Originally posted by: s.st1led

Hi everybody,

I have a strange issue while using the ILOG CP library for .NET. I'm using the x64 library delivered with CPLEX Optimization Studio 12.5.1 under Windows 8 x64 and Visual Studio 2012. Let's assume I have this pretty straightforward code:

            // Initializes the OPL Factory and Error Handler
            OplFactory.DebugMode = false;
            OplFactory oplFactory = new OplFactory();
            OplErrorHandler oplErrorHandler = oplFactory.CreateOplErrorHandler();

            // Initializes the OPL Run Settings
            OplSettings oplSettings = oplFactory.CreateOplSettings(oplErrorHandler);
            oplSettings.setWithWarnings(false);

            // Initializes the OPL Model
            OplModelSource oplModelSource = oplFactory.CreateOplModelSource(@"model.mod");
            OplModelDefinition oplModelDefinition = oplFactory.CreateOplModelDefinition(oplModelSource, oplSettings);

            // Initializes the OPL Data
            OplDataSource oplDataSource = oplFactory.CreateOplDataSource(@"data.dat");


            // Initializes the CP solver
            ILOG.CP.CP cp = oplFactory.CreateCP();
            
                StreamWriter streamWriter = File.CreateText(@"log.log");
                TextWriter synchronizedStreamWriter = TextWriter.Synchronized(streamWriter);
                cp.SetOut(synchronizedStreamWriter);


            cp.SetParameter(ILOG.CP.CP.DoubleParam.OptimalityTolerance, 0);
            cp.SetParameter(ILOG.CP.CP.DoubleParam.RelativeOptimalityTolerance, 0);
            cp.SetParameter(ILOG.CP.CP.IntParam.TimeMode, ILOG.CP.CP.ParameterValues.ElapsedTime);

            // Instantiates the OPL Model
            OplModel oplModel = oplFactory.CreateOplModel(oplModelDefinition, cp);

           
            oplModel.AddDataSource(oplDataSource);

            // Generates the OPL Model
            oplModel.Generate();

            // Returns the loaded and configured OplModel
            return oplModel;

When I execute it, I have the following runtime execption upon the CP.SetOut call:

System.OverflowException was unhandled
  HResult=-2146233066
  Message=Arithmetic operation resulted in an overflow.
  Source=mscorlib
  StackTrace:
       at System.IntPtr.ToInt32()
       at ILOG.Concert.Cppimpl.NotifierStream.initCppCallback()
       at ILOG.Concert.Cppimpl.NotifierStream..ctor(IntPtr cPtr, Boolean cMemoryOwn)
       at ILOG.Concert.Cppimpl.NotifierStream..ctor()
       at ILOG.Concert.Cppimpl.DotnetToCppOutputStreamAdapter..ctor(TextWriter os)
       at ILOG.CP.CP.SetOut(TextWriter s)
       at Test.Test.InitializeNewSearch() in Test.cs:line 42
       at Test.Program.Main(String[] args) in Program.cs:line 14
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

Am I doing something wrong? I also tried with Cp.SetOut(Console.Out), but this same exception is thrown. Basically, every CP.SetOut() call (apart from CP.SetOut(null)) throws this exception.

Ideas?

Regards,

Stefano

Originally posted by: ChrisBr

Hello Stefano,

Sorry to not have answered earlier, but I'm afraid I couldn't help so far.
We failed to reproduce the problem.
Could you give us the stacktrace? This might help us to find out the problem.

Regards,

Chris.

Originally posted by: s.st1led

Hi Chris, I posted this issue in the CPLEX forum as well because I have this error while using the CPLEX library too. The stacktrace is attached at the bottom of the previous message, I'll paste it here for commodity:

System.OverflowException was unhandled
  HResult=-2146233066
  Message=Arithmetic operation resulted in an overflow.
  Source=mscorlib
  StackTrace:
       at System.IntPtr.ToInt32()
       at ILOG.Concert.Cppimpl.NotifierStream.initCppCallback()
       at ILOG.Concert.Cppimpl.NotifierStream..ctor(IntPtr cPtr, Boolean cMemoryOwn)
       at ILOG.Concert.Cppimpl.NotifierStream..ctor()
       at ILOG.Concert.Cppimpl.DotnetToCppOutputStreamAdapter..ctor(TextWriter os)
       at ILOG.CP.CP.SetOut(TextWriter s)
       at Test.Test.InitializeNewSearch() in Test.cs:line 42
       at Test.Program.Main(String[] args) in Program.cs:line 14
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:

The strange thing is that this also happens on another computer that I'm using with the same configuration (VS 2012, CP x64 libraries, Windows 8 x64).

Regards,

Stefano

Originally posted by: ChrisBr

Hello Stefano,

As you may have noticed, both issues come from the same root cause.
We are working on this and we will update one of the forums when we'll have more information.
Sorry to not be able to help more for the moment.

Regards,

Chris.

Originally posted by: s.st1led

Thank you for you support Chris. I'm actively following both discussions (this one, and the one on the CPLEX forum). Keep me posted!

Regards,

Stefano

Originally posted by: Wooi Fun

I have the same issue too when running on Windows 8: Details below. Stefano, not sure if you manage to solve it? Thanks.

