@@ -15,15 +15,18 @@ Your application can call location-specific APIs to obtain the location informat
Location awareness helps determine where a mobile device locates. The system identifies the location of a mobile device with its coordinates, and uses location technologies such as Global Navigation Satellite System (GNSS) and network positioning (for example, base station positioning or WLAN/Bluetooth positioning) to provide diverse location-based services. These advanced location technologies make it possible to obtain the accurate location of the mobile device, regardless of whether it is indoors or outdoors.
-**Coordinate**
A coordinate describes a location on the earth using the longitude and latitude in reference to the World Geodetic Coordinate System 1984.
-**GNSS positioning**
GNSS positioning locates a mobile device by using the location algorithm offered by the device chip to compute the location information provided by the Global Navigation Satellite System, for example, GPS, GLONASS, BeiDou, and Galileo. Whichever positioning system will be used during the location process depends on a hardware capability of the device.
-**Base station positioning**
Base station positioning estimates the current location of a mobile device based on the location of the resident base station in reference to the neighboring base stations. This technology provides only a low accuracy and requires access to the cellular network.
-**WLAN or Bluetooth positioning**
WLAN or Bluetooth positioning estimates the current location of a mobile device based on the locations of WLANs and Bluetooth devices that can be discovered by the device. The location accuracy of this technology depends on the distribution of fixed WLAN access points (APs) and Bluetooth devices around the device. A high density of WLAN APs and Bluetooth devices can produce a more accurate location result than base station positioning. This technology also requires access to the network.
@@ -19,7 +19,7 @@ Applicable to: OpenHarmony SDK 3.2.2.5, stage model of API version 9
Applicable to: OpenHarmony SDK 3.2.2.5, stage model of API version 9
Error code 28 refers to **CURLE_OPERATION_TIMEDOUT**, which means a libcurl library operation timeout. For details, see any HTTP status code description available.
Error code 28 refers to **CURLE_OPERATION_TIMEDOUT**, which means a cURL operation timeout. For details, see any HTTP status code description available.
Reference: [Development Guide](https://gitee.com/openharmony/docs/blob/master/en/application-dev/reference/apis/js-apis-http.md#httpresponse) and [Curl Error Codes](https://curl.se/libcurl/c/libcurl-errors.html)
MindSpore Lite is an AI engine that provides AI model inference for different hardware devices. It has been used in a wide range of fields, such as image classification, target recognition, facial recognition, and character recognition.
This document describes the general development process for MindSpore Lite model inference.
## Basic Concepts
Before getting started, you need to understand the following basic concepts:
**Tensor**: a special data structure that is similar to arrays and matrices. It is basic data structure used in MindSpore Lite network operations.
**Float16 inference**: a mode in which Float16 is used for inference. Float16, also called half-precision, uses 16 bits to represent a number.
## Available APIs
APIs involved in MindSpore Lite model inference are categorized into context APIs, model APIs, and tensor APIs.
### Context APIs
| API | Description |
| ------------------ | ----------------- |
|OH_AI_ContextHandle OH_AI_ContextCreate()|Creates a context object.|
|void OH_AI_ContextSetThreadNum(OH_AI_ContextHandle context, int32_t thread_num)|Sets the number of runtime threads.|
| void OH_AI_ContextSetThreadAffinityMode(OH_AI_ContextHandle context, int mode)|Sets the affinity mode for binding runtime threads to CPU cores, which are categorized into little cores and big cores depending on the CPU frequency.|
|OH_AI_DeviceInfoHandle OH_AI_DeviceInfoCreate(OH_AI_DeviceType device_type)|Creates a runtime device information object.|
|void OH_AI_ContextDestroy(OH_AI_ContextHandle *context)|Destroys a context object.|
|void OH_AI_DeviceInfoSetEnableFP16(OH_AI_DeviceInfoHandle device_info, bool is_fp16)|Sets whether to enable float16 inference. This function is available only for CPU and GPU devices.|
|void OH_AI_ContextAddDeviceInfo(OH_AI_ContextHandle context, OH_AI_DeviceInfoHandle device_info)|Adds a runtime device information object.|
### Model APIs
| API | Description |
| ------------------ | ----------------- |
|OH_AI_ModelHandle OH_AI_ModelCreate()|Creates a model object.|
|OH_AI_Status OH_AI_ModelBuildFromFile(OH_AI_ModelHandle model, const char *model_path,OH_AI_ModelType odel_type, const OH_AI_ContextHandle model_context)|Loads and builds a MindSpore model from a model file.|
|void OH_AI_ModelDestroy(OH_AI_ModelHandle *model)|Destroys a model object.|
### Tensor APIs
| API | Description |
| ------------------ | ----------------- |
|OH_AI_TensorHandleArray OH_AI_ModelGetInputs(const OH_AI_ModelHandle model)|Obtains the input tensor array structure of a model.|
|int64_t OH_AI_TensorGetElementNum(const OH_AI_TensorHandle tensor)|Obtains the number of tensor elements.|
|const char *OH_AI_TensorGetName(const OH_AI_TensorHandle tensor)|Obtains the name of a tensor.|
|OH_AI_DataType OH_AI_TensorGetDataType(const OH_AI_TensorHandle tensor)|Obtains the tensor data type.|
|void *OH_AI_TensorGetMutableData(const OH_AI_TensorHandle tensor)|Obtains the pointer to variable tensor data.|
## How to Develop
The following figure shows the development process for MindSpore Lite model inference.
