Re: thread questions

Hi all,

Imagine I need a function that does a lengthy search.
For this function not to block, it should be implemented to be
asynchronous.
I guess this would be implemented this way:

DWORD WINAPI DoSearch(LPVOID lpParameter)
{
   // do some length search here
   return 0;
}

HANDLE DoSearch(LPCTSTR lpszSubject)
{
   return CreateProcess(... SearchProc ...);

}

I want the ability to have multiple simultaneous searches, e.g.:

HANDLE hSearch1 = DoSearch(_T("Search 1"));
HANDLE hSearch2 = DoSearch(_T("Search 2"));

I could wait for a search to complete this way:

WaitForSingleObject(hSearch1, INFINITE); // wait for completion
CloseHandle(hSearch1); // cleanup

So far, so good...
Now I would like the ability to ABORT the thread, by simply
performing a CloseHandle.

CloseHandle(hSearch2); // abort second search

Normally, I use some event handle or global BOOL value, and pass that
to thread, eg:
BOOL g_bAbort = FALSE;

DWORD WINAPI ThreadProc(LPVOID lpParameter)
{
   LPBOOL pBool = (LPBOOL) lpParameter;
   while (!pBool) {
       // do something
   }
   return 0;
}

However, this requires a global variable, .. and that complicates the
ability to run copies of the function simultanously (I reckon it
requires a global list that dynamically allocates data to hold
reference to each thread).. I wonder if there is an easy way.

In particular, I am wondering if a thread can be made to abort as
soon as all handles to it have been closed, eg:
CloseHandle(hSearch2); // should abort the thread

Is it possible for a thread to be aware of handles to itself having
been closed?

I assume this can not work:

I assume this will not work:

DWORD WINAPI SomeFunc(LPVOID lpParameter)
{
   HANDLE hThread = *(HANDLE*) lpParameter; // will this code execute
BEFORE the local variable in caller is destroyed???
   while (<handle is valid>) // what function can be used to know if
handle hasn't been closed by caller? GetHandleInformation?
   {
       // do something
   }
   return 0;
}

int main(...)
{
   HANDLE hThread; // local variable
   hThread = CreateThread(... SomeFunc, &hThread, ...);
}

I hope my lengthy e-mail is clear.. and that someone will be so kind
to answer each of my questions.