Windows only: Move client socket functionality from TCPClientSocket into TCPSocket.

net/socket/tcp_socket_win.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/socket/tcp_socket_win.h"
 
 #include <mstcpip.h>
 
 #include "base/logging.h"
-#include "net/base/ip_endpoint.h"
+#include "base/metrics/stats_counters.h"
+#include "base/win/windows_version.h"
+#include "net/base/address_list.h"
+#include "net/base/connection_type_histograms.h"
+#include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
+#include "net/base/network_change_notifier.h"
 #include "net/base/winsock_init.h"
 #include "net/base/winsock_util.h"
 #include "net/socket/socket_descriptor.h"
 #include "net/socket/socket_net_log_params.h"
 
 namespace net {
+namespace {

[wtc, 2013/09/06 21:55:42]

Nit: add a blank line before this line.

[yzshen1, 2013/09/09 23:14:48]

Done.

+
+const int kTCPKeepAliveSeconds = 45;

[akalin, 2013/09/05 22:52:28]

i'm assuming most of the new code here was just moved from
tcp_client_socket_win.cc?

[yzshen1, 2013/09/06 00:57:44]

Yes. A few major changes include:
- the mutiple-connect-attempts logic is split out and lives in
tcp_client_socket. (Therefore, maybe you want to look at those *Connect*()
methods.)
- the UseHistory logging logic is also split out and lives in tcp_client_socket.
- Close() is made to reset most of the internal state (except logging), so that
it is okay to reuse the object and call Create() again.

