Add support for Thrust managed memory

Closes #143

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 ## Unreleased
 ### Added
 - Ability to build Kokkos and RAJA versions against existing packages.
+- Thrust managed memory.
 
 ### Changed
 - RAJA CUDA CMake build issues resolved.

src/thrust/ThrustStream.h

@@ -8,7 +8,11 @@
 
 #include <iostream>
 #include <vector>
+#if defined(MANAGED)
+#include <thrust/universal_vector.h>
+#else
 #include <thrust/device_vector.h>
+#endif
 
 #include "Stream.h"
 
@@ -21,9 +25,15 @@ class ThrustStream : public Stream<T>
     // Size of arrays
     int array_size;
 
+  #if defined(MANAGED)
+    thrust::universtal_vector<T> a;
+    thrust::universtal_vector<T> b;
+    thrust::universtal_vector<T> c;
+  #else
     thrust::device_vector<T> a;
     thrust::device_vector<T> b;
     thrust::device_vector<T> c;
+  #endif
 
   public:
     ThrustStream(const int, int);

src/thrust/model.cmake

@@ -18,6 +18,9 @@ register_flag_optional(BACKEND
         "
         "CUDA")
 
+      register_flag_optional(MANAGED "Enabled managed memory mode."
+        "OFF")
+
 register_flag_optional(CMAKE_CUDA_COMPILER
         "[THRUST_IMPL==CUDA] Path to the CUDA nvcc compiler"
         "")
@@ -34,6 +37,9 @@ register_flag_optional(CUDA_EXTRA_FLAGS
 
 macro(setup)
     set(CMAKE_CXX_STANDARD 14)
+    if (MANAGED)
+      register_definitions(MANAGED)
+    endif ()
 
     if (${THRUST_IMPL} STREQUAL "CUDA")
 
@@ -91,4 +97,4 @@ macro(setup)
 endmacro()
 
 
- 
+