Allow server sockets to rebind to same port if there is nothing actively listening on that port.

net/socket/tcp_server_socket_libevent.h

 // 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_SOCKET_TCP_SERVER_SOCKET_LIBEVENT_H_
 #define NET_SOCKET_TCP_SERVER_SOCKET_LIBEVENT_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/threading/non_thread_safe.h"
@@ skipping 17 matching lines @@
   // net::ServerSocket implementation.
   virtual int Listen(const net::IPEndPoint& address, int backlog) OVERRIDE;
   virtual int GetLocalAddress(IPEndPoint* address) const OVERRIDE;
   virtual int Accept(scoped_ptr<StreamSocket>* socket,
                      const CompletionCallback& callback) OVERRIDE;
 
   // MessageLoopForIO::Watcher implementation.
   virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
   virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 
+  // Sets corresponding flags in |socket_options_| to allow the socket
+  // to share the local address to which the socket will be bound with
+  // other processes. Should be called before Bind().
+  void AllowAddressReuse();
+
  private:
   int AcceptInternal(scoped_ptr<StreamSocket>* socket);
   void Close();
 
+  enum SocketOptions {

[Sergey Ulanov, 2012/09/12 19:38:24]

types must be defined before methods.

[justinlin, 2012/09/12 21:11:00]

Ack.

+    SOCKET_OPTION_REUSE_ADDRESS = 1 << 0,
+  };
+
+  // Applies |socket_options_| to |socket_|. Should be called before
+  // Bind().
+  int SetSocketOptions();
+
   int socket_;
 
+  // Bitwise-or'd combination of SocketOptions. Specifies the set of
+  // options that should be applied to |socket_| before Bind().
+  int socket_options_;

[Sergey Ulanov, 2012/09/12 19:38:24]

Do we really need these options to be bit flags? it would be cleaner to have
boolean flag reuse_address.

[Sergey Ulanov, 2012/09/12 19:38:24]

You need to initialize this variable in the constructor.

[justinlin, 2012/09/12 21:11:00]

Done.

[justinlin, 2012/09/12 21:11:00]

Done.

+
   MessageLoopForIO::FileDescriptorWatcher accept_socket_watcher_;
 
   scoped_ptr<StreamSocket>* accept_socket_;
   CompletionCallback accept_callback_;
 
   BoundNetLog net_log_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SERVER_SOCKET_LIBEVENT_H_