[NaCl SDK] Enable select/poll on TTY nodes.

native_client_sdk/src/libraries/nacl_io/mount_node_tty.h

 // Copyright (c) 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.
 
 #ifndef LIBRARIES_NACL_IO_MOUNT_NODE_TTY_H_
 #define LIBRARIES_NACL_IO_MOUNT_NODE_TTY_H_
 
+#include <poll.h>
 #include <pthread.h>
 
 #include <deque>
 
 #include "nacl_io/ioctl.h"
 #include "nacl_io/mount_node_char.h"
 #include "nacl_io/ostermios.h"
 
 
 namespace nacl_io {
@@ skipping 13 matching lines @@
 
   virtual Error Write(size_t offs,
                       const void* buf,
                       size_t count,
                       int* out_bytes);
 
   virtual Error Tcgetattr(struct termios* termios_p);
   virtual Error Tcsetattr(int optional_actions,
                           const struct termios *termios_p);
 
+  virtual uint32_t GetEventStatus() {
+    uint32_t status = POLLOUT;
+    if (is_readable_)
+      status |= POLLIN;
+    return status;
+  }
+
  private:
   virtual Error Write(size_t offs,
                       const void* buf,
                       size_t count,
                       int* out_bytes,
                       bool locked);
   Error ProcessInput(struct tioc_nacl_input_string* message);
   Error Echo(const char* string, int count);
   void InitTermios();
 
   std::deque<char> input_buffer_;
   bool is_readable_;
   pthread_cond_t is_readable_cond_;
   std::string prefix_;
   struct termios termios_;
 };
 
 }
 
 #endif