[Relay] Introduce Executor and Runtime representations with associate…

…d registries (apache#9246)

This is the underpinning Executor/Runtime objects for apache/tvm-rfcs#29, this doesn't change the wiring as yet since that's a pretty big change in itself. Most of this patch is TVM boilerplate, which I've tried to minimize - there's maybe some future work to decide how to more easily define some of these things.

include/tvm/relay/executor.h

@@ -0,0 +1,276 @@
+/*
+ * 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.
+ */
+
+/*!
+ * \file tvm/relay/executor.h
+ * \brief Object representation of Executor configuration and registry
+ */
+#ifndef TVM_RELAY_EXECUTOR_H_
+#define TVM_RELAY_EXECUTOR_H_
+
+#include <dmlc/registry.h>
+#include <tvm/ir/attrs.h>
+#include <tvm/ir/expr.h>
+#include <tvm/ir/type.h>
+#include <tvm/ir/type_relation.h>
+#include <tvm/node/attr_registry_map.h>
+#include <tvm/runtime/registry.h>
+
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+namespace tvm {
+
+template <typename, typename>
+class AttrRegistry;
+
+namespace relay {
+
+/*!
+ * \brief Executor information.
+ *
+ * This data structure stores the meta-data
+ * about executors which can be used to pass around information.
+ *
+ * \sa Executor
+ */
+class ExecutorNode : public Object {
+ public:
+  /*! \brief name of the Executor */
+  String name;
+  /* \brief Additional attributes storing meta-data about the Executor. */
+  DictAttrs attrs;
+
+  /*!
+   * \brief Get an attribute.
+   *
+   * \param attr_key The attribute key.
+   * \param default_value The default value if the key does not exist, defaults to nullptr.
+   *
+   * \return The result
+   *
+   * \tparam TObjectRef the expected object type.
+   * \throw Error if the key exists but the value does not match TObjectRef
+   *
+   * \code
+   *
+   *  void GetAttrExample(const Executor& executor) {
+   *    auto value = executor->GetAttr<Integer>("AttrKey", 0);
+   *  }
+   *
+   * \endcode
+   */
+  template <typename TObjectRef>
+  Optional<TObjectRef> GetAttr(
+      const std::string& attr_key,
+      Optional<TObjectRef> default_value = Optional<TObjectRef>(nullptr)) const {
+    return attrs.GetAttr(attr_key, default_value);
+  }
+  // variant that uses TObjectRef to enable implicit conversion to default value.
+  template <typename TObjectRef>
+  Optional<TObjectRef> GetAttr(const std::string& attr_key, TObjectRef default_value) const {
+    return GetAttr<TObjectRef>(attr_key, Optional<TObjectRef>(default_value));
+  }
+
+  void VisitAttrs(AttrVisitor* v) {
+    v->Visit("name", &name);
+    v->Visit("attrs", &attrs);
+  }
+
+  bool SEqualReduce(const ExecutorNode* other, SEqualReducer equal) const {
+    return name == other->name && equal.DefEqual(attrs, other->attrs);
+  }
+
+  void SHashReduce(SHashReducer hash_reduce) const {
+    hash_reduce(name);
+    hash_reduce(attrs);
+  }
+
+  static constexpr const char* _type_key = "Executor";
+  TVM_DECLARE_FINAL_OBJECT_INFO(ExecutorNode, Object);
+};
+
+/*!
+ * \brief Managed reference class to ExecutorNode.
+ * \sa ExecutorNode
+ */
+class Executor : public ObjectRef {
+ public:
+  /*!
+   * \brief Create a new Executor object using the registry
+   * \throws Error if name is not registered
+   * \param name The name of the executor.
+   * \param attrs Attributes for the executor.
+   * \return the new Executor object.
+   */
+  TVM_DLL static Executor Create(String name, Map<String, ObjectRef> attrs);
+
+  /*!
+   * \brief List all registered Executors
+   * \return the list of Executors
+   */
+  TVM_DLL static Array<String> ListExecutors();
+
+  /*!
+   * \brief List all options for a specific Executor
+   * \param name The name of the Executor
+   * \return Map of option name to type
+   */
+  TVM_DLL static Map<String, String> ListExecutorOptions(const String& name);
+
+  /*! \brief specify container node */
+  TVM_DEFINE_NOTNULLABLE_OBJECT_REF_METHODS(Executor, ObjectRef, ExecutorNode);
+
+ private:
+  /*!
+   * \brief Private Constructor
+   * \param name The executor name
+   * \param attrs Attributes to apply to this Executor node
+   */
+  TVM_DLL Executor(String name, DictAttrs attrs) {
