应用程序可能在其主线程上做了太多工作

Question

I am new to Android SDK/API environment. It's the first I am trying to draw a plot/chart. I tried running different kinds of sample codes on the emulator using 3 different free libraries, nothing is showing on the layout screen. The logcat is repeating the following message:

 W/Trace(1378): Unexpected value from nativeGetEnabledTags: 0
 I/Choreographer(1378): Skipped 55 frames!  The application may be doing too much work on its main thread. 

The problem didn't persist and the chart worked when I ran a sample code pertaining to an evaluation copy of a licensed library.

Answer 1

taken from : Android UI : Fixing skipped frames

Anyone who begins developing android application sees this message on logcat “Choreographer(abc): Skipped xx frames! The application may be doing too much work on its main thread.” So what does it actually means, why should you be concerned and how to solve it.

What this means is that your code is taking long to process and frames are being skipped because of it, It maybe because of some heavy processing that you are doing at the heart of your application or DB access or any other thing which causes the thread to stop for a while.

Here is a more detailed explanation:

Choreographer lets apps to connect themselves to the vsync, and properly time things to improve performance.

Android view animations internally uses Choreographer for the same purpose: to properly time the animations and possibly improve performance.

Since Choreographer is told about every vsync events, I can tell if one of the Runnables passed along by the Choreographer.post* apis doesnt finish in one frame's time, causing frames to be skipped.

In my understanding Choreographer can only detect the frame skipping. It has no way of telling why this happens.

The message “The application may be doing too much work on its main thread.” could be misleading.

source : Meaning of Choreographer messages in Logcat

Why you should be concerned

When this message pops up on android emulator and the number of frames skipped are fairly small (<100) then you can take a safe bet of the emulator being slow – which happens almost all the times. But if the number of frames skipped and large and in the order of 300+ then there can be some serious trouble with your code. Android devices come in a vast array of hardware unlike ios and windows devices. The RAM and CPU varies and if you want a reasonable performance and user experience on all the devices then you need to fix this thing. When frames are skipped the UI is slow and laggy, which is not a desirable user experience.

How to fix it

Fixing this requires identifying nodes where there is or possibly can happen long duration of processing. The best way is to do all the processing no matter how small or big in a thread separate from main UI thread. So be it accessing data form SQLite Database or doing some hardcore maths or simply sorting an array – Do it in a different thread

Now there is a catch here, You will create a new Thread for doing these operations and when you run your application, it will crash saying “Only the original thread that created a view hierarchy can touch its views“. You need to know this fact that UI in android can be changed by the main thread or the UI thread only. Any other thread which attempts to do so, fails and crashes with this error. What you need to do is create a new Runnable inside runOnUiThread and inside this runnable you should do all the operations involving the UI. Find an example here .

So we have Thread and Runnable for processing data out of main Thread, what else? There is AsyncTask in android which enables doing long time processes on the UI thread. This is the most useful when you applications are data driven or web api driven or use complex UI's like those build using Canvas. The power of AsyncTask is that is allows doing things in background and once you are done doing the processing, you can simply do the required actions on UI without causing any lagging effect. This is possible because the AsyncTask derives itself from Activity's UI thread – all the operations you do on UI via AsyncTask are done is a different thread from the main UI thread, No hindrance to user interaction.

So this is what you need to know for making smooth android applications and as far I know every beginner gets this message on his console.

Answer 2

As others answered above, "Skipped 55 frames!" means some heavy processing is in your application.

For my case, there is no heavy process in my application. I double and triple checked everything and removed those process I think was a bit heavy.

I removed Fragments, Activities, Libraries until only the skeleton was left. But still the problem did not go away. I decided to check the resources and found some icons and background I use are pretty big as I forgot to check the size of those resources.

So, my suggestion is if none of the above answers help, you may also check your resource files size.

Answer 3

I too had the same problem.
Mine was a case where i was using a background image which was in drawables.That particular image was of approx 130kB and was used during splash screen and home page in my android app.

Solution - I just shifted that particular image to drawables-xxx folder from drawables and was able free a lot of memory occupied in background and the skipping frames were no longer skipping.

Update Use 'nodp' drawable resource folder for storing background drawables files.
Will a density qualified drawable folder or drawable-nodpi take precedence?

Answer 4

Another common cause of delays on UI thread is SharedPreferences access. When you call a PreferenceManager.getSharedPreferences and other similar methods for the first time, the associated .xml file is immediately loaded and parsed in the same thread .

One of good ways to combat this issue is triggering first SharedPreference load from the background thread, started as early as possible (eg from onCreate of your Application class). This way the preference object may be already constructed by the time you'd want to use it.

