create thread in class - c++

Question

Below there is a part of my code:
class MyClass
{
...
HANDLE m_ListenThr;
DWORD WINAPI ListenThread (LPVOID WorkContext);
bool CreateListenThreads();
}
bool MyClass::CreateListenThreads()
{
...
m_ListenThr = CreateThread(NULL, 0, MyClass::ListenThread,(void*)this, 0,&dwThreadId);
}
DWORD WINAPI MyClass::ListenThread (LPVOID WorkThreadContext)
{
MyClass pThis = reinterpret_cast<MyClass*>(WorkThreadContext);
...
}
After compiling i get this error:
error C3867: 'MyClass::ListenThread': function call missing argument
list; use '&MyClass::ListenThread' to create a pointer to member
what i do wrong?

Answer 1

You have to define the thread function DWORD WINAPI ListenThread (LPVOID WorkContext); as a static function of the class:
class MyClass
{
public:
static DWORD WINAPI ListenThread (LPVOID WorkContext);
}
It is not possible to call a member function without an instance of an object. In your case this is only a parameter that will be passed as WorkContext in your now static function ListenThread.
As another solution, you could also consider using C++11 std::bind so as to create a function object from that you would pass to CreateThread.
That would go something like this - sorry I have not windows so as to check if this compiles - but it gives you the idea:
bool MyClass::CreateListenThreads()
{
using std::placeholders;
std::function <void (void*)> threadFunction = std::bind(&MyClass::ListenThread, *this, _1);
m_ListenThr = CreateThread(NULL, 0, threadFunction,(void*)this, 0,&dwThreadId);
}
but that would sort of use the reference to this twice: as the instance of the class to call the function on, and as a parameter LPVOID WorkContext. Maybe it's awkward in this present case.