Addresses comments in runtime feature discovery API

CMakeLists.txt

@@ -294,8 +294,8 @@ else()
   add_definitions(-DMXNET_USE_NCCL=0)
 endif()
 
+include(cmake/ChooseBlas.cmake)
 if(USE_CUDA AND FIRST_CUDA)
-  include(cmake/ChooseBlas.cmake)
   include(3rdparty/mshadow/cmake/Utils.cmake)
   include(cmake/FirstClassLangCuda.cmake)
   include_directories(${CMAKE_CUDA_TOOLKIT_INCLUDE_DIRECTORIES})

include/mxnet/base.h

@@ -35,7 +35,7 @@
 #include "nnvm/op.h"
 #include "nnvm/tuple.h"
 #include "nnvm/symbolic.h"
-#include "mxfeatures.h"
+#include "libinfo.h"
 
 
 /*!
@@ -403,7 +403,14 @@ template<> struct hash<mxnet::Context> {
     return res;
   }
 };
+
+#if __cplusplus < 201402L && !defined(_MSC_VER)
+template<typename T, typename... Args>
+inline std::unique_ptr<T> make_unique(Args&&... args) {
+  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
 }
+#endif
+}  // namespace std
 
 #include "./tensor_blob.h"
 //! \endcond

include/mxnet/c_api.h

@@ -139,6 +139,12 @@ struct MXCallbackList {
   void **contexts;
 };
 
+struct LibFeature {
+  const char* name;
+  uint32_t index;
+  bool enabled;
+};
+
 enum CustomOpCallbacks {
   kCustomOpDelete,
   kCustomOpForward,
@@ -210,12 +216,12 @@ MXNET_DLL const char *MXGetLastError();
 //-------------------------------------
 
 /*!
- * \brief
- * \param feature to check mxfeatures.h
- * \param out set to true if the feature is enabled, false otherwise
+ * \brief Get list of features supported on the runtime
+ * \param libFeature pointer to array of LibFeature
+ * \param size of the array
  * \return 0 when success, -1 when failure happens.
  */
-MXNET_DLL int MXHasFeature(const mx_uint feature, bool* out);
+MXNET_DLL int MXLibInfoFeatures(const struct LibFeature **libFeature, size_t *size);
 
 /*!
  * \brief Seed all global random number generators in mxnet.

include/mxnet/mxfeatures.h → include/mxnet/libinfo.h

@@ -18,21 +18,27 @@
  */
 
 /*!
- *  Copyright (c) 2018 by Contributors
- * \file mxfeatures.h
- * \brief check MXNet features including compile time support
+ * Copyright (c) 2018 by Contributors
+ * \file libinfo.h
+ * \author larroy
+ * \brief get features of the MXNet library at runtime
  */
 
 #pragma once
 
+#include <string>
+#include <vector>
+#include <array>
+#include <memory>
 #include "dmlc/base.h"
 #include "mshadow/base.h"
+#include "c_api.h"
 
 /*!
  *\brief whether to use opencv support
  */
 #ifndef MXNET_USE_OPENCV
-#define MXNET_USE_OPENCV 1
+#define MXNET_USE_OPENCV 0
 #endif
 
 /*!
@@ -124,7 +130,8 @@ namespace features {
 // Check compile flags such as CMakeLists.txt
 
 /// Compile time features
-enum : uint32_t {
+// ATTENTION: When changing this enum, match the strings in the implementation file!
+enum : unsigned {
   // NVIDIA, CUDA
   CUDA = 0,
   CUDNN,
@@ -179,10 +186,25 @@ enum : uint32_t {
 };
 
 
+struct EnumNames {
+  static const std::vector<std::string> names;
+};
+
+struct LibInfo {
+  LibInfo();
+  static LibInfo* getInstance();
+  const std::array<LibFeature, MAX_FEATURES>& getFeatures() {
+    return m_lib_features;
+  }
+ private:
+  std::array<LibFeature, MAX_FEATURES> m_lib_features;
+  static std::unique_ptr<LibInfo>  m_inst;
+};
+
 /*!
  * \return true if the given feature is supported
  */
-bool is_enabled(uint32_t feat);
+bool is_enabled(unsigned feat);
 
 }  // namespace features
 }  // namespace mxnet

python/mxnet/runtime.py

@@ -0,0 +1,48 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# coding: utf-8
+# pylint: disable=not-an-iterable
+
+"""runtime querying of compile time features in the native library"""
+
+import ctypes
+from .base import _LIB, check_call
+
+class LibFeature(ctypes.Structure):
+    """
+    Compile time feature description
+    """
+    _fields_ = [
+        ("name", ctypes.c_char_p),
+        ("index", ctypes.c_uint32),
+        ("enabled", ctypes.c_bool)
+    ]
+
+def libinfo_features():
+    """
+    Check the library for compile-time features. The list of features are maintained in libinfo.h and libinfo.cc
+
+    Returns
+    -------
+    A list of class LibFeature indicating which features are available and enabled
+    """
+    lib_features = ctypes.POINTER(LibFeature)()
+    lib_features_size = ctypes.c_size_t()
+    check_call(_LIB.MXLibInfoFeatures(ctypes.byref(lib_features), ctypes.byref(lib_features_size)))
+    feature_list = [lib_features[i] for i in range(lib_features_size.value)]
+    return feature_list

src/c_api/c_api.cc

@@ -43,7 +43,7 @@
 #include "mxnet/kvstore.h"
 #include "mxnet/rtc.h"
 #include "mxnet/storage.h"
-#include "mxnet/mxfeatures.h"
+#include "mxnet/libinfo.h"
 #include "./c_api_common.h"
 #include "../operator/custom/custom-inl.h"
 #include "../operator/tensor/matrix_op-inl.h"
@@ -87,9 +87,12 @@ inline int MXAPIGetFunctionRegInfo(const FunRegType *e,
 
 // NOTE: return value is added in API_END
 
-int MXHasFeature(const mx_uint feature, bool* out) {
+int MXLibInfoFeatures(const struct LibFeature **lib_features, size_t *size) {
+  using namespace features;
   API_BEGIN();
-  *out = features::is_enabled(feature);
+  LibInfo* lib_info = LibInfo::getInstance();
+  *lib_features = lib_info->getFeatures().data();
+  *size = lib_info->getFeatures().size();
   API_END();
 }
 

src/c_api/c_api_profile.cc

@@ -52,11 +52,6 @@ struct APICallTimingData {
 #endif  // PROFILE_API_INCLUDE_AS_EVENT
 };
 
-template<typename T, typename... Args>
-inline std::unique_ptr<T> make_unique(Args&&... args) {
-  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
-}
-
 /*!
  * \brief Per-thread profiling data
  */
@@ -78,7 +73,7 @@ class ProfilingThreadData {
     auto iter = tasks_.find(name);
     if (iter == tasks_.end()) {
       iter = tasks_.emplace(std::make_pair(
-        name, make_unique<profiler::ProfileTask>(name, domain))).first;
+        name, std::make_unique<profiler::ProfileTask>(name, domain))).first;
     }
     return iter->second.get();
   }
@@ -93,7 +88,8 @@ class ProfilingThreadData {
     // Per-thread so no lock necessary
     auto iter = events_.find(name);
     if (iter == events_.end()) {
-      iter = events_.emplace(std::make_pair(name, make_unique<profiler::ProfileEvent>(name))).first;
+      iter = events_.emplace(std::make_pair(name,
+        std::make_unique<profiler::ProfileEvent>(name))).first;
     }
     return iter->second.get();
   }