Using HiDebug (C/C++)

HiDebug provides APIs for application debugging.

Available APIs

API	Description
OH_HiDebug_GetSystemCpuUsage	Obtains the CPU usage of the system.
OH_HiDebug_GetAppCpuUsage	Obtains the CPU usage of an application.
OH_HiDebug_GetAppThreadCpuUsage	Obtains the CPU usage of all threads of an application.
OH_HiDebug_FreeThreadCpuUsage	Releases the thread data structure.
OH_HiDebug_GetSystemMemInfo	Obtains system memory information.
OH_HiDebug_GetAppNativeMemInfo	Obtains the memory information of an application.
OH_HiDebug_GetAppMemoryLimit	Obtains the memory limit of an application.
OH_HiDebug_StartAppTraceCapture	Starts application trace collection.
OH_HiDebug_StopAppTraceCapture	Stops application trace collection.
OH_HiDebug_GetGraphicsMemory	Obtains the size of the GPU memory.

For details about how to use the APIs (such as parameter usage restrictions and value ranges), see HiDebug.

How to Develop

The following describes how to add a button in the application and click the button to call the HiDebug APIs.

1. Create a native C++ project. The directory structure is as follows:

   entry:
     src:
       main:
         cpp:
           - types:
               libentry:
                 - index.d.ts
           - CMakeLists.txt
           - napi_init.cpp
         ets:
           - entryability:
               - EntryAbility.ts
           - pages:
               - Index.ets
   

2. In the CMakeLists.txt file, add the dependencies.

   # Add libhiappevent_ndk.z.so and libhilog_ndk.z.so (log output). 
   target_link_libraries(entry PUBLIC libace_napi.z.so libhilog_ndk.z.so libohhidebug.so)
   

3. Import the dependencies to the napi_init.cpp file, and define LOG_TAG and the test method.

   The following calls OH_HiDebug_GetSystemCpuUsage() and outputs the return value. For details about how to use other APIs, see HiDebug.

   #include "napi/native_api.h"
   #include "hilog/log.h"
   #include "hidebug/hidebug.h"
   
   #undef LOG_TAG
   #define LOG_TAG "testTag"
   
   static napi_value TestHidebugNdk(napi_env env, napi_callback_info info)
   {
       double cpuUsage = OH_HiDebug_GetSystemCpuUsage();
       OH_LOG_INFO(LogType::LOG_APP, "GetSystemCpuUsage: %{public}f", cpuUsage);
       return 0;
   }
   

4. Register TestHidebugNdk as an ArkTS API.

   In the napi_init.cpp file, register TestHidebugNdk as an ArkTS API.

   static napi_value Init(napi_env env, napi_value exports)
   {
       napi_property_descriptor desc[] = {
           { "testHidebugNdk", nullptr, TestHidebugNdk, nullptr, nullptr, nullptr, napi_default, nullptr }
       };
       napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
       return exports;
   }
   

   In the index.d.ts file, define the ArkTS API.

   export const testHidebugNdk: () => void;
   

5. In the Index.ets file, add a click event to the Text component. The sample code is as follows:

   import testNapi from 'libentry.so'
   
   @Entry
   @Component
   struct Index {
     @State message: string = 'Hello World'
   
     build() {
       Row() {
         Column() {
           Text(this.message)
             .fontSize(50)
             .fontWeight(FontWeight.Bold)
             .onClick(testNapi.testHidebugNdk);// Add a click event to trigger testHidebugNdk().
         }
         .width('100%')
       }
       .height('100%')
     }
   }
   

6. Click the Run button in DevEco Studio to run the project, and click "Hello world".

7. At the bottom of DevEco Studio, switch to the Log tab and set the filter criteria to testTag. Then, the CPU usage logs obtained using OH_HiDebug_GetSystemCpuUsage() are displayed in the window.

   09-10 09:40:26.755 17221-17221/com.example.myapplication I A00000/testTag: GetSystemCpuUsage: 0.083904