C# COM Cross Thread problem
- by user364676
Hi,
we're developing a software to control a scientific measuring device. it provides a COM-Interface defines serveral functions to set measurement parameters and fires an event when it measured data.
in order to test our software, i'm implementing a simulation of that device.
the com-object runs a loop which periodically fires the event. another loop in the client app should now setup up the com-simulator using the given functions.
i created a class for measuring parameters which will be instanciated when setting up a new measurement.
// COM-Object
public class MeasurementParams
{
public double Param1;
public double Param2;
}
public class COM_Sim : ICOMDevice
{
public MeasurementParams newMeasurement;
IClient client;
public int NewMeasurement()
{
newMeasurment = new MeasurementParam();
}
public int SetParam1(double val)
{
// why is newMeasurement null when method is called from client loop
newMeasurement.Param1 = val;
}
void loop()
{
while(true)
{
// fire event
client.HandleEvent;
}
}
}
public class Client : IClient
{
ICOMDevice server;
public int HandleEvent()
{
// handle this event
server.NewMeasurement();
server.SetParam1(0.0);
}
void loop()
{
while(true)
{
// do some stuff...
server.NewMeasurement();
server.SetParam1(0.0);
}
}
}
both of the loops run in independent threads. when server.NewMeasurement() is called, the object on the server is set to a new instance. but in the next function, the object is null again. do the same when handling the server-event, it works perfectly, because the method runs in the servers thread. how to make it work from client-thread as well.
as the client is meant to be working with the real device, i cannot modify the interfaces given by the manufactor. also i need to setup measurements independent from the event-handler, which will be fired not regulary.
i assume this problem related to multithreaded-COM behavior but i found nothing on this topic.
