Using HiDebug (ArkTS)

HiDebug provides multiple methods for debugging and profiling applications. With these methods, you can obtain memory, CPU, GPU, and GC data, collect process trace and profiler data, and dump VM heap snapshots. Since most APIs of this module are both performance-consuming and time-consuming, and are defined based on the HiDebug module, you are advised to use these APIs only during the application debugging and profiling phases. If the APIs are required in other scenarios, evaluate the impact of the APIs on application performance.

Available APIs

API	Description
hidebug.getNativeHeapSize	Obtains the size of heap memory (including the allocator metadata) held by a process, which is measured by the memory allocator.
hidebug.getNativeHeapAllocatedSize	Obtains the size of the heap memory allocated to a process service, which is measured by the memory allocator.
hidebug.getNativeHeapFreeSize	Obtains the size of the cache memory held by the memory allocator.
hidebug.getPss	Obtains the size of the physical memory actually used by the application process.
hidebug.getVss	Obtains the virtual set size used by the application process.
hidebug.getSharedDirty	Obtains the size of the shared dirty memory of a process.
hidebug.getPrivateDirty	Obtains the size of the private dirty memory of a process.
hidebug.getCpuUsage	Obtains the CPU usage of a process.
hidebug.getServiceDump	Obtains system service information.
hidebug.dumpJsHeapData	Exports the heap data.
hidebug.startJsCpuProfiling	Starts the VM profiling method.
hidebug.stopJsCpuProfiling	Stops the VM profiling method.
hidebug.getAppVMMemoryInfo	Obtains VM memory information.
hidebug.getAppThreadCpuUsage	Obtains the CPU usage of application threads.
hidebug.startAppTraceCapture	Starts application trace collection.
hidebug.stopAppTraceCapture	Stops application trace collection.
hidebug.getAppMemoryLimit	Obtains the memory limit of the application process.
hidebug.getSystemCpuUsage	Obtains the CPU usage of the system.
hidebug.setAppResourceLimit	Sets the number of FDs, number of threads, JS memory, or native memory limit of the application.
hidebug.getAppNativeMemInfo	Obtains the memory information of the application process.
hidebug.getSystemMemInfo	Obtains system memory information.
hidebug.getVMRuntimeStats	Obtains all system GC statistics.
hidebug.getVMRuntimeStat	Obtains the specified system GC statistics based on parameters.
hidebug.isDebugState	Obtains the debugging state of an application process.
hidebug.getGraphicsMemory	Obtains the size of the GPU memory asynchronously.
hidebug.getGraphicsMemorySync	Obtains the size of the GPU memory synchronously.
hidebug.dumpJsRawHeapData	Dumps the original heap snapshot of the VM for the calling thread.

For details about how to use HiDebug, see the API Reference.

How to Develop

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

Create a project, with Empty Ability as the template.
On the project configuration page, set Model to Stage.

In the Project window, click entry > src > main > ets > pages to open the Index.ets file.

The following shows how to add hidebug.getSystemCpuUsage() to call the hidebug APIs. For details about how to use other APIs, see API Reference.

import { hidebug } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';
function testHiDebug(event?: ClickEvent) {
  try {
    console.info(`getSystemCpuUsage: ${hidebug.getSystemCpuUsage()}`);
  } catch (error) {
    console.error(`error code: ${(error as BusinessError).code}, error msg: ${(error as BusinessError).message}`);
  }
}

Add a click event to the Text component. The sample code is as follows:

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .onClick(testHiDebug);// Add a click event.
      }
      .width('100%')
    }
    .height('100%')
  }
}

Run the project on a real device and click "Hello World" on the app/service.
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 hidebug.getSystemCpuUsage() are displayed in the window.
```
 08-20 11:06:01.891   1948-1948     A03d00/JSAPP                    com.examp...lication  I     getSystemCpuUsage: 0.4722222222222222
```