+
+bool SetSocketReceiveBufferSize(SOCKET socket, int32 size) {
+  int rv = setsockopt(socket, SOL_SOCKET, SO_RCVBUF,
+                      reinterpret_cast<const char*>(&size), sizeof(size));
+  DCHECK(!rv) << "Could not set socket receive buffer size: " << GetLastError();
+  return rv == 0;
+}
+
+bool SetSocketSendBufferSize(SOCKET socket, int32 size) {
+  int rv = setsockopt(socket, SOL_SOCKET, SO_SNDBUF,
+                      reinterpret_cast<const char*>(&size), sizeof(size));
+  DCHECK(!rv) << "Could not set socket send buffer size: " << GetLastError();
+  return rv == 0;
+}
+
+// Disable Nagle.
+// The Nagle implementation on windows is governed by RFC 896.  The idea
+// behind Nagle is to reduce small packets on the network.  When Nagle is
+// enabled, if a partial packet has been sent, the TCP stack will disallow
+// further *partial* packets until an ACK has been received from the other
+// side.  Good applications should always strive to send as much data as
+// possible and avoid partial-packet sends.  However, in most real world
+// applications, there are edge cases where this does not happen, and two
+// partial packets may be sent back to back.  For a browser, it is NEVER
+// a benefit to delay for an RTT before the second packet is sent.
+//
+// As a practical example in Chromium today, consider the case of a small
+// POST.  I have verified this:
+//     Client writes 649 bytes of header  (partial packet #1)
+//     Client writes 50 bytes of POST data (partial packet #2)
+// In the above example, with Nagle, a RTT delay is inserted between these
+// two sends due to nagle.  RTTs can easily be 100ms or more.  The best
+// fix is to make sure that for POSTing data, we write as much data as
+// possible and minimize partial packets.  We will fix that.  But disabling
+// Nagle also ensure we don't run into this delay in other edge cases.
+// See also:
+//    http://technet.microsoft.com/en-us/library/bb726981.aspx
+bool DisableNagle(SOCKET socket, bool disable) {
+  BOOL val = disable ? TRUE : FALSE;
+  int rv = setsockopt(socket, IPPROTO_TCP, TCP_NODELAY,
+                      reinterpret_cast<const char*>(&val),
+                      sizeof(val));
+  DCHECK(!rv) << "Could not disable nagle";
+  return rv == 0;
+}
+
+// Enable TCP Keep-Alive to prevent NAT routers from timing out TCP
+// connections. See http://crbug.com/27400 for details.
+bool SetTCPKeepAlive(SOCKET socket, BOOL enable, int delay_secs) {
+  int delay = delay_secs * 1000;
+  struct tcp_keepalive keepalive_vals = {
+    enable ? 1 : 0,  // TCP keep-alive on.
+    delay,  // Delay seconds before sending first TCP keep-alive packet.
+    delay,  // Delay seconds between sending TCP keep-alive packets.
+  };
+  DWORD bytes_returned = 0xABAB;
+  int rv = WSAIoctl(socket, SIO_KEEPALIVE_VALS, &keepalive_vals,
+                    sizeof(keepalive_vals), NULL, 0,
+                    &bytes_returned, NULL, NULL);
+  DCHECK(!rv) << "Could not enable TCP Keep-Alive for socket: " << socket
+              << " [error: " << WSAGetLastError() << "].";
+
+  // Disregard any failure in disabling nagle or enabling TCP Keep-Alive.
+  return rv == 0;
+}
+
+int MapConnectError(int os_error) {
+  switch (os_error) {
+    // connect fails with WSAEACCES when Windows Firewall blocks the
+    // connection.
+    case WSAEACCES:
+      return ERR_NETWORK_ACCESS_DENIED;
+    case WSAETIMEDOUT:
+      return ERR_CONNECTION_TIMED_OUT;
+    default: {
+      int net_error = MapSystemError(os_error);
+      if (net_error == ERR_FAILED)
+        return ERR_CONNECTION_FAILED;  // More specific than ERR_FAILED.
+
+      // Give a more specific error when the user is offline.
+      if (net_error == ERR_ADDRESS_UNREACHABLE &&
+          NetworkChangeNotifier::IsOffline()) {
+        return ERR_INTERNET_DISCONNECTED;
+      }
+
+      return net_error;
+    }
+  }
+}
+
+}  // namespace
+
+//-----------------------------------------------------------------------------
+
+// This class encapsulates all the state that has to be preserved as long as
+// there is a network IO operation in progress. If the owner TCPSocketWin is
+// destroyed while an operation is in progress, the Core is detached and it
+// lives until the operation completes and the OS doesn't reference any resource
+// declared on this class anymore.
+class TCPSocketWin::Core : public base::RefCounted<Core> {
+ public:
+  explicit Core(TCPSocketWin* socket);
+
+  // Start watching for the end of a read or write operation.
+  void WatchForRead();
+  void WatchForWrite();
+
+  // The TCPSocketWin is going away.
+  void Detach() { socket_ = NULL; }
+
+  // The separate OVERLAPPED variables for asynchronous operation.
+  // |read_overlapped_| is used for both Connect() and Read().
+  // |write_overlapped_| is only used for Write();
+  OVERLAPPED read_overlapped_;
+  OVERLAPPED write_overlapped_;
+
+  // The buffers used in Read() and Write().
+  scoped_refptr<IOBuffer> read_iobuffer_;
+  scoped_refptr<IOBuffer> write_iobuffer_;
+  int read_buffer_length_;
+  int write_buffer_length_;
+
+  bool non_blocking_reads_initialized_;
+
+ private:
+  friend class base::RefCounted<Core>;
+
+  class ReadDelegate : public base::win::ObjectWatcher::Delegate {
+   public:
+    explicit ReadDelegate(Core* core) : core_(core) {}
+    virtual ~ReadDelegate() {}
+
+    // base::ObjectWatcher::Delegate methods:
+    virtual void OnObjectSignaled(HANDLE object);
+
+   private:
+    Core* const core_;
+  };
+
+  class WriteDelegate : public base::win::ObjectWatcher::Delegate {
+   public:
+    explicit WriteDelegate(Core* core) : core_(core) {}
+    virtual ~WriteDelegate() {}
+
+    // base::ObjectWatcher::Delegate methods:
+    virtual void OnObjectSignaled(HANDLE object);
+
+   private:
+    Core* const core_;
+  };
+
+  ~Core();
+
+  // The socket that created this object.
+  TCPSocketWin* socket_;
+
+  // |reader_| handles the signals from |read_watcher_|.
+  ReadDelegate reader_;
+  // |writer_| handles the signals from |write_watcher_|.
+  WriteDelegate writer_;
+
+  // |read_watcher_| watches for events from Connect() and Read().
+  base::win::ObjectWatcher read_watcher_;
+  // |write_watcher_| watches for events from Write();
+  base::win::ObjectWatcher write_watcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+TCPSocketWin::Core::Core(TCPSocketWin* socket)
+    : read_buffer_length_(0),
+      write_buffer_length_(0),
+      non_blocking_reads_initialized_(false),
+      socket_(socket),
+      reader_(this),
+      writer_(this) {
+  memset(&read_overlapped_, 0, sizeof(read_overlapped_));
+  memset(&write_overlapped_, 0, sizeof(write_overlapped_));
+
+  read_overlapped_.hEvent = WSACreateEvent();
+  write_overlapped_.hEvent = WSACreateEvent();
+}
+
+TCPSocketWin::Core::~Core() {
+  // Make sure the message loop is not watching this object anymore.
+  read_watcher_.StopWatching();
+  write_watcher_.StopWatching();
+
+  WSACloseEvent(read_overlapped_.hEvent);
+  memset(&read_overlapped_, 0xaf, sizeof(read_overlapped_));
+  WSACloseEvent(write_overlapped_.hEvent);
+  memset(&write_overlapped_, 0xaf, sizeof(write_overlapped_));
+}
+
+void TCPSocketWin::Core::WatchForRead() {
+  // We grab an extra reference because there is an IO operation in progress.
+  // Balanced in ReadDelegate::OnObjectSignaled().
+  AddRef();
+  read_watcher_.StartWatching(read_overlapped_.hEvent, &reader_);
+}
+
+void TCPSocketWin::Core::WatchForWrite() {
+  // We grab an extra reference because there is an IO operation in progress.
+  // Balanced in WriteDelegate::OnObjectSignaled().
+  AddRef();
+  write_watcher_.StartWatching(write_overlapped_.hEvent, &writer_);
+}
+
+void TCPSocketWin::Core::ReadDelegate::OnObjectSignaled(HANDLE object) {
+  DCHECK_EQ(object, core_->read_overlapped_.hEvent);
+  if (core_->socket_) {
+    if (core_->socket_->waiting_connect_)
+      core_->socket_->DidCompleteConnect();
+    else
+      core_->socket_->DidSignalRead();
+  }
+
+  core_->Release();
+}
+
+void TCPSocketWin::Core::WriteDelegate::OnObjectSignaled(
+    HANDLE object) {
+  DCHECK_EQ(object, core_->write_overlapped_.hEvent);
+  if (core_->socket_)
+    core_->socket_->DidCompleteWrite();
+
+  core_->Release();
+}
+
+//-----------------------------------------------------------------------------
 
