1 /*
2 * Copyright 2016 Patrick Rudolph <siro@das-labor.org>
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 #include "nine_queue.h"
24 #include "os/os_thread.h"
25 #include "util/macros.h"
26 #include "nine_helpers.h"
27
28 #define NINE_CMD_BUF_INSTR (256)
29
30 #define NINE_CMD_BUFS (32)
31 #define NINE_CMD_BUFS_MASK (NINE_CMD_BUFS - 1)
32
33 #define NINE_QUEUE_SIZE (8192 * 16 + 128)
34
35 #define DBG_CHANNEL DBG_DEVICE
36
37 /*
38 * Single producer - single consumer pool queue
39 *
40 * Producer:
41 * Calls nine_queue_alloc to get a slice of memory in current cmdbuf.
42 * Calls nine_queue_flush to flush the queue by request.
43 * The queue is flushed automatically on insufficient space or once the
44 * cmdbuf contains NINE_CMD_BUF_INSTR instructions.
45 *
46 * nine_queue_flush does block, while nine_queue_alloc doesn't block.
47 *
48 * nine_queue_alloc returns NULL on insufficent space.
49 *
50 * Consumer:
51 * Calls nine_queue_wait_flush to wait for a cmdbuf.
52 * After waiting for a cmdbuf it calls nine_queue_get until NULL is returned.
53 *
54 * nine_queue_wait_flush does block, while nine_queue_get doesn't block.
55 *
56 * Constrains:
57 * Only a single consumer and a single producer are supported.
58 *
59 */
60
61 struct nine_cmdbuf {
62 unsigned instr_size[NINE_CMD_BUF_INSTR];
63 unsigned num_instr;
64 unsigned offset;
65 void *mem_pool;
66 BOOL full;
67 };
68
69 struct nine_queue_pool {
70 struct nine_cmdbuf pool[NINE_CMD_BUFS];
71 unsigned head;
72 unsigned tail;
73 unsigned cur_instr;
74 BOOL worker_wait;
75 cnd_t event_pop;
76 cnd_t event_push;
77 mtx_t mutex_pop;
78 mtx_t mutex_push;
79 };
80
81 /* Consumer functions: */
82 void
nine_queue_wait_flush(struct nine_queue_pool * ctx)83 nine_queue_wait_flush(struct nine_queue_pool* ctx)
84 {
85 struct nine_cmdbuf *cmdbuf = &ctx->pool[ctx->tail];
86
87 /* wait for cmdbuf full */
88 mtx_lock(&ctx->mutex_push);
89 while (!cmdbuf->full)
90 {
91 DBG("waiting for full cmdbuf\n");
92 cnd_wait(&ctx->event_push, &ctx->mutex_push);
93 }
94 DBG("got cmdbuf=%p\n", cmdbuf);
95 mtx_unlock(&ctx->mutex_push);
96
97 cmdbuf->offset = 0;
98 ctx->cur_instr = 0;
99 }
100
101 /* Gets a pointer to the next memory slice.
102 * Does not block.
103 * Returns NULL on empty cmdbuf. */
104 void *
nine_queue_get(struct nine_queue_pool * ctx)105 nine_queue_get(struct nine_queue_pool* ctx)
106 {
107 struct nine_cmdbuf *cmdbuf = &ctx->pool[ctx->tail];
108 unsigned offset;
109
110 /* At this pointer there's always a cmdbuf. */
111
112 if (ctx->cur_instr == cmdbuf->num_instr) {
113 /* signal waiting producer */
114 mtx_lock(&ctx->mutex_pop);
115 DBG("freeing cmdbuf=%p\n", cmdbuf);
116 cmdbuf->full = 0;
117 cnd_signal(&ctx->event_pop);
118 mtx_unlock(&ctx->mutex_pop);
119
120 ctx->tail = (ctx->tail + 1) & NINE_CMD_BUFS_MASK;
121
122 return NULL;
123 }
124
125 /* At this pointer there's always a cmdbuf with instruction to process. */
126 offset = cmdbuf->offset;
127 cmdbuf->offset += cmdbuf->instr_size[ctx->cur_instr];
128 ctx->cur_instr ++;
129
130 return cmdbuf->mem_pool + offset;
131 }
132
133 /* Producer functions: */
134
135 /* Flushes the queue.
136 * Moves the current cmdbuf to worker thread.
