1 /*
2 * Copyright 2013 Marek Olšák <maraeo@gmail.com>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE. */
22
23 /**
24 * @file
25 * 1D integer range, capable of the union and intersection operations.
26 *
27 * It only maintains a single interval which is extended when the union is
28 * done. This implementation is partially thread-safe (readers are not
29 * protected by a lock).
30 *
31 * @author Marek Olšák
32 */
33
34 #ifndef U_RANGE_H
35 #define U_RANGE_H
36
37 #include "os/os_thread.h"
38 #include "pipe/p_state.h"
39 #include "util/u_math.h"
40 #include "util/simple_mtx.h"
41
42 struct util_range {
43 unsigned start; /* inclusive */
44 unsigned end; /* exclusive */
45
46 /* for the range to be consistent with multiple contexts: */
47 simple_mtx_t write_mutex;
48 };
49
50
51 static inline void
util_range_set_empty(struct util_range * range)52 util_range_set_empty(struct util_range *range)
53 {
54 range->start = ~0;
55 range->end = 0;
56 }
57
58 /* This is like a union of two sets. */
59 static inline void
util_range_add(struct pipe_resource * resource,struct util_range * range,unsigned start,unsigned end)60 util_range_add(struct pipe_resource *resource, struct util_range *range,
61 unsigned start, unsigned end)
62 {
63 if (start < range->start || end > range->end) {
64 if (resource->flags & PIPE_RESOURCE_FLAG_SINGLE_THREAD_USE) {
65 range->start = MIN2(start, range->start);
66 range->end = MAX2(end, range->end);
67 } else {
68 simple_mtx_lock(&range->write_mutex);
69 range->start = MIN2(start, range->start);
70 range->end = MAX2(end, range->end);
71 simple_mtx_unlock(&range->write_mutex);
72 }
73 }
74 }
75
76 static inline boolean
util_ranges_intersect(const struct util_range * range,unsigned start,unsigned end)77 util_ranges_intersect(const struct util_range *range,
78 unsigned start, unsigned end)
79 {
80 return MAX2(start, range->start) < MIN2(end, range->end);
81 }
82
83
84 /* Init/deinit */
85
86 static inline void
util_range_init(struct util_range * range)87 util_range_init(struct util_range *range)
88 {
89 (void) simple_mtx_init(&range->write_mutex, mtx_plain);
90 util_range_set_empty(range);
91 }
92
93 static inline void
util_range_destroy(struct util_range * range)94 util_range_destroy(struct util_range *range)
95 {
96 simple_mtx_destroy(&range->write_mutex);
97 }
98
99 #endif
100