onnxruntime/winml/adapter/winml_adapter_c_api.h

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

#pragma once

#include "core/session/onnxruntime_c_api.h"
#include "winrt/windows.foundation.collections.h"

/**
  * All APIs exported by winml_adapter_c_api.h are part of the private interface dedicated to supporting the WinML API.
  * This contract is subject to change based on the needs of the WinML API and is not intended for direct use by callers
  * of the onnxruntime c-api and usage of APIs in this header are *not* supported by the onnxruntime product.
  */

ORT_RUNTIME_CLASS(Model);
ORT_RUNTIME_CLASS(ExecutionProvider);
ORT_RUNTIME_CLASS(ThreadPool);

struct WinmlAdapterApi;
typedef struct WinmlAdapterApi WinmlAdapterApi;

struct ID3D12Resource;
struct ID3D12Device;
struct ID3D12CommandQueue;
struct IMLOperatorRegistry;

// TODO: Must match onnxruntime::profiling::EventRecord
enum OrtProfilerEventCategory {
  SESSION_EVENT = 0,
  NODE_EVENT,
  EVENT_CATEGORY_MAX
};

struct OrtProfilerEventRecord {
  OrtProfilerEventCategory category_;
  const char* category_name_;
  int64_t duration_;
  int64_t time_span_;
  const char* event_name_;
  int32_t process_id_;
  int32_t thread_id_;
  const char* op_name_;
  const char* execution_provider_;
};

typedef void(ORT_API_CALL* OrtProfilingFunction)(const OrtProfilerEventRecord* event_record);

enum class ThreadPoolType : uint8_t {
  INTRA_OP,
  INTER_OP
};

struct OrtThreadPoolOptions {
  //0: Use default setting. (All the physical cores or half of the logical cores)
  //1: Don't create thread pool
  //n: Create a thread pool with n threads.
  int thread_pool_size = 0;
  //If it is true and thread_pool_size = 0, populate the thread affinity information in ThreadOptions.
  //Otherwise if the thread_options has affinity information, we'll use it and set it.
  //In the other case, don't set affinity
  bool auto_set_affinity = false;
  //If it is true, the thread pool will spin a while after the queue became empty.
  bool allow_spinning = true;
  //It it is non-negative, thread pool will split a task by a decreasing block size
  //of remaining_of_total_iterations / (num_of_threads * dynamic_block_base_)
  int dynamic_block_base_ = 0;

  unsigned int stack_size = 0;
  const ORTCHAR_T* name = nullptr;

  // Set or unset denormal as zero
  bool set_denormal_as_zero = false;
};

struct WinmlAdapterApi {
  /**
    * OverrideSchema
    * This api is used to override schema inference functions for a variety of ops across opsets.
    * This exists because certain ops were failing to infer schemas and caused performance
    * issues for DML as it was forced to create resources during evaluation.
    * This can be removed when schema inference functions have been updated.
    */
  OrtStatus*(ORT_API_CALL* OverrideSchema)() NO_EXCEPTION;

  /**
    * EnvConfigureCustomLoggerAndProfiler
    * This api is used to add a custom logger and profiler to the ors environment.
    * This exists because existing methods on the c-abi to create the environment only support a custom logger.
    * Since WinML hooks the profiler events, we expose the profiler and an associated profiling function.
    */
  OrtStatus*(ORT_API_CALL* EnvConfigureCustomLoggerAndProfiler)(
    _In_ OrtEnv* env,
    OrtLoggingFunction logging_function,
    OrtProfilingFunction profiling_function,
    _In_opt_ void* logger_param,
    OrtLoggingLevel default_warning_level,
    _In_ const char* logid,
    _Outptr_ OrtEnv** out
  )NO_EXCEPTION;

  // OrtModel methods

  /**
    * CreateModelFromPath
    * This api creates an OrtModel based on a specified model path.
    * There is no inferencing or evaluation setup performed. Only ONNX load is done to reflect on the model's inputs/outputs and other properties.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* CreateModelFromPath)(_In_ const char* model_path, _In_ size_t size, _Outptr_ OrtModel** out)
    NO_EXCEPTION;

  /**
    * CreateModelFromData
    * This api creates an OrtModel from a buffer.
    * There is no inferencing or evaluation setup performed. Only ONNX load is done to reflect on the model's inputs/outputs and other properties.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* CreateModelFromData)(_In_opt_ void* data, _In_ size_t size, _Outptr_ OrtModel** out)
    NO_EXCEPTION;