 TCPSocketWin::TCPSocketWin(net::NetLog* net_log,
                            const net::NetLog::Source& source)
     : socket_(INVALID_SOCKET),
-      socket_event_(WSA_INVALID_EVENT),
+      accept_event_(WSA_INVALID_EVENT),
       accept_socket_(NULL),
       accept_address_(NULL),
+      waiting_connect_(false),
+      waiting_read_(false),
+      waiting_write_(false),
+      connect_os_error_(0),
+      logging_multiple_connect_attempts_(false),
       net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_SOCKET)) {
   net_log_.BeginEvent(NetLog::TYPE_SOCKET_ALIVE,
                       source.ToEventParametersCallback());
   EnsureWinsockInit();
 }
 
 TCPSocketWin::~TCPSocketWin() {
   Close();
   net_log_.EndEvent(NetLog::TYPE_SOCKET_ALIVE);
 }
@@ skipping 11 matching lines @@
 
   if (SetNonBlocking(socket_)) {
     int result = MapSystemError(WSAGetLastError());
     Close();
     return result;
   }
 
   return OK;
 }
 
-int TCPSocketWin::Adopt(SOCKET socket) {
+int TCPSocketWin::AdoptConnectedSocket(SOCKET socket,
+                                       const IPEndPoint& peer_address) {
   DCHECK(CalledOnValidThread());
   DCHECK_EQ(socket_, INVALID_SOCKET);
+  DCHECK(!core_.get());

[akalin, 2013/09/05 22:52:28]

no .get()

[yzshen1, 2013/09/06 00:57:44]

Done.

 
   socket_ = socket;
 
   if (SetNonBlocking(socket_)) {

[wtc, 2013/09/06 21:55:42]

Should we also call SetupSocket(socket_)?

[yzshen1, 2013/09/09 23:14:48]

IMO, what options to set is the decision of TCPSocket users.
What do you think?

On 2013/09/06 21:55:42, wtc wrote:

     int result = MapSystemError(WSAGetLastError());
     Close();
     return result;
   }
 
+  core_ = new Core(this);
+  peer_address_ = peer_address;

[wtc, 2013/09/06 21:55:42]

Is it necessary to have the peer_address_ member? It can be looked up with a
getpeername() call.

[yzshen1, 2013/09/09 23:14:48]

This is the same behavior as the previous code, which also stored the peer
address and returned it directly in GetPeerAddress().

I agree that getpeername() could be used.

On 2013/09/06 21:55:42, wtc wrote:

+
   return OK;
 }
 
-SOCKET TCPSocketWin::Release() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_EQ(socket_event_, WSA_INVALID_EVENT);
-  DCHECK(accept_callback_.is_null());
-
-  SOCKET result = socket_;
-  socket_ = INVALID_SOCKET;
-  return result;
-}
-
 int TCPSocketWin::Bind(const IPEndPoint& address) {
   DCHECK(CalledOnValidThread());
   DCHECK_NE(socket_, INVALID_SOCKET);
 
   SockaddrStorage storage;
   if (!address.ToSockAddr(storage.addr, &storage.addr_len))
     return ERR_ADDRESS_INVALID;
 
   int result = bind(socket_, storage.addr, storage.addr_len);
   if (result < 0) {
@@ skipping 14 matching lines @@
   if (!address->FromSockAddr(storage.addr, storage.addr_len))
     return ERR_FAILED;
 
   return OK;
 }
 
 int TCPSocketWin::Listen(int backlog) {
   DCHECK(CalledOnValidThread());
   DCHECK_GT(backlog, 0);
   DCHECK_NE(socket_, INVALID_SOCKET);
-  DCHECK_EQ(socket_event_, WSA_INVALID_EVENT);
+  DCHECK_EQ(accept_event_, WSA_INVALID_EVENT);
 
-  socket_event_ = WSACreateEvent();
-  if (socket_event_ == WSA_INVALID_EVENT) {
+  accept_event_ = WSACreateEvent();
+  if (accept_event_ == WSA_INVALID_EVENT) {
     PLOG(ERROR) << "WSACreateEvent()";
     return ERR_FAILED;

[wtc, 2013/09/06 21:55:42]

We should return MapSystemError(WSAGetLastError()).

[yzshen1, 2013/09/09 23:14:48]

Done.

   }
 
   int result = listen(socket_, backlog);
   if (result < 0) {
     PLOG(ERROR) << "listen() returned an error";
     result = MapSystemError(WSAGetLastError());
     return result;
   }
 
   return OK;
 }
 
 int TCPSocketWin::Accept(scoped_ptr<TCPSocketWin>* socket,
                          IPEndPoint* address,
                          const CompletionCallback& callback) {
   DCHECK(CalledOnValidThread());
   DCHECK(socket);
   DCHECK(address);
   DCHECK(!callback.is_null());
   DCHECK(accept_callback_.is_null());
 
   net_log_.BeginEvent(NetLog::TYPE_TCP_ACCEPT);
 
   int result = AcceptInternal(socket, address);
 
   if (result == ERR_IO_PENDING) {
     // Start watching.
-    WSAEventSelect(socket_, socket_event_, FD_ACCEPT);
-    accept_watcher_.StartWatching(socket_event_, this);
+    WSAEventSelect(socket_, accept_event_, FD_ACCEPT);
+    accept_watcher_.StartWatching(accept_event_, this);
 
     accept_socket_ = socket;
     accept_address_ = address;
     accept_callback_ = callback;
   }
 
   return result;
 }
 
+int TCPSocketWin::Connect(const IPEndPoint& address,
+                          const CompletionCallback& callback) {
+  DCHECK(CalledOnValidThread());
+  DCHECK_NE(socket_, INVALID_SOCKET);
+  DCHECK(!core_.get());
+
+  // If in the process of connecting or already connected, then just return OK.

