1# Using HiDebug (C/C++) 2 3HiDebug provides APIs for application debugging. 4 5## Available APIs 6| API | Description | 7| ------------------------------- | --------------------------------- | 8| OH_HiDebug_GetSystemCpuUsage | Obtains the CPU usage of the system.| 9| OH_HiDebug_GetAppCpuUsage | Obtains the CPU usage of an application. | 10| OH_HiDebug_GetAppThreadCpuUsage | Obtains the CPU usage of all threads of an application. | 11| OH_HiDebug_FreeThreadCpuUsage | Releases the thread data structure. | 12| OH_HiDebug_GetSystemMemInfo | Obtains system memory information. | 13| OH_HiDebug_GetAppNativeMemInfo | Obtains the memory information of an application. | 14| OH_HiDebug_GetAppMemoryLimit | Obtains the memory limit of an application. | 15| OH_HiDebug_StartAppTraceCapture | Starts application trace collection. | 16| OH_HiDebug_StopAppTraceCapture | Stops application trace collection. | 17 18For details about how to use the APIs (such as parameter usage restrictions and value ranges), see [HiDebug](../reference/apis-performance-analysis-kit/_hi_debug.md). 19 20## How to Develop 21The following describes how to add a button in the application and click the button to call the HiDebug APIs. 22 231. Create a native C++ project. The directory structure is as follows: 24 25 ```yml 26 entry: 27 src: 28 main: 29 cpp: 30 - types: 31 libentry: 32 - index.d.ts 33 - CMakeLists.txt 34 - napi_init.cpp 35 ets: 36 - entryability: 37 - EntryAbility.ts 38 - pages: 39 - Index.ets 40 ``` 41 422. In the **CMakeLists.txt** file, add the dependencies. 43 44 ```cmake 45 # Add libhiappevent_ndk.z.so and libhilog_ndk.z.so (log output). 46 target_link_libraries(entry PUBLIC libace_napi.z.so libhilog_ndk.z.so libohhidebug.so) 47 ``` 48 493. Import the dependencies to the **napi_init.cpp** file, and define **LOG_TAG** and the test method. 50 51 The following calls **OH_HiDebug_GetSystemCpuUsage()** and outputs the return value. For details about how to use other APIs, see [HiDebug](../reference/apis-performance-analysis-kit/_hi_debug.md). 52 53 ```c++ 54 #include "napi/native_api.h" 55 #include "hilog/log.h" 56 #include "hidebug/hidebug.h" 57 58 #undef LOG_TAG 59 #define LOG_TAG "testTag" 60 61 static napi_value TestHidebugNdk(napi_env env, napi_callback_info info) 62 { 63 double cpuUsage = OH_HiDebug_GetSystemCpuUsage(); 64 OH_LOG_INFO(LogType::LOG_APP, "GetSystemCpuUsage: %{public}f", cpuUsage); 65 return 0; 66 } 67 ``` 68 694. Register **TestHidebugNdk** as an ArkTS API. 70 71 In the **napi_init.cpp** file, register **TestHidebugNdk** as an ArkTS API. 72 73 ```c++ 74 static napi_value Init(napi_env env, napi_value exports) 75 { 76 napi_property_descriptor desc[] = { 77 { "testHidebugNdk", nullptr, TestHidebugNdk, nullptr, nullptr, nullptr, napi_default, nullptr } 78 }; 79 napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); 80 return exports; 81 } 82 ``` 83 84 In the **index.d.ts** file, define the ArkTS API. 85 86 ```typescript 87 export const testHidebugNdk: () => void; 88 ``` 89 905. In the **Index.ets** file, add a click event to the **Text** component. The sample code is as follows: 91 92 ```ts 93 import testNapi from 'libentry.so' 94 95 @Entry 96 @Component 97 struct Index { 98 @State message: string = 'Hello World' 99 100 build() { 101 Row() { 102 Column() { 103 Text(this.message) 104 .fontSize(50) 105 .fontWeight(FontWeight.Bold) 106 .onClick(testNapi.testHidebugNdk);// Add a click event to trigger testHidebugNdk(). 107 } 108 .width('100%') 109 } 110 .height('100%') 111 } 112 } 113 ``` 114 1156. Click the **Run** button in DevEco Studio to run the project, and click "Hello world". 116 1177. At the bottom of DevEco Studio, switch to the **Log** tab and set the filter criteria to **testTag**. 118 Then, the CPU usage logs obtained using **OH_HiDebug_GetSystemCpuUsage()** are displayed in the window. 119 120 ```Text 121 09-10 09:40:26.755 17221-17221/com.example.myapplication I A00000/testTag: GetSystemCpuUsage: 0.083904 122 ``` 123