From 1da345e56932b71067c069270828680aeb38d6b5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mathias=20Fr=C3=B6hlich?= Date: Wed, 28 Mar 2018 07:19:02 +0200 Subject: [PATCH] vbo: Use alloca for _vbo_draw_indirect. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Avoid using malloc in the draw path of mesa. Since the draw_count is a user api input, fall back to malloc if the amount of consumed stack space may get too high. Reviewed-by: Brian Paul Reviewed-by: Marek Olšák Signed-off-by: Mathias Fröhlich --- src/mesa/vbo/vbo_context.c | 79 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 55 insertions(+), 24 deletions(-) diff --git a/src/mesa/vbo/vbo_context.c b/src/mesa/vbo/vbo_context.c index b8c28ce..e50cee7 100644 --- a/src/mesa/vbo/vbo_context.c +++ b/src/mesa/vbo/vbo_context.c @@ -233,26 +233,20 @@ _vbo_DestroyContext(struct gl_context *ctx) } -void -_vbo_draw_indirect(struct gl_context *ctx, GLuint mode, - struct gl_buffer_object *indirect_data, - GLsizeiptr indirect_offset, unsigned draw_count, - unsigned stride, - struct gl_buffer_object *indirect_draw_count_buffer, - GLsizeiptr indirect_draw_count_offset, - const struct _mesa_index_buffer *ib) +/* + * Helper function for _vbo_draw_indirect below that additionally takes a zero + * initialized array of _mesa_prim scratch space memory as the last argument. + */ +static void +draw_indirect(struct gl_context *ctx, GLuint mode, + struct gl_buffer_object *indirect_data, + GLsizeiptr indirect_offset, unsigned draw_count, + unsigned stride, + struct gl_buffer_object *indirect_draw_count_buffer, + GLsizeiptr indirect_draw_count_offset, + const struct _mesa_index_buffer *ib, + struct _mesa_prim *prim) { - struct _mesa_prim *prim; - - prim = calloc(draw_count, sizeof(*prim)); - if (prim == NULL) { - _mesa_error(ctx, GL_OUT_OF_MEMORY, "gl%sDraw%sIndirect%s", - (draw_count > 1) ? "Multi" : "", - ib ? "Elements" : "Arrays", - indirect_data ? "CountARB" : ""); - return; - } - prim[0].begin = 1; prim[draw_count - 1].end = 1; for (unsigned i = 0; i < draw_count; ++i, indirect_offset += stride) { @@ -266,10 +260,47 @@ _vbo_draw_indirect(struct gl_context *ctx, GLuint mode, /* This should always be true at this time */ assert(indirect_data == ctx->DrawIndirectBuffer); - ctx->Driver.Draw(ctx, prim, draw_count, - ib, false, 0, ~0, - NULL, 0, - indirect_data); + ctx->Driver.Draw(ctx, prim, draw_count, ib, false, 0u, ~0u, + NULL, 0, indirect_data); +} + - free(prim); +/* + * Function to be put into dd_function_table::DrawIndirect as fallback. + * Calls into dd_function_table::Draw past adapting call arguments. + * See dd_function_table::DrawIndirect for call argument documentation. + */ +void +_vbo_draw_indirect(struct gl_context *ctx, GLuint mode, + struct gl_buffer_object *indirect_data, + GLsizeiptr indirect_offset, unsigned draw_count, + unsigned stride, + struct gl_buffer_object *indirect_draw_count_buffer, + GLsizeiptr indirect_draw_count_offset, + const struct _mesa_index_buffer *ib) +{ + /* Use alloca for the prim space if we are somehow in bounds. */ + if (draw_count*sizeof(struct _mesa_prim) < 1024) { + struct _mesa_prim *space = alloca(draw_count*sizeof(struct _mesa_prim)); + memset(space, 0, draw_count*sizeof(struct _mesa_prim)); + + draw_indirect(ctx, mode, indirect_data, indirect_offset, draw_count, + stride, indirect_draw_count_buffer, + indirect_draw_count_offset, ib, space); + } else { + struct _mesa_prim *space = calloc(draw_count, sizeof(struct _mesa_prim)); + if (space == NULL) { + _mesa_error(ctx, GL_OUT_OF_MEMORY, "gl%sDraw%sIndirect%s", + (draw_count > 1) ? "Multi" : "", + ib ? "Elements" : "Arrays", + indirect_data ? "CountARB" : ""); + return; + } + + draw_indirect(ctx, mode, indirect_data, indirect_offset, draw_count, + stride, indirect_draw_count_buffer, + indirect_draw_count_offset, ib, space); + + free(space); + } } -- 2.7.4