public Segment(string name, SharedMemoryCreationFlag creationFlag, int size)
{
if (string.IsNullOrEmpty(name))
{
throw new SharedMemoryException("You must supply a segment name");
}
if (size <= 0 && creationFlag == SharedMemoryCreationFlag.Create)
{
throw new SharedMemoryException("Size must be postive and non-zero");
}
// Create unique named mutex
guard = new Mutex(false, "m" + name);
// Create or attach to shared memory segment
if (creationFlag == SharedMemoryCreationFlag.Create)
{
nativeHandle = Win32Native.CreateFileMapping((IntPtr)Win32Native.INVALID_HANDLE_VALUE,
IntPtr.Zero,
Win32Native.ProtectionLevel.PAGE_READWRITE,
0,
size,
name);
}
else
{
nativeHandle = Win32Native.OpenFileMapping(Win32Native.FileMap.FILE_MAP_ALL_ACCESS, true, name);
}
if (nativeHandle == IntPtr.Zero)
{
uint i = Win32Native.GetLastError();
if (i == Win32Native.ERROR_INVALID_HANDLE)
{
throw new SharedMemoryException("Shared memory segment already in use");
}
else
{
throw new SharedMemoryException("Unable to access shared memory segment. GetLastError = " + i);
}
}
// Get pointer to shared memory segment
nativePointer = Win32Native.MapViewOfFile(nativeHandle, Win32Native.FileMap.FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (nativePointer == IntPtr.Zero)
{
uint i = Win32Native.GetLastError();
Win32Native.CloseHandle(nativeHandle);
nativeHandle = IntPtr.Zero;
throw new SharedMemoryException("Unable to map shared memory segment. GetLastError = " + i);
}
this.currentSize = size;
}
public Segment(string name, SharedMemoryCreationFlag creationFlag, int size)
{
if (String.IsNullOrEmpty(name))
{
throw new SharedMemoryException("You must supply a segment name");
}
if (size <= 0 && creationFlag == SharedMemoryCreationFlag.Create)
{
throw new SharedMemoryException("Size must be postive and non-zero");
}
// Create unique named mutex
guard = new Mutex(false, name + "Mutex");
// Create or attach to shared memory segment
if (creationFlag == SharedMemoryCreationFlag.Create)
{
nativeHandle = Win32Native.CreateFileMapping((IntPtr)Win32Native.INVALID_HANDLE_VALUE,
IntPtr.Zero,
Win32Native.ProtectionLevel.PAGE_READWRITE,
0,
size,
name);
}
else
{
nativeHandle = Win32Native.OpenFileMapping(Win32Native.FileMap.FILE_MAP_ALL_ACCESS, true, name);
}
if (nativeHandle == IntPtr.Zero)
{
int i = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
if (i == Win32Native.ERROR_INVALID_HANDLE)
throw new SharedMemoryException("Shared memory segment already in use");
else
throw new SharedMemoryException("Unable to access shared memory segment. GetLastError = " + i);
}
// Get pointer to shared memory segment
nativePointer = Win32Native.MapViewOfFile(nativeHandle, Win32Native.FileMap.FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (nativePointer == IntPtr.Zero)
{
int i = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
Win32Native.CloseHandle(nativeHandle);
nativeHandle = IntPtr.Zero;
throw new SharedMemoryException("Unable to map shared memory segment. GetLastError = " + i);
}
this.currentSize = size;
}
