1 /**************************************************************************
2 *
3 * Copyright 2009 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29 #include "pipe/p_screen.h"
30 #include "util/u_memory.h"
31 #include "lp_debug.h"
32 #include "lp_fence.h"
33
34
35 #include "util/timespec.h"
36
37
38 /**
39 * Create a new fence object.
40 *
41 * The rank will be the number of bins in the scene. Whenever a rendering
42 * thread hits a fence command, it'll increment the fence counter. When
43 * the counter == the rank, the fence is finished.
44 *
45 * \param rank the expected finished value of the fence counter.
46 */
47 struct lp_fence *
lp_fence_create(unsigned rank)48 lp_fence_create(unsigned rank)
49 {
50 static unsigned fence_id = 0;
51 struct lp_fence *fence = CALLOC_STRUCT(lp_fence);
52
53 if (!fence)
54 return NULL;
55
56 pipe_reference_init(&fence->reference, 1);
57
58 (void) mtx_init(&fence->mutex, mtx_plain);
59 cnd_init(&fence->signalled);
60
61 fence->id = p_atomic_inc_return(&fence_id) - 1;
62 fence->rank = rank;
63
64 if (LP_DEBUG & DEBUG_FENCE)
65 debug_printf("%s %d\n", __func__, fence->id);
66
67 return fence;
68 }
69
70
71 /** Destroy a fence. Called when refcount hits zero. */
72 void
lp_fence_destroy(struct lp_fence * fence)73 lp_fence_destroy(struct lp_fence *fence)
74 {
75 if (LP_DEBUG & DEBUG_FENCE)
76 debug_printf("%s %d\n", __func__, fence->id);
77
78 mtx_destroy(&fence->mutex);
79 cnd_destroy(&fence->signalled);
80 FREE(fence);
81 }
82
83
84 /**
85 * Called by the rendering threads to increment the fence counter.
86 * When the counter == the rank, the fence is finished.
87 */
88 void
lp_fence_signal(struct lp_fence * fence)89 lp_fence_signal(struct lp_fence *fence)
90 {
91 if (LP_DEBUG & DEBUG_FENCE)
92 debug_printf("%s %d\n", __func__, fence->id);
93
94 mtx_lock(&fence->mutex);
95
96 fence->count++;
97 assert(fence->count <= fence->rank);
98
99 if (LP_DEBUG & DEBUG_FENCE)
100 debug_printf("%s count=%u rank=%u\n", __func__,
101 fence->count, fence->rank);
102
103 /* Wakeup all threads waiting on the mutex:
104 */
105 cnd_broadcast(&fence->signalled);
106
107 mtx_unlock(&fence->mutex);
108 }
109
110
111 bool
lp_fence_signalled(struct lp_fence * f)112 lp_fence_signalled(struct lp_fence *f)
113 {
114 return f->count == f->rank;
115 }
116
117
118 void
lp_fence_wait(struct lp_fence * f)119 lp_fence_wait(struct lp_fence *f)
120 {
121 if (LP_DEBUG & DEBUG_FENCE)
122 debug_printf("%s %d\n", __func__, f->id);
123
124 mtx_lock(&f->mutex);
125 assert(f->issued);
126 while (f->count < f->rank) {
127 cnd_wait(&f->signalled, &f->mutex);
128 }
129 mtx_unlock(&f->mutex);
130 }
131
132
133 bool
lp_fence_timedwait(struct lp_fence * f,uint64_t timeout)134 lp_fence_timedwait(struct lp_fence *f, uint64_t timeout)
135 {
136 struct timespec ts, abs_ts;
137
138 timespec_get(&ts, TIME_UTC);
139
140 bool ts_overflow = timespec_add_nsec(&abs_ts, &ts, timeout);
141
142 if (LP_DEBUG & DEBUG_FENCE)
143 debug_printf("%s %d\n", __func__, f->id);
144
145 mtx_lock(&f->mutex);
146 assert(f->issued);
147 while (f->count < f->rank) {
148 int ret;
149 if (ts_overflow)
150 ret = cnd_wait(&f->signalled, &f->mutex);
151 else
152 ret = cnd_timedwait(&f->signalled, &f->mutex, &abs_ts);
153 if (ret != thrd_success)
154 break;
155 }
156
157 const bool result = (f->count >= f->rank);
158 mtx_unlock(&f->mutex);
159
160 return result;
161 }
162