Imported existing code

libraries/include/boost/asio/detail/pipe_select_interrupter.hpp

@@ -0,0 +1,117 @@
+//
+// pipe_select_interrupter.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP
+#define BOOST_ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/push_options.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+#include <boost/config.hpp>
+#include <boost/throw_exception.hpp>
+#include <boost/system/system_error.hpp>
+#include <boost/asio/detail/pop_options.hpp>
+
+#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+#include <boost/asio/detail/push_options.hpp>
+#include <fcntl.h>
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/error.hpp>
+#include <boost/asio/detail/socket_types.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+class pipe_select_interrupter
+{
+public:
+  // Constructor.
+  pipe_select_interrupter()
+  {
+    int pipe_fds[2];
+    if (pipe(pipe_fds) == 0)
+    {
+      read_descriptor_ = pipe_fds[0];
+      ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
+      write_descriptor_ = pipe_fds[1];
+      ::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK);
+    }
+    else
+    {
+      boost::system::error_code ec(errno,
+          boost::asio::error::get_system_category());
+      boost::system::system_error e(ec, "pipe_select_interrupter");
+      boost::throw_exception(e);
+    }
+  }
+
+  // Destructor.
+  ~pipe_select_interrupter()
+  {
+    if (read_descriptor_ != -1)
+      ::close(read_descriptor_);
+    if (write_descriptor_ != -1)
+      ::close(write_descriptor_);
+  }
+
+  // Interrupt the select call.
+  void interrupt()
+  {
+    char byte = 0;
+    int result = ::write(write_descriptor_, &byte, 1);
+    (void)result;
+  }
+
+  // Reset the select interrupt. Returns true if the call was interrupted.
+  bool reset()
+  {
+    char data[1024];
+    int bytes_read = ::read(read_descriptor_, data, sizeof(data));
+    bool was_interrupted = (bytes_read > 0);
+    while (bytes_read == sizeof(data))
+      bytes_read = ::read(read_descriptor_, data, sizeof(data));
+    return was_interrupted;
+  }
+
+  // Get the read descriptor to be passed to select.
+  int read_descriptor() const
+  {
+    return read_descriptor_;
+  }
+
+private:
+  // The read end of a connection used to interrupt the select call. This file
+  // descriptor is passed to select such that when it is time to stop, a single
+  // byte will be written on the other end of the connection and this
+  // descriptor will become readable.
+  int read_descriptor_;
+
+  // The write end of a connection used to interrupt the select call. A single
+  // byte may be written to this to wake up the select which is waiting for the
+  // other end to become readable.
+  int write_descriptor_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP