Fix socket usage in forwarder2.

tools/android/forwarder2/socket.h

 // Copyright (c) 2012 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 TOOLS_ANDROID_FORWARDER2_SOCKET_H_
 #define TOOLS_ANDROID_FORWARDER2_SOCKET_H_
 
 #include <fcntl.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
@@ skipping 32 matching lines @@
   int GetPort();
 
   bool IsFdInSet(const fd_set& fds) const;
   bool AddFdToSet(fd_set* fds) const;
 
   // Just a wrapper around unix read() function.
   // Reads up to buffer_size, but may read less then buffer_size.
   // Returns the number of bytes read.
   int Read(void* buffer, size_t buffer_size);
 
-  // Same as Read(), just a wrapper around write().
+  // Non-blocking version of Read() above. This must be called after a
+  // successful call to select(). The socket must also be in non-blocking mode
+  // before calling this method.
+  int NonBlockingRead(void* buffer, size_t buffer_size);
+
+  // Wrapper around send().
   int Write(const void* buffer, size_t count);
 
+  // Same as NonBlockingRead() but for writing.
+  int NonBlockingWrite(const void* buffer, size_t count);
+
   // Calls Read() multiple times until num_bytes is written to the provided
   // buffer. No bounds checking is performed.
   // Returns number of bytes read, which can be different from num_bytes in case
   // of errror.
   int ReadNumBytes(void* buffer, size_t num_bytes);
 
   // Calls Write() multiple times until num_bytes is written. No bounds checking
   // is performed. Returns number of bytes written, which can be different from
   // num_bytes in case of errror.
   int WriteNumBytes(const void* buffer, size_t num_bytes);
@@ skipping 32 matching lines @@
     sockaddr_in6 addr6;
     // Unix Domain sockaddr
     sockaddr_un addr_un;
   };
 
   struct Event {
     int fd;
     bool was_fired;
   };
 
+  bool SetNonBlocking();
+
   // If |host| is empty, use localhost.
   bool InitTcpSocket(const std::string& host, int port);
   bool InitUnixSocket(const std::string& path);
   bool BindAndListen();
   bool Connect();
 
   bool Resolve(const std::string& host);
   bool InitSocketInternal();
   void SetSocketError();
 
@@ skipping 18 matching lines @@
   // Used to listen for external events (e.g. process received a SIGTERM) while
   // blocking on I/O operations.
   std::vector<Event> events_;
 
   DISALLOW_COPY_AND_ASSIGN(Socket);
 };
 
 }  // namespace forwarder
 
 #endif  // TOOLS_ANDROID_FORWARDER2_SOCKET_H_