Thread not completing properly, preventing application close - c++

Question

I'm writing a win32 form application and drawing it with Direct2D. I have a few cross threaded functions to do animations on it and I'm doing web requests with WinHTTP. The issue is, when I use any WinHttp functions (even just opening an HINTERNET session), it will cause the thread not to terminate properly. After I run the 'login' process once, the program cannot exit calmly. I've posted the relevant code below:
//the login process
void __cdecl processloginasync(void* arg)
{
//getting text from textboxes, etc.
if(usernamestr.find(L'#') != wstring::npos && usernamestr.find(L".") != wstring::npos) {
swapdrawmode(1);
_beginthread(loadwheel,NULL,arg);
void* result = NULL;
unsigned sz = 0;
int rescode = web_request(L"appurl.mywebsite.com/func.php",ss.str().c_str(),result,sz);
//other code to handle the reply...
swapdrawmode(0);
}
else {
error_str = L"Invalid email address.";
err = TRUE;
}
if(err == TRUE) {
textopacity = 0;
animatemode = 0;
_beginthread(animatetext,NULL,arg);
}
//I realize I haven't called 'free' on result, I'll fix that.
}
//the web_request function
int web_request (const wchar_t* server, const wchar_t* object, void*& dest, unsigned& size)
{
vector<void*> retval;
vector<unsigned> szs;
HINTERNET hSess = NULL, hConn = NULL, hReq = NULL;
int res = 0;
DWORD dwDownloaded = 0;
DWORD dwSize = 0;
DWORD retcode = NULL;
short err = FALSE;
const wchar_t* accepted_types[] = {
L"image/*",
L"text/*",
NULL
};
hSess = WinHttpOpen(L"smartCARS2 Web/1.1",WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
if(hSess)
hConn = WinHttpConnect(hSess,server,INTERNET_DEFAULT_HTTP_PORT, NULL);
else {
err = TRUE;
retcode = HTTP_OPEN_FAILED;
}
if(hConn)
hReq = WinHttpOpenRequest(hConn, NULL, object, NULL, WINHTTP_NO_REFERER,accepted_types,NULL);
else {
err = TRUE;
retcode = HTTP_CONN_FAILED;
}
if(hReq)
res = WinHttpSendRequest(hReq, WINHTTP_NO_ADDITIONAL_HEADERS, NULL, WINHTTP_NO_REQUEST_DATA, NULL, NULL, NULL);
else {
err = TRUE;
retcode = HTTP_OPENREQ_FAILED;
}
if(res)
res = WinHttpReceiveResponse(hReq, NULL);
else {
err = TRUE;
retcode = HTTP_SEND_REQ_FAILED;
}
DWORD tsize = 0;
if(res) {
do {
dwSize = 0;
if(!WinHttpQueryDataAvailable(hReq, &dwSize)) {
retcode = HTTP_COULD_NOT_QUERY_SIZE;
err = TRUE;
break;
}
if(!dwSize)
break;
tsize += dwSize;
void* rets = malloc(dwSize + 1);
if(!rets) {
break;
}
if(!WinHttpReadData(hReq, (void*)rets, dwSize, &dwDownloaded)) {
retcode = HTTP_COULD_NOT_READ_DATA;
err = TRUE;
break;
}
if(!dwDownloaded) {
retcode = HTTP_COULD_NOT_DOWNLOAD;
err = TRUE;
break;
}
szs.push_back(dwSize);
retval.push_back(rets);
} while(dwSize > 0);
}
size = tsize;
unsigned int sz = retval.size();
dest = malloc(tsize);
tsize = 0;
for(unsigned i = 0; i < sz; i++) {
memcpy((BYTE*)dest + tsize,retval[i],szs[i]);
free(retval[i]);
tsize += szs[i];
}
if(hSess)
WinHttpCloseHandle(hSess);
if(hConn)
WinHttpCloseHandle(hConn);
if(hReq)
WinHttpCloseHandle(hReq);
if(err == TRUE)
return retcode;
return 0;
}

Answer 1

As far as I know, as soon as the main thread terminates, the others are not waited for. So the problem is probably in your main thread. You just need to attach a debugger if not already being debugged (Debug | Attach to process in VS) to a zombie process and press "Break all", then use "Threads" and "Call stack" windows to figure what's happening.