/* * Copyright (C) 2020 The Android Open Source Project * * Licensed 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. */ #ifndef ANDROID_FRAMEWORKS_ML_NN_COMMON_NNAPI_IDEVICE_H #define ANDROID_FRAMEWORKS_ML_NN_COMMON_NNAPI_IDEVICE_H #include #include #include #include #include "nnapi/Result.h" #include "nnapi/Types.h" namespace android::nn { // Forward declarations class IBuffer; class IPreparedModel; /** * This interface represents a device driver. * * This interface is thread-safe, and any class that implements this interface must be thread-safe. */ class IDevice { public: /** * Returns the name of the driver. * * @return Name of the driver. */ virtual const std::string& getName() const = 0; /** * Get the version string of the driver implementation. * * The version string must be a unique token among the set of version strings of drivers of a * specific device. The token identifies the device driver's implementation. The token must not * be confused with the feature level which is solely defined by the interface version. This API * is opaque to the Android framework, but the Android framework may use the information for * debugging or to pass on to NNAPI applications. * * Application developers sometimes have specific requirements to ensure good user experiences, * and they need more information to make intelligent decisions when the Android framework * cannot. For example, combined with the device name and other information, the token can help * NNAPI applications filter devices based on their needs: * - An application demands a certain level of performance, but a specific version of the driver * cannot meet that requirement because of a performance regression. The application can * disallow the driver based on the version provided. * - An application has a minimum precision requirement, but certain versions of the driver * cannot meet that requirement because of bugs or certain optimizations. The application can * filter out versions of these drivers. * * @return version The version string of the device implementation. Must have nonzero length. */ virtual const std::string& getVersionString() const = 0; /** * Returns the feature level of a driver. * * @return featureLevel The Version of the NNAPI specification this driver implements. * See {@link ANeuralNetworks_getFeatureLevel} and {@link FeatureLevelCode} * for NNAPI specification versioning information. */ virtual Version getFeatureLevel() const = 0; /** * Returns the device type of a driver. * * The device type can be used to help application developers to distribute Machine Learning * workloads and other workloads such as graphical rendering. E.g., for an app which renders AR * scenes based on real time object detection results, the developer could choose an ACCELERATOR * type device for ML workloads, and reserve GPU for graphical rendering. * * @return type The DeviceType of the device. Please note, this is not a bitfield of * DeviceTypes. Each device must only be of a single DeviceType. */ virtual DeviceType getType() const = 0; /** * Gets information about extensions supported by the driver implementation. * * Extensions of category ExtensionCategory::BASE must not appear in the list. * * All extension operations and operands must be fully supported for the extension to appear in * the list of supported extensions. * * @return extensions A list of supported extensions. */ virtual const std::vector& getSupportedExtensions() const = 0; /** * Gets the capabilities of a driver. * * @return capabilities Capabilities of the driver. */ virtual const Capabilities& getCapabilities() const = 0; /** * Gets the caching requirements of the driver implementation. * * There are two types of cache file descriptors provided to the driver: model cache and data * cache. * * The data cache is for caching constant data, possibly including preprocessed and transformed * tensor buffers. Any modification to the data cache should have no worse effect than * generating bad output values at execution time. * * The model cache is for caching security-sensitive data such as compiled executable machine * code in the device's native binary format. A modification to the model cache may affect the * driver's execution behavior, and a malicious client could make use of this to execute beyond * the granted permission. Thus, the driver must always check whether the model cache is * corrupted before preparing the model from cache. * * IDevice::getNumberOfCacheFilesNeeded returns how many of each type of cache files the driver * implementation needs to cache a single prepared model. Returning 0 for both types indicates * compilation caching is not supported by this driver. The driver may still choose not to cache * certain compiled models even if it reports that caching is supported. * * If