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Android学习22 -- perfetto

news 来源：原创 2025/4/30 18:44:46

1 前言

在之前的工作中就偶尔见到同事分析性能的时候，拿出漂亮的火焰图，或者XX图，当时非常惊讶，觉得怎么可以做这么好。

后面看多了，才知道这个原来是安卓的perfetto工具，专门用来分析性能的。别人能玩，我们当然也能玩，所以现在有时间自己也试试。

2 Camera程序

弄了一个Camera的小程序。

package com.example.cameraxdemo2;

import android.content.pm.PackageManager;
import android.os.Bundle;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.camera.lifecycle.ProcessCameraProvider;
import androidx.camera.view.PreviewView;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

import com.google.common.util.concurrent.ListenableFuture;
import androidx.annotation.NonNull;
import android.Manifest;
import androidx.camera.core.Preview;  // 关键导入
import androidx.camera.view.PreviewView;
import androidx.camera.core.CameraSelector; // 关键导入
import androidx.camera.core.Preview;
import androidx.camera.lifecycle.ProcessCameraProvider;

public class MainActivity extends AppCompatActivity {
    private PreviewView previewView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        previewView = findViewById(R.id.previewView);

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                == PackageManager.PERMISSION_GRANTED) {
            startCamera();
        } else {
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.CAMERA}, 101);
        }
    }

    private void startCamera() {
        ListenableFuture<ProcessCameraProvider> cameraProviderFuture =
                ProcessCameraProvider.getInstance(this);

        cameraProviderFuture.addListener(() -> {
            try {
                ProcessCameraProvider cameraProvider = cameraProviderFuture.get();

                Preview preview = new Preview.Builder().build();
                preview.setSurfaceProvider(previewView.getSurfaceProvider());

                CameraSelector cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA;

                cameraProvider.unbindAll();
                cameraProvider.bindToLifecycle(this, cameraSelector, preview);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }, ContextCompat.getMainExecutor(this));
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        if (requestCode == 101 && grantResults.length > 0 &&
                grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            startCamera();
        }
    }
}

代码也很简单，就是用了一下安卓的cameraProvider。运行时是这样的。还是用的祖传的荣耀平板8。

3 perfetto

3.1 命令行

根据教程，可以直接使用adb命令来操作。大概是这样

adb shell perfetto -o /sdcard/trace.perfetto-trace -c - <<EOF
buffers {
  size_kb: 10240
  fill_policy: RING_BUFFER
}
data_sources {
  config {
    name: "linux.ftrace"
    target_buffer: 0
    ftrace_config {
      ftrace_events: "sched/sched_switch"
      ftrace_events: "sched/sched_wakeup"
      ftrace_events: "tracing_mark_write"
    }
  }
}
duration_ms: 15000
EOF

导出成/sdcard/trace.perfetto-trace之后pull出来。但是一运行就报错，提示各种权限问题，还有一些参数问题。看来还是要找个root的机器才行。。。试了很多方法未果，最后放弃了。