1 /*
2 * Copyright © 2016 Advanced Micro Devices, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
14 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
15 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
16 * NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS, AUTHORS
17 * AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 * USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
24 * of the Software.
25 */
26
27 /* Job queue with execution in a separate thread.
28 *
29 * Jobs can be added from any thread. After that, the wait call can be used
30 * to wait for completion of the job.
31 */
32
33 #ifndef U_QUEUE_H
34 #define U_QUEUE_H
35
36 #include <string.h>
37
38 #include "util/futex.h"
39 #include "util/list.h"
40 #include "util/macros.h"
41 #include "util/os_time.h"
42 #include "util/u_atomic.h"
43 #include "util/u_thread.h"
44
45 #ifdef __cplusplus
46 extern "C" {
47 #endif
48
49 #define UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY (1 << 0)
50 #define UTIL_QUEUE_INIT_RESIZE_IF_FULL (1 << 1)
51 #define UTIL_QUEUE_INIT_SET_FULL_THREAD_AFFINITY (1 << 2)
52
53 #if UTIL_FUTEX_SUPPORTED
54 #define UTIL_QUEUE_FENCE_FUTEX
55 #else
56 #define UTIL_QUEUE_FENCE_STANDARD
57 #endif
58
59 #ifdef UTIL_QUEUE_FENCE_FUTEX
60 /* Job completion fence.
61 * Put this into your job structure.
62 */
63 struct util_queue_fence {
64 /* The fence can be in one of three states:
65 * 0 - signaled
66 * 1 - unsignaled
67 * 2 - unsignaled, may have waiters
68 */
69 uint32_t val;
70 };
71
72 static inline void
util_queue_fence_init(struct util_queue_fence * fence)73 util_queue_fence_init(struct util_queue_fence *fence)
74 {
75 fence->val = 0;
76 }
77
78 static inline void
util_queue_fence_destroy(struct util_queue_fence * fence)79 util_queue_fence_destroy(struct util_queue_fence *fence)
80 {
81 assert(fence->val == 0);
82 /* no-op */
83 }
84
85 static inline void
util_queue_fence_signal(struct util_queue_fence * fence)86 util_queue_fence_signal(struct util_queue_fence *fence)
87 {
88 uint32_t val = p_atomic_xchg(&fence->val, 0);
89
90 assert(val != 0);
91
92 if (val == 2)
93 futex_wake(&fence->val, INT_MAX);
94 }
95
96 /**
97 * Move \p fence back into unsignalled state.
98 *
99 * \warning The caller must ensure that no other thread may currently be
100 * waiting (or about to wait) on the fence.
101 */
102 static inline void
util_queue_fence_reset(struct util_queue_fence * fence)103 util_queue_fence_reset(struct util_queue_fence *fence)
104 {
105 #ifdef NDEBUG
106 fence->val = 1;
107 #else
108 uint32_t v = p_atomic_xchg(&fence->val, 1);
109 assert(v == 0);
110 #endif
111 }
112
113 static inline bool
util_queue_fence_is_signalled(struct util_queue_fence * fence)114 util_queue_fence_is_signalled(struct util_queue_fence *fence)
115 {
116 return fence->val == 0;
117 }
118 #endif
119
120 #ifdef UTIL_QUEUE_FENCE_STANDARD
121 /* Job completion fence.
122 * Put this into your job structure.
123 */
124 struct util_queue_fence {
125 mtx_t mutex;
126 cnd_t cond;
127 int signalled;
128 };
129
130 void util_queue_fence_init(struct util_queue_fence *fence);
131 void util_queue_fence_destroy(struct util_queue_fence *fence);
132 void util_queue_fence_signal(struct util_queue_fence *fence);
133
134 /**
135 * Move \p fence back into unsignalled state.
136 *
137 * \warning The caller must ensure that no other thread may currently be
138 * waiting (or about to wait) on the fence.
