2 * Copyright © 2012 Intel Corporation
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 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
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
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 NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
26 * Support functions for the glthread feature of Mesa.
28 * In multicore systems, many applications end up CPU-bound with about half
29 * their time spent inside their rendering thread and half inside Mesa. To
30 * alleviate this, we put a shim layer in Mesa at the GL dispatch level that
31 * quickly logs the GL commands to a buffer to be processed by a worker
35 #include "main/mtypes.h"
36 #include "main/glthread.h"
37 #include "main/marshal.h"
38 #include "main/marshal_generated.h"
43 glthread_allocate_batch(struct gl_context
*ctx
)
45 struct glthread_state
*glthread
= ctx
->GLThread
;
47 /* TODO: handle memory allocation failure. */
48 glthread
->batch
= malloc(sizeof(*glthread
->batch
));
51 memset(glthread
->batch
, 0, offsetof(struct glthread_batch
, buffer
));
55 glthread_unmarshal_batch(struct gl_context
*ctx
, struct glthread_batch
*batch
)
59 _glapi_set_dispatch(ctx
->CurrentServerDispatch
);
61 while (pos
< batch
->used
)
62 pos
+= _mesa_unmarshal_dispatch_cmd(ctx
, &batch
->buffer
[pos
]);
64 assert(pos
== batch
->used
);
70 glthread_worker(void *data
)
72 struct gl_context
*ctx
= data
;
73 struct glthread_state
*glthread
= ctx
->GLThread
;
75 ctx
->Driver
.SetBackgroundContext(ctx
);
76 _glapi_set_context(ctx
);
78 pthread_mutex_lock(&glthread
->mutex
);
81 struct glthread_batch
*batch
;
83 /* Block (dropping the lock) until new work arrives for us. */
84 while (!glthread
->batch_queue
&& !glthread
->shutdown
) {
85 pthread_cond_broadcast(&glthread
->work_done
);
86 pthread_cond_wait(&glthread
->new_work
, &glthread
->mutex
);
89 batch
= glthread
->batch_queue
;
91 if (glthread
->shutdown
&& !batch
) {
92 pthread_cond_broadcast(&glthread
->work_done
);
93 pthread_mutex_unlock(&glthread
->mutex
);
96 glthread
->batch_queue
= batch
->next
;
97 if (glthread
->batch_queue_tail
== &batch
->next
)
98 glthread
->batch_queue_tail
= &glthread
->batch_queue
;
100 glthread
->busy
= true;
101 pthread_mutex_unlock(&glthread
->mutex
);
103 glthread_unmarshal_batch(ctx
, batch
);
105 pthread_mutex_lock(&glthread
->mutex
);
106 glthread
->busy
= false;
114 _mesa_glthread_init(struct gl_context
*ctx
)
116 struct glthread_state
*glthread
= calloc(1, sizeof(*glthread
));
121 ctx
->MarshalExec
= _mesa_create_marshal_table(ctx
);
122 if (!ctx
->MarshalExec
) {
127 ctx
->CurrentClientDispatch
= ctx
->MarshalExec
;
129 pthread_mutex_init(&glthread
->mutex
, NULL
);
130 pthread_cond_init(&glthread
->new_work
, NULL
);
131 pthread_cond_init(&glthread
->work_done
, NULL
);
133 glthread
->batch_queue_tail
= &glthread
->batch_queue
;
134 ctx
->GLThread
= glthread
;
136 glthread_allocate_batch(ctx
);
138 pthread_create(&glthread
->thread
, NULL
, glthread_worker
, ctx
);
142 _mesa_glthread_destroy(struct gl_context
*ctx
)
144 struct glthread_state
*glthread
= ctx
->GLThread
;
149 _mesa_glthread_flush_batch(ctx
);
151 pthread_mutex_lock(&glthread
->mutex
);
152 glthread
->shutdown
= true;
153 pthread_cond_broadcast(&glthread
->new_work
);
154 pthread_mutex_unlock(&glthread
->mutex
);
156 /* Since this waits for the thread to exit, it means that all queued work
157 * will have been completed.
159 pthread_join(glthread
->thread
, NULL
);
161 pthread_cond_destroy(&glthread
->new_work
);
162 pthread_cond_destroy(&glthread
->work_done
);
163 pthread_mutex_destroy(&glthread
->mutex
);
165 /* Due to the join above, there should be one empty batch allocated at this
166 * point, and no batches queued.
168 assert(!glthread
->batch
->used
);
169 assert(!glthread
->batch
->next
);
170 free(glthread
->batch
);
171 assert(!glthread
->batch_queue
);
174 ctx
->GLThread
= NULL
;
176 /* Remove ourselves from the dispatch table except if another ctx/thread
177 * already installed a new dispatch table.
179 * Typically glxMakeCurrent will bind a new context (install new table) then
180 * old context might be deleted.
182 if (_glapi_get_dispatch() == ctx
->MarshalExec
) {
183 ctx
->CurrentClientDispatch
= ctx
->CurrentServerDispatch
;
184 _glapi_set_dispatch(ctx
->CurrentClientDispatch
);
189 _mesa_glthread_flush_batch(struct gl_context
*ctx
)
191 struct glthread_state
*glthread
= ctx
->GLThread
;
192 struct glthread_batch
*batch
;
197 batch
= glthread
->batch
;
201 /* Immediately reallocate a new batch, since the next marshalled call would
204 glthread_allocate_batch(ctx
);
206 /* Debug: execute the batch immediately from this thread.
208 * Note that glthread_unmarshal_batch() changes the dispatch table so we'll
209 * need to restore it when it returns.
212 glthread_unmarshal_batch(ctx
, batch
);
213 _glapi_set_dispatch(ctx
->CurrentClientDispatch
);
217 pthread_mutex_lock(&glthread
->mutex
);
218 *glthread
->batch_queue_tail
= batch
;
219 glthread
->batch_queue_tail
= &batch
->next
;
220 pthread_cond_broadcast(&glthread
->new_work
);
221 pthread_mutex_unlock(&glthread
->mutex
);
225 * Waits for all pending batches have been unmarshaled.
227 * This can be used by the main thread to synchronize access to the context,
228 * since the worker thread will be idle after this.
231 _mesa_glthread_finish(struct gl_context
*ctx
)
233 struct glthread_state
*glthread
= ctx
->GLThread
;
238 /* If this is called from the worker thread, then we've hit a path that
239 * might be called from either the main thread or the worker (such as some
240 * dri interface entrypoints), in which case we don't need to actually
241 * synchronize against ourself.
243 if (pthread_self() == glthread
->thread
)
246 _mesa_glthread_flush_batch(ctx
);
248 pthread_mutex_lock(&glthread
->mutex
);
250 while (glthread
->batch_queue
|| glthread
->busy
)
251 pthread_cond_wait(&glthread
->work_done
, &glthread
->mutex
);
253 pthread_mutex_unlock(&glthread
->mutex
);