  /**
    * CloneModel
    * This api copies the OrtModel along with its internal proto buffer and cached metadata.
    * The OrtSession type expects to own the model proto buffer.
    * WinML uses this to yield copies of the model proto held by OrtModel to OrtSession.
    */
  OrtStatus*(ORT_API_CALL* CloneModel)(_In_ const OrtModel* in, _Outptr_ OrtModel** out)NO_EXCEPTION;

  /**
    * ModelGetAuthor
    * This api gets the model author from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetAuthor)(
    _In_ const OrtModel* model, _Out_ const char** const author, _Out_ size_t* len
  )NO_EXCEPTION;

  /**
    * ModelGetName
    * This api gets the model name from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetName)(_In_ const OrtModel* model, _Out_ const char** const name, _Out_ size_t* len)
    NO_EXCEPTION;

  /**
    * ModelSetName
    * This api set the model name from the OrtModel.
    * This is used by the Windows ML Samples Gallery to change the model name for telemetry.
    */
  OrtStatus*(ORT_API_CALL* ModelSetName)(_In_ const OrtModel* model, _In_ const char* name)NO_EXCEPTION;

  /**
    * ModelGetDomain
    * This api gets the model domain from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetDomain)(
    _In_ const OrtModel* model, _Out_ const char** const domain, _Out_ size_t* len
  )NO_EXCEPTION;

  /**
    * ModelGetDescription
    * This api gets the model description from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetDescription)(
    _In_ const OrtModel* model, _Out_ const char** const description, _Out_ size_t* len
  )NO_EXCEPTION;

  /**
    * ModelGetVersion
    * This api gets the model version from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetVersion)(_In_ const OrtModel* model, _Out_ int64_t* version)NO_EXCEPTION;

  /**
    * ModelGetInputCount
    * This api gets the number of inputs from the OrtModel. It closely matches the API of a similar name similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetInputCount)(_In_ const OrtModel* model, _Out_ size_t* count)NO_EXCEPTION;

  /**
    * ModelGetOutputCount
    * This api gets the number of outputs from the OrtModel. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetOutputCount)(_In_ const OrtModel* model, _Out_ size_t* count)NO_EXCEPTION;

  /**
    * ModelGetInputName
    * This api gets the input name from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetInputName)(
    _In_ const OrtModel* model, _In_ size_t index, _Out_ const char** input_name, _Out_ size_t* count
  )NO_EXCEPTION;

  /**
    * ModelGetOutputName
    * This api gets the output name from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetOutputName)(
    _In_ const OrtModel* model, _In_ size_t index, _Out_ const char** output_name, _Out_ size_t* count
  )NO_EXCEPTION;

  /**
    * ModelGetInputDescription
    * This api gets the input description from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetInputDescription)(
    _In_ const OrtModel* model, _In_ size_t index, _Out_ const char** input_description, _Out_ size_t* count
  )NO_EXCEPTION;

  /**
    * ModelGetOutputDescription
    * This api gets the output description from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetOutputDescription)(
    _In_ const OrtModel* model, _In_ size_t index, _Out_ const char** output_description, _Out_ size_t* count
  )NO_EXCEPTION;

  /**
    * ModelGetInputTypeInfo
    * This api gets the input OrtTypeInfo from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetInputTypeInfo)(
    _In_ const OrtModel* model, _In_ size_t index, _Outptr_ OrtTypeInfo** type_info
  )NO_EXCEPTION;

  /**
    * ModelGetOutputTypeInfo
    * This api gets the output OrtTypeInfo from the OrtModel given an index. It closely matches the API of a similar name for retrieving model metadata from OrtSession.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetOutputTypeInfo)(
    _In_ const OrtModel* model, _In_ size_t index, _Outptr_ OrtTypeInfo** type_info
  )NO_EXCEPTION;

  /**
    * ModelGetMetadataCount
    * This api gets the number of metadata entries from the OrtModel.
    * This is used by WinML to support model reflection APIs.
    */
  OrtStatus*(ORT_API_CALL* ModelGetMetadataCount)(_In_ const OrtModel* model, _Out_ size_t* count)NO_EXCEPTION;

  /**
    * ModelGetMetadata
    * This api gets the model metadata from the OrtModel.
    * This is used by WinML to deduce whether model input and output formats are supported by the WinML tensorization code paths.
    */
  OrtStatus*(ORT_API_CALL* ModelGetMetadata)(
    _In_ const OrtModel* model,
    _Out_ size_t count,
    _Out_ const char** const key,
    _Out_ size_t* key_len,
    _Out_ const char** const value,
    _Out_ size_t* value_len
  )NO_EXCEPTION;

