From 265e5def76cc08f633e8851236af1ee903d87ff0 Mon Sep 17 00:00:00 2001 From: lazydodo Date: Fri, 25 Nov 2016 12:02:37 -0700 Subject: Fix T50104, Race condition in SVMShaderManager::device_update_shader --- intern/cycles/render/svm.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'intern') diff --git a/intern/cycles/render/svm.cpp b/intern/cycles/render/svm.cpp index 9d3f49a3c84..955b892f4c3 100644 --- a/intern/cycles/render/svm.cpp +++ b/intern/cycles/render/svm.cpp @@ -71,14 +71,13 @@ void SVMShaderManager::device_update_shader(Scene *scene, scene->light_manager->need_update = true; } - /* We only calculate offset and do re-allocation from the locked block, - * actual copy we do after the lock is releases to hopefully gain some - * percent of performance. + /* The copy needs to be done inside the lock, if another thread resizes the array + * while memcpy is running, it'll be copying into possibly invalid/freed ram. */ nodes_lock_.lock(); size_t global_nodes_size = global_svm_nodes->size(); global_svm_nodes->resize(global_nodes_size + svm_nodes.size()); - nodes_lock_.unlock(); + /* Offset local SVM nodes to a global address space. */ int4& jump_node = global_svm_nodes->at(shader->id); jump_node.y = svm_nodes[0].y + global_nodes_size - 1; @@ -88,6 +87,7 @@ void SVMShaderManager::device_update_shader(Scene *scene, memcpy(&global_svm_nodes->at(global_nodes_size), &svm_nodes[1], sizeof(int4) * (svm_nodes.size() - 1)); + nodes_lock_.unlock(); } void SVMShaderManager::device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress) -- cgit v1.2.3