**Figure 1** Development process for MindSpore Lite model inference
The development process consists of the following main steps:
1. Prepare the required model.
The required model can be downloaded directly or obtained using the model conversion tool.
- If the downloaded model is in the `.ms` format, you can use it directly for inference. The following uses the **mobilenetv2.ms** model as an example.
- If the downloaded model uses a third-party framework, such as TensorFlow, TensorFlow Lite, Caffe, or ONNX, you can use the [model conversion tool](https://www.mindspore.cn/lite/docs/en/r1.5/use/benchmark_tool.html) to convert it to the `.ms` format.
2. Create a context, and set parameters such as the number of runtime threads and device type.
```c
// Create a context, and set the number of runtime threads to 2 and the thread affinity mode to 1 (big cores first).
OH_AI_ContextHandlecontext=OH_AI_ContextCreate();
if(context==NULL){
printf("OH_AI_ContextCreate failed.\n");
returnOH_AI_STATUS_LITE_ERROR;
}
constintthread_num=2;
OH_AI_ContextSetThreadNum(context,thread_num);
OH_AI_ContextSetThreadAffinityMode(context,1);
// Set the device type to CPU, and disable Float16 inference.
If the MindSpore Lite inference framework is no longer needed, you need to destroy the created model.
```c
// Destroy the model.
OH_AI_ModelDestroy(&model);
```
## Verification
1. Compile **CMakeLists.txt**.
```cmake
cmake_minimum_required(VERSION 3.14)
project(Demo)
add_executable(demo main.c)
target_link_libraries(
demo
mindspore-lite.huawei
pthread
dl
)
```
- To use ohos-sdk for cross compilation, you need to set the native toolchain path for the CMake tool as follows: `-DCMAKE_TOOLCHAIN_FILE="/xxx/ohos-sdk/linux/native/build/cmake/ohos.toolchain.cmake"`.
- The toolchain builds a 64-bit application by default. To build a 32-bit application, add the following configuration: `-DOHOS_ARCH="armeabi-v7a"`.
2. Run the CMake tool.
- Use hdc_std to connect to the RK3568 development board and put **demo** and **mobilenetv2.ms** to the same directory on the board.
- Run the hdc_std shell command to access the development board, go to the directory where **demo** is located, and run the following command:
```shell
./demo mobilenetv2.ms
```
The inference is successful if the output is similar to the following:
```shell
# ./QuickStart ./mobilenetv2.ms
Tensor name: Softmax-65, tensor size is 4004 ,elements num: 1001.
Provides system event logging APIs for system HAP applications.
> **NOTE**<br>
> **NOTE**
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
| info | [SysEventInfo](#syseventinfo) | Yes| System event information.|
| callback | AsyncCallback<void> | Yes| Callback used to process the received return value.<br>- Value **0**: The event verification is successful, and the event will be written to the event file asynchronously. <br>- A value greater than **0**: Invalid parameters are present in the event, and the event will be written to the event file asynchronously after the invalid parameters are ignored.<br>- A value smaller than **0**: The event parameter verification fails, and the event will not be written to the event file.|
...
...
@@ -91,13 +91,13 @@ Writes event information to the event file. This API uses a promise to return th
| Promise<void> | Promise used to return the result. Depending on whether event writing is successful, you can use the **then()** or **catch()** method to process the callback.|
| locale | string \| Array<string> | Yes | A string containing locale information, including the language, optional script, and region.|
| options | [RelativeTimeFormatInputOptions](#relativetimeformatinputoptions) | No | Options for creating a **RelativeTimeFormat** object. |
| options<sup>9+</sup> | [RelativeTimeFormatInputOptions](#relativetimeformatinputoptions9) | No | Options for creating a **RelativeTimeFormat** object. |
**Example**
```
...
...
@@ -710,7 +710,7 @@ Obtains the formatting options for **RelativeTimeFormat** objects.
Reports connection of the data network. This API uses an asynchronous callback to return the result.
Reports connection of the data network to the network management module. This API uses an asynchronous callback to return the result. If this API is called, the application considers that the network connection state (**ohos.net.connection.NetCap.NET_CAPABILITY_VAILDATED**) is inconsistent with that in the network management module.
**Permission required**: ohos.permission.GET_NETWORK_INFO and ohos.permission.INTERNET
Reports connection of the data network. This API uses a promise to return the result.
Reports connection of the data network to the network management module. This API uses a promise to return the result. If this API is called, the application considers that the network connection state (**ohos.net.connection.NetCap.NET_CAPABILITY_VAILDATED**) is inconsistent with that in the network management module.
**Permission required**: ohos.permission.GET_NETWORK_INFO and ohos.permission.INTERNET
Reports disconnection of the data network. This API uses an asynchronous callback to return the result.