  /**
    * ModelEnsureNoFloat16
    * This api checks whether the model requires float 16 support.
    * This is used by WinML to fail gracefully when float 16 support is not available on the device.
    *
    * Can this API be moved into the EP during session initialization. Currently we do an early fp16 check to avoid initialization when it is not supported.
    */
  OrtStatus*(ORT_API_CALL* ModelEnsureNoFloat16)(_In_ const OrtModel* model)NO_EXCEPTION;

  /**
    * SaveModel
    * This api save the model to the fiven file
    */
  OrtStatus*(ORT_API_CALL* SaveModel)(_In_ const OrtModel* in, _In_ const wchar_t* const file_name, _In_ size_t len)
    NO_EXCEPTION;

  // OrtSessionOptions methods

  /**
    * OrtSessionOptionsAppendExecutionProvider_CPU
    * This api is used to add the cpu EP to OrtSessionOptions so that WinML Gpu session are configures with CPU fallback.
    */
  OrtStatus*(ORT_API_CALL* OrtSessionOptionsAppendExecutionProvider_CPU)(_In_ OrtSessionOptions* options, int use_arena)
    NO_EXCEPTION;

  /**
    * OrtSessionOptionsAppendExecutionProvider_DML
    * This api is used to add the DML EP to OrtSessionOptions.
    */
  OrtStatus*(ORT_API_CALL* OrtSessionOptionsAppendExecutionProvider_DML)(
    _In_ OrtSessionOptions* options, ID3D12Device* device, ID3D12CommandQueue* queue, bool metacommands_enabled
  )NO_EXCEPTION;

  // OrtSession methods

  /**
    * CreateSessionWithoutModel
    * This api is used to create a Session that is completely uninitialized. While there are other Session creation APIs in the
    * c-abi, WinML uses this so that it can perform optimizations prior to loading the model, and initializing.
    * Moreover, WinML needs a new api to support the OrtModel type, and prevent the parsing model protobufs again on session creation.
    */
  OrtStatus*(ORT_API_CALL* CreateSessionWithoutModel)(
    _In_ OrtEnv* env,
    _In_ const OrtSessionOptions* options,
    _In_ OrtThreadPool* inter_op_thread_pool,
    _In_ OrtThreadPool* intra_op_thread_pool,
    _Outptr_ OrtSession** session
  )NO_EXCEPTION;

  /**
    * SessionGetExecutionProvider
    * This api is used to get a handle to an OrtExecutionProvider.
    * Currently WinML uses this to talk directly to the DML EP and configure settings on it.
    */
  OrtStatus*(ORT_API_CALL* SessionGetExecutionProvider)(
    _In_ OrtSession* session, _In_ size_t index, _Out_ OrtExecutionProvider** provider
  )NO_EXCEPTION;

  /**
    * SessionInitialize
    * This api is used to initialize an OrtSession. This is one component of creating a usable OrtSession, and is a part of CreateSession in the c-abi.
    * Currently WinML uses this to finalize session creation, after configuring a variety of properties on the OrtSession.
    */
  OrtStatus*(ORT_API_CALL* SessionInitialize)(_In_ OrtSession* session)NO_EXCEPTION;

  /**
    * SessionRegisterGraphTransformers
    * This api is used to enable DML specific graph transformations on an OrtSession.
    *
    * Ideally these transformations should be configured by the contract between the runtime and the EP and not overridden by WinML.
    */
  OrtStatus*(ORT_API_CALL* SessionRegisterGraphTransformers)(_In_ OrtSession* session)NO_EXCEPTION;

  /**
    * SessionRegisterCustomRegistry
    * This api is used to support custom operators as they were shipped in WinML RS5.
    */
  OrtStatus*(ORT_API_CALL* SessionRegisterCustomRegistry)(_In_ OrtSession* session, _In_ IMLOperatorRegistry* registry)
    NO_EXCEPTION;

  /**
    * SessionLoadAndPurloinModel
    * This api is used to load an OrtModel into an OrtSession.
    *
    * Don't free the 'out' value as this API will defunct and release the OrtModel internally.
    */
  OrtStatus*(ORT_API_CALL* SessionLoadAndPurloinModel)(_In_ OrtSession* session, _In_ OrtModel* model)NO_EXCEPTION;

  /**
    * SessionStartProfiling
    * This api is used to start profiling OrtSession. The existing mechanism only allows configuring profiling at session creation.
    *
    * WinML uses this to toggle profilling on and off based on if a telemetry providers are being listened to.
    */
  OrtStatus*(ORT_API_CALL* SessionStartProfiling)(_In_ OrtEnv* env, _In_ OrtSession* session)NO_EXCEPTION;

