remove global var (#47659)

paddle/fluid/distributed/collective/ProcessGroup.h

@@ -92,7 +92,7 @@ class ProcessGroup {
 
   int GetSize() const { return size_; }
 
-  virtual const std::string GetBackendName() const = 0;
+  virtual std::string GetBackendName() const = 0;
   virtual const phi::DeviceContext& GetDeviceContext(const Place& place) const {
     PADDLE_THROW(platform::errors::InvalidArgument(
         "Does not support to get device_context from ProcessGroup%s.",

paddle/fluid/distributed/collective/ProcessGroupCustom.h

@@ -69,9 +69,7 @@ class ProcessGroupCustom : public ProcessGroup {
                      const platform::Place& place,
                      int gid);
 
-  const std::string GetBackendName() const override {
-    return "XCCL_" + device_type_;
-  }
+  std::string GetBackendName() const override { return "XCCL_" + device_type_; }
 
   std::shared_ptr<ProcessGroup::Task> AllGather(
       std::vector<phi::DenseTensor>& in_tensors,

paddle/fluid/distributed/collective/ProcessGroupGloo.h

@@ -26,8 +26,6 @@
 #include "paddle/fluid/distributed/store/store.h"
 #include "paddle/fluid/distributed/store/tcp_store.h"
 
-constexpr const char* GLOO_BACKEND_NAME = "GLOO";
-
 namespace paddle {
 namespace distributed {
 
@@ -146,9 +144,7 @@ class ProcessGroupGloo : public ProcessGroup {
   std::shared_ptr<::gloo::Context> get_context() { return _context; }
   uint64_t next_tag() { return _tag++; }
 
-  const std::string GetBackendName() const override {
-    return GLOO_BACKEND_NAME;
-  }
+  std::string GetBackendName() const override { return "GLOO"; }
 
   const phi::DeviceContext& GetDeviceContext(
       const Place& place) const override {

paddle/fluid/distributed/collective/ProcessGroupHCCL.h

@@ -30,8 +30,6 @@
 #include "paddle/fluid/platform/gen_comm_id_helper.h"
 #include "paddle/fluid/platform/place.h"
 
-constexpr const char* HCCL_BACKEND_NAME = "HCCL";
-
 namespace paddle {
 namespace distributed {
 
@@ -77,9 +75,7 @@ class ProcessGroupHCCL : public ProcessGroup {
                    const platform::Place& place,
                    int gid);
 
-  const std::string GetBackendName() const override {
-    return std::string(HCCL_BACKEND_NAME);
-  }
+  std::string GetBackendName() const override { return "HCCL"; }
 
   std::shared_ptr<ProcessGroup::Task> AllReduce(
       std::vector<phi::DenseTensor>& in_tensors,
@@ -114,8 +110,8 @@ class ProcessGroupHCCL : public ProcessGroup {
   std::set<int> used_place_ids_;
 
  private:
-  void BcastHCCLId(std::vector<HcclRootInfo>& hccl_ids,
-                   int root,  // NOLINT
+  void BcastHCCLId(std::vector<HcclRootInfo>& hccl_ids,  // NOLINT
+                   int root,                             // NOLINT
                    int server_fd);
 
   void BroadcastUniqueHCCLID(std::vector<HcclRootInfo>& hccl_ids);  // NOLINT

paddle/fluid/distributed/collective/ProcessGroupHeter.h

@@ -58,8 +58,6 @@
 
 #include "paddle/fluid/distributed/collective/Common.h"
 
-constexpr const char* HETER_BACKEND_NAME = "HETER_BACKEND";
-
 namespace paddle {
 namespace distributed {
 
@@ -99,9 +97,7 @@ class ProcessGroupHeter : public ProcessGroup {
                     int src_rank,
                     int dst_rank);
 
-  const std::string GetBackendName() const override {
-    return std::string(HETER_BACKEND_NAME);
-  }
+  std::string GetBackendName() const override { return "HETER_BACKEND"; }
 
   std::shared_ptr<ProcessGroup::Task> AllReduce(
       std::vector<phi::DenseTensor>&,

paddle/fluid/distributed/collective/ProcessGroupMPI.h

@@ -33,8 +33,6 @@
 #include "paddle/fluid/distributed/collective/MPITools.h"
 #endif
 
-constexpr const char* MPI_BACKEND_NAME = "MPI";
-
 namespace paddle {
 namespace distributed {
 
@@ -137,9 +135,7 @@ class ProcessGroupMPI : public ProcessGroup {
 
   virtual ~ProcessGroupMPI();
 
-  const std::string GetBackendName() const override {
-    return std::string(MPI_BACKEND_NAME);
-  }
+  std::string GetBackendName() const override { return "MPI"; }
 
   std::shared_ptr<ProcessGroup::Task> AllReduce(
       std::vector<phi::DenseTensor>& in_tensors,

paddle/fluid/distributed/collective/ProcessGroupNCCL.h

@@ -39,8 +39,6 @@
 #include "paddle/fluid/platform/dynload/nccl.h"
 #endif
 
-constexpr const char* NCCL_BACKEND_NAME = "NCCL";
-
 namespace paddle {
 namespace distributed {
 
@@ -94,9 +92,7 @@ class ProcessGroupNCCL : public ProcessGroupStream {
                    const platform::Place& place,
                    int gid);
 
-  const std::string GetBackendName() const override {
-    return std::string(NCCL_BACKEND_NAME);
-  }
+  std::string GetBackendName() const override { return "NCCL"; }
 
   const phi::DeviceContext& GetDeviceContext(const Place& place) const override;