From 2a0fb946e147f5482c93702fbf46ffdf5208f57c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Andreas=20F=C3=A4nger?= Date: Tue, 7 Jan 2014 03:10:00 -0700 Subject: [PATCH] swrast: fix delayed texel buffer allocation regression for OpenMP Commit 9119269ca14ed42b51c7d8e2e662500311b29fa3 moved the texel buffer allocation to _swrast_texture_span(), however, when compiled with OpenMP support this code already runs multi-threaded so a critical section is required to prevent multiple allocations and rendering errors. Cc: "10.0" Reviewed-by: Brian Paul --- src/mesa/swrast/s_texcombine.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/mesa/swrast/s_texcombine.c b/src/mesa/swrast/s_texcombine.c index 7e07f4f..297491e 100644 --- a/src/mesa/swrast/s_texcombine.c +++ b/src/mesa/swrast/s_texcombine.c @@ -602,6 +602,14 @@ _swrast_texture_span( struct gl_context *ctx, SWspan *span ) if (!swrast->TexelBuffer) { #ifdef _OPENMP const GLint maxThreads = omp_get_max_threads(); + + /* TexelBuffer memory allocation needs to be done in a critical section + * as this code runs in a parallel loop. + * When entering the section, first check if TexelBuffer has been + * initialized already by another thread while this thread was waiting. + */ + #pragma omp critical + if (!swrast->TexelBuffer) { #else const GLint maxThreads = 1; #endif @@ -613,6 +621,10 @@ _swrast_texture_span( struct gl_context *ctx, SWspan *span ) swrast->TexelBuffer = malloc(ctx->Const.FragmentProgram.MaxTextureImageUnits * maxThreads * SWRAST_MAX_WIDTH * 4 * sizeof(GLfloat)); +#ifdef _OPENMP + } /* critical section */ +#endif + if (!swrast->TexelBuffer) { _mesa_error(ctx, GL_OUT_OF_MEMORY, "texture_combine"); return; -- 2.7.4