[wtc, 2013/09/06 21:55:42]

This seems wrong. I think we should return an error code if waiting_connect_
is true. Also, IsConnected() means something different -- it means the socket
has been connected AND the TCP connection is still good.

[yzshen1, 2013/09/09 23:14:48]

Returning OK is the behavior of the previous code. I agree that an error makes
more sense.
And you are right about the IsConnected() call. Thanks!

I changed the code and added more comments. (I decided to do this purely based
on what I read from MSDN and POSIX documents. Please take a close look and let
me know if it doesn't make sense.)

+  if (waiting_connect_ || IsConnected())
+    return OK;
+
+  if (!logging_multiple_connect_attempts_)
+    LogConnectStart(AddressList(address));
+
+  peer_address_ = address;
+
+  int rv = DoConnect();
+  if (rv == ERR_IO_PENDING) {
+    // Synchronous operation not supported.
+    DCHECK(!callback.is_null());
+    // TODO(ajwong): Is setting read_callback_ the right thing to do here??

[wtc, 2013/09/06 21:55:42]

Remove this TODO comment. It is correct to use read_callback_ for connect or
read. This is documented in tcp_socket_win.h.

[yzshen1, 2013/09/09 23:14:48]

Done.

+    read_callback_ = callback;
+    waiting_connect_ = true;
+  } else {
+    DoConnectComplete(rv);
+  }
+
+  return rv;
+}
+
+bool TCPSocketWin::IsConnected() const {
+  DCHECK(CalledOnValidThread());
+
+  if (socket_ == INVALID_SOCKET || waiting_connect_)
+    return false;
+
+  if (waiting_read_)
+    return true;
+
+  // Check if connection is alive.
+  char c;
+  int rv = recv(socket_, &c, 1, MSG_PEEK);
+  if (rv == 0)
+    return false;
+  if (rv == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK)
+    return false;
+
+  return true;
+}
+
+bool TCPSocketWin::IsConnectedAndIdle() const {
+  DCHECK(CalledOnValidThread());
+
+  if (socket_ == INVALID_SOCKET || waiting_connect_)
+    return false;
+
+  if (waiting_read_)
+    return true;
+
+  // Check if connection is alive and we haven't received any data
+  // unexpectedly.
+  char c;
+  int rv = recv(socket_, &c, 1, MSG_PEEK);
+  if (rv >= 0)
+    return false;
+  if (WSAGetLastError() != WSAEWOULDBLOCK)
+    return false;
+
+  return true;
+}
+
+int TCPSocketWin::GetPeerAddress(IPEndPoint* address) const {
+  DCHECK(CalledOnValidThread());
+  DCHECK(address);
+  if (!IsConnected())
+    return ERR_SOCKET_NOT_CONNECTED;
+  *address = peer_address_;
+  return OK;
+}
+
+int TCPSocketWin::Read(IOBuffer* buf,
+                       int buf_len,
+                       const CompletionCallback& callback) {
+  DCHECK(CalledOnValidThread());
+  DCHECK_NE(socket_, INVALID_SOCKET);
+  DCHECK(!waiting_read_);
+  DCHECK(read_callback_.is_null());
+  DCHECK(!core_->read_iobuffer_);
+
+  return DoRead(buf, buf_len, callback);
+}
+
+int TCPSocketWin::Write(IOBuffer* buf,
+                        int buf_len,
+                        const CompletionCallback& callback) {
+  DCHECK(CalledOnValidThread());
+  DCHECK_NE(socket_, INVALID_SOCKET);
+  DCHECK(!waiting_write_);
+  DCHECK(write_callback_.is_null());
+  DCHECK_GT(buf_len, 0);
+  DCHECK(!core_->write_iobuffer_);
+
+  base::StatsCounter writes("tcp.writes");
+  writes.Increment();
+
+  WSABUF write_buffer;
+  write_buffer.len = buf_len;
+  write_buffer.buf = buf->data();
+
+  // TODO(wtc): Remove the assertion after enough testing.
+  AssertEventNotSignaled(core_->write_overlapped_.hEvent);
+  DWORD num;
+  int rv = WSASend(socket_, &write_buffer, 1, &num, 0,
+                   &core_->write_overlapped_, NULL);
+  if (rv == 0) {
+    if (ResetEventIfSignaled(core_->write_overlapped_.hEvent)) {
+      rv = static_cast<int>(num);
+      if (rv > buf_len || rv < 0) {
+        // It seems that some winsock interceptors report that more was written
+        // than was available. Treat this as an error.  http://crbug.com/27870
+        LOG(ERROR) << "Detected broken LSP: Asked to write " << buf_len
+                   << " bytes, but " << rv << " bytes reported.";
+        return ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
+      }
+      base::StatsCounter write_bytes("tcp.write_bytes");
+      write_bytes.Add(rv);
+      net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_SENT, rv,
+                                    buf->data());
+      return rv;
+    }
+  } else {
+    int os_error = WSAGetLastError();
+    if (os_error != WSA_IO_PENDING) {
+      int net_error = MapSystemError(os_error);
+      net_log_.AddEvent(NetLog::TYPE_SOCKET_WRITE_ERROR,
+                        CreateNetLogSocketErrorCallback(net_error, os_error));
+      return net_error;
+    }
+  }
+  waiting_write_ = true;
+  write_callback_ = callback;
+  core_->write_iobuffer_ = buf;
+  core_->write_buffer_length_ = buf_len;
+  core_->WatchForWrite();
+  return ERR_IO_PENDING;
+}
+
 int TCPSocketWin::SetDefaultOptionsForServer() {
   return SetExclusiveAddrUse();
 }
 