137 * Blocks until next cmdbuf is free. */
138 void
nine_queue_flush(struct nine_queue_pool * ctx)139 nine_queue_flush(struct nine_queue_pool* ctx)
140 {
141 struct nine_cmdbuf *cmdbuf = &ctx->pool[ctx->head];
142
143 DBG("flushing cmdbuf=%p instr=%d size=%d\n",
144 cmdbuf, cmdbuf->num_instr, cmdbuf->offset);
145
146 /* Nothing to flush */
147 if (!cmdbuf->num_instr)
148 return;
149
150 /* signal waiting worker */
151 mtx_lock(&ctx->mutex_push);
152 cmdbuf->full = 1;
153 cnd_signal(&ctx->event_push);
154 mtx_unlock(&ctx->mutex_push);
155
156 ctx->head = (ctx->head + 1) & NINE_CMD_BUFS_MASK;
157
158 cmdbuf = &ctx->pool[ctx->head];
159
160 /* wait for queue empty */
161 mtx_lock(&ctx->mutex_pop);
162 while (cmdbuf->full)
163 {
164 DBG("waiting for empty cmdbuf\n");
165 cnd_wait(&ctx->event_pop, &ctx->mutex_pop);
166 }
167 DBG("got empty cmdbuf=%p\n", cmdbuf);
168 mtx_unlock(&ctx->mutex_pop);
169 cmdbuf->offset = 0;
170 cmdbuf->num_instr = 0;
171 }
172
173 /* Gets a a pointer to slice of memory with size @space.
174 * Does block if queue is full.
175 * Returns NULL on @space > NINE_QUEUE_SIZE. */
176 void *
nine_queue_alloc(struct nine_queue_pool * ctx,unsigned space)177 nine_queue_alloc(struct nine_queue_pool* ctx, unsigned space)
178 {
179 unsigned offset;
180 struct nine_cmdbuf *cmdbuf = &ctx->pool[ctx->head];
181
182 if (space > NINE_QUEUE_SIZE)
183 return NULL;
184
185 /* at this pointer there's always a free queue available */
186
187 if ((cmdbuf->offset + space > NINE_QUEUE_SIZE) ||
188 (cmdbuf->num_instr == NINE_CMD_BUF_INSTR)) {
189
190 nine_queue_flush(ctx);
191
192 cmdbuf = &ctx->pool[ctx->head];
193 }
194
195 DBG("cmdbuf=%p space=%d\n", cmdbuf, space);
196
197 /* at this pointer there's always a free queue with sufficient space available */
198
199 offset = cmdbuf->offset;
200 cmdbuf->offset += space;
201 cmdbuf->instr_size[cmdbuf->num_instr] = space;
202 cmdbuf->num_instr ++;
203
204 return cmdbuf->mem_pool + offset;
205 }
206
207 /* Returns the current queue flush state.
208 * TRUE nothing flushed
209 * FALSE one ore more instructions queued flushed. */
210 bool
nine_queue_no_flushed_work(struct nine_queue_pool * ctx)211 nine_queue_no_flushed_work(struct nine_queue_pool* ctx)
212 {
213 return (ctx->tail == ctx->head);
214 }
215
216 /* Returns the current queue empty state.
217 * TRUE no instructions queued.
218 * FALSE one ore more instructions queued. */
219 bool
nine_queue_isempty(struct nine_queue_pool * ctx)220 nine_queue_isempty(struct nine_queue_pool* ctx)
221 {
222 struct nine_cmdbuf *cmdbuf = &ctx->pool[ctx->head];
223
224 return (ctx->tail == ctx->head) && !cmdbuf->num_instr;
225 }
226
227 struct nine_queue_pool*
nine_queue_create(void)228 nine_queue_create(void)
229 {
230 unsigned i;
231 struct nine_queue_pool *ctx;
232
233 ctx = CALLOC_STRUCT(nine_queue_pool);
234 if (!ctx)
235 goto failed;
236
237 for (i = 0; i < NINE_CMD_BUFS; i++) {
238 ctx->pool[i].mem_pool = MALLOC(NINE_QUEUE_SIZE);
239 if (!ctx->pool[i].mem_pool)
240 goto failed;
241 }
242
243 cnd_init(&ctx->event_pop);
244 (void) mtx_init(&ctx->mutex_pop, mtx_plain);
245
246 cnd_init(&ctx->event_push);
247 (void) mtx_init(&ctx->mutex_push, mtx_plain);
248
249 /* Block until first cmdbuf has been flushed. */
250 ctx->worker_wait = TRUE;
251
252 return ctx;
253 failed:
254 if (ctx) {
255 for (i = 0; i < NINE_CMD_BUFS; i++) {
256 if (ctx->pool[i].mem_pool)
257 FREE(ctx->pool[i].mem_pool);
258 }
259 FREE(ctx);
260 }
261 return NULL;
262 }
263
264 void
nine_queue_delete(struct nine_queue_pool * ctx)265 nine_queue_delete(struct nine_queue_pool *ctx)
266 {
267 unsigned i;
268 mtx_destroy(&ctx->mutex_pop);
269 mtx_destroy(&ctx->mutex_push);
270
271 for (i = 0; i < NINE_CMD_BUFS; i++)
272 FREE(ctx->pool[i].mem_pool);
273
274 FREE(ctx);
275 }
276