add voting based parallel

include/LightGBM/config.h

@@ -181,13 +181,14 @@ public:
   // And the max leaves will be min(num_leaves, pow(2, max_depth - 1))
   // max_depth < 0 means not limit
   int max_depth = -1;
+  int top_k = 20;
   void Set(const std::unordered_map<std::string, std::string>& params) override;
 };
 
 /*! \brief Types of tree learning algorithms */
 enum TreeLearnerType {
   kSerialTreeLearner, kFeatureParallelTreelearner,
-  kDataParallelTreeLearner
+  kDataParallelTreeLearner, KVotingParallelTreeLearner
 };
 
 /*! \brief Config for Boosting */
@@ -385,6 +386,7 @@ struct ParameterAlias {
       { "raw_score", "is_predict_raw_score" },
       { "leaf_index", "is_predict_leaf_index" },
       { "min_split_gain", "min_gain_to_split" },
+      { "topk", "top_k" },
       { "reg_alpha", "lambda_l1" },
       { "reg_lambda", "lambda_l2" },
       { "num_classes", "num_class" }

src/io/config.cpp

@@ -289,6 +289,7 @@ void TreeConfig::Set(const std::unordered_map<std::string, std::string>& params)
   CHECK(feature_fraction > 0.0f && feature_fraction <= 1.0f);
   GetDouble(params, "histogram_pool_size", &histogram_pool_size);
   GetInt(params, "max_depth", &max_depth);
+  GetInt(params, "top_k", &top_k);
   CHECK(max_depth > 1 || max_depth < 0);
 }
 
@@ -327,8 +328,9 @@ void BoostingConfig::GetTreeLearnerType(const std::unordered_map<std::string, st
       tree_learner_type = TreeLearnerType::kFeatureParallelTreelearner;
     } else if (value == std::string("data") || value == std::string("data_parallel")) {
       tree_learner_type = TreeLearnerType::kDataParallelTreeLearner;
-    }
-    else {
+    } else if (value == std::string("voting") || value == std::string("voting_parallel")) {
+      tree_learner_type = TreeLearnerType::KVotingParallelTreeLearner;
+    } else {
       Log::Fatal("Unknown tree learner type %s", value.c_str());
     }
   }

src/treelearner/parallel_tree_learner.h

@@ -88,6 +88,88 @@ private:
   std::vector<data_size_t> global_data_count_in_leaf_;
 };
 
+/*!
+* \brief Voting based data parallel learning algorithm.
+* Like data parallel, but not aggregate histograms for all features.
+* Here using voting to reduce features, and only aggregate histograms for selected features.
+* When #data is large and #feature is large, you can use this to have better speed-up
+*/
+class VotingParallelTreeLearner: public SerialTreeLearner {
+public:
+  explicit VotingParallelTreeLearner(const TreeConfig& tree_config);
+  ~VotingParallelTreeLearner() { }
+  void Init(const Dataset* train_data) override;
+
+protected:
+  void BeforeTrain() override;
+  bool BeforeFindBestSplit(int left_leaf, int right_leaf) override;
+  void FindBestThresholds() override;
+  void FindBestSplitsForLeaves() override;
+  void Split(Tree* tree, int best_Leaf, int* left_leaf, int* right_leaf) override;
+
+  inline data_size_t GetGlobalDataCountInLeaf(int leaf_idx) const override {
+    if (leaf_idx >= 0) {
+      return global_data_count_in_leaf_[leaf_idx];
+    } else {
+      return 0;
+    }
+  }
+  /*!
+  * \brief Perform global voting
+  * \param leaf_idx index of leaf
+  * \param splits All splits from local voting
+  * \param out Result of gobal voting, only store feature indices
+  */
+  void GlobalVoting(int leaf_idx, const std::vector<SplitInfo>& splits,
+    std::vector<int>* out);
+  /*!
+  * \brief Copy local histgram to buffer
+  * \param smaller_top_features Selected features for smaller leaf
+  * \param larger_top_features Selected features for larger leaf
+  */
+  void CopyLocalHistogram(const std::vector<int>& smaller_top_features,
+    const std::vector<int>& larger_top_features);
+
+private:
+  /*! \brief Tree config used in local mode */
+  TreeConfig local_tree_config_;
+  /*! \brief Voting size */
+  int top_k_;
+  /*! \brief Rank of local machine*/
+  int rank_;
+  /*! \brief Number of machines */
+  int num_machines_;
+  /*! \brief Buffer for network send */
+  std::vector<char> input_buffer_;
+  /*! \brief Buffer for network receive */
+  std::vector<char> output_buffer_;
+  /*! \brief different machines will aggregate histograms for different features,
+  use this to mark local aggregate features*/
+  std::vector<bool> smaller_is_feature_aggregated_;
+  /*! \brief different machines will aggregate histograms for different features,
+  use this to mark local aggregate features*/
+  std::vector<bool> larger_is_feature_aggregated_;
+  /*! \brief Block start index for reduce scatter */
+  std::vector<int> block_start_;
+  /*! \brief Block size for reduce scatter */
+  std::vector<int> block_len_;
+  /*! \brief Read positions for feature histgrams at smaller leaf */
+  std::vector<int> smaller_buffer_read_start_pos_;
+  /*! \brief Read positions for feature histgrams at larger leaf */
+  std::vector<int> larger_buffer_read_start_pos_;
+  /*! \brief Size for reduce scatter */
+  int reduce_scatter_size_;
+  /*! \brief Store global number of data in leaves  */
+  std::vector<data_size_t> global_data_count_in_leaf_;
+  /*! \brief Store global split information for smaller leaf  */
+  std::unique_ptr<LeafSplits> smaller_leaf_splits_global_;
+  /*! \brief Store global split information for larger leaf  */
+  std::unique_ptr<LeafSplits> larger_leaf_splits_global_;
+  /*! \brief Store global histogram for smaller leaf  */
+  std::unique_ptr<FeatureHistogram[]> smaller_leaf_histogram_array_global_;
+  /*! \brief Store global histogram for larger leaf  */
+  std::unique_ptr<FeatureHistogram[]> larger_leaf_histogram_array_global_;
+};
 
