Thanks for the reply once again.
Actually in my second post I did mention all the problems I was having with C++ only. Initially I wanted solution to two separate things, one multithreading and second doevents. if we just forget about the doevents thing, my multithreading code (written in VC++.NET) has two problems ( Its been ages since I programmed in VC++ so I know how to do the things in VC# I cant find what I am looking for in C++).
I have two threads ... one as a sender and the other a receiver for data sent over sockets. But the sockets are being created and handled in a dll ( a VC# dll which has a class named Class1). so when I call these threads I have to pass the object of the class in the dll because the sender and receiver use the same sockets right!!.
Here is what I have in the sender and receiver threads... ( and I dont know a work around for the DoEvents thing, because I have to enforce the processor to do other tasks while the thread is in a while loop .... and I have removed the doevents completely as well and it doesnt make any difference. So the problem is not with doevents).
DWORD WINAPI SenderThread(LPVOID iValue)
{
Mutex^ mut =
gcnew Mutex();
mut->WaitOne();
Class1^ senderdll = *((Class1^*)iValue);
mut->Close();
int returnval;
DoEvents();
while(true)
{
returnval = senderdll->SenderEntryPoint();
if(returnval == 1) // sockets closed
{
break;
//dynamic_cast<AutoResetEvent^>(stateInfo)->Set();
}
}
return 0;
}
DWORD WINAPI ReceiverThread(LPVOID iValue)
{
Mutex^ mut =
gcnew Mutex();
mut->WaitOne();
Class1^ receiverdll = *((Class1^*)iValue);
mut->Close ();
int returnval;
DoEvents();
while(true)
{
returnval = receiverdll->ReceiverEntryPoint();
if(returnval == 1) // the sockets closed
break;
}
return 0;
}
and here is how I am creating these threads. (The cmdListen_Click function creates the sockets.)
Class1^ c =
gcnew Class1();
c->cmdListen_Click(NewPosition);//call the dll function to create sockets
////Threads start
DWORD dwGenericThread;
hThread2 = CreateThread(NULL,0,SenderThread,&c,0,&dwGenericThread);//the sender thread
if(hThread2 == NULL)
{
DWORD dwError = GetLastError();
return 0;
}
hThread3 = CreateThread(NULL,0,ReceiverThread,&c,0,&dwGenericThread);
//the receiver thread
if(hThread3 == NULL)
{
DWORD dwError = GetLastError();
return 0;
}
//////Threads end
Now the two problems I am facing are:
1) How do I synchronize the threads The AutoResetEvent (as given in http://msdn2.microsoft.com/en-us/library/system.threading.autoresetevent.aspx), uses a threadpool to create threads. My problem is if I use the threadpool instead of using the CreateThread how do I pass the Class1 object in the threads
2) My second problem is the AccessViolation error, which I am getting at the point where I create the instance of the Class in the thread. ( in both sender or receiver, depending upon which thread I am creating first !!).
Class1^ receiverdll = *((Class1^*)iValue);
What am I doing wrong here When I was getting an access violation error in VC#, I used LOCK to enforce resource allocation. How do I do this in VC++
Saania wrote: