disable parallel kdtree construction on windows

koide3 · May 1, 2024 · 21f963f · 21f963f
1 parent de8502f
commit 21f963f
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Showing 2 changed files with 21 additions and 3 deletions.
diff --git a/include/small_gicp/ann/kdtree_omp.hpp b/include/small_gicp/ann/kdtree_omp.hpp
@@ -5,6 +5,12 @@
 #include <atomic>
 #include <small_gicp/ann/kdtree.hpp>
 
+#ifdef _MSC_VER
+#pragma message("warning: Task-based OpenMP parallelism causes run-time memory errors with Eigen matrices.")
+#pragma message("warning: Thus, OpenMP-based multi-threading for KdTree construction is disabled on MSVC.")
+#endif
+
+
 namespace small_gicp {
 
 /// @brief Kd-tree builder with OpenMP.
@@ -23,14 +29,17 @@ struct KdTreeBuilderOMP {
     std::atomic_uint64_t node_count = 0;
     kdtree.nodes.resize(traits::size(points));
 
+#ifndef _MSC_VER
 #pragma omp parallel num_threads(num_threads)
     {
 #pragma omp single nowait
       {
-        //
         kdtree.root = create_node(kdtree, node_count, points, kdtree.indices.begin(), kdtree.indices.begin(), kdtree.indices.end());
       }
     }
+#else
+    kdtree.root = create_node(kdtree, node_count, points, kdtree.indices.begin(), kdtree.indices.begin(), kdtree.indices.end());
+#endif
 
     kdtree.nodes.resize(node_count);
   }
@@ -74,11 +83,16 @@ struct KdTreeBuilderOMP {
     node.node_type.sub.thresh = proj(traits::point(points, *median_itr));
 
     // Create left and right child nodes.
+#ifndef _MSC_VER
 #pragma omp task default(shared) if (N > 512)
     node.left = create_node(kdtree, node_count, points, global_first, first, median_itr);
 #pragma omp task default(shared) if (N > 512)
     node.right = create_node(kdtree, node_count, points, global_first, median_itr, last);
 #pragma omp taskwait
+#else
+    node.left = create_node(kdtree, node_count, points, global_first, first, median_itr);
+    node.right = create_node(kdtree, node_count, points, global_first, median_itr, last);
+#endif
 
     return node_index;
   }

diff --git a/include/small_gicp/ann/projection.hpp b/include/small_gicp/ann/projection.hpp
@@ -34,7 +34,9 @@ struct AxisAlignedProjection {
     Eigen::Vector4d sum_sq = Eigen::Vector4d::Zero();
 
     const size_t step = N < setting.max_scan_count ? 1 : N / setting.max_scan_count;
-    for (auto itr = first; itr < last; itr += step) {
+    const size_t num_steps = N / step;
+    for (int i = 0; i < num_steps; i++) {
+      const auto itr = first + step * i;
       const Eigen::Vector4d pt = traits::point(points, *itr);
       sum_pt += pt;
       sum_sq += pt.cwiseProduct(pt);
@@ -71,7 +73,9 @@ struct NormalProjection {
     Eigen::Matrix4d sum_sq = Eigen::Matrix4d::Zero();
 
     const size_t step = N < setting.max_scan_count ? 1 : N / setting.max_scan_count;
-    for (auto itr = first; itr < last; itr += step) {
+    const size_t num_steps = N / step;
+    for (int i = 0; i < num_steps; i++) {
+      const auto itr = first + step * i;
       const Eigen::Vector4d pt = traits::point(points, *itr);
       sum_pt += pt;
       sum_sq += pt * pt.transpose();