 }  // namespace LightGBM
 #endif   // LightGBM_TREELEARNER_PARALLEL_TREE_LEARNER_H_

src/treelearner/tree_learner.cpp

@@ -12,6 +12,8 @@ TreeLearner* TreeLearner::CreateTreeLearner(TreeLearnerType type, const TreeConf
     return new FeatureParallelTreeLearner(tree_config);
   } else if (type == TreeLearnerType::kDataParallelTreeLearner) {
     return new DataParallelTreeLearner(tree_config);
+  } else if (type == TreeLearnerType::KVotingParallelTreeLearner) {
+    return new VotingParallelTreeLearner(tree_config);
   }
   return nullptr;
 }

src/treelearner/voting_parallel_tree_learner.cpp

@@ -0,0 +1,347 @@
+#include "parallel_tree_learner.h"
+
+#include <LightGBM/utils/common.h>
+
+#include <cstring>
+
+#include <tuple>
+#include <vector>
+
+namespace LightGBM {
+
+VotingParallelTreeLearner::VotingParallelTreeLearner(const TreeConfig& tree_config)
+  :SerialTreeLearner(tree_config) {
+  top_k_ = tree_config.top_k;
+}
+
+void VotingParallelTreeLearner::Init(const Dataset* train_data) {
+  SerialTreeLearner::Init(train_data);
+  rank_ = Network::rank();
+  num_machines_ = Network::num_machines();
+
+  // limit top k
+  if (top_k_ > num_features_) {
+    top_k_ = num_features_;
+  }
+  // get max bin
+  int max_bin = 0;
+  for (int i = 0; i < num_features_; ++i) {
+    if (max_bin < train_data_->FeatureAt(i)->num_bin()) {
+      max_bin = train_data_->FeatureAt(i)->num_bin();
+    }
+  }
+  // calculate buffer size
+  size_t buffer_size = 2 * top_k_ * std::max(max_bin * sizeof(HistogramBinEntry), sizeof(SplitInfo) * num_machines_);
+  // left and right on same time, so need double size
+  input_buffer_.resize(buffer_size);
+  output_buffer_.resize(buffer_size);
+
+  smaller_is_feature_aggregated_.resize(num_features_);
+  larger_is_feature_aggregated_.resize(num_features_);
+
+  block_start_.resize(num_machines_);
+  block_len_.resize(num_machines_);
+
+  smaller_buffer_read_start_pos_.resize(num_features_);
+  larger_buffer_read_start_pos_.resize(num_features_);
+  global_data_count_in_leaf_.resize(tree_config_.num_leaves);
+
+  smaller_leaf_splits_global_.reset(new LeafSplits(train_data_->num_features(), train_data_->num_data()));
+  larger_leaf_splits_global_.reset(new LeafSplits(train_data_->num_features(), train_data_->num_data()));
+
+  local_tree_config_ = tree_config_;
+  local_tree_config_.min_data_in_leaf /= num_machines_;
+  local_tree_config_.min_sum_hessian_in_leaf /= num_machines_;
+
+  auto histogram_create_function = [this]() {
+    auto tmp_histogram_array = std::unique_ptr<FeatureHistogram[]>(new FeatureHistogram[train_data_->num_features()]);
+    for (int j = 0; j < train_data_->num_features(); ++j) {
+      tmp_histogram_array[j].Init(train_data_->FeatureAt(j),
+        j, &local_tree_config_);
+    }
+    return tmp_histogram_array.release();
+  };
+  histogram_pool_.Fill(histogram_create_function);
+
+  // initialize histograms for global
+  smaller_leaf_histogram_array_global_.reset(new FeatureHistogram[num_features_]);
+  larger_leaf_histogram_array_global_.reset(new FeatureHistogram[num_features_]);
+  for (int j = 0; j < num_features_; ++j) {
+    smaller_leaf_histogram_array_global_[j].Init(train_data_->FeatureAt(j), j, &tree_config_);
+    larger_leaf_histogram_array_global_[j].Init(train_data_->FeatureAt(j), j, &tree_config_);
+  }
+}
+
+
+void VotingParallelTreeLearner::BeforeTrain() {
+  SerialTreeLearner::BeforeTrain();
+  // sync global data sumup info
