private void ProcessPipeMessage()
{
NativeOverlapped overlapped = new NativeOverlapped();
byte[] readMessage;
using (MemoryStream ms = new MemoryStream())
{
while (true)
{
// Loop as follows:
// Peek at the pipe to see how much data is available
// Read the data and append it to the buffer
// If we get ERROR_MORE_DATA, repeat
UInt32 bytesRead, bytesAvailable, bytesLeft;
// First peek into the pipe to see how much data is waiting.
byte[] peekBuf = new byte[0];
if (!PeekNamedPipe(Handle, peekBuf, (UInt32)peekBuf.Length, out bytesRead, out bytesAvailable, out bytesLeft))
{
throw new Win32Exception(
string.Format("PeekNamedPipe failed. bytesRead={0} bytesAvailable={1} bytesLeft={2}",
bytesRead, bytesAvailable, bytesLeft),
new Win32Exception());
}
// Sanity check: throw away message if it is > 1 MB
if (ms.Length + bytesLeft > 1024 * 1024)
{
throw new Exception("Indecently large message sent into named pipe: rejecting.");
}
// Now allocate a buffer of the correct size and read in the message.
byte[] readBuf = new byte[bytesAvailable];
if (!ReadFile(Handle, readBuf, (UInt32)readBuf.Length, out bytesRead, ref overlapped))
{
Win32Exception exn = new Win32Exception();
if (exn.NativeErrorCode == ERROR_MORE_DATA)
{
// The peek may have looked into the pipe before the write operation
// had completed, and so reported a message size before the whole
// message was sent. In this case we need to go round the loop again
// with a larger buffer.
ms.Write(readBuf, 0, (int)bytesRead);
continue;
}
else
{
throw new Win32Exception(
string.Format("ReadFile failed. readBuf.Length={0} bytesRead={1}",
readBuf.Length, bytesRead), exn);
}
}
else
{
ms.Write(readBuf, 0, (int)bytesRead);
break;
}
}
readMessage = ms.ToArray();
}
// Now perform a zero-byte write. This causes the CallNamedPipe call to
// return successfully in the splash screen.
UInt32 bytesWritten;
byte[] toWrite = new byte[0];
if (!WriteFile(Handle, toWrite, (UInt32)toWrite.Length, out bytesWritten, ref overlapped))
{
throw new Win32Exception(
string.Format("WriteFile failed. toWrite.Length={0} bytesWritten={1}",
toWrite.Length, bytesWritten),
new Win32Exception());
}
PipeReadEventArgs e = new PipeReadEventArgs(readMessage);
if (e.Message == STOP_LISTENING_MSG)
{
log.Debug("NamedPipe thread was told to stop listening");
run = false;
return;
}
// Now inform any listeners of the received data.
if (Read != null)
{
Read(null, e);
}
}
private void ProcessPipeMessage()
{
NativeOverlapped overlapped = new NativeOverlapped();
byte[] readMessage;
using (MemoryStream ms = new MemoryStream())
{
while (true)
{
// Loop as follows:
// Peek at the pipe to see how much data is available
// Read the data and append it to the buffer
// If we get ERROR_MORE_DATA, repeat
UInt32 bytesRead, bytesAvailable, bytesLeft;
// First peek into the pipe to see how much data is waiting.
byte[] peekBuf = new byte[0];
if (!PeekNamedPipe(Handle, peekBuf, (UInt32)peekBuf.Length, out bytesRead, out bytesAvailable, out bytesLeft))
{
throw new Win32Exception(
string.Format("PeekNamedPipe failed. bytesRead={0} bytesAvailable={1} bytesLeft={2}",
bytesRead, bytesAvailable, bytesLeft),
new Win32Exception());
}
// Sanity check: throw away message if it is > 1 MB
if (ms.Length + bytesLeft > 1024 * 1024)
{
throw new Exception("Indecently large message sent into named pipe: rejecting.");
}
// Now allocate a buffer of the correct size and read in the message.
byte[] readBuf = new byte[bytesAvailable];
if (!ReadFile(Handle, readBuf, (UInt32)readBuf.Length, out bytesRead, ref overlapped))
{
Win32Exception exn = new Win32Exception();
if (exn.NativeErrorCode == ERROR_MORE_DATA)
{
// The peek may have looked into the pipe before the write operation
// had completed, and so reported a message size before the whole
// message was sent. In this case we need to go round the loop again
// with a larger buffer.
ms.Write(readBuf, 0, (int)bytesRead);
continue;
}
else
{
throw new Win32Exception(
string.Format("ReadFile failed. readBuf.Length={0} bytesRead={1}",
readBuf.Length, bytesRead), exn);
}
}
else
{
ms.Write(readBuf, 0, (int)bytesRead);
break;
}
}
readMessage = ms.ToArray();
}
// Now perform a zero-byte write. This causes the CallNamedPipe call to
// return successfully in the splash screen.
UInt32 bytesWritten;
byte[] toWrite = new byte[0];
if (!WriteFile(Handle, toWrite, (UInt32)toWrite.Length, out bytesWritten, ref overlapped))
{
throw new Win32Exception(
string.Format("WriteFile failed. toWrite.Length={0} bytesWritten={1}",
toWrite.Length, bytesWritten),
new Win32Exception());
}
PipeReadEventArgs e = new PipeReadEventArgs(readMessage);
if (e.Message == STOP_LISTENING_MSG)
{
log.Debug("NamedPipe thread was told to stop listening");
run = false;
return;
}
// Now inform any listeners of the received data.
if (Read != null)
{
Read(null, e);
}
}
