1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_ML_NN_RUNTIME_VERSIONED_IDEVICE_H
18 #define ANDROID_ML_NN_RUNTIME_VERSIONED_IDEVICE_H
19 
20 #include "HalInterfaces.h"
21 
22 #include <android-base/macros.h>
23 #include <string>
24 #include <tuple>
25 
26 namespace android {
27 namespace nn {
28 
29 /**
30  * This object is either a V1_1::IDevice or V1_0::IDevice object. This class
31  * abstracts away version differences, allowing the remainder of the runtime to
32  * always use the most up-to-date version of all HIDL types. As such, any
33  * reference to a HIDL type in the rest of the runtime will--by default--be the
34  * latest HIDL version.
35  *
36  * This class will attempt to call the latest version of each interface method
37  * if possible. If the latest method is unavailable, the VersionedIDevice class
38  * will attempt to upcast the type (e.g., V1_1::Model to V1_0::Model), and
39  * invoke the latest interface method possible. If the VersionedIDevice class
40  * fails to find a matching applicable function, it will return an error.
41  */
42 class VersionedIDevice {
43     DISALLOW_IMPLICIT_CONSTRUCTORS(VersionedIDevice);
44 public:
45     /**
46      * Constructor for the VersionedIDevice object.
47      *
48      * VersionedIDevice is constructed with the V1_0::IDevice object, which
49      * represents a device that is at least v1.0 of the interface. The
50      * constructor downcasts to the latest version of the IDevice interface, and
51      * will default to using the latest version of all IDevice interface
52      * methods automatically.
53      *
54      * @param device A device object that is least version 1.0 of the IDevice
55      *               interface.
56      */
57     VersionedIDevice(sp<V1_0::IDevice> device);
58 
59     /**
60      * Gets the capabilities of a driver.
61      *
62      * @return status Error status of the call, must be:
63      *                - NONE if successful
64      *                - DEVICE_UNAVAILABLE if driver is offline or busy
65      *                - GENERAL_FAILURE if there is an unspecified error
66      * @return capabilities Capabilities of the driver.
67      */
68     std::pair<ErrorStatus, Capabilities> getCapabilities();
69 
70     /**
71      * Gets the supported operations in a model.
72      *
73      * getSupportedSubgraph indicates which operations of a model are fully
74      * supported by the vendor driver. If an operation may not be supported for
75      * any reason, getSupportedOperations must return false for that operation.
76      *
77      * @param model A model whose operations--and their corresponding
78      *              operands--are to be verified by the driver.
79      * @return status Error status of the call, must be:
80      *                - NONE if successful
81      *                - DEVICE_UNAVAILABLE if driver is offline or busy
82      *                - GENERAL_FAILURE if there is an unspecified error
83      *                - INVALID_ARGUMENT if provided model is invalid
84      * @return supportedOperations A list of supported operations, where true
85      *                             indicates the operation is supported and
86      *                             false indicates the operation is not
87      *                             supported. The index of "supported"
88      *                             corresponds with the index of the operation
89      *                             it is describing.
90      */
91     std::pair<ErrorStatus, hidl_vec<bool>> getSupportedOperations(const Model& model);
92 
93     /**
94      * Creates a prepared model for execution.
95      *
96      * prepareModel is used to make any necessary transformations or alternative
97      * representations to a model for execution, possiblly including
98      * transformations on the constant data, optimization on the model's graph,
99      * or compilation into the device's native binary format. The model itself
100      * is not changed.
101      *
102      * The model is prepared asynchronously with respect to the caller. The
103      * prepareModel function must verify the inputs to the prepareModel function
104      * are correct. If there is an error, prepareModel must immediately invoke
105      * the callback with the appropriate ErrorStatus value and nullptr for the
106      * IPreparedModel, then return with the same ErrorStatus. If the inputs to
107      * the prepareModel function are valid and there is no error, prepareModel
108      * must launch an asynchronous task to prepare the model in the background,
109      * and immediately return from prepareModel with ErrorStatus::NONE. If the
110      * asynchronous task fails to launch, prepareModel must immediately invoke
111      * the callback with ErrorStatus::GENERAL_FAILURE and nullptr for the
112      * IPreparedModel, then return with ErrorStatus::GENERAL_FAILURE.
