internal static extern IntPtr MapViewOfFile(
SafeFileMappingHandle handle, uint dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow, UIntPtr dwNumerOfBytesToMap);
protected unsafe byte* GetSharedMemory(int iSize)
{
// Build our name
String strName = GetMemorySectionName();
IntPtr mappedFileHandle;
// This gets shared memory for our map. If its can't, it gives us clean memory.
Byte *pMemorySection = EncodingTable.nativeCreateOpenFileMapping(strName, iSize, out mappedFileHandle);
Contract.Assert(pMemorySection != null,
"[BaseCodePageEncoding.GetSharedMemory] Expected non-null memory section to be opened");
// If that failed, we have to die.
if (pMemorySection == null)
throw new OutOfMemoryException(
Environment.GetResourceString("Arg_OutOfMemoryException"));
// if we have null file handle. this means memory was allocated after
// failing to open the mapped file.
if (mappedFileHandle != IntPtr.Zero)
{
safeMemorySectionHandle = new SafeViewOfFileHandle((IntPtr) pMemorySection, true);
safeFileMappingHandle = new SafeFileMappingHandle(mappedFileHandle, true);
}
return pMemorySection;
}
internal static extern SafeFileMapViewHandle MapViewOfFile(SafeFileMappingHandle hFileMappingObject, int dwDesiredAccess, int dwFileOffsetHigh, int dwFileOffsetLow, UIntPtr dwNumberOfBytesToMap);
internal static extern SafeFileMapViewHandle MapViewOfFile(SafeFileMappingHandle hFileMappingObject, int dwDesiredAccess, int dwFileOffsetHigh, int dwFileOffsetLow, UIntPtr dwNumberOfBytesToMap);
private void Map() {
if (m_Disposed) {
// This can happen in the case where an IsolatedStorageFileStream is used after the underlying IsolatedStorageFile object is disposed.
// which we allowed in Silverlight 3. If this is the case, we will rebuild our state.
Init();
m_Disposed = false;
GC.ReRegisterForFinalize(this);
}
if (m_QuotaFileMapping == null || m_QuotaFileMapping.IsInvalid) {
m_QuotaFileMapping = Win32Native.CreateFileMapping(m_QuotaFileStream.SafeFileHandle, IntPtr.Zero, Win32Native.PAGE_READWRITE, 0, 0, null);
if (m_QuotaFileMapping.IsInvalid) {
throw Marshal.GetExceptionForHR(Marshal.GetLastWin32Error());
}
}
if (m_UsedSizeFileMapping == null || m_UsedSizeFileMapping.IsInvalid) {
m_UsedSizeFileMapping = Win32Native.CreateFileMapping(m_UsedSizeFileStream.SafeFileHandle, IntPtr.Zero, Win32Native.PAGE_READWRITE, 0, 0, null);
if (m_UsedSizeFileMapping.IsInvalid) {
throw Marshal.GetExceptionForHR(Marshal.GetLastWin32Error());
}
}
m_QuotaView = Win32Native.MapViewOfFile(m_QuotaFileMapping, Win32Native.FILE_MAP_WRITE | Win32Native.FILE_MAP_READ, 0, 0, UIntPtr.Zero);
if (m_QuotaView == IntPtr.Zero) {
throw Marshal.GetExceptionForHR(Marshal.GetLastWin32Error());
}
m_UsedSizeView = Win32Native.MapViewOfFile(m_UsedSizeFileMapping, Win32Native.FILE_MAP_WRITE | Win32Native.FILE_MAP_READ, 0, 0, UIntPtr.Zero);
if (m_UsedSizeView == IntPtr.Zero) {
throw Marshal.GetExceptionForHR(Marshal.GetLastWin32Error());
}
}
internal static extern SafeViewOfFileHandle MapViewOfFileEx(SafeFileMappingHandle hFileMappingObject, int dwDesiredAccess, int dwFileOffsetHigh, int dwFileOffsetLow, IntPtr dwNumberOfBytesToMap, IntPtr lpBaseAddress);
public void Dispose(bool disposing) {
lock(this) {
if (!m_Disposed) {
if (disposing) {
if (m_QuotaFileStream != null) {
m_QuotaFileStream.Dispose();
m_QuotaFileStream = null;
}
if (m_UsedSizeFileStream != null) {
m_UsedSizeFileStream.Dispose();
m_UsedSizeFileStream = null;
}
if (m_QuotaFileMapping != null) {
m_QuotaFileMapping.Dispose();
