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Diffstat (limited to 'src/mesa/main/glthread.c')
-rw-r--r-- | src/mesa/main/glthread.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/src/mesa/main/glthread.c b/src/mesa/main/glthread.c new file mode 100644 index 00000000000..31cc6a2ef4e --- /dev/null +++ b/src/mesa/main/glthread.c @@ -0,0 +1,225 @@ +/* + * Copyright © 2012 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +/** @file glthread.c + * + * Support functions for the glthread feature of Mesa. + * + * In multicore systems, many applications end up CPU-bound with about half + * their time spent inside their rendering thread and half inside Mesa. To + * alleviate this, we put a shim layer in Mesa at the GL dispatch level that + * quickly logs the GL commands to a buffer to be processed by a worker + * thread. + */ + +#include "main/mtypes.h" +#include "main/glthread.h" +#include "main/marshal.h" +#include "main/marshal_generated.h" + +#ifdef HAVE_PTHREAD + +void * +_mesa_glthread_allocate_command(struct gl_context *ctx, + enum marshal_dispatch_cmd_id cmd_id, + size_t size) +{ + struct glthread_state *glthread = ctx->GLThread; + struct marshal_cmd_base *cmd_base; + + assert(size <= MARSHAL_MAX_CMD_SIZE); + + if (glthread->batch != NULL && + glthread->batch->used + size > MARSHAL_MAX_CMD_SIZE) { + _mesa_glthread_flush_batch(ctx); + } + + if (glthread->batch == NULL) { + /* TODO: handle memory allocation failure. */ + glthread->batch = calloc(1, sizeof(*glthread->batch)); + if (!glthread->batch) + return NULL; + glthread->batch->buffer = malloc(MARSHAL_MAX_CMD_SIZE); + } + + cmd_base = (struct marshal_cmd_base *) + &glthread->batch->buffer[glthread->batch->used]; + glthread->batch->used += size; + cmd_base->cmd_id = cmd_id; + cmd_base->cmd_size = size; + return cmd_base; +} + +static void +glthread_unmarshal_batch(struct gl_context *ctx, struct glthread_batch *batch) +{ + free(batch->buffer); + free(batch); +} + +static void * +glthread_worker(void *data) +{ + struct gl_context *ctx = data; + struct glthread_state *glthread = ctx->GLThread; + + ctx->Driver.SetBackgroundContext(ctx); + _glapi_set_context(ctx); + + pthread_mutex_lock(&glthread->mutex); + + while (!glthread->shutdown) { + /* Block (dropping the lock) until new work arrives for us. */ + while (!glthread->batch_queue && !glthread->shutdown) { + pthread_cond_broadcast(&glthread->work_done); + pthread_cond_wait(&glthread->new_work, &glthread->mutex); + } + + if (glthread->shutdown) { + pthread_mutex_unlock(&glthread->mutex); + return NULL; + } + + struct glthread_batch *batch = glthread->batch_queue; + glthread->batch_queue = batch->next; + if (glthread->batch_queue_tail == &batch->next) + glthread->batch_queue_tail = &glthread->batch_queue; + + glthread->busy = true; + pthread_mutex_unlock(&glthread->mutex); + + glthread_unmarshal_batch(ctx, batch); + + pthread_mutex_lock(&glthread->mutex); + glthread->busy = false; + } + + pthread_mutex_unlock(&glthread->mutex); + + return NULL; +} + +void +_mesa_glthread_init(struct gl_context *ctx) +{ + struct glthread_state *glthread = calloc(1, sizeof(*glthread)); + + if (!glthread) + return; + + pthread_mutex_init(&glthread->mutex, NULL); + pthread_cond_init(&glthread->new_work, NULL); + pthread_cond_init(&glthread->work_done, NULL); + + pthread_create(&glthread->thread, NULL, glthread_worker, ctx); + + glthread->batch_queue_tail = &glthread->batch_queue; + ctx->GLThread = glthread; +} + +void +_mesa_glthread_destroy(struct gl_context *ctx) +{ + struct glthread_state *glthread = ctx->GLThread; + + if (!glthread) + return; + + pthread_mutex_lock(&glthread->mutex); + glthread->shutdown = true; + pthread_cond_broadcast(&glthread->new_work); + pthread_mutex_unlock(&glthread->mutex); + + pthread_join(glthread->thread, NULL); + + pthread_cond_destroy(&glthread->new_work); + pthread_cond_destroy(&glthread->work_done); + pthread_mutex_destroy(&glthread->mutex); + free(glthread); + ctx->GLThread = NULL; +} + +void +_mesa_glthread_flush_batch(struct gl_context *ctx) +{ + struct glthread_state *glthread = ctx->GLThread; + struct glthread_batch *batch; + + if (!glthread) + return; + + batch = glthread->batch; + if (!batch) + return; + glthread->batch = NULL; + + /* Debug: execute the batch immediately from this thread. + * + * Note that glthread_unmarshal_batch() changes the dispatch table so we'll + * need to restore it when it returns. + */ + if (false) { + glthread_unmarshal_batch(ctx, batch); + return; + } + + pthread_mutex_lock(&glthread->mutex); + *glthread->batch_queue_tail = batch; + glthread->batch_queue_tail = &batch->next; + pthread_cond_broadcast(&glthread->new_work); + pthread_mutex_unlock(&glthread->mutex); +} + +/** + * Waits for all pending batches have been unmarshaled. + * + * This can be used by the main thread to synchronize access to the context, + * since the worker thread will be idle after this. + */ +void +_mesa_glthread_finish(struct gl_context *ctx) +{ + struct glthread_state *glthread = ctx->GLThread; + + if (!glthread) + return; + + /* If this is called from the worker thread, then we've hit a path that + * might be called from either the main thread or the worker (such as some + * dri interface entrypoints), in which case we don't need to actually + * synchronize against ourself. + */ + if (pthread_self() == glthread->thread) + return; + + _mesa_glthread_flush_batch(ctx); + + pthread_mutex_lock(&glthread->mutex); + + while (glthread->batch_queue || glthread->busy) + pthread_cond_wait(&glthread->work_done, &glthread->mutex); + + pthread_mutex_unlock(&glthread->mutex); +} + +#endif |