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 "pipe/p_screen.h"
40 #include "util/u_atomic.h"
41 #include "util/u_math.h"
42 #include "util/simple_mtx.h"
43
44 struct util_range {
45 unsigned start; /* inclusive */
46 unsigned end; /* exclusive */
47
48 /* for the range to be consistent with multiple contexts: */
49 simple_mtx_t write_mutex;
50 };
51
52
53 static inline void
util_range_set_empty(struct util_range * range)54 util_range_set_empty(struct util_range *range)
55 {
56 range->start = ~0;
57 range->end = 0;
58 }
59
60 /* This is like a union of two sets. */
61 static inline void
util_range_add(struct pipe_resource * resource,struct util_range * range,unsigned start,unsigned end)62 util_range_add(struct pipe_resource *resource, struct util_range *range,
63 unsigned start, unsigned end)
64 {
65 if (start < range->start || end > range->end) {
66 if (resource->flags & PIPE_RESOURCE_FLAG_SINGLE_THREAD_USE ||
67 p_atomic_read(&resource->screen->num_contexts) == 1) {
68 range->start = MIN2(start, range->start);
69 range->end = MAX2(end, range->end);
70 } else {
71 simple_mtx_lock(&range->write_mutex);
72 range->start = MIN2(start, range->start);
73 range->end = MAX2(end, range->end);
74 simple_mtx_unlock(&range->write_mutex);
75 }
76 }
77 }
78
79 static inline boolean
util_ranges_intersect(const struct util_range * range,unsigned start,unsigned end)80 util_ranges_intersect(const struct util_range *range,
81 unsigned start, unsigned end)
82 {
83 return MAX2(start, range->start) < MIN2(end, range->end);
84 }
85
86
87 /* Init/deinit */
88
89 static inline void
util_range_init(struct util_range * range)90 util_range_init(struct util_range *range)
91 {
92 (void) simple_mtx_init(&range->write_mutex, mtx_plain);
93 util_range_set_empty(range);
94 }
95
96 static inline void
util_range_destroy(struct util_range * range)97 util_range_destroy(struct util_range *range)
98 {
99 simple_mtx_destroy(&range->write_mutex);
100 }
101
102 #endif
103