GT源码：https://github.com/TencentOpen/GT
一.流畅度模块的代码结构
流畅度插件总共就几个类，其实处理方式也比较简单粗暴，就是通过Choreographer输出的log信息获取跳帧数据。SMActivity.java为插件的入口类，你可以通过预设环境操作来实现log打印操作，然后通过SMLogService.java过滤出当前进程的丢帧值，最后由SMServiceHelper.java来进行数据处理。流畅度值为60减去1s内的跳帧数。
二.流畅度测试
1.简要流程
- 执行setprop debug.choreographer.skipwarning 1
- 执行getprop debug.choreographer.skipwarning判断，为1则可以进行测试
- 执行adb logcat -v time -s Choreographer:I *:S
- 过滤获取当前pid丢帧值
- 数据处理得到sm值
2.代码流程
执行setprop debug.choreographer.skipwarning 1
View.OnClickListener button_write_property = new View.OnClickListener() { @Override
public void onClick(View v) {
String cmd = "setprop debug.choreographer.skipwarning 1";
ProcessBuilder execBuilder = new ProcessBuilder("su", "-c", cmd);
execBuilder.redirectErrorStream(true);
try {
execBuilder.start();
} catch (IOException e) {
e.printStackTrace();
}
}
};执行getprop debug.choreographer.skipwarning判断，为1则可以进行测试
View.OnClickListener button_check_status = new View.OnClickListener() { @Override
public void onClick(View v) {
String cmd = "getprop debug.choreographer.skipwarning";
ProcessBuilder execBuilder = new ProcessBuilder("sh", "-c", cmd);
execBuilder.redirectErrorStream(true);
try {
TextView textview = (TextView) findViewById(R.id.textviewInformation);
Process p = execBuilder.start();
InputStream is = p.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
Boolean flag = false;
String line;
while ((line = br.readLine()) != null) {
if (line.compareTo("1") == 0) {
flag = true;
break;
}
} if (flag) {
textview.setText("OK");
} else {
textview.setText("NOT OK");
}
} catch (IOException e) {
e.printStackTrace();
}
}
};- 执行adb logcat -v time -s Choreographer:I *:S
过滤获取当前pid丢帧值
protected void onHandleIntent(Intent intent) {
try { String str = intent.getStringExtra("pid");
int pid = Integer.parseInt(str); List<String> args = new ArrayList<String>(Arrays.asList("logcat", "-v", "time", "Choreographer:I", "*:S")); dumpLogcatProcess = RuntimeHelper.exec(args);
reader = new BufferedReader(new InputStreamReader(dumpLogcatProcess.getInputStream()), 8192); String line; while ((line = reader.readLine()) != null && !killed) { // filter "The application may be doing too much work on its main thread."
if (!line.contains("uch work on its main t")) {
continue;
}
int pID = LogLine.newLogLine(line, false).getProcessId();
if (pID != pid){
continue;
} line = line.substring(50, line.length() - 71);
Integer value = Integer.parseInt(line.trim()); SMServiceHelper.getInstance().dataQueue.offer(value);
}
} catch (IOException e) {
Log.e(TAG, e.toString() + "unexpected exception");
} finally {
killProcess();
}
}数据处理得到sm值
腾讯这边的处理方案是：当丢帧<60时，流畅度SM =60-frame； 当丢帧frame>60时，流畅度SM = 60-frame%60。不过这种处理方式是有问题的。在这里要先说下流畅度计算的原理：
VSync机制可以通过其Loop来了解当前App最高绘制能力，固定每隔16.6ms执行一次，这样最高的刷新的帧率就控制在60FPS以内，Choreographer日志可以打印当前丢帧数，因此通过计算，得到当前APP的流畅度。
而计算这样来计算可能会更加准确：
SM= 60-丢帧frame/每两行同一线程的丢帧时间差（单位：s），如果只关心UI线程，那就只需要统计UI线程即可。
while (true) {
if (pause) {
break;
}
int x = count.getAndSet(0);
// 卡顿大于60时，要将之前几次SM计数做修正
if (x > 60) {
int n = x / 60;
int v = x % 60;
TagTimeEntry tte = OpPerfBridge.getProfilerData(key);
int len = tte.getRecordSize();
// 补偿参数
int p = n;
//Math.min(len, n);
/*
* n > len是刚启动测试的情况，日志中的亡灵作祟，这种情况不做补偿;
* 并且本次也记为60。本逻辑在两次测试间会清理数据的情况生效。
*/
if (n > len) {
globalClient.setOutPara(key, 60);
// globalClient.setOutPara(SFKey, 0);
} else {
for (int i = 0; i < p; i++) {
TimeEntry te = tte.getRecord(len - 1 - i);
te.reduce = 0;
}
globalClient.setOutPara(key, v);
// globalClient.setOutPara(SFKey, 60 - v);
}
} else {
int sm = 60 - x;
globalClient.setOutPara(key, sm);
// globalClient.setOutPara(SFKey, x);
}