CreateThread() function question

So just by looking at the msdn document of the following kernal32 function,

Code:

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HANDLE WINAPI CreateThread(
  __in_opt  LPSECURITY_ATTRIBUTES lpThreadAttributes,
  __in      SIZE_T dwStackSize,
  __in      LPTHREAD_START_ROUTINE lpStartAddress,
  __in_opt  LPVOID lpParameter,
  __in      DWORD dwCreationFlags,
  __out_opt  LPDWORD lpThreadId
);

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Quote:

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lpStartAddress [in]
A pointer to the application-defined function to be executed by the thread. This pointer represents the starting address of the thread. For more information on the thread function, see ThreadProc.

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I am not sure whether the function specified by the argument should be defined within the same .cpp file where I call the CreateThread() from. Right now, within the .cpp file that I call the CreateThread() function, I included a header file that has the declaration of the function and the definition of the function is in a .obj file that I am linking my program against.

Thanks!

There is no reason the function needs to be defined in the same .cpp file, or for that matter the same module (DLL) as the call to CreateThread().

However, consider also this page:
_beginthread, _beginthreadex (CRT)

To sum up the blathering on that page, if you use the CRT, use __beginthreadex instead of CreateThread, or you will leak memory in some special circumstances.

Awesome, thank you guys :)

Just one more quick question regarding thread programming. After creating the thread, is it generally recommended to use WaitForSingleObject() to wait for the thread to finish the function, instead of polling with GetExitCodeThread() (by checking if it returns STILL_ACTIVE)? I am doing the latter, but while I was reading some WiX(Windows Installer wrapper module) implementations, I realized that they take the formal approach.

Use one of the Wait functions on the thread handle. Don't poll if you don' t have to.

gg

I'll put it in stronger words: never poll unless there's really no other way.

It's also recommended that after creating the thread, you continue doing work instead of doing anything that waits for the thread to finish, since that would pretty much defeat the point. You only wait for a thread when you really need the result right there.