xref: /netbsd-src/external/bsd/ntp/dist/tests/libntp/tvtots.c (revision cdfa2a7ef92791ba9db70a584a1d904730e6fb46)
1 /*	$NetBSD: tvtots.c,v 1.2 2020/05/25 20:47:36 christos Exp $	*/
2 
3 #include "config.h"
4 
5 #include "lfptest.h"
6 #include "timevalops.h"
7 
8 #include "unity.h"
9 
10 #include <math.h> /* Required on Solaris for ldexp. */
11 
12 void test_Seconds(void);
13 void test_MicrosecondsRounded(void);
14 void test_MicrosecondsExact(void);
15 
16 void
test_Seconds(void)17 test_Seconds(void)
18 {
19 	struct timeval input = {500, 0}; /* 500.0 s */
20 	l_fp expected = {{500}, 0};
21 	l_fp actual;
22 
23 	TVTOTS(&input, &actual);
24 
25 	TEST_ASSERT_TRUE(IsEqual(expected, actual));
26 }
27 
28 
29 void
test_MicrosecondsRounded(void)30 test_MicrosecondsRounded(void)
31 {
32 	/* 0.0005 can not be represented exact in a l_fp structure.
33 	 * It would equal to 2147483,648. This means that
34 	 * HALF_PROMILLE_UP (which is 2147484) should be
35 	 * the correct rounding. */
36 
37 	struct timeval input = {0, 500}; /* 0.0005 exact */
38 	l_fp expected = {{0}, HALF_PROMILLE_UP};
39 	l_fp actual;
40 
41 	TVTOTS(&input, &actual);
42 
43 	TEST_ASSERT_TRUE(IsEqual(expected, actual));
44 }
45 
46 
47 void
test_MicrosecondsExact(void)48 test_MicrosecondsExact(void)
49 {
50 	/* 0.5 can be represented exact in both l_fp and timeval. */
51 	const struct timeval input = {10, 500000}; /* 0.5 exact */
52 	const l_fp expected = {{10}, HALF};        /* 0.5 exact */
53 	l_fp actual;
54 
55 	TVTOTS(&input, &actual);
56 
57 	/* Compare the fractional part with an absolute error given. */
58 	TEST_ASSERT_EQUAL_UINT(expected.l_ui, actual.l_ui);
59 
60 	double expectedDouble, actualDouble;
61 	M_LFPTOD(0, expected.l_uf, expectedDouble);
62 	M_LFPTOD(0, actual.l_uf, actualDouble);
63 
64 	/* The error should be less than 0.5 us */
65 	TEST_ASSERT_DOUBLE_WITHIN(0.0000005, expectedDouble, actualDouble);
66 }
67