+  std::tuple<data_size_t, double, double> data(smaller_leaf_splits_->num_data_in_leaf(), smaller_leaf_splits_->sum_gradients(), smaller_leaf_splits_->sum_hessians());
+  int size = sizeof(std::tuple<data_size_t, double, double>);
+  std::memcpy(input_buffer_.data(), &data, size);
+
+  Network::Allreduce(input_buffer_.data(), size, size, output_buffer_.data(), [](const char *src, char *dst, int len) {
+    int used_size = 0;
+    int type_size = sizeof(std::tuple<data_size_t, double, double>);
+    const std::tuple<data_size_t, double, double> *p1;
+    std::tuple<data_size_t, double, double> *p2;
+    while (used_size < len) {
+      p1 = reinterpret_cast<const std::tuple<data_size_t, double, double> *>(src);
+      p2 = reinterpret_cast<std::tuple<data_size_t, double, double> *>(dst);
+      std::get<0>(*p2) = std::get<0>(*p2) + std::get<0>(*p1);
+      std::get<1>(*p2) = std::get<1>(*p2) + std::get<1>(*p1);
+      std::get<2>(*p2) = std::get<2>(*p2) + std::get<2>(*p1);
+      src += type_size;
+      dst += type_size;
+      used_size += type_size;
+    }
+  });
+
+  std::memcpy(&data, output_buffer_.data(), size);
+
+  // set global sumup info
+  smaller_leaf_splits_global_->Init(std::get<1>(data), std::get<2>(data));
+  larger_leaf_splits_global_->Init();
+  // init global data count in leaf
+  global_data_count_in_leaf_[0] = std::get<0>(data);
+}
+
+bool VotingParallelTreeLearner::BeforeFindBestSplit(int left_leaf, int right_leaf) {
+  if (SerialTreeLearner::BeforeFindBestSplit(left_leaf, right_leaf)) {
+    data_size_t num_data_in_left_child = GetGlobalDataCountInLeaf(left_leaf);
+    data_size_t num_data_in_right_child = GetGlobalDataCountInLeaf(right_leaf);
+    if (right_leaf < 0) {
+      return true;
+    } else if (num_data_in_left_child < num_data_in_right_child) {
+      // get local sumup
+      smaller_leaf_splits_->Init(left_leaf, data_partition_.get(), gradients_, hessians_);
+      larger_leaf_splits_->Init(right_leaf, data_partition_.get(), gradients_, hessians_);
+    } else {
+      // get local sumup
+      smaller_leaf_splits_->Init(right_leaf, data_partition_.get(), gradients_, hessians_);
+      larger_leaf_splits_->Init(left_leaf, data_partition_.get(), gradients_, hessians_);
+    }
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void VotingParallelTreeLearner::GlobalVoting(int leaf_idx, const std::vector<SplitInfo>& splits, std::vector<int>* out) {
+  out->clear();
+  if (leaf_idx < 0) {
+    return;
+  }
+  // get mean number on machines
+  score_t mean_num_data = GetGlobalDataCountInLeaf(leaf_idx) / static_cast<score_t>(num_machines_);
+  std::vector<SplitInfo> feature_best_split(num_features_, SplitInfo());
+  for (auto & split : splits) {
+    int fid = split.feature;
+    if (fid < 0) {
+      continue;
+    }
+    // weighted gain
+    double gain = split.gain * (split.left_count + split.right_count) / mean_num_data;
+    if (gain > feature_best_split[fid].gain) {
+      feature_best_split[fid] = split;
+      feature_best_split[fid].gain = gain;
+    }
+  }
+  // get top k
+  std::vector<SplitInfo> top_k_splits;
+  ArrayArgs<SplitInfo>::MaxK(feature_best_split, top_k_, &top_k_splits);
+  for (auto& split : top_k_splits) {
+    if (split.gain == kMinScore || split.feature == -1) {
+      continue;
+    }
+    out->push_back(split.feature);
+  }
+}
+
+void VotingParallelTreeLearner::CopyLocalHistogram(const std::vector<int>& smaller_top_features, const std::vector<int>& larger_top_features) {