139 */
140 static inline void
util_queue_fence_reset(struct util_queue_fence * fence)141 util_queue_fence_reset(struct util_queue_fence *fence)
142 {
143 assert(fence->signalled);
144 fence->signalled = 0;
145 }
146
147 static inline bool
util_queue_fence_is_signalled(struct util_queue_fence * fence)148 util_queue_fence_is_signalled(struct util_queue_fence *fence)
149 {
150 return fence->signalled != 0;
151 }
152 #endif
153
154 void
155 _util_queue_fence_wait(struct util_queue_fence *fence);
156
157 static inline void
util_queue_fence_wait(struct util_queue_fence * fence)158 util_queue_fence_wait(struct util_queue_fence *fence)
159 {
160 if (unlikely(!util_queue_fence_is_signalled(fence)))
161 _util_queue_fence_wait(fence);
162 }
163
164 bool
165 _util_queue_fence_wait_timeout(struct util_queue_fence *fence,
166 int64_t abs_timeout);
167
168 /**
169 * Wait for the fence to be signaled with a timeout.
170 *
171 * \param fence the fence
172 * \param abs_timeout the absolute timeout in nanoseconds, relative to the
173 * clock provided by os_time_get_nano.
174 *
175 * \return true if the fence was signaled, false if the timeout occurred.
176 */
177 static inline bool
util_queue_fence_wait_timeout(struct util_queue_fence * fence,int64_t abs_timeout)178 util_queue_fence_wait_timeout(struct util_queue_fence *fence,
179 int64_t abs_timeout)
180 {
181 if (util_queue_fence_is_signalled(fence))
182 return true;
183
184 if (abs_timeout == (int64_t)OS_TIMEOUT_INFINITE) {
185 _util_queue_fence_wait(fence);
186 return true;
187 }
188
189 return _util_queue_fence_wait_timeout(fence, abs_timeout);
190 }
191
192 typedef void (*util_queue_execute_func)(void *job, int thread_index);
193
194 struct util_queue_job {
195 void *job;
196 size_t job_size;
197 struct util_queue_fence *fence;
198 util_queue_execute_func execute;
199 util_queue_execute_func cleanup;
200 };
201
202 /* Put this into your context. */
203 struct util_queue {
204 char name[14]; /* 13 characters = the thread name without the index */
205 mtx_t finish_lock; /* for util_queue_finish and protects threads/num_threads */
206 mtx_t lock;
207 cnd_t has_queued_cond;
208 cnd_t has_space_cond;
209 thrd_t *threads;
210 unsigned flags;
211 int num_queued;
212 unsigned max_threads;
213 unsigned num_threads; /* decreasing this number will terminate threads */
214 int max_jobs;
215 int write_idx, read_idx; /* ring buffer pointers */
216 size_t total_jobs_size; /* memory use of all jobs in the queue */
217 struct util_queue_job *jobs;
218
219 /* for cleanup at exit(), protected by exit_mutex */
220 struct list_head head;
221 };
222
223 bool util_queue_init(struct util_queue *queue,
224 const char *name,
225 unsigned max_jobs,
226 unsigned num_threads,
227 unsigned flags);
228 void util_queue_destroy(struct util_queue *queue);
229
230 /* optional cleanup callback is called after fence is signaled: */
231 void util_queue_add_job(struct util_queue *queue,
232 void *job,
233 struct util_queue_fence *fence,
234 util_queue_execute_func execute,
235 util_queue_execute_func cleanup,
236 const size_t job_size);
237 void util_queue_drop_job(struct util_queue *queue,
238 struct util_queue_fence *fence);
239
240 void util_queue_finish(struct util_queue *queue);
241
242 /* Adjust the number of active threads. The new number of threads can't be
243 * greater than the initial number of threads at the creation of the queue,
244 * and it can't be less than 1.
245 */
246 void
247 util_queue_adjust_num_threads(struct util_queue *queue, unsigned num_threads);
248
249 int64_t util_queue_get_thread_time_nano(struct util_queue *queue,
250 unsigned thread_index);
251
252 /* util_queue needs to be cleared to zeroes for this to work */
253 static inline bool
util_queue_is_initialized(struct util_queue * queue)254 util_queue_is_initialized(struct util_queue *queue)
255 {
256 return queue->threads != NULL;
257 }
258
259 /* Convenient structure for monitoring the queue externally and passing
260 * the structure between Mesa components. The queue doesn't use it directly.
261 */
262 struct util_queue_monitoring
263 {
264 /* For querying the thread busyness. */
265 struct util_queue *queue;
266
267 /* Counters updated by the user of the queue. */
268 unsigned num_offloaded_items;
269 unsigned num_direct_items;
270 unsigned num_syncs;
271 };
272
273 #ifdef __cplusplus
274 }
275 #endif
276
277 #endif
278