @tc.name      : thrd_yield_0100
47 * @tc.desc      : Busy wait while yielding
48 * @tc.level     : Level 0
49 */
50void thrd_yield_0100(void)
51{
52    int result;
53    struct timespec tss, tse;
54
55    result = timespec_get(&tss, TIME_UTC);
56    if (result != TIME_UTC) {
57        t_error("%s timespec_get start failed", __func__);
58        return;
59    }
60
61    yieldfunc();
62
63    result = timespec_get(&tse, TIME_UTC);
64    if (result != TIME_UTC) {
65        t_error("%s timespec_get end failed", __func__);
66        return;
67    }
68
69    if ((ustimer(tss, tse) - 100.0) < 0) {
70        t_error("%s sleep time is not 100us", __func__);
71        return;
72    }
73}
74
75int main(int argc, char *argv[])
76{
77    thrd_yield_0100();
78    return t_status;
79}