Arithmetic operation resulted in an overflow. |    at System.IntPtr.ToInt32()
   at ILOG.Concert.Cppimpl.NotifierStream.initCppCallback()
   at ILOG.Concert.Cppimpl.NotifierStream..ctor(IntPtr cPtr, Boolean cMemoryOwn)
   at ILOG.Concert.Cppimpl.NotifierStream..ctor()
   at ILOG.Concert.Cppimpl.DotnetToCppOutputStreamAdapter..ctor(TextWriter os)
   at ILOG.CP.CP.WriteConflict(TextWriter s)
  

Originally posted by: s.st1led

Actually, I never managed to fix this issue, so I just commented out the SetOut call in my code. Updating CPLEX to 12.6.0.1 did not help, and indeed there is no mention for this particular issue in the update release notes (http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r6/index.jsp?topic=%2Filog.odms.studio.help%2FOptimization_Studio%2Ftopics%2FCOS_relnotes_intro.html).

I was told in another topic I opened (https://www.ibm.com/developerworks/community/forums/html/topic?id=01aa8faa-66e5-41c2-a9dd-384026934874#5fa8186a-a40e-4790-aee4-5dcf3ac7f798) that they identified the cause of the problem, and I have to guess a fix will be released in the next update (or major version), but I'd rather to wait for someone from IBM to confirm it. It has been almost a year now.

Regards,

Stefano

Originally posted by: Wooi Fun

Stefano, Thanks for the reply. Regards.

Originally posted by: s.st1led

I got an update on this issue (sorry for crossposting on https://www.ibm.com/developerworks/community/forums/html/topic?id=01aa8faa-66e5-41c2-a9dd-384026934874#5fa8186a-a40e-4790-aee4-5dcf3ac7f798).

After updating to v.12.6.1, this issue just seems to have gotten worse. Instead of an OverflowException upon calling CP.SetOut(), now I seem to be getting a System.ExecutionEngineException upon calling CP.Next() later in the code. For some obscure reason I'm not even able to catch this exception with try/catch statements, so upon execution my program simply crashes.

This is the (not very meaningful) exception log that I get in Visual Studio:

System.ExecutionEngineException was unhandled
  HResult=-2146233082
  Message=Exception of type 'System.ExecutionEngineException' was thrown.
  InnerException:

Any update from IBM side?

Regards,

Stefano

Originally posted by: PhilippeLaborie

Hello,

This is probably a different issue than the one you found with 12.6. Could you send a small model that illustrates the problem ?

Is it like the original problem: can you reproduce it only using the .NET API of CP Optimizer (no OPL) ?

Do you still get the crash if you do not change the output stream ?

Philippe

Originally posted by: s.st1led

Hi Philippe,

this is a MWE that fires the exception upon calling CP.Next()

            // Initializes the OPL Factory and Error Handler
            OplFactory.DebugMode = false;
            OplFactory oplFactory = new OplFactory();
            OplErrorHandler oplErrorHandler = oplFactory.CreateOplErrorHandler();

            // Initializes the OPL Run Settings
            OplSettings oplSettings = oplFactory.CreateOplSettings(oplErrorHandler);
            oplSettings.setWithWarnings(false);

            // Initializes the OPL Model
            OplModelSource oplModelSource = oplFactory.CreateOplModelSource(@"model.mod");           
            OplModelDefinition oplModelDefinition = oplFactory.CreateOplModelDefinition(oplModelSource, oplSettings);

            // Initializes the OPL Data
            OplDataSource oplDataSource = oplFactory.CreateOplDataSource(@"data.dat");


            // Initializes the CP solver
            ILOG.CP.CP cp = oplFactory.CreateCP();

            StreamWriter streamWriter = File.CreateText(@"C:\Users\Stefano\Desktop\TestLogCp.log");
            TextWriter synchronizedStreamWriter = TextWriter.Synchronized(streamWriter);
            cp.SetOut(synchronizedStreamWriter)

           
            // Instantiates the OPL Model
            OplModel oplModel = oplFactory.CreateOplModel(oplModelDefinition, cp);

            


            // Adds the data source to the model
            oplModel.AddDataSource(oplDataSource);

            // Generates the OPL Model
            oplModel.Generate();


            cp.StartNewSearch();
        

            // Solves the model
            while (oplModel.CP.Next())
            {
                // Sets the optimal value
                double objectiveValue = cp.ObjValue;

                Console.Out.WriteLine("Obj Value: " + objectiveValue);
            }

            // Terminates the Program
            Console.WriteLine(Environment.NewLine + "Press any key to exit");
            Console.ReadKey();

If I comment out the CP.SetOut() call, then I have no exception and the code runs fine. The OPL model and data can be something arbitrarily trivial I guess. For instance, I get the error with these model and data files:

using CP;

int wx = ...;
int wy = ...;

dvar int x in 1..10;
dvar int y in 1..10;

maximize
    wx * x + wy * y;

subject to {
    x > y;
}

wx = 1;
wy = 2;

Regards,

Stefano

Originally posted by: PhilippeLaborie

Hello,

We identified the problem. It will be fixed in a forthcoming release.

Regards,

Philippe

Originally posted by: s.st1led

Hi Philippe,

I almost forgot I posted this issue! Good to hear that a fix is coming.

Regards,

Stefano

Originally posted by: s.st1led

And this is just to confirm that v12.6.2.0 fixed this issue!

Regards,

Stefano