Time elapsed increases in debugging?

Question

I'm using time elapsed as a variable in a program which I am currently debugging. As I am debugging this the time elapsed variable still increases whilst I am examining variables giving undesired results and makes debugging ineffective. Is there anyway to freeze time or stop the variable from changing? (I am using System.currentTimeMillis() to calculate the time).

Edit: I have an object in a space that moves as time increases, because I am using System.currentTimeMillis() to calculate how much time has passed, it doesn't work in debugging. I'd like to know if there is a way I can work around this, thanks.

Your question is not very clear. Please paste some screenshots or code snippets to make things clear. — Drona, Mar 15 '12 at 15:14
calculate the elapsed time and store it in another variable?? you wouldn't want to (and I don't think you can) stop System.currentTimeMillis(). — Matt K, Mar 15 '12 at 15:16

score 2 · Answer 1 · answered Mar 15 '12 at 15:14

2

System.currentTimeMillis() does what it is supposed to do: Give you the time at the moment the instruction is executed. When you are "examining variables" your program thread is suspended but time still is moving on... Thus the time increase

answered Mar 15 '12 at 15:14

UmNyobe

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Yes, I am aware of that but I want to know how to work around it. – John Mar 15 '12 at 15:20
Is your program correctness depend on the elapsed running time you measure? if yes, there is probably something wrong (explain how in your question). If no then why bother – UmNyobe Mar 15 '12 at 15:22

score 2 · Accepted Answer · answered Mar 23 '12 at 07:22

One common approach to this kind of problem is to use Dependency Injection. Create a class Clock (for example) which is initialized (injected) with a time source. In production code this source might well be System.nanotime() or System.currentTimeMillis(). In debugging you use a controllable clock. The debugging implementation of the Clock class has additional methods (e.g. suspend(), resume(), setClockTo()) that allow one to use simulated time.

score 0 · Answer 3 · answered Mar 15 '12 at 15:16

Your alternative is to not use to System.currentTimeMillis(). This is rather complicated because when you are debugging you want to time to step forward when the code is running.

The best solution is to change this requirement, so that this is not a problem.

e.g. say you have a timeout which is short, you can have it increase the timeout when you are running in the debugger.

Time elapsed increases in debugging?

3 Answers3