+int TCPSocketWin::SetDefaultOptionsForClient() {

[wtc, 2013/09/06 21:55:42]

1. Please copy (and update as appropriate) the original comment:

  // Sets socket parameters. Returns the OS error code (or 0 on
  // success).

2. IMPORTANT: This function is also suitable for an accepted socket
returned by a listening server socket. So perhaps we should not have "ForClient"
in the function's name.

[yzshen1, 2013/09/09 23:14:48]

Updated comments in .h file.
But these options are not needed for server sockets, right? The "accepted"
sockets are still client sockets.

+  // Increase the socket buffer sizes from the default sizes for WinXP.  In
+  // performance testing, there is substantial benefit by increasing from 8KB
+  // to 64KB.
+  // See also:
+  //    http://support.microsoft.com/kb/823764/EN-US
+  // On Vista, if we manually set these sizes, Vista turns off its receive
+  // window auto-tuning feature.
+  //    http://blogs.msdn.com/wndp/archive/2006/05/05/Winhec-blog-tcpip-2.aspx
+  // Since Vista's auto-tune is better than any static value we can could set,
+  // only change these on pre-vista machines.
+  if (base::win::GetVersion() < base::win::VERSION_VISTA) {
+    const int32 kSocketBufferSize = 64 * 1024;
+    SetSocketReceiveBufferSize(socket_, kSocketBufferSize);
+    SetSocketSendBufferSize(socket_, kSocketBufferSize);
+  }
+
+  DisableNagle(socket_, true);
+  SetTCPKeepAlive(socket_, true, kTCPKeepAliveSeconds);
+  return OK;
+}
+
 int TCPSocketWin::SetExclusiveAddrUse() {
   // On Windows, a bound end point can be hijacked by another process by
   // setting SO_REUSEADDR. Therefore a Windows-only option SO_EXCLUSIVEADDRUSE
   // was introduced in Windows NT 4.0 SP4. If the socket that is bound to the
   // end point has SO_EXCLUSIVEADDRUSE enabled, it is not possible for another
   // socket to forcibly bind to the end point until the end point is unbound.
   // It is recommend that all server applications must use SO_EXCLUSIVEADDRUSE.
   // MSDN: http://goo.gl/M6fjQ.
   //
   // Unlike on *nix, on Windows a TCP server socket can always bind to an end
   // point in TIME_WAIT state without setting SO_REUSEADDR, therefore it is not
   // needed here.
   //
   // SO_EXCLUSIVEADDRUSE will prevent a TCP client socket from binding to an end
   // point in TIME_WAIT status. It does not have this effect for a TCP server
   // socket.
 
   BOOL true_value = 1;
   int rv = setsockopt(socket_, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
                       reinterpret_cast<const char*>(&true_value),
                       sizeof(true_value));
   if (rv < 0)
     return MapSystemError(errno);
   return OK;
 }
 
+bool TCPSocketWin::SetReceiveBufferSize(int32 size) {
+  DCHECK(CalledOnValidThread());
+  return SetSocketReceiveBufferSize(socket_, size);
+}
+
+bool TCPSocketWin::SetSendBufferSize(int32 size) {
+  DCHECK(CalledOnValidThread());
+  return SetSocketSendBufferSize(socket_, size);
+}
+
+bool TCPSocketWin::SetKeepAlive(bool enable, int delay) {
+  return SetTCPKeepAlive(socket_, enable, delay);
+}
+
+bool TCPSocketWin::SetNoDelay(bool no_delay) {
+  return DisableNagle(socket_, no_delay);
+}
+
 void TCPSocketWin::Close() {
+  DCHECK(CalledOnValidThread());
+
   if (socket_ != INVALID_SOCKET) {
+    // Note: don't use CancelIo to cancel pending IO because it doesn't work
+    // when there is a Winsock layered service provider.
+
+    // In most socket implementations, closing a socket results in a graceful
+    // connection shutdown, but in Winsock we have to call shutdown explicitly.
+    // See the MSDN page "Graceful Shutdown, Linger Options, and Socket Closure"
+    // at http://msdn.microsoft.com/en-us/library/ms738547.aspx
+    shutdown(socket_, SD_SEND);
+
+    // This cancels any pending IO.
     if (closesocket(socket_) < 0)
       PLOG(ERROR) << "closesocket";
     socket_ = INVALID_SOCKET;

[wtc, 2013/09/06 21:55:42]

I think most of the following code (except the accept_xxx code) should be moved
inside this "if (socket_ != INVALID_SOCKET)" block. That's what the original
code in tcp_client_socket_win.cc is like.

