/* $Id: ntGetTimerResolution.cpp $ */ /** @file * IPRT - Win32 (NT) testcase for getting the timer resolution. */ /* * Copyright (C) 2006-2023 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included * in the VirtualBox distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. * * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #define _WIN32_WINNT 0x0500 #include #include #include extern "C" { /* from sysinternals. */ NTSYSAPI LONG NTAPI NtQueryTimerResolution(OUT PULONG MaximumResolution, OUT PULONG MinimumResolution, OUT PULONG CurrentResolution); } int main() { ULONG Min = UINT32_MAX; ULONG Max = UINT32_MAX; ULONG Cur = UINT32_MAX; NtQueryTimerResolution(&Max, &Min, &Cur); printf("NtQueryTimerResolution -> Max=%08luns Min=%08luns Cur=%08luns\n", Min * 100, Max * 100, Cur * 100); #if 0 /* figure out the 100ns relative to the 1970 epoc. */ SYSTEMTIME st; st.wYear = 1970; st.wMonth = 1; st.wDayOfWeek = 4; /* Thor's day. */ st.wDay = 1; st.wHour = 0; st.wMinute = 0; st.wSecond = 0; st.wMilliseconds = 0; FILETIME ft; if (SystemTimeToFileTime(&st, &ft)) { printf("epoc is %I64u (0x%08x%08x)\n", ft, ft.dwHighDateTime, ft.dwLowDateTime); if (FileTimeToSystemTime(&ft, &st)) printf("unix epoc: %d-%02d-%02d %02d:%02d:%02d.%03d (week day %d)\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds, st.wDayOfWeek); else printf("FileTimeToSystemTime failed, lasterr=%d\n", GetLastError()); } else printf("SystemTimeToFileTime failed, lasterr=%d\n", GetLastError()); ft.dwHighDateTime = 0; ft.dwLowDateTime = 0; if (FileTimeToSystemTime(&ft, &st)) printf("nt time start: %d-%02d-%02d %02d:%02d:%02d.%03d (week day %d)\n", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds, st.wDayOfWeek); else printf("FileTimeToSystemTime failed, lasterr=%d\n", GetLastError()); #endif return 0; }