private static bool GetView(SafeFileMappingHandle fileMapping, bool writable, out SafeViewOfFileHandle handle)
{
handle = UnsafeNativeMethods.MapViewOfFile(fileMapping, writable ? 2 : 4, 0, 0, (IntPtr) sizeof(SharedMemoryContents));
int error = Marshal.GetLastWin32Error();
if (!handle.IsInvalid)
{
return true;
}
handle.SetHandleAsInvalid();
fileMapping.Close();
if (writable || (error != 2))
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(error));
}
return false;
}
public static unsafe SharedMemory Create(string name, Guid content, List<SecurityIdentifier> allowedSids)
{
int errorCode = UnsafeNativeMethods.ERROR_SUCCESS;
byte[] binarySecurityDescriptor = SecurityDescriptorHelper.FromSecurityIdentifiers(allowedSids, UnsafeNativeMethods.GENERIC_READ);
SafeFileMappingHandle fileMapping;
UnsafeNativeMethods.SECURITY_ATTRIBUTES securityAttributes = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
fixed (byte* pinnedSecurityDescriptor = binarySecurityDescriptor)
{
securityAttributes.lpSecurityDescriptor = (IntPtr)pinnedSecurityDescriptor;
fileMapping = UnsafeNativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes, UnsafeNativeMethods.PAGE_READWRITE, 0, sizeof(SharedMemoryContents), name);
errorCode = Marshal.GetLastWin32Error();
}
if (fileMapping.IsInvalid)
{
fileMapping.SetHandleAsInvalid();
fileMapping.Close();
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
}
SharedMemory sharedMemory = new SharedMemory(fileMapping);
SafeViewOfFileHandle view;
// Ignore return value.
GetView(fileMapping, true, out view);
try
{
SharedMemoryContents* contents = (SharedMemoryContents*)view.DangerousGetHandle();
contents->pipeGuid = content;
Thread.MemoryBarrier();
contents->isInitialized = true;
return sharedMemory;
}
finally
{
view.Close();
}
}
static bool GetView(SafeFileMappingHandle fileMapping, bool writable, out SafeViewOfFileHandle handle)
{
handle = UnsafeNativeMethods.MapViewOfFile(fileMapping, writable ? UnsafeNativeMethods.FILE_MAP_WRITE : UnsafeNativeMethods.FILE_MAP_READ, 0, 0, (IntPtr)sizeof(SharedMemoryContents));
int errorCode = Marshal.GetLastWin32Error();
if (!handle.IsInvalid)
{
return true;
}
else
{
handle.SetHandleAsInvalid();
fileMapping.Close();
// Only return false when it's reading time.
if (!writable && errorCode == UnsafeNativeMethods.ERROR_FILE_NOT_FOUND)
{
return false;
}
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
}
}
public unsafe static bool TryCreate(List<SecurityIdentifier> allowedSids, Uri pipeUri, string sharedMemoryName, out PipeSharedMemory result)
{
Guid pipeGuid = Guid.NewGuid();
string pipeName = BuildPipeName(pipeGuid.ToString());
byte[] binarySecurityDescriptor;
try
{
binarySecurityDescriptor = SecurityDescriptorHelper.FromSecurityIdentifiers(allowedSids, UnsafeNativeMethods.GENERIC_READ);
}
catch (Win32Exception e)
{
// While Win32exceptions are not expected, if they do occur we need to obey the pipe/communication exception model.
Exception innerException = new PipeException(e.Message, e);
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new CommunicationException(innerException.Message, innerException));
}
SafeFileMappingHandle fileMapping;
int error;
result = null;
fixed (byte* pinnedSecurityDescriptor = binarySecurityDescriptor)
{
UnsafeNativeMethods.SECURITY_ATTRIBUTES securityAttributes = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
securityAttributes.lpSecurityDescriptor = (IntPtr)pinnedSecurityDescriptor;
fileMapping = UnsafeNativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes,
UnsafeNativeMethods.PAGE_READWRITE, 0, sizeof(SharedMemoryContents), sharedMemoryName);
error = Marshal.GetLastWin32Error();
}
if (fileMapping.IsInvalid)
{
fileMapping.SetHandleAsInvalid();
if (error == UnsafeNativeMethods.ERROR_ACCESS_DENIED)
{
return false;
}
else
{
Exception innerException = new PipeException(SR.GetString(SR.PipeNameCantBeReserved,
pipeUri.AbsoluteUri, PipeError.GetErrorString(error)), error);
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new AddressAccessDeniedException(innerException.Message, innerException));
}
}
// now we have a valid file mapping handle
if (error == UnsafeNativeMethods.ERROR_ALREADY_EXISTS)
{
fileMapping.Close();
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(CreatePipeNameInUseException(error, pipeUri));
}
PipeSharedMemory pipeSharedMemory = new PipeSharedMemory(fileMapping, pipeUri, pipeName);
bool disposeSharedMemory = true;
try
{
pipeSharedMemory.InitializeContents(pipeGuid);
disposeSharedMemory = false;
result = pipeSharedMemory;
if (TD.PipeSharedMemoryCreatedIsEnabled())
{
TD.PipeSharedMemoryCreated(sharedMemoryName);
}
return true;
}
finally
{
if (disposeSharedMemory)
{
pipeSharedMemory.Dispose();
}
}
}