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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5563 | serge | 1 | /* |
| 2 | * Copyright 2013 Marek Olšák |
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| 3 | * |
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| 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 5 | * copy of this software and associated documentation files (the "Software"), |
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| 6 | * to deal in the Software without restriction, including without limitation |
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| 7 | * on the rights to use, copy, modify, merge, publish, distribute, sub |
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| 8 | * license, and/or sell copies of the Software, and to permit persons to whom |
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| 9 | * the Software is furnished to do so, subject to the following conditions: |
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| 10 | * |
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| 11 | * The above copyright notice and this permission notice (including the next |
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| 12 | * paragraph) shall be included in all copies or substantial portions of the |
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| 13 | * Software. |
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| 14 | * |
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| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
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| 18 | * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, |
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| 19 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
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| 20 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
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| 21 | * USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
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| 22 | |||
| 23 | /** |
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| 24 | * @file |
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| 25 | * 1D integer range, capable of the union and intersection operations. |
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| 26 | * |
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| 27 | * It only maintains a single interval which is extended when the union is |
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| 28 | * done. This implementation is partially thread-safe (readers are not |
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| 29 | * protected by a lock). |
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| 30 | * |
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| 31 | * @author Marek Olšák |
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| 32 | */ |
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| 33 | |||
| 34 | #ifndef U_RANGE_H |
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| 35 | #define U_RANGE_H |
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| 36 | |||
| 37 | #include "os/os_thread.h" |
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| 38 | |||
| 39 | struct util_range { |
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| 40 | unsigned start; /* inclusive */ |
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| 41 | unsigned end; /* exclusive */ |
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| 42 | |||
| 43 | /* for the range to be consistent with multiple contexts: */ |
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| 44 | pipe_mutex write_mutex; |
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| 45 | }; |
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| 46 | |||
| 47 | |||
| 48 | static INLINE void |
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| 49 | util_range_set_empty(struct util_range *range) |
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| 50 | { |
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| 51 | range->start = ~0; |
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| 52 | range->end = 0; |
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| 53 | } |
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| 54 | |||
| 55 | /* This is like a union of two sets. */ |
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| 56 | static INLINE void |
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| 57 | util_range_add(struct util_range *range, unsigned start, unsigned end) |
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| 58 | { |
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| 59 | if (start < range->start || end > range->end) { |
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| 60 | pipe_mutex_lock(range->write_mutex); |
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| 61 | range->start = MIN2(start, range->start); |
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| 62 | range->end = MAX2(end, range->end); |
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| 63 | pipe_mutex_unlock(range->write_mutex); |
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| 64 | } |
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| 65 | } |
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| 66 | |||
| 67 | static INLINE boolean |
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| 68 | util_ranges_intersect(struct util_range *range, unsigned start, unsigned end) |
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| 69 | { |
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| 70 | return MAX2(start, range->start) < MIN2(end, range->end); |
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| 71 | } |
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| 72 | |||
| 73 | |||
| 74 | /* Init/deinit */ |
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| 75 | |||
| 76 | static INLINE void |
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| 77 | util_range_init(struct util_range *range) |
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| 78 | { |
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| 79 | pipe_mutex_init(range->write_mutex); |
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| 80 | util_range_set_empty(range); |
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| 81 | } |
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| 82 | |||
| 83 | static INLINE void |
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| 84 | util_range_destroy(struct util_range *range) |
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| 85 | { |
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| 86 | pipe_mutex_destroy(range->write_mutex); |
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| 87 | } |
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| 88 | |||
| 89 | #endif |