  /**
    * SessionEndProfiling
    * This api is used to end profiling OrtSession. The existing mechanism only allows configuring profiling at session creation.
    *
    * WinML uses this to toggle profilling on and off based on if a telemetry providers are being listened to.
    */
  OrtStatus*(ORT_API_CALL* SessionEndProfiling)(_In_ OrtSession* session)NO_EXCEPTION;

  /**
    * SessionCopyOneInputAcrossDevices
    * This api is used to copy and create an OrtValue input to prepare the input on the correct device.
    *
    * WinML uses this to copy gpu device OrtValues to the CPU and vice-versa.
    */
  OrtStatus*(ORT_API_CALL* SessionCopyOneInputAcrossDevices)(
    _In_ OrtSession* session,
    _In_ const char* const input_name,
    _In_ OrtValue* orig_value,
    _Outptr_ OrtValue** new_value
  )NO_EXCEPTION;

  // Dml methods (TODO need to figure out how these need to move to session somehow...)

  /**
    * SessionGetNumberOfIntraOpThreads
    * This api returns the number of intra operator threads set on the OrtSession.
    *
    * WinML uses this to determine that the correct number of threads was set correctly through OrtSessionOptions.
    */
  OrtStatus*(ORT_API_CALL* SessionGetNumberOfIntraOpThreads)(_In_ OrtSession* session, _Out_ uint32_t* num_threads)
    NO_EXCEPTION;

  /**
    * SessionGetIntrapOpThreadSpinning
    * This api returns false if the ort session options config entry "session.intra_op.allow_spinning" is set to "0", and true otherwise
    *
    * WinML uses this to determine that the intra op thread spin policy was set correctly through OrtSessionOptions
    */
  OrtStatus*(ORT_API_CALL* SessionGetIntraOpThreadSpinning)(_In_ OrtSession* session, _Out_ bool* allow_spinning)
    NO_EXCEPTION;

  /**
    * SessionGetNamedDimensionsOverrides
    * This api returns the named dimension overrides that are specified for this session
    *
    * WinML uses this to determine that named dimension overrides were set correctly through OrtSessionOptions.
    */
  OrtStatus*(ORT_API_CALL* SessionGetNamedDimensionsOverrides)(
    _In_ OrtSession* session,
    _Out_ winrt::Windows::Foundation::Collections::IMapView<winrt::hstring, uint32_t>& overrides
  )NO_EXCEPTION;

  /**
    * DmlExecutionProviderFlushContext
    * This api is used to flush the DML EP.
    *
    * WinML communicates directly with DML to perform this as an optimization.
    */
  OrtStatus*(ORT_API_CALL* DmlExecutionProviderFlushContext)(_In_ OrtExecutionProvider* dml_provider)NO_EXCEPTION;

  /**
    * DmlExecutionProviderReleaseCompletedReferences
    * This api is used to release completed references after first run the DML EP.
    *
    * WinML communicates directly with DML to perform this as an optimization.
    */
  OrtStatus*(ORT_API_CALL* DmlExecutionProviderReleaseCompletedReferences)(_In_ OrtExecutionProvider* dml_provider
  )NO_EXCEPTION;

  /**
    * DmlCopyTensor
    * This api is used copy a tensor allocated by the DML EP Allocator to the CPU.
    *
    * WinML uses this when graphs are evaluated with DML, and their outputs remain on the GPU but need to be copied back to the CPU.
    */
  OrtStatus*(ORT_API_CALL* DmlCopyTensor)(_In_ OrtExecutionProvider* provider, _In_ OrtValue* src, _In_ OrtValue* dst)
    NO_EXCEPTION;

  /**
    * GetProviderMemoryInfo
    * This api gets the memory info object associated with an EP.
    *
    * WinML uses this to manage caller specified D3D12 inputs/outputs. It uses the memory info here to call DmlCreateGPUAllocationFromD3DResource.
    */
  OrtStatus*(ORT_API_CALL* GetProviderMemoryInfo)(_In_ OrtExecutionProvider* provider, OrtMemoryInfo** memory_info)
    NO_EXCEPTION;

  /**
    * GetProviderAllocator
    * This api gets associated allocator used by a provider.
    *
    * WinML uses this to create tensors, and needs to hold onto the allocator for the duration of the associated value's lifetime.
    */
  OrtStatus*(ORT_API_CALL* GetProviderAllocator)(
    _In_ OrtSession* session, _In_ OrtExecutionProvider* provider, OrtAllocator** allocator
  )NO_EXCEPTION;

