From d8d81fbc31619f6ecf0a1b5ded22e5576e1d1739 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 28 Dec 2012 15:05:34 -0800 Subject: mesa: Add infrastructure for a worker thread to process GL commands. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit v2: Keep an allocated buffer around instead of checking for one at the start of every GL command. Inline the now-small space allocation function. v3: Remove duplicate !glthread->shutdown check, process remaining work before shutdown. v4: Fix leaks on destroy. V5: (Timothy Arceri) fix order of source files in makefile Acked-by: Timothy Arceri Acked-by: Marek Olšák Tested-by: Dieter Nützel Tested-by: Mike Lothian --- src/mesa/main/glthread.c | 228 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) create mode 100644 src/mesa/main/glthread.c (limited to 'src/mesa/main/glthread.c') diff --git a/src/mesa/main/glthread.c b/src/mesa/main/glthread.c new file mode 100644 index 00000000000..76eb0cf7dac --- /dev/null +++ b/src/mesa/main/glthread.c @@ -0,0 +1,228 @@ +/* + * 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 + +static void +glthread_allocate_batch(struct gl_context *ctx) +{ + struct glthread_state *glthread = ctx->GLThread; + + /* TODO: handle memory allocation failure. */ + glthread->batch = calloc(1, sizeof(*glthread->batch)); + if (!glthread->batch) + return; + glthread->batch->buffer = malloc(MARSHAL_MAX_CMD_SIZE); +} + +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 (true) { + struct glthread_batch *batch; + + /* 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); + } + + batch = glthread->batch_queue; + + if (glthread->shutdown && !batch) { + pthread_cond_broadcast(&glthread->work_done); + pthread_mutex_unlock(&glthread->mutex); + return NULL; + } + 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; + } + + /* UNREACHED */ + 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); + + glthread->batch_queue_tail = &glthread->batch_queue; + ctx->GLThread = glthread; + + glthread_allocate_batch(ctx); + + pthread_create(&glthread->thread, NULL, glthread_worker, ctx); +} + +void +_mesa_glthread_destroy(struct gl_context *ctx) +{ + struct glthread_state *glthread = ctx->GLThread; + + if (!glthread) + return; + + _mesa_glthread_flush_batch(ctx); + + pthread_mutex_lock(&glthread->mutex); + glthread->shutdown = true; + pthread_cond_broadcast(&glthread->new_work); + pthread_mutex_unlock(&glthread->mutex); + + /* Since this waits for the thread to exit, it means that all queued work + * will have been completed. + */ + pthread_join(glthread->thread, NULL); + + pthread_cond_destroy(&glthread->new_work); + pthread_cond_destroy(&glthread->work_done); + pthread_mutex_destroy(&glthread->mutex); + + /* Due to the join above, there should be one empty batch allocated at this + * point, and no batches queued. + */ + assert(!glthread->batch->used); + assert(!glthread->batch->next); + free(glthread->batch); + assert(!glthread->batch_queue); + + 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->used) + return; + + /* Immediately reallocate a new batch, since the next marshalled call would + * just do it. + */ + glthread_allocate_batch(ctx); + + /* 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 -- cgit v1.2.3