private static unsafe int Receive(int fd, int flags, int available, BufferList buffers, byte[] socketAddress, ref int socketAddressLen, out int receivedFlags, out Interop.Error errno)
{
// Pin buffers and set up iovecs.
int maxBuffers = buffers.Count;
var handles = new GCHandle[maxBuffers];
var iovecs = new Interop.libc.iovec[maxBuffers];
var pinnedSocketAddress = default(GCHandle);
Interop.libc.sockaddr* sockAddr = null;
uint sockAddrLen = 0;
int received = 0;
int toReceive = 0, iovCount = maxBuffers;
try
{
for (int i = 0; i < maxBuffers; i++)
{
ArraySegment<byte> buffer = buffers[i];
handles[i] = GCHandle.Alloc(buffer.Array, GCHandleType.Pinned);
iovecs[i].iov_base = &((byte*)handles[i].AddrOfPinnedObject())[buffer.Offset];
int space = buffer.Count;
toReceive += space;
if (toReceive >= available)
{
iovecs[i].iov_len = (IntPtr)(space - (toReceive - available));
toReceive = available;
iovCount = i + 1;
break;
}
iovecs[i].iov_len = (IntPtr)space;
}
if (socketAddress != null)
{
pinnedSocketAddress = GCHandle.Alloc(socketAddress, GCHandleType.Pinned);
sockAddr = (Interop.libc.sockaddr*)pinnedSocketAddress.AddrOfPinnedObject();
sockAddrLen = (uint)socketAddressLen;
}
// Make the call.
fixed (Interop.libc.iovec* iov = iovecs)
{
var msghdr = new Interop.libc.msghdr(sockAddr, sockAddrLen, iov, iovCount, null, 0, 0);
received = (int)Interop.libc.recvmsg(fd, &msghdr, flags);
receivedFlags = msghdr.msg_flags;
sockAddrLen = msghdr.msg_namelen;
}
}
finally
{
// Free GC handles.
for (int i = 0; i < iovCount; i++)
{
if (handles[i].IsAllocated)
{
handles[i].Free();
}
}
if (pinnedSocketAddress.IsAllocated)
{
pinnedSocketAddress.Free();
}
}
if (received == -1)
{
errno = Interop.Sys.GetLastError();
return -1;
}
socketAddressLen = (int)sockAddrLen;
errno = Interop.Error.SUCCESS;
return received;
}
private static unsafe int Send(int fd, int flags, BufferList buffers, ref int bufferIndex, ref int offset, byte[] socketAddress, int socketAddressLen, out Interop.Error errno)
{
// Pin buffers and set up iovecs.
int startIndex = bufferIndex, startOffset = offset;
var pinnedSocketAddress = default(GCHandle);
Interop.libc.sockaddr* sockAddr = null;
uint sockAddrLen = 0;
int maxBuffers = buffers.Count - startIndex;
var handles = new GCHandle[maxBuffers];
var iovecs = new Interop.libc.iovec[maxBuffers];
int sent;
int toSend = 0, iovCount = maxBuffers;
try
{
for (int i = 0; i < maxBuffers; i++, startOffset = 0)
{
ArraySegment<byte> buffer = buffers[startIndex + i];
Debug.Assert(buffer.Offset + startOffset < buffer.Array.Length);
handles[i] = GCHandle.Alloc(buffer.Array, GCHandleType.Pinned);
iovecs[i].iov_base = &((byte*)handles[i].AddrOfPinnedObject())[buffer.Offset + startOffset];
toSend += (buffer.Count - startOffset);
iovecs[i].iov_len = (IntPtr)(buffer.Count - startOffset);
}
if (socketAddress != null)
{
pinnedSocketAddress = GCHandle.Alloc(socketAddress, GCHandleType.Pinned);
sockAddr = (Interop.libc.sockaddr*)pinnedSocketAddress.AddrOfPinnedObject();
sockAddrLen = (uint)socketAddressLen;
}
// Make the call
fixed (Interop.libc.iovec* iov = iovecs)
{
var msghdr = new Interop.libc.msghdr(sockAddr, sockAddrLen, iov, iovCount, null, 0, 0);
sent = (int)Interop.libc.sendmsg(fd, &msghdr, flags);
}
errno = Interop.Sys.GetLastError();
}
finally
{
// Free GC handles.