Unfortunately, sometimes reading a preference files is necessary during early phases of startup (eg in the initial Activity or even Application itself). In such cases it is still possible to avoid stalling UI by using MessageQueue.IdleHandler . Do everything else you need to perform on the main thread, then install the IdleHandler to execute code once your Activity have been fully drawn. In that Runnable you should be able to access SharedPreferences without delaying too many drawing operations and making Choreographer unhappy.

Answer 5

Try to use the following strategies in order to improve your app performance:

• Use multi-threading programming if possible. The performance benefits are huge, even if your smart phone has one core (threads can run in different cores, if the processor has two or more). It's useful to make your app logic separated from the UI. Use Java threads, AsyncTask or IntentService. Check this .
• Read and follow the misc performance tips of Android development website. Check here .

Answer 6

I had the same problem. Android Emulator worked perfectly on Android < 6.0. When I used emulator Nexus 5 (Android 6.0), the app worked very slow with I/Choreographer: Skipped frames in the logs.

So, I solved this problem by changing in Manifest file hardwareAccelerated option to true like this:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapplication">

    <application android:hardwareAccelerated="true">
        ...
    </application>
</manifest>

Answer 7

I am not an expert, but I got this debug message when I wanted to send data from my android application to a web server. Though I used AsyncTask class and did the data transfer in background, for getting the result data back from server I used get() method of the AsyncTask class which makes the UI synchronous which means that your UI will be waiting for too long. So my advice is to make your app do every network oriented tasks on a separate thread.

Answer 8

优化您的图片...不要使用大于 100KB 的图片...图片加载占用太多 CPU 并导致您的应用程序挂起。

Answer 9

I had the same problem. In my case I had 2 nested Relative Layouts. RelativeLayout always has to do two measure passes. If you nest RelativeLayouts, you get an exponential measurement algorithm.

Answer 10

this usually happens when you are executing huge processes in main thread. it's OK to skip frames less than 200. but if you have more than 200 skipped frames, it can slow down your application UI thread. what you can do is to do these processes in a new thread called worker thread and after that, when you want to access and do something with UI thread(ex: do something with views, findView etc...) you can use handler or runOnUiThread (I like this more) in order to display the processing results. this absolutely solves the problem. using worker threads are very useful or even must be used when it comes to this cases.

Answer 11

I had the same problem. When I ran the code on another computer, it worked fine. On mine, however, it displayed "The application may be doing too much work on its main thread".

I solved my problem by restarting Android studio [File -> Invalidated caches / Restart -> click on "Invalidate and Restart"].

Answer 12

In my case, it was because I had accidentally set a breakpoint on a method. Once I cleared it, the message went away and performance improved a lot.

Answer 13

My app had same problem. But it was not doing other than displaying list of cards and text on it. Nothing running in background. But then after some investigation found that the image set for card background was causing this, even though it was small(350kb). Then I converted the image to 9patch images using http://romannurik.github.io/AndroidAssetStudio/index.html .
This worked for me.

Answer 14

I got same issue while developing an app which uses a lot of drawable png files on grid layout. I also tried to optimize my code as far as possible.. but it didn't work out for me.. Then i tried to reduce the size of those png.. and guess its working absolutely fine.. So my suggestion is to reduce size of drawable resources if any..

Answer 15

After doing much R&D on this issue I got the Solution,

In my case I am using Service that will run every 2 second and with the runonUIThread, I was wondering the problem was there but not at all. The next issue that I found is that I am using large Image in may App and thats the problem.

I removed the Images and set new Images.

Conclusion :- Look into your code is there any raw file that you are using is of big size.

Answer 16

First read the warning. It says more load on main thread. So what you have to do is just run functions with more work in a thread.

Answer 17

As I did first preferably use SVG images instead of all other types, If not possible compress all of your PNG and JPG resources using some image processing tools such as Adobe Photoshop or Fotosizer . one of the easiest ways is online image compressing tools like this which helped me to decrease all my image files to almost 50% of their initial size.

Answer 18

Have not resolved yet but will do. For my tiny project with one composable function (button) and logic to check if "com.whatsapp" packages exists on device (emulator) i have the following in the same log while starting simulator :

I/Choreographer: Skipped 34 frames!  The application may be doing too much work on its main thread.

Answer 19

This is actually not a problem. This happens when you have the debugger for a long time. Remove the brake point and check again.

Answer 20

For me that was RoundedBackgroundColorSpan, in textview. I remove it so (burn my brain to find it because It doesn't appear in real smartphones like Pixel 4 Xl or Samsung note 10+ also in emulator but in chip device this slow a view).

Answer 21

如果您在应用程序中使用 async/await 功能，这是正常的。