[#3325] Removed ext/coroutine

Makefile.am

@@ -128,7 +128,6 @@ endif
 if HAVE_BOTAN
 			botan/\* \
 endif
-			ext/coroutine/\* \
 			gtest/\* \
 			include/\* \
 			lib/\eval/\* \
@@ -182,9 +181,6 @@ install-exec-hook:
 add-changelog-entry:
 	@./changelog_unreleased/.add-entry.sh
 
-#### include external sources in the distributed tarball:
-EXTRA_DIST = ext/coroutine/coroutine.hpp
-
 CLEANFILES = $(abs_top_builddir)/logger_lockfile
 
 # config.h may be included by headers supplied for building user-written

ext/coroutine/LICENSE_1_0.txt

@@ -1,23 +0,0 @@
-Boost Software License - Version 1.0 - August 17th, 2003
-
-Permission is hereby granted, free of charge, to any person or organization
-obtaining a copy of the software and accompanying documentation covered by
-this license (the "Software") to use, reproduce, display, distribute,
-execute, and transmit the Software, and to prepare derivative works of the
-Software, and to permit third-parties to whom the Software is furnished to
-do so, all subject to the following:
-
-The copyright notices in the Software and this entire statement, including
-the above license grant, this restriction and the following disclaimer,
-must be included in all copies of the Software, in whole or in part, and
-all derivative works of the Software, unless such copies or derivative
-works are solely in the form of machine-executable object code generated by
-a source language processor.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
-SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
-FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
-ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.

ext/coroutine/Makefile.am

@@ -1 +0,0 @@
-EXTRA_DIST = LICENSE_1_0.txt README

ext/coroutine/README

@@ -1,12 +0,0 @@
-This directory contains a coroutine.hpp header file. This self-contained
-header is needed by Kea. It is part of Boost library for a long time.
-Unfortunately, RedHat (and CentOS) provide only a very old version
-of Boost that doesn't have coroutine.hpp header included.
-
-This caused Kea to require building new version of Boost on RHEL and
-CentOS, just for the sake of getting this 9KB header. Note that although
-the coroutine is included in Boost, it does not include anything from
-Boost and is self contained.
-
-This header and the whole directory will be removed eventually once
-RHEL and CentOS start providing more modern Boost version.