Reports disconnection of the data network to the network management module. This API uses an asynchronous callback to return the result. If this API is called, the application considers that the network connection state (**ohos.net.connection.NetCap.NET_CAPABILITY_VAILDATED**) is inconsistent with that in the network management module.
**Permission required**: ohos.permission.GET_NETWORK_INFO and ohos.permission.INTERNET
Reports disconnection of the data network. This API uses a promise to return the result.
Reports disconnection of the data network to the network management module. This API uses a promise to return the result. If this API is called, the application considers that the network connection state (**ohos.net.connection.NetCap.NET_CAPABILITY_VAILDATED**) is inconsistent with that in the network management module.
**Permission required**: ohos.permission.GET_NETWORK_INFO and ohos.permission.INTERNET
Obtains the handle of the network specified by **netSpecifier**.
Creates a **NetConnection** object. **netSpecifier** specifies the network, and **timeout** specifies the timeout interval in ms. **timeout** is configurable only when **netSpecifier** is specified. If neither of them is present, the default network is used.
| NET_CAPABILITY_MMS | 0 | The network can connect to the carrier's Multimedia Messaging Service Center (MMSC) to send and receive multimedia messages.|
| NET_CAPABILITY_NOT_METERED | 11 | The network traffic is not metered.|
| NET_CAPABILITY_INTERNET | 12 | The network can connect to the Internet.|
| NET_CAPABILITY_INTERNET | 12 | The network has the Internet access capability, which is set by the network provider.|
| NET_CAPABILITY_NOT_VPN | 15 | The network does not use a Virtual Private Network (VPN).|
| NET_CAPABILITY_VALIDATED | 16 | The network is available. |
| NET_CAPABILITY_VALIDATED | 16 | The Internet access capability of the network is successfully verified by the network management module. |
Enables listening for the **message** events of a WebSocket connection. This API uses an asynchronous callback to return the result.
Enables listening for the **message** events of a WebSocket connection. This API uses an asynchronous callback to return the result. The maximum length of each message is 4 KB. If the length exceeds 4 KB, the message is automatically fragmented.
Disables listening for the **message** events of a WebSocket connection. This API uses an asynchronous callback to return the result.
Disables listening for the **message** events of a WebSocket connection. This API uses an asynchronous callback to return the result. The maximum length of each message is 4 KB. If the length exceeds 4 KB, the message is automatically fragmented.
@@ -163,6 +163,22 @@ By parsing the <strong>*.cfg</strong> file, you can obtain **service** fields, a
| int StartServiceByTimer(const char *serviceName, uint64_t timeout) | Starts a service by timer.| Return value: Returns **0** if the operation is successful; returns **-1** otherwise.<br> Arguments:<br> **serviceName**: service name.<br> timeout: timeout interval.|
| int StopServiceTimer(const char *serviceName) | Stops a service timer.| Return value: Returns **0** if the operation is successful; returns **-1** otherwise.<br> Arguments:<br> **serviceName**: service name.|
- DAC configuration for service control APIs
Go to **/base/startup/init/services/etc/group** and add the correct user ID to **servicectrl**. For example:
Add the required SELinux permissions to the **init.te** file. For example, grant the system parameter write permission for services such as **init**, **samgr**, and **hdf_devmgr**.
@@ -98,6 +98,55 @@ Each subsystem defines the system parameters of its own modules, including the s
- SELinux policy for system parameter configuration
- Add SELinux tags.
To add a SELinux tag to system parameters, you first need to define the tag in the **/base/security/selinux/sepolicy/base/public/parameter.te** file. For example:
```java
type servicectrl_param, parameter_attr
```
After the tag is defined, add the system parameter prefix associated with the tag to **/base/security/selinux/sepolicy/base/public/parameter_contexts**. The following uses the prefix **ohos.servicectrl** as an example:
```java
ohos.servicectrl. u:object_r:servicectrl_param:s0
```
- Grant operation permissions. For example, to grant operation permissions such as map for the init process, add the following content to the **/base/security/selinux/sepolicy/ohos_policy/startup/init/public/init.te** file:
Keep only two system parameter tags for each subsystem:
- A private tag to control system parameter settings.
- A public tag to grant access from all services.
- Loading sequence
The following table provides the sequence of loading system parameters.
...
...
@@ -111,6 +160,22 @@ Each subsystem defines the system parameters of its own modules, including the s
| System parameters| /system/etc/param/*.para | Load the parameters defined by each subsystem. If a system parameter already exists, ignore it.|
| Persistent parameters| /data/parameters/ | If persistent parameters exist, load them at last. Persistent parameters will overwrite the default system parameters that have been loaded.|
#### System Parameter Tag File Size
If one tag corresponds to more than five system parameters, you need to set the size of the system parameter tag file in **/base/startup/init/services/etc/param/ohos.para.size**. The size value is **512** by default.
Configuring rule:
System parameter tag = Size
Example:
```java
startup_init_param=40960
```
### Constraints
The service management module is available only for the mini system and standard system.
