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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tv.h,v 1.7 2004/04/08 01:36:13 mdw Exp $ |
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4 | * |
5 | * Manipulation of timeval structures |
6 | * |
7 | * (c) 1998 Straylight/Edgeware |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
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15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
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18 | * |
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19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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22 | * GNU Library General Public License for more details. |
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23 | * |
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24 | * You should have received a copy of the GNU Library General Public |
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25 | * License along with mLib; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
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28 | */ |
29 | |
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30 | #ifndef MLIB_TV_H |
31 | #define MLIB_TV_H |
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32 | |
33 | #ifdef __cplusplus |
34 | extern "C" { |
35 | #endif |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #include <sys/time.h> |
40 | |
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41 | /*----- A macro to make reading easier ------------------------------------*/ |
42 | |
43 | #define MILLION 1000000 |
44 | |
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45 | /*----- Functions provided ------------------------------------------------*/ |
46 | |
47 | /* --- @tv_add@ --- * |
48 | * |
49 | * Arguments: @struct timeval *dst@ = destination block |
50 | * @const struct timeval *a, *b@ = source blocks |
51 | * |
52 | * Returns: --- |
53 | * |
54 | * Use: Adds two timevals. |
55 | */ |
56 | |
57 | extern void tv_add(struct timeval */*dst*/, |
58 | const struct timeval */*a*/, |
59 | const struct timeval */*b*/); |
60 | |
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61 | #define TV_ADD(dst, a, b) TV_ADDL(dst, a, (b)->tv_sec, (b)->tv_usec) |
62 | |
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63 | /* --- @tv_addl@ --- * |
64 | * |
65 | * Arguments: @struct timeval *dst@ = destination block |
66 | * @const struct timeval *a@ = source blocks |
67 | * @time_t sec@, @unsigned long usec@ = time to add |
68 | * |
69 | * Returns: --- |
70 | * |
71 | * Use: Adds a literal time in seconds and microseconds. |
72 | */ |
73 | |
74 | extern void tv_addl(struct timeval */*dst*/, |
75 | const struct timeval */*a*/, |
76 | time_t /*sec*/, unsigned long /*usec*/); |
77 | |
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78 | #define TV_ADDL(dst, a, sec, usec) do { \ |
79 | (dst)->tv_sec = (a)->tv_sec + (sec); \ |
80 | (dst)->tv_usec = (a)->tv_usec + (usec); \ |
81 | if ((dst)->tv_usec >= MILLION) { \ |
82 | (dst)->tv_usec -= MILLION; \ |
83 | (dst)->tv_sec++; \ |
84 | } \ |
85 | } while (0) |
86 | |
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87 | /* --- @tv_sub@ --- * |
88 | * |
89 | * Arguments: @struct timeval *dst@ = destination block |
90 | * @const struct timeval *a, *b@ = source blocks |
91 | * |
92 | * Returns: --- |
93 | * |
94 | * Use: Subtracts two timevals. |
95 | */ |
96 | |
97 | extern void tv_sub(struct timeval */*dst*/, |
98 | const struct timeval */*a*/, |
99 | const struct timeval */*b*/); |
100 | |
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101 | #define TV_SUB(dst, a, b) TV_SUBL(dst, a, (b)->tv_sec, (b)->tv_usec) |
102 | |
103 | /* --- @tv_subl@ --- * |
104 | * |
105 | * Arguments: @struct timeval *dst@ = destination block |
106 | * @const struct timeval *a@ = source blocks |
107 | * @time_t sec@, @unsigned long usec@ = time to subtract |
108 | * |
109 | * Returns: --- |
110 | * |
111 | * Use: Subtracts a literal time in seconds and microseconds. |
112 | */ |
113 | |
114 | extern void tv_subl(struct timeval */*dst*/, |
115 | const struct timeval */*a*/, |
116 | time_t /*sec*/, unsigned long /*usec*/); |
117 | |
118 | #define TV_SUBL(dst, a, sec, usec) do { \ |
119 | (dst)->tv_sec = (a)->tv_sec - (sec); \ |
120 | if ((a)->tv_usec >= (usec)) \ |
121 | (dst)->tv_usec = (a)->tv_usec - (usec); \ |
122 | else { \ |
123 | (dst)->tv_usec = (a)->tv_usec + MILLION - (usec); \ |
124 | (dst)->tv_sec--; \ |
125 | } \ |
126 | } while (0) |
127 | |
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128 | /* --- @tv_cmp@ --- * |
129 | * |
130 | * Arguments: @const struct timeval *a, *b@ = source blocks |
131 | * |
132 | * Returns: Less than, equal to, or greater than zero. |
133 | * |
134 | * Use: Compares two timevals. |
135 | */ |
136 | |
137 | extern int tv_cmp(const struct timeval */*a*/, |
138 | const struct timeval */*b*/); |
139 | |
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140 | #define TV_CMP(a, op, b) ((a)->tv_sec == (b)->tv_sec ? \ |
141 | (a)->tv_usec op (b)->tv_usec : \ |
142 | (a)->tv_sec op (b)->tv_sec) |
143 | |
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144 | /*----- That's all, folks -------------------------------------------------*/ |
145 | |
146 | #ifdef __cplusplus |
147 | } |
148 | #endif |
149 | |
150 | #endif |