Add backend runtime context (#209)

Summary:
Pull Request resolved: #209

Add backend runtime context. Items to be added there:
- Event tracer
- temp allocator

The signature breaking change will be in D48872100

Reviewed By: tarun292

Differential Revision: D48872102

fbshipit-source-id: c3ddbd61e8006e8f0d95563501222ce5e4352b3b

Author: cccclai

runtime/backend/backend_runtime_context.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace torch {
+namespace executor {
+
+/**
+ * BackendContext will be used to inject run time context.
+ * The current plan is to add temp allocator and event tracer (for profiling) as
+ * part of the runtime context.
+ */
+class BackendRuntimeContext final {};
+
+} // namespace executor
+} // namespace torch

runtime/backend/targets.bzl

@@ -7,6 +7,17 @@ def define_common_targets():
     TARGETS and BUCK files that call this function.
     """
 
+    runtime.cxx_library(
+        name = "backend_runtime_context",
+        exported_headers = [
+            "backend_runtime_context.h",
+        ],
+        visibility = [
+            "//executorch/...",
+            "@EXECUTORCH_CLIENTS",
+        ],
+    )
+
     for aten_mode in (True, False):
         aten_suffix = ("_aten" if aten_mode else "")
         runtime.cxx_library(
@@ -23,6 +34,7 @@ def define_common_targets():
                 "@EXECUTORCH_CLIENTS",
             ],
             exported_deps = [
+                "//executorch/runtime/backend:backend_runtime_context",
                 "//executorch/runtime/core:core",
                 "//executorch/runtime/core:evalue" + aten_suffix,
                 "//executorch/runtime/core:memory_allocator",