/* $Id: ntGetTimerResolution.cpp 93115 2022-01-01 11:31:46Z vboxsync $ */ /** @file * IPRT - Win32 (NT) testcase for getting the timer resolution. */ /* * Copyright (C) 2006-2022 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE 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. */ /********************************************************************************************************************************* * 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; }