+  for (int i = 0; i < num_features_; ++i) {
+    smaller_is_feature_aggregated_[i] = false;
+    larger_is_feature_aggregated_[i] = false;
+  }
+  size_t total_num_features = smaller_top_features.size() + larger_top_features.size();
+  size_t average_feature = (total_num_features + num_machines_ - 1) / num_machines_;
+  size_t used_num_features = 0, smaller_idx = 0, larger_idx = 0;
+  block_start_[0] = 0;
+  reduce_scatter_size_ = 0;
+  // Copy histogram to buffer, and Get local aggregate features
+  for (int i = 0; i < num_machines_; ++i) {
+    size_t cur_size = 0, cur_used_features = 0;
+    size_t cur_total_feature = std::min(average_feature, total_num_features - used_num_features);
+    // copy histograms.
+    while (cur_used_features < cur_total_feature) {
+      // copy smaller leaf histograms first
+      if (smaller_idx < smaller_top_features.size()) {
+        int fid = smaller_top_features[smaller_idx];
+        ++cur_used_features;
+        // mark local aggregated feature
+        if (i == rank_) {
+          smaller_is_feature_aggregated_[fid] = true;
+          smaller_buffer_read_start_pos_[fid] = static_cast<int>(cur_size);
+        }
+        // copy
+        std::memcpy(input_buffer_.data() + reduce_scatter_size_, smaller_leaf_histogram_array_[fid].HistogramData(), smaller_leaf_histogram_array_[fid].SizeOfHistgram());
+        cur_size += smaller_leaf_histogram_array_[fid].SizeOfHistgram();
+        reduce_scatter_size_ += smaller_leaf_histogram_array_[fid].SizeOfHistgram();
+        ++smaller_idx;
+      }
+      if (cur_used_features >= cur_total_feature) {
+        break;
+      }
+      // then copy larger leaf histograms
+      if (larger_idx < larger_top_features.size()) {
+        int fid = larger_top_features[larger_idx];
+        ++cur_used_features;
+        // mark local aggregated feature
+        if (i == rank_) {
+          larger_is_feature_aggregated_[fid] = true;
+          larger_buffer_read_start_pos_[fid] = static_cast<int>(cur_size);
+        }
+        // copy
+        std::memcpy(input_buffer_.data() + reduce_scatter_size_, larger_leaf_histogram_array_[fid].HistogramData(), larger_leaf_histogram_array_[fid].SizeOfHistgram());
+        cur_size += larger_leaf_histogram_array_[fid].SizeOfHistgram();
+        reduce_scatter_size_ += larger_leaf_histogram_array_[fid].SizeOfHistgram();
+        ++larger_idx;
+      }
+    }
+    used_num_features += cur_used_features;
+    block_len_[i] = static_cast<int>(cur_size);
+    if (i < num_machines_ - 1) {
+      block_start_[i + 1] = block_start_[i] + block_len_[i];
+    }
+  }
+}
+
+void VotingParallelTreeLearner::FindBestThresholds() {
+  // use local data to find local best splits
+  SerialTreeLearner::FindBestThresholds();
+  std::vector<SplitInfo> smaller_top_k_splits, larger_top_k_splits;
+  // local voting
+  ArrayArgs<SplitInfo>::MaxK(smaller_leaf_splits_->BestSplitPerFeature(), top_k_, &smaller_top_k_splits);
+  ArrayArgs<SplitInfo>::MaxK(larger_leaf_splits_->BestSplitPerFeature(), top_k_, &larger_top_k_splits);
+  // gather
+  int offset = 0;
+  for (int i = 0; i < top_k_; ++i) {
+    std::memcpy(input_buffer_.data() + offset, &smaller_top_k_splits[i], sizeof(SplitInfo));
+    offset += sizeof(SplitInfo);
+    std::memcpy(input_buffer_.data() + offset, &larger_top_k_splits[i], sizeof(SplitInfo));
+    offset += sizeof(SplitInfo);
+  }
+  Network::Allgather(input_buffer_.data(), offset, output_buffer_.data());
+  // get all top-k from all machines