ext/coroutine/coroutine.hpp

@@ -1,330 +0,0 @@
-//
-// coroutine.hpp
-// ~~~~~~~~~~~~~
-//
-// Copyright (c) 2003-2018 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_COROUTINE_HPP
-#define BOOST_ASIO_COROUTINE_HPP
-
-namespace boost {
-namespace asio {
-namespace detail {
-
-class coroutine_ref;
-
-} // namespace detail
-
-/// Provides support for implementing stackless coroutines.
-/**
- * The @c coroutine class may be used to implement stackless coroutines. The
- * class itself is used to store the current state of the coroutine.
- *
- * Coroutines are copy-constructible and assignable, and the space overhead is
- * a single int. They can be used as a base class:
- *
- * @code class session : coroutine
- * {
- *   ...
- * }; @endcode
- *
- * or as a data member:
- *
- * @code class session
- * {
- *   ...
- *   coroutine coro_;
- * }; @endcode
- *
- * or even bound in as a function argument using lambdas or @c bind(). The
- * important thing is that as the application maintains a copy of the object
- * for as long as the coroutine must be kept alive.
- *
- * @par Pseudo-keywords
- *
- * A coroutine is used in conjunction with certain "pseudo-keywords", which
- * are implemented as macros. These macros are defined by a header file:
- *
- * @code #include <boost/asio/yield.hpp>@endcode
- *
- * and may conversely be undefined as follows:
- *
- * @code #include <boost/asio/unyield.hpp>@endcode
- *
- * <b>reenter</b>
- *
- * The @c reenter macro is used to define the body of a coroutine. It takes a
- * single argument: a pointer or reference to a coroutine object. For example,
- * if the base class is a coroutine object you may write:
- *
- * @code reenter (this)
- * {
- *   ... coroutine body ...
- * } @endcode
- *
- * and if a data member or other variable you can write:
- *
- * @code reenter (coro_)
- * {
- *   ... coroutine body ...
- * } @endcode
- *
- * When @c reenter is executed at runtime, control jumps to the location of the
- * last @c yield or @c fork.
- *
- * The coroutine body may also be a single statement, such as:
- *
- * @code reenter (this) for (;;)
- * {
- *   ...
- * } @endcode
- *
- * @b Limitation: The @c reenter macro is implemented using a switch. This
- * means that you must take care when using local variables within the
- * coroutine body. The local variable is not allowed in a position where
- * reentering the coroutine could bypass the variable definition.
- *
- * <b>yield <em>statement</em></b>
- *
- * This form of the @c yield keyword is often used with asynchronous operations:
- *
- * @code yield socket_->async_read_some(buffer(*buffer_), *this); @endcode
- *
- * This divides into four logical steps:
- *
- * @li @c yield saves the current state of the coroutine.
- * @li The statement initiates the asynchronous operation.
- * @li The resume point is defined immediately following the statement.
- * @li Control is transferred to the end of the coroutine body.
- *
- * When the asynchronous operation completes, the function object is invoked
- * and @c reenter causes control to transfer to the resume point. It is
- * important to remember to carry the coroutine state forward with the
- * asynchronous operation. In the above snippet, the current class is a
- * function object object with a coroutine object as base class or data member.
- *
- * The statement may also be a compound statement, and this permits us to
- * define local variables with limited scope:
- *
- * @code yield
- * {
- *   mutable_buffers_1 b = buffer(*buffer_);
- *   socket_->async_read_some(b, *this);
- * } @endcode
- *
- * <b>yield return <em>expression</em> ;</b>
- *
- * This form of @c yield is often used in generators or coroutine-based parsers.
- * For example, the function object:
- *
- * @code struct interleave : coroutine
- * {
- *   istream& is1;
- *   istream& is2;
- *   char operator()(char c)
- *   {
- *     reenter (this) for (;;)
- *     {
- *       yield return is1.get();
- *       yield return is2.get();
- *     }
- *   }
- * }; @endcode
- *
- * defines a trivial coroutine that interleaves the characters from two input
- * streams.
- *
- * This type of @c yield divides into three logical steps:
- *
- * @li @c yield saves the current state of the coroutine.
- * @li The resume point is defined immediately following the semicolon.
- * @li The value of the expression is returned from the function.
- *
- * <b>yield ;</b>
- *
- * This form of @c yield is equivalent to the following steps:
- *
- * @li @c yield saves the current state of the coroutine.
- * @li The resume point is defined immediately following the semicolon.
- * @li Control is transferred to the end of the coroutine body.
- *
- * This form might be applied when coroutines are used for cooperative
- * threading and scheduling is explicitly managed. For example:
- *
- * @code struct task : coroutine
- * {
- *   ...
- *   void operator()()
- *   {
- *     reenter (this)
- *     {
- *       while (... not finished ...)
- *       {
- *         ... do something ...
- *         yield;
- *         ... do some more ...
- *         yield;
- *       }
- *     }
- *   }
- *   ...
- * };
- * ...
- * task t1, t2;
- * for (;;)
- * {
- *   t1();
- *   t2();
- * } @endcode
- *
- * <b>yield break ;</b>
- *
- * The final form of @c yield is used to explicitly terminate the coroutine.
- * This form is comprised of two steps:
- *
- * @li @c yield sets the coroutine state to indicate termination.
- * @li Control is transferred to the end of the coroutine body.
- *
- * Once terminated, calls to is_complete() return true and the coroutine cannot
- * be reentered.
- *
- * Note that a coroutine may also be implicitly terminated if the coroutine
- * body is exited without a yield, e.g. by return, throw or by running to the
- * end of the body.
- *
- * <b>fork <em>statement</em></b>
- *
- * The @c fork pseudo-keyword is used when "forking" a coroutine, i.e. splitting
- * it into two (or more) copies. One use of @c fork is in a server, where a new
- * coroutine is created to handle each client connection:
- * 
- * @code reenter (this)
- * {
- *   do
- *   {
- *     socket_.reset(new tcp::socket(io_context_));
- *     yield acceptor->async_accept(*socket_, *this);
- *     fork server(*this)();
- *   } while (is_parent());
- *   ... client-specific handling follows ...
- * } @endcode
- * 
- * The logical steps involved in a @c fork are:
- * 
- * @li @c fork saves the current state of the coroutine.
- * @li The statement creates a copy of the coroutine and either executes it
- *     immediately or schedules it for later execution.
- * @li The resume point is defined immediately following the semicolon.
- * @li For the "parent", control immediately continues from the next line.
- *
- * The functions is_parent() and is_child() can be used to differentiate
- * between parent and child. You would use these functions to alter subsequent
- * control flow.
- *
- * Note that @c fork doesn't do the actual forking by itself. It is the
- * application's responsibility to create a clone of the coroutine and call it.
- * The clone can be called immediately, as above, or scheduled for delayed
- * execution using something like io_context::post().
- *
- * @par Alternate macro names
- *
- * If preferred, an application can use macro names that follow a more typical
- * naming convention, rather than the pseudo-keywords. These are:
- *
- * @li @c BOOST_ASIO_CORO_REENTER instead of @c reenter
- * @li @c BOOST_ASIO_CORO_YIELD instead of @c yield
- * @li @c BOOST_ASIO_CORO_FORK instead of @c fork
- */
-class coroutine
-{
-public:
-  /// Constructs a coroutine in its initial state.
-  coroutine() : value_(0) {}
-
-  /// Returns true if the coroutine is the child of a fork.
-  bool is_child() const { return value_ < 0; }
-
-  /// Returns true if the coroutine is the parent of a fork.
-  bool is_parent() const { return !is_child(); }
-
-  /// Returns true if the coroutine has reached its terminal state.
-  bool is_complete() const { return value_ == -1; }
-
-private:
-  friend class detail::coroutine_ref;
-  int value_;
-};
-
-
-namespace detail {
-
-class coroutine_ref
-{
-public:
-  coroutine_ref(coroutine& c) : value_(c.value_), modified_(false) {}
-  coroutine_ref(coroutine* c) : value_(c->value_), modified_(false) {}
-  ~coroutine_ref() { if (!modified_) value_ = -1; }
-  operator int() const { return value_; }
-  int& operator=(int v) { modified_ = true; return value_ = v; }
-private:
-  void operator=(const coroutine_ref&);
-  int& value_;
-  bool modified_;
-};
-
-} // namespace detail
-} // namespace asio
-} // namespace boost
-
-#define BOOST_ASIO_CORO_REENTER(c) \
-  switch (::boost::asio::detail::coroutine_ref _coro_value = c) \
-    case -1: if (_coro_value) \
-    { \
-      goto terminate_coroutine; \
-      terminate_coroutine: \
-      _coro_value = -1; \
-      goto bail_out_of_coroutine; \
-      bail_out_of_coroutine: \
-      break; \
-    } \
-    else /* fall-through */ case 0:
-
-#define BOOST_ASIO_CORO_YIELD_IMPL(n) \
-  for (_coro_value = (n);;) \
-    if (_coro_value == 0) \
-    { \
-      case (n): ; \
-      break; \
-    } \
-    else \
-      switch (_coro_value ? 0 : 1) \
-        for (;;) \
-          /* fall-through */ case -1: if (_coro_value) \
-            goto terminate_coroutine; \
-          else for (;;) \
-            /* fall-through */ case 1: if (_coro_value) \
-              goto bail_out_of_coroutine; \
-            else /* fall-through */ case 0:
-
-#define BOOST_ASIO_CORO_FORK_IMPL(n) \
-  for (_coro_value = -(n);; _coro_value = (n)) \
-    if (_coro_value == (n)) \
-    { \
-      case -(n): ; \
-      break; \
-    } \
-    else
-
-#if defined(_MSC_VER)
-# define BOOST_ASIO_CORO_YIELD BOOST_ASIO_CORO_YIELD_IMPL(__COUNTER__ + 1)
-# define BOOST_ASIO_CORO_FORK BOOST_ASIO_CORO_FORK_IMPL(__COUNTER__ + 1)
-#else // defined(_MSC_VER)
-# define BOOST_ASIO_CORO_YIELD BOOST_ASIO_CORO_YIELD_IMPL(__LINE__)
-# define BOOST_ASIO_CORO_FORK BOOST_ASIO_CORO_FORK_IMPL(__LINE__)
-#endif // defined(_MSC_VER)
-
-#endif // BOOST_ASIO_COROUTINE_HPP