the device reports that caching is not supported, the user may avoid calling * IDevice::prepareModelFromCache or providing cache file descriptors to IDevice::prepareModel. * * @return A pair of: * - numModelCache An unsigned integer indicating how many files for model cache the driver * needs to cache a single prepared model. It must be less than or equal to * ::android::nn::kMaxNumberOfCacheFiles. * - numDataCache An unsigned integer indicating how many files for data cache the driver * needs to cache a single prepared model. It must be less than or equal to * ::android::nn::kMaxNumberOfCacheFiles. */ virtual std::pair getNumberOfCacheFilesNeeded() const = 0; /** * Blocks until the device is not in a bad state. * * @return Nothing on success, otherwise GeneralError. */ virtual GeneralResult wait() const = 0; /** * Gets the supported operations in a model. * * IDevice::getSupportedOperations indicates which operations of the top-level subgraph are * fully supported by the vendor driver. If an operation may not be supported for any reason, * IDevice::getSupportedOperations must return `false` for that operation. * * The {@link OperationType::IF} and {@link OperationType::WHILE} operations may only be fully * supported if the vendor driver fully supports all operations in the referenced subgraphs. * * @param model A Model whose operations--and their corresponding operands--are to be verified * by the driver. * @return supportedOperations A list of supported operations, where `true` indicates the * operation is supported and `false` indicates the operation is not supported. The index of * "supported" corresponds with the index of the operation it is describing. */ virtual GeneralResult> getSupportedOperations(const Model& model) const = 0; /** * Creates a prepared model for execution. * * IDevice::prepareModel is used to make any necessary transformations or alternative * representations to a model for execution, possibly including transformations on the constant * data, optimization on the model's graph, or compilation into the device's native binary * format. The model itself is not changed. * * Optionally, caching information may be provided for the driver to save the prepared model to * cache files for faster model compilation time when the same model preparation is requested in * the future. There are two types of cache file handles provided to the driver: model cache and * data cache. For more information on the two types of cache handles, refer to * IDevice::getNumberOfCacheFilesNeeded. * * The file descriptors must be opened with read and write permission. A file may have any size, * and the corresponding file descriptor may have any offset. The driver must truncate a file to * zero size before writing to that file. The file descriptors may be closed by the client once * the preparation has finished. The driver must dup a file descriptor if it wants to get access * to the cache file later. * * IDevice::prepareModel must verify its inputs related to preparing the model (as opposed to * saving the prepared model to cache) are correct. If there is an error, IDevice::prepareModel * must immediately return {@link ErrorStatus::INVALID_ARGUMENT} as a GeneralError. If the * inputs to IDevice::prepareModel are valid and there is no error, IDevice::prepareModel must * prepare the model. * * The model is prepared with a priority. This priority is relative to other prepared models * owned by the same client. Higher priority executions may use more compute resources than * lower priority executions, and may preempt or starve lower priority executions. * * IDevice::prepareModel can be called with an optional deadline. If the model is not able to be * prepared before the provided deadline, the model preparation may be aborted, and either * {@link ErrorStatus::MISSED_DEADLINE_TRANSIENT} or {@link * ErrorStatus::MISSED_DEADLINE_PERSISTENT} may be returned as a GeneralError. * * Optionally, the driver may save the prepared model to cache during the preparation. Any error * that occurs when saving to cache must not affect the status of preparing the model. Even if * the input arguments related to the cache may be invalid, or the driver may fail to save to * cache, IDevice::prepareModel must finish preparing the model. The driver may choose not to * save to cache even if the caching information is provided and valid. * * The only information that may be unknown to the model at this stage is the shape of the * tensors, which may only be known at execution time. As such, some driver services may return * partially prepared models, where the prepared model may only be finished when it is paired * with a set of inputs to the model. Note that the same prepared model object may be used with * different shapes of inputs on different (possibly