m_QuotaFileMapping = null;
}
if (m_UsedSizeFileMapping != null) {
m_UsedSizeFileMapping.Dispose();
m_UsedSizeFileMapping = null;
}
}
if (m_QuotaView != IntPtr.Zero) {
Win32Native.UnmapViewOfFile(m_QuotaView);
m_QuotaView = IntPtr.Zero;
}
if (m_UsedSizeView != IntPtr.Zero) {
Win32Native.UnmapViewOfFile(m_UsedSizeView);
m_UsedSizeView = IntPtr.Zero;
}
m_Disposed = true;
}
}
}
private unsafe void Initialize(string fileMappingName, int fileMappingSize, int initialOffset) {
string mappingName = fileMappingName;
SharedUtils.CheckEnvironment();
SafeLocalMemHandle securityDescriptorPointer = null;
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Assert();
try {
// The sddl string consists of these parts:
// D: it's a DACL
// (A; this is an allow ACE
// OICI; object inherit and container inherit
// FRFWGRGW;;; allow file read, file write, generic read and generic write
// AU) granted to Authenticated Users
// ;S-1-5-33) the same permission granted to AU is also granted to restricted services
string sddlString = "D:(A;OICI;FRFWGRGW;;;AU)(A;OICI;FRFWGRGW;;;S-1-5-33)";
if (!SafeLocalMemHandle.ConvertStringSecurityDescriptorToSecurityDescriptor(sddlString, NativeMethods.SDDL_REVISION_1,
out securityDescriptorPointer, IntPtr.Zero))
throw new InvalidOperationException(SR.GetString(SR.SetSecurityDescriptorFailed));
NativeMethods.SECURITY_ATTRIBUTES securityAttributes = new NativeMethods.SECURITY_ATTRIBUTES();
securityAttributes.lpSecurityDescriptor = securityDescriptorPointer;
securityAttributes.bInheritHandle = false;
//
//
// Here we call CreateFileMapping to create the memory mapped file. When CreateFileMapping fails
// with ERROR_ACCESS_DENIED, we know the file mapping has been created and we then open it with OpenFileMapping.
//
// There is chance of a race condition between CreateFileMapping and OpenFileMapping; The memory mapped file
// may actually be closed in between these two calls. When this happens, OpenFileMapping returns ERROR_FILE_NOT_FOUND.
// In this case, we need to loop back and retry creating the memory mapped file.
//
// This loop will timeout in approximately 1.4 minutes. An InvalidOperationException is thrown in the timeout case.
//
//
int waitRetries = 14; //((2^13)-1)*10ms == approximately 1.4mins
int waitSleep = 0;
bool created = false;
while (!created && waitRetries > 0) {
fileMappingHandle = NativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes,
NativeMethods.PAGE_READWRITE, 0, fileMappingSize, mappingName);
if ((Marshal.GetLastWin32Error() != NativeMethods.ERROR_ACCESS_DENIED) || !fileMappingHandle.IsInvalid) {
created = true;
}
else {
// Invalidate the old safehandle before we get rid of it. This prevents it from trying to finalize
fileMappingHandle.SetHandleAsInvalid();
fileMappingHandle = NativeMethods.OpenFileMapping(NativeMethods.FILE_MAP_WRITE, false, mappingName);
if ((Marshal.GetLastWin32Error() != NativeMethods.ERROR_FILE_NOT_FOUND) || !fileMappingHandle.IsInvalid) {
created = true;
}
else {
--waitRetries;
if (waitSleep == 0) {
waitSleep = 10;
}
else {
System.Threading.Thread.Sleep(waitSleep);
waitSleep *= 2;
}
}
}
}
if (fileMappingHandle.IsInvalid) {
throw new InvalidOperationException(SR.GetString(SR.CantCreateFileMapping));
}
fileViewAddress = SafeFileMapViewHandle.MapViewOfFile(fileMappingHandle, NativeMethods.FILE_MAP_WRITE, 0,0, UIntPtr.Zero);
if (fileViewAddress.IsInvalid)
throw new InvalidOperationException(SR.GetString(SR.CantMapFileView));
// figure out what size the share memory really is.
