Fix bugs in StaticInitializer and CudaContextManager (#1321)

* Bug fix: StaticInitializer.

* Make CudaContextManager a member of GPU_Backend::BackendContext.

* fix formatting

src/ngraph/runtime/gpu/gpu_backend.cpp

@@ -53,11 +53,12 @@ runtime::gpu::GPU_Backend::GPU_Backend()
 runtime::gpu::GPU_Backend::BackendContext::BackendContext()
     : m_runtime_context(new GPURuntimeContext)
     , m_primitive_emitter(new GPUPrimitiveEmitter(m_runtime_context))
+    , m_cuda_manager(new CudaContextManager)
 {
     // Create context use driver API and make it current, the runtime call will pickup the context
     // http://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html
     // #interoperability-between-runtime-and-driver-apis
-    ngraph::runtime::gpu::CudaContextManager::Instance().SetContextCurrent();
+    m_cuda_manager->SetContextCurrent();
 
     m_runtime_context->cublas_handle = new cublasHandle_t;
     cublasStatus_t cublasStatus = cublasCreate(m_runtime_context->cublas_handle);

src/ngraph/runtime/gpu/gpu_backend.hpp

@@ -33,6 +33,7 @@ namespace ngraph
             class GPU_CallFrame;
             class GPUPrimitiveEmitter;
             struct GPURuntimeContext;
+            class CudaContextManager;
 
             class GPU_Backend : public Backend
             {
@@ -71,6 +72,9 @@ namespace ngraph
 
                     std::unique_ptr<GPURuntimeContext> m_runtime_context;
                     std::unique_ptr<GPUPrimitiveEmitter> m_primitive_emitter;
+
+                private:
+                    std::unique_ptr<CudaContextManager> m_cuda_manager;
                 };
 
             private:

src/ngraph/runtime/gpu/gpu_cuda_context_manager.cpp

@@ -21,12 +21,6 @@
 
 using namespace ngraph;
 
-runtime::gpu::CudaContextManager& runtime::gpu::CudaContextManager::Instance()
-{
-    static CudaContextManager manager;
-    return manager;
-}
-
 runtime::gpu::CudaContextManager::CudaContextManager()
 {
     CUDA_SAFE_CALL(cuInit(0));

src/ngraph/runtime/gpu/gpu_cuda_context_manager.hpp

@@ -30,7 +30,9 @@ namespace ngraph
             class CudaContextManager
             {
             public:
-                static CudaContextManager& Instance();
+                CudaContextManager();
+                ~CudaContextManager();
+
                 CudaContextManager(CudaContextManager const&) = delete;
                 CudaContextManager(CudaContextManager&&) = delete;
                 CudaContextManager& operator=(CudaContextManager const&) = delete;
@@ -39,8 +41,6 @@ namespace ngraph
                 CUcontext GetContext() { return m_context; }
                 void SetContextCurrent() { cuCtxSetCurrent(m_context); }
             protected:
-                CudaContextManager();
-                ~CudaContextManager();
                 CUdevice m_device;
                 CUcontext m_context;
             };

src/ngraph/runtime/gpu/gpu_external_function.cpp

@@ -112,10 +112,10 @@ using namespace ngraph;
 static const string s_output_dir = "gpu_codegen";
 static std::mutex s_compilation;
 
-class StaticInitializers
+class GPUStaticInitializers
 {
 public:
-    StaticInitializers()
+    GPUStaticInitializers()
     {
         file_util::remove_directory(s_output_dir);
         file_util::make_directory(s_output_dir);
@@ -154,7 +154,7 @@ static string emit_string_array(const vector<string>& s, size_t max_line_length)
     return ss.str();
 }
 
-static StaticInitializers s_static_initializers;
+static GPUStaticInitializers s_static_initializers;
 
 #define TI(x) type_index(typeid(x))