concurrent) executions. * * @param model The model to be prepared for execution. * @param preference Indicates the intended execution behavior of a prepared model. * @param priority Priority of the prepared model relative to other prepared models owned by an * application. * @param deadline Optional time point. If provided, prepareModel is expected to complete by * this time point. If it is not able to be completed by the deadline, the execution may be * aborted. * @param modelCache A vector of handles with each entry holding exactly one cache file * descriptor for the security-sensitive cache. The length of the vector must either be 0 * indicating that caching information is not provided, or match numModelCache returned from * IDevice::getNumberOfCacheFilesNeeded. The cache handles will be provided in the same * order when retrieving the preparedModel from cache files with * IDevice::prepareModelFromCache. * @param dataCache A vector of handles with each entry holding exactly one cache file * descriptor for the constants' cache. The length of the vector must either be 0 indicating * that caching information is not provided, or match numDataCache returned from * IDevice::getNumberOfCacheFilesNeeded. The cache handles will be provided in the same * order when retrieving the preparedModel from cache files with * IDevice::prepareModelFromCache. * @param token An caching token of length ::android::nn::kByteSizeOfCacheToken identifying the * prepared model. The same token will be provided when retrieving the prepared model from * the cache files with IDevice::prepareModelFromCache. Tokens should be chosen to have a * low rate of collision for a particular application. The driver cannot detect a collision; * a collision will result in a failed execution or in a successful execution that produces * incorrect output values. If both modelCache and dataCache are empty indicating that * caching information is not provided, this token must be ignored. * @return preparedModel An IPreparedModel object representing a model that has been prepared * for execution, otherwise GeneralError. */ virtual GeneralResult prepareModel( const Model& model, ExecutionPreference preference, Priority priority, OptionalTimePoint deadline, const std::vector& modelCache, const std::vector& dataCache, const CacheToken& token) const = 0; /** * Creates a prepared model from cache files for execution. * * IDevice::prepareModelFromCache is used to retrieve a prepared model directly from cache files * to avoid slow model compilation time. There are two types of cache file handles provided to * the driver: model cache and data cache. For more information on the two types of cache * handles, refer to IDevice::getNumberOfCacheFilesNeeded. * * The file descriptors must be opened with read and write permission. A file may have any size, * and the corresponding file descriptor may have any offset. The driver must truncate a file to * zero size before writing to that file. The file descriptors may be closed by the client once * the preparation has finished. The driver must dup a file descriptor if it wants to get access * to the cache file later. * * IDevice::prepareModelFromCache must verify its inputs are correct, and that the * security-sensitive cache has not been modified since it was last written by the driver. If * there is an error, or if compilation caching is not supported, or if the security-sensitive * cache has been modified, IDevice::prepareModelFromCache must immediately return {@link * ErrorStatus::INVALID_ARGUMENT} as a GeneralError. If the inputs to * IDevice::prepareModelFromCache are valid, the security-sensitive cache is not modified, and * there is no error, IDevice::prepareModelFromCache must prepare the model * * IDevice::prepareModelFromCache can be called with an optional deadline. If the model is not * able to prepared before the provided deadline, the model preparation may be aborted, and * either {@link ErrorStatus::MISSED_DEADLINE_TRANSIENT} or {@link * ErrorStatus::MISSED_DEADLINE_PERSISTENT} may be returned as a GeneralError. * * The only information that may be unknown to the model at this stage is the shape of the * tensors, which may only be known at execution time. As such, some driver services may return * partially prepared models, where the prepared model may only be finished when it is paired * with a set of inputs to the model. Note that the same prepared model object may be used with * different shapes of inputs on different (possibly concurrent) executions. * * @param deadline Optional time point. If provided, prepareModel is expected to complete by * this time point. If it is not able to be completed by the deadline, the execution may be * aborted. * @param modelCache A vector of handles with each entry holding exactly one cache