internal unsafe MemoryMapFile(String fileName, String fileMappingName) {
//
// Use native API to create the file directly.
//
SafeFileHandle fileHandle = Win32Native.UnsafeCreateFile(fileName, FileStream.GENERIC_READ, FileShare.Read, null, FileMode.Open, 0, IntPtr.Zero);
int lastError = Marshal.GetLastWin32Error();
if (fileHandle.IsInvalid)
{
BCLDebug.Assert(false, "Failed to create file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
int highSize;
int lowSize = Win32Native.GetFileSize(fileHandle, out highSize);
if (lowSize == Win32Native.INVALID_FILE_SIZE)
{
BCLDebug.Assert(false, "Failed to get the file size of " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
fileSize = (((long) highSize) << 32) | ((uint) lowSize);
if (fileSize == 0)
{
// we cannot map zero size file. the caller should check for the file size.
fileHandle.Close();
return;
}
SafeFileMappingHandle fileMapHandle = Win32Native.CreateFileMapping(fileHandle, IntPtr.Zero, PAGE_READONLY, 0, 0, fileMappingName);
fileHandle.Close();
lastError = Marshal.GetLastWin32Error();
if (fileMapHandle.IsInvalid) {
BCLDebug.Assert(false, "Failed to create file mapping for file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
viewOfFileHandle = Win32Native.MapViewOfFile(fileMapHandle, SECTION_MAP_READ, 0, 0, UIntPtr.Zero);
lastError = Marshal.GetLastWin32Error();
if (viewOfFileHandle.IsInvalid) {
BCLDebug.Assert(false, "Failed to map a view of file " + fileName + ", GetLastError = " + lastError);
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError));
}
bytes = (byte*)viewOfFileHandle.DangerousGetHandle ();
fileMapHandle.Close();
}
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;
}
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;
}