- rename get_ngraph_allocator to get_default_allocator

- return nullptr if caller queries get_device_allocator from allocator base ptr

src/ngraph/runtime/aligned_buffer.hpp

@@ -36,7 +36,7 @@ class ngraph::runtime::AlignedBuffer
 public:
     AlignedBuffer(size_t byte_size,
                   size_t alignment,
-                  Allocator* allocator = get_ngraph_allocator());
+                  Allocator* allocator = get_default_allocator());
     AlignedBuffer();
     ~AlignedBuffer();
 

src/ngraph/runtime/allocator.cpp

@@ -49,7 +49,7 @@ public:
     }
 };
 
-ngraph::runtime::Allocator* ngraph::runtime::get_ngraph_allocator()
+ngraph::runtime::Allocator* ngraph::runtime::get_default_allocator()
 {
     static DefaultAllocator* allocator = new DefaultAllocator();
     return allocator;

src/ngraph/runtime/allocator.hpp

@@ -30,7 +30,7 @@ namespace ngraph
         class DefaultAllocator;
         /// \brief Returns a statically allocated default ngraph allocator
         //         that calls into system allocation libraries
-        Allocator* get_ngraph_allocator();
+        Allocator* get_default_allocator();
     }
 }
 

src/ngraph/runtime/backend.hpp

@@ -145,7 +145,7 @@ public:
     /// \brief Returns memory allocator used by backend for host allocations
     virtual Allocator* get_host_memory_allocator()
     {
-        return ngraph::runtime::get_ngraph_allocator();
+        return ngraph::runtime::get_default_allocator();
     }
 
     /// \brief Set the host memory allocator to be used by the backend
@@ -154,7 +154,9 @@ public:
     /// \brief Returns memory allocator used by backend for device allocations
     virtual Allocator* get_device_memory_allocator()
     {
-        return ngraph::runtime::get_ngraph_allocator();
+        // override this method from each supported backend to return
+        // its own device memory allocator
+        return nullptr;
     }
 
     /// \brief method for each supported backend to determine if the passed pointer is in device pinned memory or not

src/ngraph/runtime/cpu/cpu_backend.cpp

@@ -165,7 +165,7 @@ runtime::Allocator* runtime::cpu::CPU_Backend::get_host_memory_allocator()
     }
     else
     {
-        return runtime::get_ngraph_allocator();
+        return runtime::get_default_allocator();
     }
 }