public static void ClearFileSystemCache(bool ClearStandbyCache)
{
SetIncreasePrivilege(SE_INCREASE_QUOTA_NAME);
//clear the active file system cache
int iReturn;
if (!Is64BitMode())
{
SYSTEM_CACHE_INFORMATION info = new SYSTEM_CACHE_INFORMATION();
info.MinimumWorkingSet = uint.MaxValue; //means to clear the active file system cache
info.MaximumWorkingSet = uint.MaxValue; //means to clear the active file system cache
int iSize = Marshal.SizeOf(info);
GCHandle gch = GCHandle.Alloc(info, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
}
else
{
SYSTEM_CACHE_INFORMATION_64_BIT info = new SYSTEM_CACHE_INFORMATION_64_BIT();
info.MinimumWorkingSet = -1; //means to clear the active file system cache
info.MaximumWorkingSet = -1; //means to clear the active file system cache
int iSize = Marshal.SizeOf(info);
GCHandle gch = GCHandle.Alloc(info, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
}
if (iReturn != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMCACHEINFORMATION) error: ", new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error()));
}
if (ClearStandbyCache)
{
try
{
SetIncreasePrivilege(SE_PROFILE_SINGLE_PROCESS_NAME);
int iSize = Marshal.SizeOf(ClearStandbyPageList);
GCHandle gch = GCHandle.Alloc(ClearStandbyPageList, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
if (iReturn != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION) error: ", new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error()));
}
}
catch (Exception ex)
{
Context.TraceEvent(1, 101, "Problem clearing standby cache with API call: " + ex.Message);
//this is a fallback if the API call doesn't work on an older OS
ClearStandbyFileSystemCacheByConsumingAvailableMemory();
}
}
}
public static void ClearFileSystemCache(bool clearStandbyCache)
{
SetIncreasePrivilege(SE_INCREASE_QUOTA_NAME);
// clear the active file system cache
int iReturn;
if (!Is64BitMode())
{
SYSTEM_CACHE_INFORMATION info = new SYSTEM_CACHE_INFORMATION();
info.MinimumWorkingSet = uint.MaxValue; // means to clear the active file system cache
info.MaximumWorkingSet = uint.MaxValue; // means to clear the active file system cache
int iSize = Marshal.SizeOf(info);
GCHandle gch = GCHandle.Alloc(info, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
}
else
{
SYSTEM_CACHE_INFORMATION_64_BIT info = new SYSTEM_CACHE_INFORMATION_64_BIT();
info.MinimumWorkingSet = -1; // means to clear the active file system cache
info.MaximumWorkingSet = -1; // means to clear the active file system cache
int iSize = Marshal.SizeOf(info);
GCHandle gch = GCHandle.Alloc(info, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
}
if (iReturn != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMCACHEINFORMATION) error: ", new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error()));
}
if (clearStandbyCache)
{
try
{
SetIncreasePrivilege(SE_PROFILE_SINGLE_PROCESS_NAME);
int iSize = Marshal.SizeOf(ClearStandbyPageList);
GCHandle gch = GCHandle.Alloc(ClearStandbyPageList, GCHandleType.Pinned);
iReturn = NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION, gch.AddrOfPinnedObject(), iSize);
gch.Free();
if (iReturn != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION) error: ", new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error()));
}
}
catch (Exception ex)
{
Console.WriteLine("Problem clearing standby cache with API call: " + ex.Message);
// this is a fallback if the API call doesn't work on an older OS
ClearStandbyFileSystemCacheByConsumingAvailableMemory();
}
}
}
//Function used to clear file system cache, returns boolean
public void ClearFileSystemCache(bool ClearStandbyCache)
{
try
{
//Check if privilege can be increased
if (SetIncreasePrivilege(SE_INCREASE_QUOTA_NAME))
{
uint num1;
int SystemInfoLength;
GCHandle gcHandle;
//First check which version is running, then fill structure with cache information. Throw error is cache information cannot be read.
