summaryrefslogtreecommitdiffstats
path: root/src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
commitf8fe689a81f906d1b91bb3220acde2a4ecb14c5b (patch)
tree26484e9d7e2c67806c2d1760196ff01aaa858e8c /src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp
parentInitial commit. (diff)
downloadvirtualbox-f8fe689a81f906d1b91bb3220acde2a4ecb14c5b.tar.xz
virtualbox-f8fe689a81f906d1b91bb3220acde2a4ecb14c5b.zip
Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp')
-rw-r--r--src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp61
1 files changed, 61 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp b/src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp
new file mode 100644
index 00000000..d1f599c6
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/nt/RTTimerGetSystemGranularity-r0drv-nt.cpp
@@ -0,0 +1,61 @@
+/* $Id: RTTimerGetSystemGranularity-r0drv-nt.cpp $ */
+/** @file
+ * IPRT - RTTimerGetSystemGranularity, Ring-0 Driver, NT.
+ */
+
+/*
+ * Copyright (C) 2006-2019 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 *
+*********************************************************************************************************************************/
+#include "the-nt-kernel.h"
+
+#include <iprt/timer.h>
+#include <iprt/errcore.h>
+#include <iprt/asm.h>
+#include <iprt/assert.h>
+
+#include "internal-r0drv-nt.h"
+#include "internal/magics.h"
+
+
+RTDECL(uint32_t) RTTimerGetSystemGranularity(void)
+{
+ /*
+ * Get the default/max timer increment value, return it if ExSetTimerResolution
+ * isn't available. According to the sysinternals guys NtQueryTimerResolution
+ * is only available in userland and they find it equally annoying.
+ */
+ ULONG ulTimeInc = KeQueryTimeIncrement();
+ if (!g_pfnrtNtExSetTimerResolution)
+ return ulTimeInc * 100; /* The value is in 100ns, the funny NT unit. */
+
+ /*
+ * Use the value returned by ExSetTimerResolution. Since the kernel is keeping
+ * count of these calls, we have to do two calls that cancel each other out.
+ */
+ g_pfnrtNtExSetTimerResolution(ulTimeInc, TRUE);
+ ULONG ulResolution = g_pfnrtNtExSetTimerResolution(0 /*ignored*/, FALSE);
+ return ulResolution * 100; /* NT -> ns */
+}
+