UDP sockets implementation for windows.

net/udp/udp_socket_win.h

Index: net/udp/udp_socket_win.h
diff --git a/net/udp/udp_socket_win.h b/net/udp/udp_socket_win.h
new file mode 100644
index 0000000000000000000000000000000000000000..b5789202275f3c84c1b54d5da06a313b4723a473
--- /dev/null
+++ b/net/udp/udp_socket_win.h
@@ -0,0 +1,185 @@
+// Copyright (c) 2011 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.
+
+#ifndef NET_UDP_UDP_SOCKET_WIN_H_
+#define NET_UDP_UDP_SOCKET_WIN_H_
+#pragma once
+
+#include <winsock2.h>
+
+#include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/win/object_watcher.h"
+#include "net/base/completion_callback.h"
+#include "net/base/ip_endpoint.h"
+#include "net/base/net_log.h"
+#include "net/socket/client_socket.h"

[Mike Belshe, 2011/03/10 06:53:38]

nit: do you need client_socket.h?

[Sergey Ulanov, 2011/03/11 00:54:37]

Done.

+
+namespace net {
+
+class BoundNetLog;
+
+class UDPSocketWin : public base::NonThreadSafe {
+ public:
+  UDPSocketWin(net::NetLog* net_log,
+                    const net::NetLog::Source& source);

[Mike Belshe, 2011/03/10 06:53:38]

nit: spacing

[Sergey Ulanov, 2011/03/11 00:54:37]

Done.

+  virtual ~UDPSocketWin();
+
+  // Connect the socket to connect with a certain |address|.
+  // Returns a net error code.
+  int Connect(const IPEndPoint& address);
+
+  // Bind the address/port for this socket to |address|.  This is generally
+  // only used on a server.
+  // Returns a net error code.
+  int Bind(const IPEndPoint& address);
+
+  // Close the socket.
+  void Close();
+
+  // Copy the remote udp address into |address| and return a network error code.
+  int GetPeerAddress(IPEndPoint* address) const;
+
+  // Copy the local udp address into |address| and return a network error code.
+  // (similar to getsockname)
+  int GetLocalAddress(IPEndPoint* address) const;
+
+  // IO:
+  // Multiple outstanding read requests are not supported.
+  // Full duplex mode (reading and writing at the same time) is supported
+
+  // Read from the socket.
+  // Only usable from the client-side of a UDP socket, after the socket
+  // has been connected.
+  int Read(IOBuffer* buf, int buf_len, CompletionCallback* callback);
+
+  // Write to the socket.
+  // Only usable from the client-side of a UDP socket, after the socket
+  // has been connected.
+  int Write(IOBuffer* buf, int buf_len, CompletionCallback* callback);
+
+  // Read from a socket and receive sender address information.
+  // |buf| is the buffer to read data into.
+  // |buf_len| is the maximum amount of data to read.
+  // |address| is a buffer provided by the caller for receiving the sender
+  //   address information about the received data.  This buffer must be kept
+  //   alive by the caller until the callback is placed.
+  // |address_length| is a ptr to the length of the |address| buffer.  This
+  //   is an input parameter containing the maximum size |address| can hold
+  //   and also an output parameter for the size of |address| upon completion.
+  // |callback| the callback on completion of the Recv.
+  // Returns a net error code, or ERR_IO_PENDING if the IO is in progress.
+  // If ERR_IO_PENDING is returned, the caller must keep |buf|, |address|,
+  // and |address_length| alive until the callback is called.
+  int RecvFrom(IOBuffer* buf,
+               int buf_len,
+               IPEndPoint* address,
+               CompletionCallback* callback);
+
+  // Send to a socket with a particular destination.
+  // |buf| is the buffer to send
+  // |buf_len| is the number of bytes to send
+  // |address| is the recipient address.
+  // |address_length| is the size of the recipient address
+  // |callback| is the user callback function to call on complete.
+  // Returns a net error code, or ERR_IO_PENDING if the IO is in progress.
+  // If ERR_IO_PENDING is returned, the caller must keep |buf| and |address|
+  // alive until the callback is called.
+  int SendTo(IOBuffer* buf,
+             int buf_len,
+             const IPEndPoint& address,
+             CompletionCallback* callback);
+
+  // Returns true if the socket is already connected or bound.
+  bool is_connected() const { return socket_ != kInvalidSocket; }
+
+ private:
+  static const int kInvalidSocket = -1;

[Mike Belshe, 2011/03/10 06:53:38]

For windows, I'd get rid of kInvalidSocket, and just use INVALID_SOCKET (see
also udp_socket_win.h:97)

[Sergey Ulanov, 2011/03/11 00:54:37]

Done.