if (!Is64BitMode())
{
SYSTEM_CACHE_INFORMATION cacheInformation = new SYSTEM_CACHE_INFORMATION();
cacheInformation.MinimumWorkingSet = uint.MaxValue;
cacheInformation.MaximumWorkingSet = uint.MaxValue;
SystemInfoLength = Marshal.SizeOf(cacheInformation);
gcHandle = GCHandle.Alloc(cacheInformation, GCHandleType.Pinned);
num1 = NtSetSystemInformation(SystemFileCacheInformation, gcHandle.AddrOfPinnedObject(), SystemInfoLength);
gcHandle.Free();
}
else
{
SYSTEM_CACHE_INFORMATION_64_BIT information64Bit = new SYSTEM_CACHE_INFORMATION_64_BIT();
information64Bit.MinimumWorkingSet = -1L;
information64Bit.MaximumWorkingSet = -1L;
SystemInfoLength = Marshal.SizeOf(information64Bit);
gcHandle = GCHandle.Alloc(information64Bit, GCHandleType.Pinned);
num1 = NtSetSystemInformation(SystemFileCacheInformation, gcHandle.AddrOfPinnedObject(), SystemInfoLength);
gcHandle.Free();
}
if (num1 != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMCACHEINFORMATION) error: ", new Win32Exception(Marshal.GetLastWin32Error()));
}
}
//If passes paramater is 'true' and the privilege can be increased, then clear standby lists through MemoryPurgeStandbyList
if (ClearStandbyCache && SetIncreasePrivilege(SE_PROFILE_SINGLE_PROCESS_NAME))
{
int SystemInfoLength = Marshal.SizeOf(MemoryPurgeStandbyList);
GCHandle gcHandle = GCHandle.Alloc(MemoryPurgeStandbyList, GCHandleType.Pinned);
uint num2 = NtSetSystemInformation(SystemMemoryListInformation, gcHandle.AddrOfPinnedObject(), SystemInfoLength);
gcHandle.Free();
if (num2 != 0)
{
throw new Exception("NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION) error: ", new Win32Exception(Marshal.GetLastWin32Error()));
}
}
}
catch (Exception ex)
{
Console.Write(ex.ToString());
}
}
/// <summary>
/// Clear the active file system cache
/// </summary>
public static void ClearFileSystemCache(bool clearStandbyCache)
{
SetIncreasePrivilege(SE_INCREASE_QUOTA_NAME);
int result;
if (!Is64BitMode())
{
var info = new SYSTEM_CACHE_INFORMATION
{
MinimumWorkingSet = uint.MaxValue, //means to clear the active file system cache
MaximumWorkingSet = uint.MaxValue //means to clear the active file system cache
};
int iSize = Marshal.SizeOf(info);
var gch = GCHandle.Alloc(info, GCHandleType.Pinned);
try
{
result = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
}
finally
{
gch.Free();
}
}
else
{
var info = new SYSTEM_CACHE_INFORMATION_64_BIT
{
MinimumWorkingSet = -1, //means to clear the active file system cache
MaximumWorkingSet = -1 //means to clear the active file system cache
};
int iSize = Marshal.SizeOf(info);
var gch = GCHandle.Alloc(info, GCHandleType.Pinned);
try
{
result = NtSetSystemInformation(SYSTEMCACHEINFORMATION, gch.AddrOfPinnedObject(), iSize);
}
finally
{
gch.Free();
}
}
if (result != 0)
{
throw new ApplicationException("NtSetSystemInformation(SYSTEMCACHEINFORMATION) error", new Win32Exception(Marshal.GetLastWin32Error()));
}
if (clearStandbyCache)
{
try
{
SetIncreasePrivilege(SE_PROFILE_SINGLE_PROCESS_NAME);
int iSize = Marshal.SizeOf(ClearStandbyPageList);
var gch = GCHandle.Alloc(ClearStandbyPageList, GCHandleType.Pinned);
try
{
result = NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION, gch.AddrOfPinnedObject(), iSize);
}
finally
{
gch.Free();
}
if (result != 0)
{
throw new ApplicationException("NtSetSystemInformation(SYSTEMMEMORYLISTINFORMATION) error", new Win32Exception(Marshal.GetLastWin32Error()));
}
}
catch
{
//this is a fallback if the API call doesn't work on an older OS
ClearStandbyFileSystemCacheByConsumingAvailableMemory();
}
}
}
public static extern uint ZwQuerySystemInformation(SYSTEM_INFORMATION_CLASS SystemInformationClass,
ref SYSTEM_CACHE_INFORMATION SystemInformation, int SystemInformationLength, out int ReturnLength);
public static extern uint ZwQuerySystemInformation(SYSTEM_INFORMATION_CLASS SystemInformationClass,
ref SYSTEM_CACHE_INFORMATION SystemInformation, int SystemInformationLength, out int ReturnLength);