file * descriptor for the security-sensitive cache. The length of the vector must match the * numModelCache returned from IDevice::getNumberOfCacheFilesNeeded. The cache handles will * be provided in the same order as with IDevice::prepareModel. * @param dataCache A vector of handles with each entry holding exactly one cache file * descriptor for the constants' cache. The length of the vector must match the numDataCache * returned from IDevice::getNumberOfCacheFilesNeeded. The cache handles will be provided in * the same order as with IDevice::prepareModel. * @param token A caching token of length ::android::nn::kByteSizeOfCacheToken identifying the * prepared model. It is the same token provided when saving the cache files with * IDevice::prepareModel. Tokens should be chosen to have a low rate of collision for a * particular application. The driver cannot detect a collision; a collision will result in * a failed execution or in a successful execution that produces incorrect output values. * @return preparedModel An IPreparedModel object representing a model that has been prepared * for execution, otherwise GeneralError. */ virtual GeneralResult prepareModelFromCache( OptionalTimePoint deadline, const std::vector& modelCache, const std::vector& dataCache, const CacheToken& token) const = 0; /** * Allocates a driver-managed buffer with the properties specified by the descriptor as well as * the input and output roles of prepared models. * * IDevice::allocate must verify its inputs are correct. If there is an error, or if a certain * role or property is not supported by the driver, IDevice::allocate must return with {@link * ErrorStatus::INVALID_ARGUMENT} as a GeneralError. If the allocation is successful, this * method must return the produced IBuffer. A successful allocation must accommodate all of the * specified roles and buffer properties. * * The buffer is allocated as an uninitialized state. An uninitialized buffer may only be used * in ways that are specified by outputRoles. A buffer is initialized after it is used as an * output in a successful execution, or after a successful invocation of IBuffer::copyFrom on * the buffer. An initialized buffer may be used according to all roles specified in inputRoles * and outputRoles. A buffer will return to the uninitialized state if it is used as an output * in a failed execution, or after a failed invocation of IBuffer::copyFrom on the buffer. * * The driver may deduce the dimensions of the buffer according to the buffer descriptor as well * as the input and output roles. The dimensions or rank of the buffer may be unknown at this * stage. As such, some driver services may only create a placeholder and defer the actual * allocation until execution time. Note that the same buffer may be used for different shapes * of outputs on different executions. When the buffer is used as an input, the input shape must * be the same as the output shape from the last execution using this buffer as an output. * * The driver must apply proper validatation upon every usage of the buffer, and fail the * execution immediately if the usage is illegal. * * @param desc A buffer descriptor specifying the properties of the buffer to allocate. * @param preparedModels A vector of IPreparedModel objects. Must only contain IPreparedModel * objects from the same IDevice as this method invoked on. * @param inputRoles A vector of roles with each specifying an input to a prepared model. * @param outputRoles A vector of roles with each specifying an output to a prepared model. * Each role specified in inputRoles and outputRoles must be unique. The corresponding model * operands of the roles must have the same OperandType, scale, zero point, and ExtraParams. * The dimensions of the operands and the dimensions specified in the buffer descriptor must * be compatible with each other. Two dimensions are incompatible if there is at least one * axis that is fully specified in both but has different values. * @return The allocated IBuffer object. If the buffer was unable to be allocated due to an * error, a GeneralError is returned instead. */ virtual GeneralResult allocate( const BufferDesc& desc, const std::vector& preparedModels, const std::vector& inputRoles, const std::vector& outputRoles) const = 0; // Public virtual destructor to allow objects to be stored (and destroyed) as smart pointers. // E.g., std::unique_ptr. virtual ~IDevice() = default; protected: // Protect the non-destructor special member functions to prevent object slicing. IDevice() = default; IDevice(const IDevice&) = default; IDevice(IDevice&&) noexcept = default; IDevice& operator=(const IDevice&) = default; IDevice& operator=(IDevice&&) noexcept = default; }; } // namespace android::nn #endif // ANDROID_FRAMEWORKS_ML_NN_COMMON_NNAPI_IDEVICE_H