+
+  class ReadDelegate : public base::win::ObjectWatcher::Delegate {
+   public:
+    explicit ReadDelegate(UDPSocketWin* socket) : socket_(socket) {}
+    virtual ~ReadDelegate() {}
+
+    // base::ObjectWatcher::Delegate methods:
+    virtual void OnObjectSignaled(HANDLE object);
+
+   private:
+    UDPSocketWin* const socket_;
+  };
+
+  class WriteDelegate : public base::win::ObjectWatcher::Delegate {
+   public:
+    explicit WriteDelegate(UDPSocketWin* socket) : socket_(socket) {}
+    virtual ~WriteDelegate() {}
+
+    // base::ObjectWatcher::Delegate methods:
+    virtual void OnObjectSignaled(HANDLE object);
+
+   private:
+    UDPSocketWin* const socket_;
+  };
+
+  void DoReadCallback(int rv);
+  void DoWriteCallback(int rv);
+  void DidCompleteRead();
+  void DidCompleteWrite();
+  bool ProcessSuccessfulRead(int num_bytes);
+  void ProcessSuccessfulWrite(int num_bytes);
+
+  // Returns the OS error code (or 0 on success).
+  int CreateSocket(const IPEndPoint& address);
+
+  int InternalRead();
+  int InternalWrite();
+
+  SOCKET socket_;
+
+  // These are mutable since they're just cached copies to make
+  // GetPeerAddress/GetLocalAddress smarter.
+  mutable scoped_ptr<IPEndPoint> local_address_;
+  mutable scoped_ptr<IPEndPoint> remote_address_;
+
+  // The socket's win wrappers
+  ReadDelegate read_delegate_;
+  WriteDelegate write_delegate_;
+
+  // Watchers to watch for events from Read() and Write().
+  base::win::ObjectWatcher read_watcher_;
+  base::win::ObjectWatcher write_watcher_;
+
+  // OVERLAPPED for pending read and write operations.
+  OVERLAPPED read_overlapped_;
+  OVERLAPPED write_overlapped_;
+
+  // The buffer used by InternalRead() to retry Read requests
+  WSABUF read_buffer_;
+  scoped_refptr<IOBuffer> read_iobuffer_;
+  int read_buf_len_;

[Mike Belshe, 2011/03/10 06:53:38]

I think we can get rid of read_iobuffer_ and read_buf_len_.  (in fact,
read_buf_len_ is already unused).  You're now storing the buffer and length into
the read_buffer_, so I think read_iobuffer is just not necessary.

[Sergey Ulanov, 2011/03/11 00:54:37]

We do need read_iobuffer_ to keep the buffer alive while there is a pending
read. I removed read_buf_len_, write_buf_len_, read_buffer_, write_buffer_.

+  struct sockaddr_storage recv_addr_storage_;
+  socklen_t recv_addr_len_;
+  IPEndPoint* recv_from_address_;
+
+  // The buffer used by InternalWrite() to retry Write requests
+  WSABUF write_buffer_;
+  scoped_refptr<IOBuffer> write_iobuffer_;
+  int write_buf_len_;

[Mike Belshe, 2011/03/10 06:53:38]

Same comments - nix write_iobuffer_ and write_buf_len_.

[Sergey Ulanov, 2011/03/11 00:54:37]

Done.

+  scoped_ptr<IPEndPoint> send_to_address_;
+
+  // External callback; called when read is complete.
+  CompletionCallback* read_callback_;
+
+  // External callback; called when write is complete.
+  CompletionCallback* write_callback_;
+
+  BoundNetLog net_log_;
+
+  DISALLOW_COPY_AND_ASSIGN(UDPSocketWin);
+};
+
+}  // namespace net
+
+#endif  // NET_UDP_UDP_SOCKET_WIN_H_