  /**
    * FreeProviderAllocator
    * This api frees an allocator.
    *
    * WinML uses this to free the associated allocator for an ortvalue when creating tensors.
    * Internally this derefs a shared_ptr.
    */
  OrtStatus*(ORT_API_CALL* FreeProviderAllocator)(_In_ OrtAllocator* allocator)NO_EXCEPTION;

  /**
    * ExecutionProviderSync
    * This api syncs the EP.
    *
    * WinML uses this to sync EP inputs/outputs directly.
    */
  OrtStatus*(ORT_API_CALL* ExecutionProviderSync)(_In_ OrtExecutionProvider* provider)NO_EXCEPTION;

  /**
    * CreateCustomRegistry
    * This api creates a custom registry that callers can populate with custom ops.
    *
    * WinML uses this to support custom ops.
    */
  OrtStatus*(ORT_API_CALL* CreateCustomRegistry)(_Out_ IMLOperatorRegistry** registry)NO_EXCEPTION;

  /**
    * ValueGetDeviceId
    * This api returns the device id of the OrtValue.
    *
    * WinML uses this to determine if an OrtValue is created on the needed device.
    */
  OrtStatus*(ORT_API_CALL* ValueGetDeviceId)(_In_ OrtValue* ort_value, _Out_ int16_t* device_id)NO_EXCEPTION;

  /**
    * SessionGetInputRequiredDeviceId
    * This api returns the required device id for a model input.
    *
    * WinML uses this to determine if an OrtValue is created on the needed device.
    */
  OrtStatus*(ORT_API_CALL* SessionGetInputRequiredDeviceId)(
    _In_ OrtSession* session, _In_ const char* const input_name, _Out_ int16_t* device_id
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* CreateTensorTypeInfo)(
    _In_ const int64_t* shape, size_t shape_len, ONNXTensorElementDataType type, _Out_ OrtTypeInfo** type_info
  )NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* CreateSequenceTypeInfo)(_Out_ OrtTypeInfo** type_info)NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* CreateMapTypeInfo)(_Out_ OrtTypeInfo** type_info)NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* CreateModel)(_In_ int64_t opset, _Outptr_ OrtModel** out)NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* ModelAddInput)(
    _In_ OrtModel* model, _In_ const char* const input_name, _In_ OrtTypeInfo* info
  )NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* ModelAddConstantInput)(
    _In_ OrtModel* model, _In_ const char* const input_name, _In_ OrtTypeInfo* info, _In_ OrtValue* value
  )NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* ModelAddOutput)(
    _In_ OrtModel* model, _In_ const char* const output_name, _In_ OrtTypeInfo* info
  )NO_EXCEPTION;
  OrtStatus*(ORT_API_CALL* ModelAddOperator)(
    _In_ OrtModel* model,
    _In_ const char* const op_type,
    _In_ const char* const op_name,
    _In_ int64_t opset,
    _In_ const char* const op_domain,
    _In_ const char* const* input_names,
    _In_ size_t num_inputs,
    _In_ const char* const* output_names,
    _In_ size_t num_outputs,
    _In_ const char* const* attribute_names,
    _In_ OrtValue** attribute_values,
    _In_ size_t num_attributes
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* ModelGetOpsetVersion)(
    _In_ OrtModel* model, _In_ const char* const domain, _Out_ int32_t* version
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* OperatorGetNumInputs)(
    _In_ const char* const op_type, _In_ int64_t opset, _In_ const char* const op_domain, _Out_ size_t* num_inputs
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* OperatorGetInputName)(
    _In_ const char* const op_type,
    _In_ int64_t opset,
    _In_ const char* const op_domain,
    _In_ size_t index,
    _Out_ const char** const name
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* OperatorGetNumOutputs)(
    _In_ const char* const op_type, _In_ int64_t opset, _In_ const char* const op_domain, _Out_ size_t* num_inputs
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* OperatorGetOutputName)(
    _In_ const char* const op_type,
    _In_ int64_t opset,
    _In_ const char* const op_domain,
    _In_ size_t index,
    _Out_ const char** const name
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* JoinModels)(
    _In_ OrtModel* first_model,
    _In_ OrtModel* second_model,
    _In_ const char* const* output_names,
    _In_ const char* const* input_names,
    size_t num_linkages,
    bool promote_unlinked_outputs,
    _In_ const char* const join_node_prefix
  )NO_EXCEPTION;

  OrtStatus*(ORT_API_CALL* CreateThreadPool)(
    _In_ ThreadPoolType type, _In_ OrtThreadPoolOptions* params, _Outptr_ OrtThreadPool** out
  )NO_EXCEPTION;

  ORT_CLASS_RELEASE(Model);
  ORT_CLASS_RELEASE(ThreadPool);
};