thread_local for network interface (#982)

* thread local for the network interface.

* fix bug.

include/LightGBM/c_api.h

@@ -735,12 +735,8 @@ LIGHTGBM_C_EXPORT int LGBM_BoosterFeatureImportance(BoosterHandle handle,
                                                     int importance_type,
                                                     double* out_results);
 
-#if defined(_MSC_VER)
 // exception handle and error msg
-static char* LastErrorMsg() { static __declspec(thread) char err_msg[512] = "Everything is fine"; return err_msg; }
-#else
-static char* LastErrorMsg() { static thread_local char err_msg[512] = "Everything is fine"; return err_msg; }
-#endif
+static char* LastErrorMsg() { static THREAD_LOCAL char err_msg[512] = "Everything is fine"; return err_msg; }
 
 #pragma warning(disable : 4996)
 inline void LGBM_SetLastError(const char* msg) {

include/LightGBM/network.h

@@ -191,23 +191,24 @@ public:
 
 private:
   /*! \brief Number of all machines */
-  static int num_machines_;
+  static THREAD_LOCAL int num_machines_;
   /*! \brief Rank of local machine */
-  static int rank_;
+  static THREAD_LOCAL int rank_;
   /*! \brief The network interface, provide send/recv functions  */
-  static std::unique_ptr<Linkers> linkers_;
+  static THREAD_LOCAL std::unique_ptr<Linkers> linkers_;
   /*! \brief Bruck map for all gather algorithm*/
-  static BruckMap bruck_map_;
+  static THREAD_LOCAL BruckMap bruck_map_;
   /*! \brief Recursive halving map for reduce scatter */
-  static RecursiveHalvingMap recursive_halving_map_;
+  static THREAD_LOCAL RecursiveHalvingMap recursive_halving_map_;
   /*! \brief Buffer to store block start index */
-  static std::vector<int> block_start_;
+  static THREAD_LOCAL std::vector<int> block_start_;
   /*! \brief Buffer to store block size */
-  static std::vector<int> block_len_;
+  static THREAD_LOCAL std::vector<int> block_len_;
   /*! \brief Buffer  */
-  static std::vector<char> buffer_;
+  static THREAD_LOCAL std::vector<char> buffer_;
   /*! \brief Size of buffer_ */
-  static int buffer_size_;
+  static THREAD_LOCAL int buffer_size_;
+
 };
 
 inline int Network::rank() {

include/LightGBM/utils/log.h

@@ -11,6 +11,11 @@
 
 namespace LightGBM {
 
+#if defined(_MSC_VER)
+#define THREAD_LOCAL __declspec(thread) 
+#else
+#define THREAD_LOCAL thread_local
+#endif
 
 #ifndef CHECK
 #define CHECK(condition)                                   \
@@ -92,11 +97,7 @@ private:
 
   // a trick to use static variable in header file.
   // May be not good, but avoid to use an additional cpp file
-#if defined(_MSC_VER)
-  static LogLevel& GetLevel() { static __declspec(thread) LogLevel level = LogLevel::Info; return level; }
-#else
-  static LogLevel& GetLevel() { static thread_local LogLevel level = LogLevel::Info; return level; }
-#endif
+  static LogLevel& GetLevel() { static THREAD_LOCAL LogLevel level = LogLevel::Info; return level; }
 
 };
 

src/network/network.cpp

@@ -10,15 +10,15 @@
 namespace LightGBM {
 
 // static member definition
-int Network::num_machines_;
-int Network::rank_;
-std::unique_ptr<Linkers> Network::linkers_;
-BruckMap Network::bruck_map_;
-RecursiveHalvingMap Network::recursive_halving_map_;
-std::vector<int> Network::block_start_;
-std::vector<int>  Network::block_len_;
-int Network::buffer_size_;
-std::vector<char> Network::buffer_;
+THREAD_LOCAL int Network::num_machines_;
+THREAD_LOCAL int Network::rank_;
+THREAD_LOCAL std::unique_ptr<Linkers> Network::linkers_;
+THREAD_LOCAL BruckMap Network::bruck_map_;
+THREAD_LOCAL RecursiveHalvingMap Network::recursive_halving_map_;
+THREAD_LOCAL std::vector<int> Network::block_start_;
+THREAD_LOCAL std::vector<int>  Network::block_len_;
+THREAD_LOCAL int Network::buffer_size_;
+THREAD_LOCAL std::vector<char> Network::buffer_;
 
 void Network::Init(NetworkConfig config) {
   linkers_.reset(new Linkers(config));