1 | /* |
2 | * Copyright (c) 2017-2018 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | #include <netinet/in_stat.h> |
30 | |
31 | #define IN_STAT_ACTIVITY_GRANULARITY 8 /* 8 sec granularity */ |
32 | #define IN_STAT_ACTIVITY_TIME_SEC_SHIFT 3 /* 8 sec per bit */ |
33 | #define IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE ((uint64_t) 128) |
34 | #define IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE ((uint64_t) 64) |
35 | #define IN_STAT_ACTIVITY_TOTAL_TIME ((uint64_t) (8 * 128)) |
36 | #define IN_STAT_SET_MOST_SIGNIFICANT_BIT ((u_int64_t )0x8000000000000000) |
37 | |
38 | void |
39 | in_stat_set_activity_bitmap(activity_bitmap_t *activity, uint64_t now) |
40 | { |
41 | uint64_t elapsed_time, slot; |
42 | uint64_t *bitmap; |
43 | if (activity->start == 0) { |
44 | // Align all activity maps |
45 | activity->start = now - (now % IN_STAT_ACTIVITY_GRANULARITY); |
46 | } |
47 | elapsed_time = now - activity->start; |
48 | |
49 | slot = elapsed_time >> IN_STAT_ACTIVITY_TIME_SEC_SHIFT; |
50 | if (slot < IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE) { |
51 | if (slot < IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE) { |
52 | bitmap = &activity->bitmap[0]; |
53 | } else { |
54 | bitmap = &activity->bitmap[1]; |
55 | slot -= IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE; |
56 | } |
57 | *bitmap |= (((u_int64_t) 1) << slot); |
58 | } else { |
59 | if (slot >= (IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE * 2)) { |
60 | activity->start = now - IN_STAT_ACTIVITY_TOTAL_TIME; |
61 | activity->bitmap[0] = activity->bitmap[1] = 0; |
62 | } else { |
63 | uint64_t shift = |
64 | slot - (IN_STAT_ACTIVITY_BITMAP_TOTAL_SIZE - 1); |
65 | /* |
66 | * Move the start time and bitmap forward to |
67 | * cover the lost time |
68 | */ |
69 | activity->start += |
70 | (shift << IN_STAT_ACTIVITY_TIME_SEC_SHIFT); |
71 | if (shift > IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE) { |
72 | activity->bitmap[0] = activity->bitmap[1]; |
73 | activity->bitmap[1] = 0; |
74 | shift -= IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE; |
75 | if (shift == IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE) { |
76 | activity->bitmap[0] = 0; |
77 | } else { |
78 | activity->bitmap[0] >>= shift; |
79 | } |
80 | } else { |
81 | uint64_t mask_lower, tmp; |
82 | uint64_t b1_low, b0_high; |
83 | |
84 | /* |
85 | * generate a mask with all of lower |
86 | * 'shift' bits set |
87 | */ |
88 | tmp = (((uint64_t)1) << (shift - 1)); |
89 | mask_lower = ((tmp - 1) ^ tmp); |
90 | activity->bitmap[0] >>= shift; |
91 | b1_low = (activity->bitmap[1] & mask_lower); |
92 | |
93 | b0_high = (b1_low << |
94 | (IN_STAT_ACTIVITY_BITMAP_FIELD_SIZE - |
95 | shift)); |
96 | activity->bitmap[0] |= b0_high; |
97 | activity->bitmap[1] >>= shift; |
98 | } |
99 | } |
100 | activity->bitmap[1] |= IN_STAT_SET_MOST_SIGNIFICANT_BIT; |
101 | } |
102 | } |
103 | |
104 | void |
105 | in_stat_clear_activity_bitmap(activity_bitmap_t *activity) |
106 | { |
107 | activity->start = 0; |
108 | activity->bitmap[0] = 0; |
109 | activity->bitmap[1] = 0; |
110 | } |
111 | |