[Mirror] [Tpetra] Revisit "initialize Kokkos if needed" pattern [rebase]

packages/teuchos/core/src/Teuchos_GlobalMPISession.cpp

@@ -17,12 +17,6 @@
 #  include "mpi.h"
 #endif
 
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
-#  include "Kokkos_Core.hpp"
-#endif // HAVE_TEUCHOSCORE_KOKKOS
-
-
-
 namespace Teuchos {
 
 
@@ -31,15 +25,10 @@ bool GlobalMPISession::mpiIsFinalized_ = false;
 int GlobalMPISession::rank_ = 0 ;
 int GlobalMPISession::nProc_ = 1 ;
 
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
-
 // We have to invoke the std::vector's constructor here,
 // because it's a class (static) variable.
 std::vector<std::string> GlobalMPISession::argvCopy_;
 
-#endif // HAVE_TEUCHOSCORE_KOKKOS
-
-
 GlobalMPISession::GlobalMPISession( int* argc, char*** argv, std::ostream *out )
 {
   std::ostringstream oss;
@@ -120,7 +109,6 @@ GlobalMPISession::GlobalMPISession( int* argc, char*** argv, std::ostream *out )
 
 #endif
 
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
   // mfh 15/16 Apr 2016: This is the one chance we get to save the
   // command-line arguments, so that we can (later) initialize Kokkos
   // with the correct number of threads as specified by (e.g.,) the
@@ -136,36 +124,23 @@ GlobalMPISession::GlobalMPISession( int* argc, char*** argv, std::ostream *out )
   // requirement.
 
   const int numArgs = *argc;
-  argvCopy_.resize (numArgs);  
+  argvCopy_.resize (numArgs);
   for (int c = 0; c < numArgs; ++c) {
     argvCopy_[c] = std::string ((*argv)[c]); // deep copy
   }
-#endif // HAVE_TEUCHOSCORE_KOKKOS
+
+
 }
 
-
-#ifdef HAVE_TEUCHOSCORE_KOKKOS  
+
 std::vector<std::string> GlobalMPISession::getArgv ()
 {
   return argvCopy_;
 }
-#endif // HAVE_TEUCHOSCORE_KOKKOS  
 
-  
+
 GlobalMPISession::~GlobalMPISession()
 {
-
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
-  try {
-    if (Kokkos::is_initialized())
-      Kokkos::finalize();
-  }
-  catch (const std::runtime_error& e) {
-    std::cerr << "Kokkos::finalize failed:\n"
-              << e.what() << "\n";
-  }
-#endif
-
   haveMPIState_ = false;
 #ifdef HAVE_MPI
   const int mpierr = ::MPI_Finalize();

packages/teuchos/core/src/Teuchos_GlobalMPISession.hpp

@@ -231,7 +231,6 @@ class TEUCHOSCORE_LIB_DLL_EXPORT GlobalMPISession
    */
   static void allGather(int localVal, const ArrayView<int> &allVals);
 
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
   /// \brief Fetch a deep copy of the input arguments to \c main()
   ///   (that is, \c argv), as given to GlobalMPISession's
   ///   constructor.
@@ -240,7 +239,6 @@ class TEUCHOSCORE_LIB_DLL_EXPORT GlobalMPISession
   ///   yet, return an empty vector.  Else, return the input
   ///   arguments.
   static std::vector<std::string> getArgv ();
-#endif // HAVE_TEUCHOSCORE_KOKKOS
   //@}
 
 private:
@@ -249,7 +247,7 @@ class TEUCHOSCORE_LIB_DLL_EXPORT GlobalMPISession
   static bool mpiIsFinalized_;
   static int rank_;
   static int nProc_;
-#ifdef HAVE_TEUCHOSCORE_KOKKOS
+
   /// \brief Deep copy of the input arguments.
   ///
   /// This is useful if we want to call Kokkos::initialize later with
@@ -258,7 +256,6 @@ class TEUCHOSCORE_LIB_DLL_EXPORT GlobalMPISession
   /// after calling this object's constructor.  That could mess up
   /// indexing if we just keep a pointer to the original.
   static std::vector<std::string> argvCopy_;
-#endif // HAVE_TEUCHOSCORE_KOKKOS
 
   static void initialize( std::ostream *out );
 

packages/tpetra/core/src/Tpetra_Details_initializeKokkos.cpp

@@ -19,36 +19,39 @@
 namespace Tpetra {
 namespace Details {
 
-void finalizeKokkosIfNeeded() {
-  if (!Kokkos::is_finalized()) {
-    Kokkos::finalize();
-  }
-}
-
 void initializeKokkos() {
-  if (!Kokkos::is_initialized()) {
-    std::vector<std::string> args = Teuchos::GlobalMPISession::getArgv();
-    int narg                      = static_cast<int>(args.size());  // must be nonconst
-
-    std::vector<char*> args_c;
-    std::vector<std::unique_ptr<char[]>> args_;
-    for (auto const& x : args) {
-      args_.emplace_back(new char[x.size() + 1]);
-      char* ptr = args_.back().get();
-      strcpy(ptr, x.c_str());
-      args_c.push_back(ptr);
+  static const int initialized = []() {
+    TEUCHOS_TEST_FOR_EXCEPTION(Kokkos::is_finalized(), std::runtime_error,
+                               "Tpetra::Details::initializeKokkos: Kokkos is already finalized");
+    if (!Kokkos::is_initialized()) {
+      std::vector<std::string> args = Teuchos::GlobalMPISession::getArgv();
+      int narg                      = static_cast<int>(args.size());  // must be nonconst
+
+      std::vector<char*> args_c;
+      std::vector<std::unique_ptr<char[]>> args_;
+      for (auto const& x : args) {
+        args_.emplace_back(new char[x.size() + 1]);
+        char* ptr = args_.back().get();
+        strcpy(ptr, x.c_str());
+        args_c.push_back(ptr);
+      }
+      args_c.push_back(nullptr);
+
+      Kokkos::initialize(narg, args_c.data());
+      checkOldCudaLaunchBlocking();
+
+      std::atexit(Kokkos::finalize);
     }
-    args_c.push_back(nullptr);
 
-    Kokkos::initialize(narg, narg == 0 ? nullptr : args_c.data());
-    checkOldCudaLaunchBlocking();
+    // Add Kokkos calls to the TimeMonitor if the environment says so
+    Tpetra::Details::AddKokkosDeepCopyToTimeMonitor();
+    Tpetra::Details::AddKokkosFenceToTimeMonitor();
+    Tpetra::Details::AddKokkosFunctionsToTimeMonitor();
+    return 1;
+  }();
 
-    std::atexit(finalizeKokkosIfNeeded);
-  }
-  // Add Kokkos calls to the TimeMonitor if the environment says so
-  Tpetra::Details::AddKokkosDeepCopyToTimeMonitor();
-  Tpetra::Details::AddKokkosFenceToTimeMonitor();
-  Tpetra::Details::AddKokkosFunctionsToTimeMonitor();
+  TEUCHOS_TEST_FOR_EXCEPTION(!Kokkos::is_initialized() || initialized != 1, std::runtime_error,
+                             "Tpetra::Details::initializeKokkos: Initialization failed or Kokkos has already been finalized.");
 }
 
 }  // namespace Details