private void ProcessSend(SocketAsyncEventArgs e)
{
SendingContext sctx = null;
try {
sctx = (SendingContext)e.UserToken;
if (e.SocketError != SocketError.Success)
{
var err = e.SocketError;
ProcessSendFailed(sctx.SendingBatch, RpcErrorCode.SendFailed, new Exception("Send Body Failed: " + err));
Disconnect(e.SocketError);
RpcTcpBufferManager.Release(e);
e = null;
}
else
{
_tracing.InfoFmt("Socket Send {0} Bytes", e.Count);
RpcTcpBufferManager.Release(e);
e = null;
SendPackets(sctx.NextPacket);
}
} catch (Exception ex) {
_tracing.ErrorFmt(ex, "ProcessSend Failed {0}:{1}", e, e.Buffer.Length);
Disconnect(ex, "ProcessSend");
} finally {
//
// 保护，如果出现了异常，则在此处释放
if (e != null)
{
RpcTcpBufferManager.Release(e);
}
}
}
/// <summary>
/// 发送报文
/// 如果sendFirst == null, 则优先从queue中dequeue
/// 否则, 先取出sendFirst, 然后再从queue中取
/// 这是一个回调链，完全靠回调组织起来的，当_sending = 1时，存在一个回调链
/// </summary>
/// <param name="sendFirst"></param>
private void SendPackets(IRpcTcpSendingPacket sendFirst)
{
int size;
SocketAsyncEventArgs eSend = null;
List <IRpcTcpSendingPacket> batch = new List <IRpcTcpSendingPacket>();
//
// 阶段1. 获得第一个能够发送的报文
try {
//
// 先至少放置一个报文进去
if (sendFirst != null)
{
batch.Add(sendFirst);
}
else
{
if (_pendingPackets.Count == 0)
{
//
// 回调链的最终返回，只有当Queue完全清空以后，置空标记位
_sending = 0;
return;
}
else
{
lock (_syncSend) {
batch.Add(_pendingPackets.Dequeue());
}
_counter.SendPending.Decrement();
}
}
//
// 获取第一个包的大小, 并估算对缓冲区的大小的需求
size = GetExpectSize(batch[0]);
} catch (Exception ex) {
//
// 在上面的代码块中如果出现异常，则本次发送失败
_tracing.ErrorFmt(ex, "SendPackets 1 failed");
ProcessSendFailed(batch, RpcErrorCode.SendFailed, ex);
//
// 扔出异常会导致连接断开，所以直接引发下一个调用链
SendPackets(null);
return;
}
//
// 阶段2. 获取缓冲区，并写入数据
try {
//
// 创建缓冲区, 如果过大会建立新缓冲区
eSend = RpcTcpBufferManager.FetchSendArgs(size, _pendingPackets.Count);
MemoryStream stream = new MemoryStream(eSend.Buffer, 0, eSend.Buffer.Length, true, true);
int bufferRemain = eSend.Buffer.Length;
//
// 写入第一个报文
TryWriteBuffer(batch[0], stream, bufferRemain);
bufferRemain = bufferRemain - (int)stream.Position;
//
// 尝试向缓冲区内放置能够发送出去的最多的报文
IRpcTcpSendingPacket packet = null;
while (true)
{
if (_pendingPackets.Count > 0)
{
lock (_syncSend) {
if (_pendingPackets.Count > 0)
{
packet = _pendingPackets.Dequeue();
}
}
_counter.SendPending.Decrement();
}
else
{
break;
}
int offsetBefore = (int)stream.Position;
if (TryWriteBuffer(packet, stream, bufferRemain))
{
batch.Add(packet);
packet = null;
}
else
{
break;
}
int offsetAfter = (int)stream.Position;
bufferRemain = bufferRemain - (offsetAfter - offsetBefore);
}
int bufferSize = (int)stream.Position;
_counter.SendPerSec.Increment();
_counter.SendTotal.Increment();
_counter.SendMessageTotal.IncrementBy(batch.Count);
_counter.SendMessagePerSec.IncrementBy(batch.Count);
_counter.SendBytesPerSec.IncrementBy(bufferSize);
_counter.SendBytesTotal.IncrementBy(bufferSize);
eSend.UserToken = new SendingContext()
{
NextPacket = packet,
SendingBatch = batch,
};
if (eSend is RpcTcpAsyncArgs)
{
((RpcTcpAsyncArgs)eSend).Callback = delegate(SocketAsyncEventArgs e) {
ProcessSend(e);
};
}
else
{
eSend.Completed += new EventHandler <SocketAsyncEventArgs>(
(sender, e) => ProcessSend(e)
);
}
eSend.SetBuffer(0, bufferSize);
} catch (Exception ex) {
//
// 无论如何，先交回缓冲区
RpcTcpBufferManager.Release(eSend);
//
// 在组织缓冲区的代码块中如果出现异常，则本次发送失败，整批失败
_tracing.ErrorFmt(ex, "SendPackets 2 failed");
ProcessSendFailed(batch, RpcErrorCode.SendFailed, ex);
//
// 扔出异常会导致连接断开，所以直接引发下一个调用链
SendPackets(null);
return;
}
if (!_socket.SendAsync(eSend))
{
ProcessSend(eSend);
}
}
/// <summary>
/// 断开连接，这个方法不会抛出异常
/// </summary>
/// <param name="err"></param>
public void Close(Exception err)
{
if (_closed)
{
return;
}
else
{
lock (_syncClose) {
if (_closed)
{
return;
}
else
{
_closed = true;
_connected = false;
}
}
}
_counter.Connections.Decrement();
if (_socket.Connected)
{
_socket.Shutdown(SocketShutdown.Both);
}
_socket.Close();
_releasing = true;
var l = new List <IRpcTcpSendingPacket>();
lock (_syncSend) {
while (_pendingPackets.Count > 0)
{
l.Add(_pendingPackets.Dequeue());
}
_pendingPackets.Clear();
}
if (l.Count > 0)
{
_counter.SendPending.IncrementBy(-l.Count);
ProcessSendFailed(l, RpcErrorCode.SendFailed, err);
}
if (_eRecv != null)
{
//
// TODO: 应该有更优雅的实现方式
// 最好 _eRecv有一个opertion的标志位， 如果正在recieve中，就在receive返回后Release(_eRecv),否则在此处release
Thread.Sleep(500);
RpcTcpBufferManager.Release(_eRecv);
}
if (err != null)
{
_counter.CorruptedTransmissions.Increment();
}
if (Disconnected != null)
{
Disconnected(this);
}
}
