Exception in DateTime.Add

Question

Using C#, .NET 4.0 update 4.0.3, Windows 7 64bit:

For reasons beyond my responsibilities, I have to let the GUI thread "sleep" while handling messages in the background. Up until now, this worked flawlessly:

    private void SleepWithEventLoop(int ms)
    {
        var timeout = DateTime.UtcNow.AddMilliseconds(ms);
        while (DateTime.UtcNow < timeout && !disposed)
        {
            System.Windows.Forms.Application.DoEvents();
            Thread.Sleep(1);
        }
    }

Since I booted the PC this morning, for no apparent reason, I start getting exceptions like this (snippet from log file):

2012-12-18 12:50:41.204 | - None -             | Exception | Exception caught: Der hinzuzufügende Wert war außerhalb des Bereichs.
                        |                      |           | Parametername: value
                        |                      |           | Details:
                        |                      |           |    bei System.DateTime.Add(Double value, Int32 scale)
                        |                      |           |    bei System.DateTime.AddMilliseconds(Double value)
                        |                      |           |    bei com.<...>.CanOpenProxyServer.SleepWithEventLoop(Int32 ms) in C:\Users\<...>\CanOpenProxy.cs:Zeile 78.
                        |                      |           |    bei com.<...>.CanOpenProxyServer.HandleConnection(MessageChannel channel) in C:\Users\<...>\CanOpenProxy.cs:Zeile 55.

I've had some problems with DateTime.Now concerning DST that went away after switching to DateTime.UtcNow, but the exception above remains. IT dept didn't install any updates lately, and I certainly didn't install or remove any programs or mess with the registry. How can DateTime just suddenly "break"?!?

I copied the code above into a new project to test it alone with

while (true) SleepWithEventLoop(5);

and it still crashed. Re-installing .NET didn't work either. Any ideas?

EDIT: The same problem on two colleagues' PCs, but NOT on a freshly installed VmWare system. Starts to look like our company PCs are configured a little funnily. Does DateTime need any "special" configuration?

EDIT 2: So I "fixed" the problem by P-Invoking into a small C DLL that exposes the time.h functions, wrapped in a DateTime like class. Search/replace in all projects. I feel dirty doing this, but it solves at least the symptoms. I'll look into this again when the schedule gets a little less stressful (yeah, right).

Why are you using DoEvents()....? not a recommended thing to do if you are doing multi-Threading — MethodMan, Dec 18 '12 at 13:07
here is a Stackoverflow post that you can read and there is good explanation on why you should not use Application.DoEvents() http://stackoverflow.com/questions/5181777/use-of-application-doevents — MethodMan, Dec 18 '12 at 13:12
DoEvents() doesn't really bother me here as the form is hidden. But that part of the code MUST run in the GUI thread while simultaneously capturing WM_USER messages, so there seems to be no other choice here. Removing the DoEvents() doesn't solve the problem either, DateTime still crashes. — , Dec 18 '12 at 13:16
The translationof your exception read: `The value to add was out of range.` What is the value of the ms var passed in. — Steve, Dec 18 '12 at 13:20
@Steve: The value passed is always 5 at the moment. Simply calling DateTime.Now throws a similar exception, with the Add() call buried inside mscorlib. Only DateTime.UtcNow doesn't throw... — , Dec 18 '12 at 13:24
Strange, just tested with LinqPad and works without problem here. Same Win7 64bit and Net 4.0.3. Restart? — Steve, Dec 18 '12 at 13:28
@Steve: See edit above: In VmWare it works, on the PCs it doesn't. Looks like a configuration problem to me... — , Dec 18 '12 at 13:33
That exception can't happen with a value of 5. Is it possible this value is read from a configuration file, and on the computers you've tried that file has changed or become invalid? — Jon B, Dec 18 '12 at 13:44
No config files, nothing. `while (true) SleepWithEventLoop(5);` fails. — , Dec 18 '12 at 14:02
Stupid question, but given the weirdness, I figure it's worth asking: What happens if you change your method to take a double and call it with 5.0 (instead of counting on the implicit cast from int to double)? — Joel Rondeau, Dec 18 '12 at 14:46

score 0 · Answer 1 · answered Dec 18 '12 at 15:40

0

When I have code that works properly on one computer and incorrectly on a second one, I expect the problem is the DLLs being used by my application. So my recommendation is this:

Run the app on both your machine and the VM where it works.
Run ProcessExplorer on both machines.
Show the DLLs in the lower pane of ProcessExplorer.
Compare the DLL versions to see which, if any are different.

answered Dec 18 '12 at 15:40

Joel Rondeau

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Good idea, but it's the same DLLs. Looks more like a misconfiguration or some interference caused by those remote management / virus scanners / other tools to me, which are not present on the VMs... – Dec 19 '12 at 09:52

Exception in DateTime.Add

1 Answers1