m4macros/ax_boost_for_kea.m4

@@ -80,6 +80,7 @@ fi
 AC_CHECK_HEADERS(
   [                                                             \
     boost/asio.hpp                                              \
+    boost/asio/coroutine.hpp                                    \
     boost/asio/ip/address.hpp                                   \
     boost/asio/signal_set.hpp                                   \
     boost/atomic.hpp                                            \
@@ -97,8 +98,6 @@ AC_CHECK_HEADERS(
   ]]
 )
 
-AC_CHECK_HEADERS(boost/asio/coroutine.hpp,,AC_MSG_RESULT(not found, using built-in header.))
-
 AC_CHECK_HEADERS(boost/integer/common_factor.hpp)
 
 AC_CHECK_HEADERS(boost/asio/io_context.hpp,,AC_MSG_ERROR([Missing boost asio io_context header: boost version must be at least 1.66]))

src/lib/asiodns/io_fetch.h

@@ -9,21 +9,13 @@
 
 #include <config.h>
 
-// We want to use coroutine.hpp from the system's boost headers if possible.
-// However, very old Boost versions (provided by RHEL 7 or CentOS 7) didn't have
-// this header. So we can resort to our bundled version, but only if necessary.
-#ifdef HAVE_BOOST_ASIO_COROUTINE_HPP
-#include <boost/asio/coroutine.hpp>
-#else
-#include <ext/coroutine/coroutine.hpp>
-#endif
-
 #include <asiolink/io_address.h>
 #include <asiolink/io_service.h>
 #include <dns/message.h>
 #include <dns/question.h>
 #include <util/buffer.h>
 
+#include <boost/asio/coroutine.hpp>
 #include <boost/shared_array.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/date_time/posix_time/posix_time_types.hpp>

src/lib/asiolink/io_asio_socket.h

@@ -23,14 +23,7 @@
 
 #include <unistd.h>             // for some network system calls
 
-// We want to use coroutine.hpp from the system's boost headers if possible.
-// However, very old Boost versions (provided by RHEL 7 or CentOS 7) didn't have
-// this header. So we can resort to our bundled version, but only if necessary.
-#ifndef HAVE_BOOST_ASIO_COROUTINE_HPP
-#include <ext/coroutine/coroutine.hpp>
-#else
 #include <boost/asio/coroutine.hpp>
-#endif
 
 namespace isc {
 namespace asiolink {