for (int i = 0; i < iovCount; i++)
{
if (handles[i].IsAllocated)
{
handles[i].Free();
}
}
if (pinnedSocketAddress.IsAllocated)
{
pinnedSocketAddress.Free();
}
}
if (sent == -1)
{
return -1;
}
// Update position.
int endIndex = bufferIndex, endOffset = offset, unconsumed = sent;
for (; endIndex < buffers.Count && unconsumed > 0; endIndex++, endOffset = 0)
{
int space = buffers[endIndex].Count - endOffset;
if (space > unconsumed)
{
endOffset += unconsumed;
break;
}
unconsumed -= space;
}
bufferIndex = endIndex;
offset = endOffset;
return sent;
}
public static SocketError Send(SafeCloseSocket handle, IList<ArraySegment<byte>> buffers, SocketFlags socketFlags, out int bytesTransferred)
{
var bufferList = new BufferList(buffers);
int platformFlags = GetPlatformSocketFlags(socketFlags);
if (!handle.IsNonBlocking)
{
return handle.AsyncContext.Send(bufferList, platformFlags, handle.SendTimeout, out bytesTransferred);
}
bytesTransferred = 0;
int bufferIndex = 0;
int offset = 0;
SocketError errorCode;
bool completed = TryCompleteSendTo(handle.FileDescriptor, bufferList, ref bufferIndex, ref offset, platformFlags, null, 0, ref bytesTransferred, out errorCode);
return completed ? errorCode : SocketError.WouldBlock;
}
public static bool TryCompleteSendTo(int fileDescriptor, byte[] buffer, BufferList buffers, ref int bufferIndex, ref int offset, ref int count, int flags, byte[] socketAddress, int socketAddressLen, ref int bytesSent, out SocketError errorCode)
{
for (;;)
{
int sent;
Interop.Error errno;
if (buffer != null)
{
sent = Send(fileDescriptor, flags, buffer, ref offset, ref count, socketAddress, socketAddressLen, out errno);
}
else
{
Debug.Assert(buffers.IsInitialized);
sent = Send(fileDescriptor, flags, buffers, ref bufferIndex, ref offset, socketAddress, socketAddressLen, out errno);
}
if (sent == -1)
{
if (errno != Interop.Error.EAGAIN && errno != Interop.Error.EWOULDBLOCK)
{
errorCode = GetSocketErrorForErrorCode(errno);
return true;
}
errorCode = SocketError.Success;
return false;
}
bytesSent += sent;
bool isComplete = sent == 0 ||
(buffer != null && count == 0) ||
(buffers.IsInitialized && bufferIndex == buffers.Count);
if (isComplete)
{
errorCode = SocketError.Success;
return true;
}
}
}
public static bool TryCompleteSendTo(int fileDescriptor, BufferList buffers, ref int bufferIndex, ref int offset, int flags, byte[] socketAddress, int socketAddressLen, ref int bytesSent, out SocketError errorCode)
{
int count = 0;
return TryCompleteSendTo(fileDescriptor, null, buffers, ref bufferIndex, ref offset, ref count, flags, socketAddress, socketAddressLen, ref bytesSent, out errorCode);
}
public static unsafe bool TryCompleteReceiveFrom(int fileDescriptor, byte[] buffer, BufferList buffers, int offset, int count, int flags, byte[] socketAddress, ref int socketAddressLen, out int bytesReceived, out int receivedFlags, out SocketError errorCode)
{
int available;
int err = Interop.libc.ioctl(fileDescriptor, (UIntPtr)Interop.libc.FIONREAD, &available);
if (err == -1)
{
bytesReceived = 0;
receivedFlags = 0;
errorCode = GetLastSocketError();
return true;
}
if (available == 0)
{
// Always request at least one byte.
available = 1;
}
int received;
Interop.Error errno;
if (buffer != null)
{
received = Receive(fileDescriptor, flags, available, buffer, offset, count, socketAddress, ref socketAddressLen, out receivedFlags, out errno);
}
else
{
Debug.Assert(buffers.IsInitialized);
received = Receive(fileDescriptor, flags, available, buffers, socketAddress, ref socketAddressLen, out receivedFlags, out errno);
}
if (received != -1)
{
bytesReceived = received;
errorCode = SocketError.Success;
return true;
}
bytesReceived = 0;
if (errno != Interop.Error.EAGAIN && errno != Interop.Error.EWOULDBLOCK)
{
errorCode = GetSocketErrorForErrorCode(errno);
return true;
}
errorCode = SocketError.Success;
return false;
}