+  std::vector<SplitInfo> smaller_top_k_splits_global;
+  std::vector<SplitInfo> larger_top_k_splits_global;
+  offset = 0;
+  for (int i = 0; i < num_machines_; ++i) {
+    for (int j = 0; j < top_k_; ++j) {
+      smaller_top_k_splits_global.push_back(SplitInfo());
+      std::memcpy(&smaller_top_k_splits_global.back(), output_buffer_.data() + offset, sizeof(SplitInfo));
+      offset += sizeof(SplitInfo);
+      larger_top_k_splits_global.push_back(SplitInfo());
+      std::memcpy(&larger_top_k_splits_global.back(), output_buffer_.data() + offset, sizeof(SplitInfo));
+      offset += sizeof(SplitInfo);
+    }
+  }
+  // global voting
+  std::vector<int> smaller_top_features, larger_top_features;
+  GlobalVoting(smaller_leaf_splits_->LeafIndex(), smaller_top_k_splits_global, &smaller_top_features);
+  GlobalVoting(larger_leaf_splits_->LeafIndex(), larger_top_k_splits_global, &larger_top_features);
+  // copy local histgrams to buffer
+  CopyLocalHistogram(smaller_top_features, larger_top_features);
+
+  // Reduce scatter for histogram
+  Network::ReduceScatter(input_buffer_.data(), reduce_scatter_size_, block_start_.data(), block_len_.data(),
+                         output_buffer_.data(), &HistogramBinEntry::SumReducer);
+  // find best split from local aggregated histograms
+  #pragma omp parallel for schedule(guided)
+  for (int feature_index = 0; feature_index < num_features_; ++feature_index) {
+
+    if (smaller_is_feature_aggregated_[feature_index]) {
+      smaller_leaf_histogram_array_global_[feature_index].SetSumup(
+                                   GetGlobalDataCountInLeaf(smaller_leaf_splits_global_->LeafIndex()),
+                                                            smaller_leaf_splits_global_->sum_gradients(),
+                                                            smaller_leaf_splits_global_->sum_hessians());
+      // restore from buffer
+      smaller_leaf_histogram_array_global_[feature_index].FromMemory(
+                                   output_buffer_.data() + smaller_buffer_read_start_pos_[feature_index]);
+      // find best threshold
+      smaller_leaf_histogram_array_global_[feature_index].FindBestThreshold(
+                                   &smaller_leaf_splits_global_->BestSplitPerFeature()[feature_index]);
+    }
+
+    if (larger_is_feature_aggregated_[feature_index]) {
+      larger_leaf_histogram_array_global_[feature_index].SetSumup(GetGlobalDataCountInLeaf(larger_leaf_splits_global_->LeafIndex()),
+                                                                  larger_leaf_splits_global_->sum_gradients(), larger_leaf_splits_global_->sum_hessians());
+      // restore from buffer
+      larger_leaf_histogram_array_global_[feature_index].FromMemory(output_buffer_.data() + larger_buffer_read_start_pos_[feature_index]);
+      // find best threshold
+      larger_leaf_histogram_array_global_[feature_index].FindBestThreshold(&larger_leaf_splits_global_->BestSplitPerFeature()[feature_index]);
+    }
+  }
+
+}
+
+void VotingParallelTreeLearner::FindBestSplitsForLeaves() {
+  int smaller_best_feature = -1, larger_best_feature = -1;
+  // find local best
+  SplitInfo smaller_best, larger_best;
+  std::vector<double> gains;
+  for (size_t i = 0; i < smaller_leaf_splits_global_->BestSplitPerFeature().size(); ++i) {
+    gains.push_back(smaller_leaf_splits_global_->BestSplitPerFeature()[i].gain);
+  }
+  smaller_best_feature = static_cast<int>(ArrayArgs<double>::ArgMax(gains));