113      *
114      * When the asynchronous task has finished preparing the model, it must
115      * immediately invoke the callback function provided as an input to
116      * prepareModel. If the model was prepared successfully, the callback object
117      * must be invoked with an error status of ErrorStatus::NONE and the
118      * produced IPreparedModel object. If an error occurred preparing the model,
119      * the callback object must be invoked with the appropriate ErrorStatus
120      * value and nullptr for the IPreparedModel.
121      *
122      * The only information that may be unknown to the model at this stage is
123      * the shape of the tensors, which may only be known at execution time. As
124      * such, some driver services may return partially prepared models, where
125      * the prepared model can only be finished when it is paired with a set of
126      * inputs to the model. Note that the same prepared model object can be
127      * used with different shapes of inputs on different (possibly concurrent)
128      * executions.
129      *
130      * Multiple threads can call prepareModel on the same model concurrently.
131      *
132      * @param model The model to be prepared for execution.
133      * @param callback A callback object used to return the error status of
134      *                 preparing the model for execution and the prepared model
135      *                 if successful, nullptr otherwise. The callback object's
136      *                 notify function must be called exactly once, even if the
137      *                 model could not be prepared.
138      * @return status Error status of launching a task which prepares the model
139      *                in the background; must be:
140      *                - NONE if preparation task is successfully launched
141      *                - DEVICE_UNAVAILABLE if driver is offline or busy
142      *                - GENERAL_FAILURE if there is an unspecified error
143      *                - INVALID_ARGUMENT if one of the input arguments is
144      *                  invalid
145      */
146     ErrorStatus prepareModel(const Model& model, ExecutionPreference preference,
147                              const sp<IPreparedModelCallback>& callback);
148 
149     /**
150      * Returns the current status of a driver.
151      *
152      * @return status Status of the driver, one of:
153      *                - DeviceStatus::AVAILABLE
154      *                - DeviceStatus::BUSY
155      *                - DeviceStatus::OFFLINE
156      *                - DeviceStatus::UNKNOWN
157      */
158     DeviceStatus getStatus();
159 
160     /**
161      * Returns whether this handle to an IDevice object is valid or not.
162      *
163      * @return bool true if V1_0::IDevice (which could be V1_1::IDevice) is
164      *              valid, false otherwise.
165      */
166     bool operator!=(nullptr_t);
167 
168     /**
169      * Returns whether this handle to an IDevice object is valid or not.
170      *
171      * @return bool true if V1_0::IDevice (which could be V1_1::IDevice) is
172      *              invalid, false otherwise.
173      */
174     bool operator==(nullptr_t);
175 
176 private:
177     /**
178      * Both versions of IDevice are necessary because the driver could be v1.0,
179      * v1.1, or a later version. These two pointers logically represent the same
180      * object.
181      *
182      * The general strategy is: HIDL returns a V1_0 device object, which
183      * (if not nullptr) could be v1.0, v1.1, or a greater version. The V1_0
184      * object is then "dynamically cast" to a V1_1 object. If successful,
185      * mDeviceV1_1 will point to the same object as mDeviceV1_0; otherwise,
186      * mDeviceV1_1 will be nullptr.
187      *
188      * In general:
189      * * If the device is truly v1.0, mDeviceV1_0 will point to a valid object
190      *   and mDeviceV1_1 will be nullptr.
191      * * If the device is truly v1.1 or later, both mDeviceV1_0 and mDeviceV1_1
192      *   will point to the same valid object.
193      *
194      * Idiomatic usage: if mDeviceV1_1 is non-null, do V1_1 dispatch; otherwise,
195      * do V1_0 dispatch.
196      */
197     sp<V1_0::IDevice> mDeviceV1_0;
198     sp<V1_1::IDevice> mDeviceV1_1;
199 };
200 
201 }  // namespace nn
202 }  // namespace android
203 
204 #endif  // ANDROID_ML_NN_RUNTIME_VERSIONED_IDEVICE_H
205