NativeMethods.MEMORY_BASIC_INFORMATION meminfo = new NativeMethods.MEMORY_BASIC_INFORMATION();
if (NativeMethods.VirtualQuery(fileViewAddress, ref meminfo, (IntPtr) sizeof(NativeMethods.MEMORY_BASIC_INFORMATION)) == IntPtr.Zero)
throw new InvalidOperationException(SR.GetString(SR.CantGetMappingSize));
FileMappingSize = (int) meminfo.RegionSize;
}
finally {
if (securityDescriptorPointer != null) securityDescriptorPointer.Close();
SecurityPermission.RevertAssert();
}
SafeNativeMethods.InterlockedCompareExchange(fileViewAddress.DangerousGetHandle(), initialOffset, 0);
}
private void Initialize(string fileMappingName, int fileMappingSize, int initialOffset)
{
string lpName = fileMappingName;
SharedUtils.CheckEnvironment();
SafeLocalMemHandle pSecurityDescriptor = null;
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Assert();
try
{
string stringSecurityDescriptor = "D:(A;OICI;FRFWGRGW;;;AU)(A;OICI;FRFWGRGW;;;S-1-5-33)";
if (!SafeLocalMemHandle.ConvertStringSecurityDescriptorToSecurityDescriptor(stringSecurityDescriptor, 1, out pSecurityDescriptor, IntPtr.Zero))
{
throw new InvalidOperationException(SR.GetString("SetSecurityDescriptorFailed"));
}
Microsoft.Win32.NativeMethods.SECURITY_ATTRIBUTES lpFileMappingAttributes = new Microsoft.Win32.NativeMethods.SECURITY_ATTRIBUTES {
lpSecurityDescriptor = pSecurityDescriptor,
bInheritHandle = false
};
int num = 14;
int millisecondsTimeout = 0;
bool flag = false;
while (!flag && (num > 0))
{
this.fileMappingHandle = Microsoft.Win32.NativeMethods.CreateFileMapping((IntPtr) (-1), lpFileMappingAttributes, 4, 0, fileMappingSize, lpName);
if ((Marshal.GetLastWin32Error() != 5) || !this.fileMappingHandle.IsInvalid)
{
flag = true;
}
else
{
this.fileMappingHandle.SetHandleAsInvalid();
this.fileMappingHandle = Microsoft.Win32.NativeMethods.OpenFileMapping(2, false, lpName);
if ((Marshal.GetLastWin32Error() != 2) || !this.fileMappingHandle.IsInvalid)
{
flag = true;
continue;
}
num--;
if (millisecondsTimeout == 0)
{
millisecondsTimeout = 10;
}
else
{
Thread.Sleep(millisecondsTimeout);
millisecondsTimeout *= 2;
}
}
}
if (this.fileMappingHandle.IsInvalid)
{
throw new InvalidOperationException(SR.GetString("CantCreateFileMapping"));
}
this.fileViewAddress = SafeFileMapViewHandle.MapViewOfFile(this.fileMappingHandle, 2, 0, 0, UIntPtr.Zero);
if (this.fileViewAddress.IsInvalid)
{
throw new InvalidOperationException(SR.GetString("CantMapFileView"));
}
Microsoft.Win32.NativeMethods.MEMORY_BASIC_INFORMATION buffer = new Microsoft.Win32.NativeMethods.MEMORY_BASIC_INFORMATION();
if (Microsoft.Win32.NativeMethods.VirtualQuery(this.fileViewAddress, ref buffer, (IntPtr) sizeof(Microsoft.Win32.NativeMethods.MEMORY_BASIC_INFORMATION)) == IntPtr.Zero)
{
throw new InvalidOperationException(SR.GetString("CantGetMappingSize"));
}
this.FileMappingSize = (int) ((uint) buffer.RegionSize);
}
finally
{
if (pSecurityDescriptor != null)
{
pSecurityDescriptor.Close();
}
CodeAccessPermission.RevertAssert();
}
Microsoft.Win32.SafeNativeMethods.InterlockedCompareExchange(this.fileViewAddress.DangerousGetHandle(), initialOffset, 0);
}
public static extern IntPtr MapViewOfFile(
SafeFileMappingHandle hFileMappingObject,
FileMapAccess dwDesiredAccess,
uint dwFileOffsetHigh,
uint dwFileOffsetLow,
uint dwNumberOfBytesToMap);
protected unsafe byte* GetSharedMemory(int iSize)
{
IntPtr ptr;
byte* numPtr = EncodingTable.nativeCreateOpenFileMapping(this.GetMemorySectionName(), iSize, out ptr);
if (numPtr == null)
{
throw new OutOfMemoryException(Environment.GetResourceString("Arg_OutOfMemoryException"));
}
if (ptr != IntPtr.Zero)
{
this.safeMemorySectionHandle = new SafeViewOfFileHandle((IntPtr) numPtr, true);
this.safeFileMappingHandle = new SafeFileMappingHandle(ptr, true);
}
return numPtr;
}