+  smaller_best = smaller_leaf_splits_global_->BestSplitPerFeature()[smaller_best_feature];
+
+  if (larger_leaf_splits_global_->LeafIndex() >= 0) {
+    gains.clear();
+    for (size_t i = 0; i < larger_leaf_splits_global_->BestSplitPerFeature().size(); ++i) {
+      gains.push_back(larger_leaf_splits_global_->BestSplitPerFeature()[i].gain);
+    }
+    larger_best_feature = static_cast<int>(ArrayArgs<double>::ArgMax(gains));
+    larger_best = larger_leaf_splits_global_->BestSplitPerFeature()[larger_best_feature];
+  }
+  // sync global best info
+  std::memcpy(input_buffer_.data(), &smaller_best, sizeof(SplitInfo));
+  std::memcpy(input_buffer_.data() + sizeof(SplitInfo), &larger_best, sizeof(SplitInfo));
+
+  Network::Allreduce(input_buffer_.data(), sizeof(SplitInfo) * 2, sizeof(SplitInfo), output_buffer_.data(), &SplitInfo::MaxReducer);
+
+  std::memcpy(&smaller_best, output_buffer_.data(), sizeof(SplitInfo));
+  std::memcpy(&larger_best, output_buffer_.data() + sizeof(SplitInfo), sizeof(SplitInfo));
+
+  // copy back
+  best_split_per_leaf_[smaller_leaf_splits_global_->LeafIndex()] = smaller_best;
+  if (larger_best.feature >= 0 && larger_leaf_splits_global_->LeafIndex() >= 0) {
+    best_split_per_leaf_[larger_leaf_splits_global_->LeafIndex()] = larger_best;
+  }
+}
+
+void VotingParallelTreeLearner::Split(Tree* tree, int best_Leaf, int* left_leaf, int* right_leaf) {
+  SerialTreeLearner::Split(tree, best_Leaf, left_leaf, right_leaf);
+  const SplitInfo& best_split_info = best_split_per_leaf_[best_Leaf];
+  // set the global number of data for leaves
+  global_data_count_in_leaf_[*left_leaf] = best_split_info.left_count;
+  global_data_count_in_leaf_[*right_leaf] = best_split_info.right_count;
+  // init the global sumup info
+  if (best_split_info.left_count < best_split_info.right_count) {
+    smaller_leaf_splits_global_->Init(*left_leaf, data_partition_.get(),
+                                      best_split_info.left_sum_gradient,
+                                      best_split_info.left_sum_hessian);
+    larger_leaf_splits_global_->Init(*right_leaf, data_partition_.get(),
+                                     best_split_info.right_sum_gradient,
+                                     best_split_info.right_sum_hessian);
+  } else {
+    smaller_leaf_splits_global_->Init(*right_leaf, data_partition_.get(),
+                                      best_split_info.right_sum_gradient,
+                                      best_split_info.right_sum_hessian);
+    larger_leaf_splits_global_->Init(*left_leaf, data_partition_.get(),
+                                     best_split_info.left_sum_gradient,
+                                     best_split_info.left_sum_hessian);
+  }
+}
+
+}  // namespace FTLBoost

windows/LightGBM.vcxproj

@@ -259,6 +259,7 @@
     <ClCompile Include="..\src\treelearner\feature_parallel_tree_learner.cpp" />
     <ClCompile Include="..\src\treelearner\serial_tree_learner.cpp" />
     <ClCompile Include="..\src\treelearner\tree_learner.cpp" />
+    <ClCompile Include="..\src\treelearner\voting_parallel_tree_learner.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

windows/LightGBM.vcxproj.filters

@@ -242,5 +242,8 @@
     <ClCompile Include="..\src\io\dataset_loader.cpp">
       <Filter>src\io</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\treelearner\voting_parallel_tree_learner.cpp">
+      <Filter>src\treelearner</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>