xgboost/src/tree/updater_sync.cc
2019-12-11 11:20:40 +08:00

61 lines
1.4 KiB
C++

/*!
* Copyright 2014-2019 by Contributors
* \file updater_sync.cc
* \brief synchronize the tree in all distributed nodes
*/
#include <xgboost/tree_updater.h>
#include <vector>
#include <string>
#include <limits>
#include "xgboost/json.h"
#include "../common/io.h"
namespace xgboost {
namespace tree {
DMLC_REGISTRY_FILE_TAG(updater_sync);
/*!
* \brief syncher that synchronize the tree in all distributed nodes
* can implement various strategies, so far it is always set to node 0's tree
*/
class TreeSyncher: public TreeUpdater {
public:
void Configure(const Args& args) override {}
void LoadConfig(Json const& in) override {}
void SaveConfig(Json* p_out) const override {}
char const* Name() const override {
return "prune";
}
void Update(HostDeviceVector<GradientPair> *gpair,
DMatrix* dmat,
const std::vector<RegTree*> &trees) override {
if (rabit::GetWorldSize() == 1) return;
std::string s_model;
common::MemoryBufferStream fs(&s_model);
int rank = rabit::GetRank();
if (rank == 0) {
for (auto tree : trees) {
tree->Save(&fs);
}
}
fs.Seek(0);
rabit::Broadcast(&s_model, 0);
for (auto tree : trees) {
tree->Load(&fs);
}
}
};
XGBOOST_REGISTER_TREE_UPDATER(TreeSyncher, "sync")
.describe("Syncher that synchronize the tree in all distributed nodes.")
.set_body([]() {
return new TreeSyncher();
});
} // namespace tree
} // namespace xgboost