[yzshen1, 2013/09/09 23:14:48]

I was thinking that it is more clear this way that all state (except logging) is
reset by Close(). Do you concern about the performance?

   }
 
-  if (socket_event_) {
-    WSACloseEvent(socket_event_);
-    socket_event_ = WSA_INVALID_EVENT;
+  if (accept_event_) {
+    WSACloseEvent(accept_event_);
+    accept_event_ = WSA_INVALID_EVENT;
+  }
+
+  if (!accept_callback_.is_null()) {
+    accept_watcher_.StopWatching();
+    accept_socket_ = NULL;
+    accept_address_ = NULL;
+    accept_callback_.Reset();
+  }

[wtc, 2013/09/06 21:55:42]

This code is not in the original code. Is that a bug?

[yzshen1, 2013/09/09 23:14:48]

This is intended. I would like this Close() to reset all internal state except
logging-related things. So that we can do:

socket.Create();
socket.Connect();
socket.Close();
// |socket| is reset completely so that we can reuse it.
socket.Create();
...

+
+  if (core_.get()) {
+    if (waiting_connect_) {
+      // We closed the socket, so this notification will never come.
+      // From MSDN' WSAEventSelect documentation:
+      // "Closing a socket with closesocket also cancels the association and
+      // selection of network events specified in WSAEventSelect for the
+      // socket".
+      core_->Release();
+    }
+    core_->Detach();
+    core_ = NULL;
+  }
+
+  waiting_connect_ = false;
+  waiting_read_ = false;
+  waiting_write_ = false;
+
+  read_callback_.Reset();
+  write_callback_.Reset();

[wtc, 2013/09/06 21:55:42]

Are these two lines necessary? They are not in the original
tcp_client_socket_win.cc code. Perhaps that was a bug?

[yzshen1, 2013/09/09 23:14:48]

Please see my comments above.
On 2013/09/06 21:55:42, wtc wrote:

+  peer_address_ = IPEndPoint();
+  connect_os_error_ = 0;
+}
+
+bool TCPSocketWin::UsingTCPFastOpen() const {
+  // Not supported on windows.
+  return false;
+}
+
+void TCPSocketWin::StartLoggingMultipleConnectAttempts(
+    const AddressList& addresses) {
+  if (!logging_multiple_connect_attempts_) {
+    logging_multiple_connect_attempts_ = true;
+    LogConnectStart(addresses);
+  } else {
+    NOTREACHED();
   }
 }
 
+void TCPSocketWin::EndLoggingMultipleConnectAttempts(int net_error) {
+  if (logging_multiple_connect_attempts_) {
+    LogConnectCompletion(net_error);
+    logging_multiple_connect_attempts_ = false;
+  } else {
+    NOTREACHED();
+  }
+}
+
 int TCPSocketWin::AcceptInternal(scoped_ptr<TCPSocketWin>* socket,
                                  IPEndPoint* address) {
   SockaddrStorage storage;
   int new_socket = accept(socket_, storage.addr, &storage.addr_len);
   if (new_socket < 0) {
     int net_error = MapSystemError(WSAGetLastError());
     if (net_error != ERR_IO_PENDING)
       net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, net_error);
     return net_error;
   }
 
   IPEndPoint ip_end_point;
   if (!ip_end_point.FromSockAddr(storage.addr, storage.addr_len)) {
     NOTREACHED();
     if (closesocket(new_socket) < 0)
       PLOG(ERROR) << "closesocket";
     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, ERR_FAILED);
     return ERR_FAILED;
   }
   scoped_ptr<TCPSocketWin> tcp_socket(new TCPSocketWin(
       net_log_.net_log(), net_log_.source()));
-  int adopt_result = tcp_socket->Adopt(new_socket);
+  int adopt_result = tcp_socket->AdoptConnectedSocket(new_socket, ip_end_point);
   if (adopt_result != OK) {
     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_ACCEPT, adopt_result);
     return adopt_result;
   }
   *socket = tcp_socket.Pass();
   *address = ip_end_point;
   net_log_.EndEvent(NetLog::TYPE_TCP_ACCEPT,
                     CreateNetLogIPEndPointCallback(&ip_end_point));
   return OK;
 }
 
 void TCPSocketWin::OnObjectSignaled(HANDLE object) {
   WSANETWORKEVENTS ev;
-  if (WSAEnumNetworkEvents(socket_, socket_event_, &ev) == SOCKET_ERROR) {
+  if (WSAEnumNetworkEvents(socket_, accept_event_, &ev) == SOCKET_ERROR) {
     PLOG(ERROR) << "WSAEnumNetworkEvents()";
     return;
   }
 
   if (ev.lNetworkEvents & FD_ACCEPT) {
     int result = AcceptInternal(accept_socket_, accept_address_);
     if (result != ERR_IO_PENDING) {
       accept_socket_ = NULL;
       accept_address_ = NULL;
       CompletionCallback callback = accept_callback_;
       accept_callback_.Reset();
       callback.Run(result);
     }
   }
 }
 
