auto-reset event.cpp

const wstring SHUTDOWN_ACK = L"Server Shutdown";

HANDLE  g_requestSubmitted;
HANDLE  g_requestReturned;
HWND    g_mainDlg;
wstring g_requestText;

UINT APIENTRY ServerThreadFunc(PVOID param)
{
    bool isShutdown = false;

    while (!isShutdown) {
        WaitForSingleObject(g_requestSubmitted, INFINITE);

        isShutdown = (g_mainDlg == NULL) && (g_requestText == SHUTDOWN_ACK);
        if (!isShutdown) {
            std::reverse(g_requestText.begin(), g_requestText.end());
        }

        SetEvent(g_requestReturned);
    }

    return 0;
}

int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine,
                       int nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // create auto-reset event objects
    g_requestSubmitted = CreateEvent(NULL, FALSE, FALSE, NULL);
    g_requestReturned = CreateEvent(NULL, FALSE, FALSE, NULL);
    ON_SCOPE_EXIT([&]{ CloseHandle(g_requestSubmitted); });
    ON_SCOPE_EXIT([&]{ CloseHandle(g_requestReturned); });

    // create the server thread
    UINT threadId;
    HANDLE hThread = reinterpret_cast<HANDLE>(_beginthreadex(NULL,
                                                             0, 
                                                             ServerThreadFunc, 
                                                             NULL, 
                                                             0,
                                                             &threadId));
    ON_SCOPE_EXIT([&]{ CloseHandle(hThread); });

    DialogBox(hInstance, MAKEINTRESOURCE(IDD_DLGMAIN), NULL, DlgProc);
    g_mainDlg = NULL;

    g_requestText = SHUTDOWN_ACK;
    SetEvent(g_requestSubmitted);

    // wait for server thread to ACK the shutdown and to fully exit
    WaitForSingleObject(g_requestReturned, INFINITE);
    WaitForSingleObject(hThread, INFINITE);

    return 0;
}

void OnClose(HWND hwnd)
{
    EndDialog(hwnd, FALSE);
}

BOOL OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam)
{
    //InitializeSRWLock(&g_srwLock);
    g_mainDlg = hwnd;
    return TRUE;
}

void OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
{
    switch (id) {
        case IDC_BTN_SUBMIT: {
            vector<wchar_t> v(255);
            UINT cnt = GetDlgItemText(hwnd, IDC_EDT_REQTXT, &v[0], 255);
            g_requestText.assign(v.begin(), v.begin() + cnt);

            SetEvent(g_requestSubmitted);
            WaitForSingleObject(g_requestReturned, INFINITE);

            SetDlgItemText(hwnd, IDC_EDT_RETTXT, g_requestText.c_str());
        }
            break;
    }
}

INT_PTR CALLBACK DlgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg) {
        HANDLE_MSG(hwnd, WM_INITDIALOG, OnInitDialog);
        HANDLE_MSG(hwnd, WM_COMMAND, OnCommand);
        HANDLE_MSG(hwnd, WM_CLOSE, OnClose);

        default:
            return FALSE;
    }

    return FALSE;
}