+    auto n = make_object<ExecutorNode>();
+    n->name = std::move(name);
+    n->attrs = std::move(attrs);
+    data_ = std::move(n);
+  }
+};
+
+/*!
+ * \brief Helper structure to register Executors
+ * \sa TVM_REGISTER_EXECUTOR
+ */
+class ExecutorRegEntry {
+ public:
+  /*! \brief Set name of the Executor to be the same as registry if it is empty */
+  inline ExecutorRegEntry& set_name();
+
+  /*!
+   * \brief Register a valid configuration option and its ValueType for validation
+   * \param key The configuration key
+   * \tparam ValueType The value type to be registered
+   */
+  template <typename ValueType>
+  inline ExecutorRegEntry& add_attr_option(const String& key);
+
+  /*!
+   * \brief Register a valid configuration option and its ValueType for validation
+   * \param key The configuration key
+   * \param default_value The default value of the key
+   * \tparam ValueType The value type to be registered
+   */
+  template <typename ValueType>
+  inline ExecutorRegEntry& add_attr_option(const String& key, ObjectRef default_value);
+
+  /*!
+   * \brief Register or get a new entry.
+   * \param name The name of the operator.
+   * \return the corresponding entry.
+   */
+  TVM_DLL static ExecutorRegEntry& RegisterOrGet(const String& name);
+
+ private:
+  /*! \brief Internal storage of value types */
+  struct ValueTypeInfo {
+    std::string type_key;
+    uint32_t type_index;
+  };
+  std::unordered_map<std::string, ValueTypeInfo> key2vtype_;
+  /*! \brief A hash table that stores the default value of each attr */
+  std::unordered_map<String, ObjectRef> key2default_;
+
+  /*! \brief Index used for internal lookup of attribute registry */
+  uint32_t index_;
+
+  // the name
+  std::string name;
+
+  /*! \brief Return the index stored in attr registry */
+  uint32_t AttrRegistryIndex() const { return index_; }
+  /*! \brief Return the name stored in attr registry */
+  String AttrRegistryName() const { return name; }
+
+  /*! \brief private constructor */
+  explicit ExecutorRegEntry(uint32_t reg_index) : index_(reg_index) {}
+
+  // friend class
+  template <typename>
+  friend class AttrRegistryMapContainerMap;
+  template <typename, typename>
+  friend class tvm::AttrRegistry;
+  friend class Executor;
+};
+
+inline ExecutorRegEntry& ExecutorRegEntry::set_name() {
+  if (name.empty()) {
+    name = name;
+  }
+  return *this;
+}
+
+template <typename ValueType>
+inline ExecutorRegEntry& ExecutorRegEntry::add_attr_option(const String& key) {
+  ICHECK(!key2vtype_.count(key)) << "AttributeError: add_attr_option failed because '" << key
+                                 << "' has been set once";
+
+  using ValueNodeType = typename ValueType::ContainerType;
+  // NOTE: we could further update the function later.
+  uint32_t value_type_index = ValueNodeType::_GetOrAllocRuntimeTypeIndex();
+
+  ValueTypeInfo info;
+  info.type_index = value_type_index;
+  info.type_key = runtime::Object::TypeIndex2Key(value_type_index);
+  key2vtype_[key] = info;
+  return *this;
+}
+
+template <typename ValueType>
+inline ExecutorRegEntry& ExecutorRegEntry::add_attr_option(const String& key,
+                                                           ObjectRef default_value) {
+  add_attr_option<ValueType>(key);
+  key2default_[key] = default_value;
+  return *this;
+}
+
+// internal macros to make executor entries
+#define TVM_EXECUTOR_REGISTER_VAR_DEF \
+  static DMLC_ATTRIBUTE_UNUSED ::tvm::relay::ExecutorRegEntry& __make_##Executor
+
+/*!
+ * \def TVM_REGISTER_EXECUTOR
+ * \brief Register a new executor, or set attribute of the corresponding executor.
+ *
+ * \param ExecutorName The name of registry
+ *
+ * \code
+ *
+ *  TVM_REGISTER_EXECUTOR("aot")
+ *  .add_attr_option<String>("my_option");
+ *  .add_attr_option<String>("my_option_default", String("default"));
+ *
+ * \endcode
+ */
+#define TVM_REGISTER_EXECUTOR(ExecutorName)                    \
+  TVM_STR_CONCAT(TVM_EXECUTOR_REGISTER_VAR_DEF, __COUNTER__) = \
+      ::tvm::relay::ExecutorRegEntry::RegisterOrGet(ExecutorName).set_name()
+}  // namespace relay
+}  // namespace tvm
+
+#endif  // TVM_RELAY_EXECUTOR_H_