+int TCPSocketWin::DoConnect() {
+  DCHECK_EQ(connect_os_error_, 0);
+  DCHECK(!core_);
+
+  net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT,
+                      CreateNetLogIPEndPointCallback(&peer_address_));
+
+  core_ = new Core(this);
+  // WSAEventSelect sets the socket to non-blocking mode as a side effect.
+  // Our connect() and recv() calls require that the socket be non-blocking.
+  WSAEventSelect(socket_, core_->read_overlapped_.hEvent, FD_CONNECT);
+
+  SockaddrStorage storage;
+  if (!peer_address_.ToSockAddr(storage.addr, &storage.addr_len))
+    return ERR_INVALID_ARGUMENT;
+  if (!connect(socket_, storage.addr, storage.addr_len)) {
+    // Connected without waiting!
+    //
+    // The MSDN page for connect says:
+    //   With a nonblocking socket, the connection attempt cannot be completed
+    //   immediately. In this case, connect will return SOCKET_ERROR, and
+    //   WSAGetLastError will return WSAEWOULDBLOCK.
+    // which implies that for a nonblocking socket, connect never returns 0.
+    // It's not documented whether the event object will be signaled or not
+    // if connect does return 0.  So the code below is essentially dead code
+    // and we don't know if it's correct.
+    NOTREACHED();
+
+    if (ResetEventIfSignaled(core_->read_overlapped_.hEvent))
+      return OK;
+  } else {
+    int os_error = WSAGetLastError();
+    if (os_error != WSAEWOULDBLOCK) {
+      LOG(ERROR) << "connect failed: " << os_error;
+      connect_os_error_ = os_error;
+      return MapConnectError(os_error);
+    }
+  }
+
+  core_->WatchForRead();
+  return ERR_IO_PENDING;
+}
+
+void TCPSocketWin::DoConnectComplete(int result) {
+  // Log the end of this attempt (and any OS error it threw).
+  int os_error = connect_os_error_;
+  connect_os_error_ = 0;
+  if (result != OK) {
+    net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT,
+                      NetLog::IntegerCallback("os_error", os_error));
+  } else {
+    net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT);
+  }
+
+  if (!logging_multiple_connect_attempts_)
+    LogConnectCompletion(result);
+}
+
+void TCPSocketWin::LogConnectStart(const AddressList& addresses) {

[wtc, 2013/09/06 21:55:42]

I think this function and LogConnectCompletion belong in TCPClientSocketWin.
It is confusing how to use the two LogXXX functions.

[yzshen1, 2013/09/09 23:14:48]

I agree that this is some kind of layer violation. The best way is to re-define
the logging format for connect. I wish that could be done in a separate CL
later.

I will try to talk with you in person and listen to your suggestions.

On 2013/09/06 21:55:42, wtc wrote:

