MustafaFerhan/DebugLog

it might cause multithread problem i think..

SR1s opened this issue · 3 comments

SR1s commented

I saw that className and methodName variates is static,
that means when using this class on multithread condition,
it will be incorrect if there is loging too much

SR1s commented

Ok, the major difference is that you add extra message like class name, function name and line number. It's a good feature for debug program. But the problem is that you store these extra message in the static variate, in multithread context, it will be change by other thread when it is loging one log but interrupt by the VM.

Let me show you a example.

I did a test, the code is below, using DebugLog to log the message.

public class App extends Application {

    private static Context sContext;

    @Override
    public void onCreate() {
        super.onCreate();

        Thread t1 = new LogOne();
        Thread t2 = new LogTwo();
        t1.start();
        t2.start();

    }

    public static Context getContext() {
        return sContext;
    }


    class LogOne extends Thread {

        @Override
        public void run() {
            super.run();
            int i = 10000;
            while (i-- > 0) {
            messageOne();
            }
        }

        private void messageOne() {
            DebugLog.i("log by LogOne");
        }
    }

    class LogTwo extends Thread {

        @Override
        public void run() {
            super.run();
            int i = 10000;
            while (i-- > 0) {
                messageTwo();
            }
        }

        private void messageTwo() {
            DebugLog.i("log by LogTwo");
        }
    }

}

It should always only log these two message:

  1. [messageOne:41]log by LogOne
  2. [messageTwo:57]log by LogTwo

However, in the logcat, I saw this:
error output
error output2

This is what I mean the multithread problem.

My suggestion is using local variate instead of static variate to avoid these problem.

davideas commented

Another simpler suggestion is to create local variable or private function that returns the tag and the line number, also because every log line is different of the previous, let's say, at 99% of the times. So why keep them in a static variable if they are changed at every call?

I've created a new Log class based on the roboguice/util/Ln.java class and this one. This class resolves also the issue #10.