Sample _beginthreadex

The following is a sample use of _beginthreadex. In this sample, an event is created and passed as an argument. The thread checks the event in a loop and when the event is signaled (by the main thread) the thread returns. Please read the _beginthreadex() and _endthreadex() documentation; this sample assumes you have and that you are familiar with it.

#if !defined(_MT)
#error _beginthreadex requires a multithreaded C run-time library.
#endif

#define STRICT 1
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <process.h>
#include <iostream>
using namespace std;

#define Second (1000)

unsigned __stdcall Thread(void *ArgList) {
HANDLE hEvent = *((HANDLE*)ArgList);
while (WaitForSingleObject(hEvent, 0) != WAIT_OBJECT_0) {
	Sleep(Second>>2); // sleep for a quarter of a second
	cout << "Waiting for signal\n";
	}
cout << "Thread ending\n";
return 0;
}

int main(int argc, char *argv[], char *envp[]) {
	int ErrorNumber, DOSErrorNumber;
	unsigned ThreadId;
	HANDLE hThread, hEvent;

// Create a manual-reset nonsignaled unnamed event
hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

hThread = (HANDLE)_beginthreadex(NULL, 0, Thread, &hEvent, 0, &ThreadId);
if (hThread == 0) {
	ErrorNumber = errno;
	DOSErrorNumber = _doserrno;
	cerr << "Begin thread error: " << strerror(ErrorNumber) << '\n';
	cerr << "Begin thread DOS error code: " << DOSErrorNumber << '\n';
	return 16;
	}
cout << "Thread begun\n";

Sleep(Second<<1); // wait 2 seconds
SetEvent(hEvent); // signal thread to end
int rv = WaitForSingleObject(hThread, Second<<3); // wait up to 8 seconds
cout << "Thread wait rv " << rv << '\n';
CloseHandle(hEvent);
CloseHandle(hThread);

return 0;
}

Microsoft Knowledge Base article 132078 ("How to Use _beginthreadex() and _endthreadex()")

The KB article 132078 ("How to Use _beginthreadex() and _endthreadex()") seems to have been archived, so I will summarize here what it says. It essentially says that it is better to use _beginthreadex() and _endthreadex() and it has a sample program. My sample above is an improved version of the sample in the KB article.

Use of the Win32 APIs CreateThread() and EndThread() directly is incompatible with the C Runtime (CRT) Library. In particular, use of CreateThread() and EndThread() directly can cause loss of memory that the CRT allocates. Instead, we must use either _beginthread() and _endthread() or _beginthreadex() and _endthreadex().

The advantage of _beginthreadex() compared to _beginthread() is that _beginthreadex() provides more control and is safer. For example, with _beginthreadex(), you can:

use security information
create the thread suspended initially
get the thread identifier of the thread
use the thread handle after the thread completes, allowing use of the the synchronization APIs (as above) for the thread

The advantage of _endthreadex() compared to _endthread() is that _endthreadex() is more flexible.