+  base::StatsCounter connects("tcp.connect");
+  connects.Increment();
+
+  net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT,
+                      addresses.CreateNetLogCallback());
+}
+
+void TCPSocketWin::LogConnectCompletion(int net_error) {
+  if (net_error == OK)
+    UpdateConnectionTypeHistograms(CONNECTION_ANY);
+
+  if (net_error != OK) {
+    net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, net_error);
+    return;
+  }
+
+  struct sockaddr_storage source_address;
+  socklen_t addrlen = sizeof(source_address);
+  int rv = getsockname(
+      socket_, reinterpret_cast<struct sockaddr*>(&source_address), &addrlen);
+  if (rv != 0) {
+    LOG(ERROR) << "getsockname() [rv: " << rv
+               << "] error: " << WSAGetLastError();
+    NOTREACHED();
+    net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, rv);
+    return;
+  }
+
+  net_log_.EndEvent(
+      NetLog::TYPE_TCP_CONNECT,
+      CreateNetLogSourceAddressCallback(
+          reinterpret_cast<const struct sockaddr*>(&source_address),
+          sizeof(source_address)));
+}
+
+int TCPSocketWin::DoRead(IOBuffer* buf, int buf_len,
+                         const CompletionCallback& callback) {
+  if (!core_->non_blocking_reads_initialized_) {
+    WSAEventSelect(socket_, core_->read_overlapped_.hEvent,
+                   FD_READ | FD_CLOSE);
+    core_->non_blocking_reads_initialized_ = true;
+  }
+  int rv = recv(socket_, buf->data(), buf_len, 0);
+  if (rv == SOCKET_ERROR) {
+    int os_error = WSAGetLastError();
+    if (os_error != WSAEWOULDBLOCK) {
+      int net_error = MapSystemError(os_error);
+      net_log_.AddEvent(
+          NetLog::TYPE_SOCKET_READ_ERROR,
+          CreateNetLogSocketErrorCallback(net_error, os_error));
+      return net_error;
+    }
+  } else {
+    base::StatsCounter read_bytes("tcp.read_bytes");
+    if (rv > 0)
+      read_bytes.Add(rv);
+    net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_RECEIVED, rv,
+                                  buf->data());
+    return rv;
+  }
+
+  waiting_read_ = true;
+  read_callback_ = callback;
+  core_->read_iobuffer_ = buf;
+  core_->read_buffer_length_ = buf_len;
+  core_->WatchForRead();
+  return ERR_IO_PENDING;
+}
+
+void TCPSocketWin::DoReadCallback(int rv) {
+  DCHECK_NE(rv, ERR_IO_PENDING);
+  DCHECK(!read_callback_.is_null());
+
+  // Since Run may result in Read being called, clear read_callback_ up front.
+  CompletionCallback c = read_callback_;
+  read_callback_.Reset();
+  c.Run(rv);
+}
+
+void TCPSocketWin::DoWriteCallback(int rv) {
+  DCHECK_NE(rv, ERR_IO_PENDING);
+  DCHECK(!write_callback_.is_null());
+
+  // Since Run may result in Write being called, clear write_callback_ up front.
+  CompletionCallback c = write_callback_;
+  write_callback_.Reset();
+  c.Run(rv);
+}
+
+void TCPSocketWin::DidCompleteConnect() {
+  DCHECK(waiting_connect_);
+  int result;
+
+  WSANETWORKEVENTS events;
+  int rv = WSAEnumNetworkEvents(socket_, core_->read_overlapped_.hEvent,
+                                &events);
+  int os_error = 0;
+  if (rv == SOCKET_ERROR) {
+    NOTREACHED();
+    os_error = WSAGetLastError();
+    result = MapSystemError(os_error);
+  } else if (events.lNetworkEvents & FD_CONNECT) {
+    os_error = events.iErrorCode[FD_CONNECT_BIT];
+    result = MapConnectError(os_error);
+  } else {
+    NOTREACHED();
+    result = ERR_UNEXPECTED;
+  }
+
+  connect_os_error_ = os_error;
+  DoConnectComplete(result);
+  waiting_connect_ = false;
+  DoReadCallback(result);
+}
+
+void TCPSocketWin::DidCompleteWrite() {
+  DCHECK(waiting_write_);
+
+  DWORD num_bytes, flags;
+  BOOL ok = WSAGetOverlappedResult(socket_, &core_->write_overlapped_,
+                                   &num_bytes, FALSE, &flags);
+  WSAResetEvent(core_->write_overlapped_.hEvent);
+  waiting_write_ = false;
+  int rv;
+  if (!ok) {
+    int os_error = WSAGetLastError();
+    rv = MapSystemError(os_error);
+    net_log_.AddEvent(NetLog::TYPE_SOCKET_WRITE_ERROR,
+                      CreateNetLogSocketErrorCallback(rv, os_error));
+  } else {
+    rv = static_cast<int>(num_bytes);
+    if (rv > core_->write_buffer_length_ || rv < 0) {
+      // It seems that some winsock interceptors report that more was written
+      // than was available. Treat this as an error.  http://crbug.com/27870
+      LOG(ERROR) << "Detected broken LSP: Asked to write "
+                 << core_->write_buffer_length_ << " bytes, but " << rv
+                 << " bytes reported.";
+      rv = ERR_WINSOCK_UNEXPECTED_WRITTEN_BYTES;
+    } else {
+      base::StatsCounter write_bytes("tcp.write_bytes");
+      write_bytes.Add(num_bytes);
+      net_log_.AddByteTransferEvent(NetLog::TYPE_SOCKET_BYTES_SENT, num_bytes,
+                                    core_->write_iobuffer_->data());
+    }
+  }
+  core_->write_iobuffer_ = NULL;
+  DoWriteCallback(rv);
+}
+
+void TCPSocketWin::DidSignalRead() {
+  DCHECK(waiting_read_);
+  int os_error = 0;
+  WSANETWORKEVENTS network_events;
+  int rv = WSAEnumNetworkEvents(socket_, core_->read_overlapped_.hEvent,
+                                &network_events);
+  if (rv == SOCKET_ERROR) {
+    os_error = WSAGetLastError();
+    rv = MapSystemError(os_error);
+  } else if (network_events.lNetworkEvents) {
+    DCHECK_EQ(network_events.lNetworkEvents & ~(FD_READ | FD_CLOSE), 0);
+    // If network_events.lNetworkEvents is FD_CLOSE and
+    // network_events.iErrorCode[FD_CLOSE_BIT] is 0, it is a graceful
+    // connection closure. It is tempting to directly set rv to 0 in
+    // this case, but the MSDN pages for WSAEventSelect and
+    // WSAAsyncSelect recommend we still call DoRead():
+    //   FD_CLOSE should only be posted after all data is read from a
+    //   socket, but an application should check for remaining data upon
+    //   receipt of FD_CLOSE to avoid any possibility of losing data.
+    //
+    // If network_events.iErrorCode[FD_READ_BIT] or
+    // network_events.iErrorCode[FD_CLOSE_BIT] is nonzero, still call
+    // DoRead() because recv() reports a more accurate error code
+    // (WSAECONNRESET vs. WSAECONNABORTED) when the connection was
+    // reset.
+    rv = DoRead(core_->read_iobuffer_, core_->read_buffer_length_,
+                read_callback_);
+    if (rv == ERR_IO_PENDING)
+      return;
+  } else {
+    // This may happen because Read() may succeed synchronously and
+    // consume all the received data without resetting the event object.
+    core_->WatchForRead();
+    return;
+  }
+  waiting_read_ = false;
+  core_->read_iobuffer_ = NULL;
+  core_->read_buffer_length_ = 0;
+  DoReadCallback(rv);
+}
+
 }  // namespace net
+