externals: Update boost to 1.72 and add Boost Context

boost/thread/executors/generic_executor_ref.hpp

@@ -0,0 +1,215 @@
+// Copyright (C) 2014 Vicente J. Botet Escriba
+//
+//  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_THREAD_EXECUTORS_GENERIC_EXECUTOR_REF_HPP
+#define BOOST_THREAD_EXECUTORS_GENERIC_EXECUTOR_REF_HPP
+
+#include <boost/thread/detail/config.hpp>
+#if defined BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION && defined BOOST_THREAD_PROVIDES_EXECUTORS && defined BOOST_THREAD_USES_MOVE
+
+#include <boost/thread/detail/delete.hpp>
+#include <boost/thread/detail/move.hpp>
+#include <boost/thread/executors/executor.hpp>
+
+#include <boost/shared_ptr.hpp>
+
+#include <boost/config/abi_prefix.hpp>
+
+namespace boost
+{
+  namespace executors
+  {
+
+  template <class Executor>
+  class executor_ref : public executor
+  {
+    Executor& ex;
+  public:
+    /// type-erasure to store the works to do
+    typedef  executors::work work;
+
+    /// executor is not copyable.
+    BOOST_THREAD_NO_COPYABLE(executor_ref)
+    executor_ref(Executor& ex_) : ex(ex_) {}
+
+    /**
+     * \par Effects
+     * Destroys the executor.
+     *
+     * \par Synchronization
+     * The completion of all the closures happen before the completion of the executor destructor.
+     */
+    ~executor_ref() {}
+
+    /**
+     * \par Effects
+     * Close the \c executor for submissions.
+     * The worker threads will work until there is no more closures to run.
+     */
+    void close() { ex.close(); }
+
+    /**
+     * \par Returns
+     * Whether the pool is closed for submissions.
+     */
+    bool closed() { return ex.closed(); }
+
+    /**
+     * \par Effects
+     * The specified closure will be scheduled for execution at some point in the future.
+     * If invoked closure throws an exception the executor will call std::terminate, as is the case with threads.
+     *
+     * \par Synchronization
+     * Ccompletion of closure on a particular thread happens before destruction of thread's thread local variables.
+     *
+     * \par Throws
+     * \c sync_queue_is_closed if the thread pool is closed.
+     * Whatever exception that can be throw while storing the closure.
+     */
+    void submit(BOOST_THREAD_RV_REF(work) closure) {
+      ex.submit(boost::move(closure));
+    }
+//    void submit(work& closure) {
+//      ex.submit(closure);
+//    }
+
+
+    /**
+     * \par Effects
+     * Try to execute one task.
+     *
+     * \par Returns
+     * Whether a task has been executed.
+     *
+     * \par Throws
+     * Whatever the current task constructor throws or the task() throws.
+     */
+    bool try_executing_one() { return ex.try_executing_one(); }
+
+  };
+
+  class generic_executor_ref
+  {
+    shared_ptr<executor> ex;
+  public:
+    /// type-erasure to store the works to do
+    typedef executors::work work;
+
+    template<typename Executor>
+    generic_executor_ref(Executor& ex_)
+    //: ex(make_shared<executor_ref<Executor> >(ex_)) // todo check why this doesn't works with C++03
+    : ex( new executor_ref<Executor>(ex_) )
+    {
+    }
+
+    //generic_executor_ref(generic_executor_ref const& other) noexcept    {}
+    //generic_executor_ref& operator=(generic_executor_ref const& other) noexcept    {}
+
+
+    /**
+     * \par Effects
+     * Close the \c executor for submissions.
+     * The worker threads will work until there is no more closures to run.
+     */
+    void close() { ex->close(); }
+
+    /**
+     * \par Returns
+     * Whether the pool is closed for submissions.
+     */
+    bool closed() { return ex->closed(); }
+
+    /**
+     * \par Requires
+     * \c Closure is a model of Callable(void()) and a model of CopyConstructible/MoveConstructible.
+     *
+     * \par Effects
+     * The specified closure will be scheduled for execution at some point in the future.
+     * If invoked closure throws an exception the thread pool will call std::terminate, as is the case with threads.
+     *
+     * \par Synchronization
+     * Completion of closure on a particular thread happens before destruction of thread's thread local variables.
+     *
+     * \par Throws
+     * \c sync_queue_is_closed if the thread pool is closed.
+     * Whatever exception that can be throw while storing the closure.
+     */
+
+    void submit(BOOST_THREAD_RV_REF(work) closure)
+    {
+      ex->submit(boost::move(closure));
+    }
+
+#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+    template <typename Closure>
+    void submit(Closure & closure)
+    {
+      //work w ((closure));
+      //submit(boost::move(w));
+      submit(work(closure));
+    }
+#endif
+    void submit(void (*closure)())
+    {
+      work w ((closure));
+      submit(boost::move(w));
+      //submit(work(closure));
+    }
+
+    template <typename Closure>
+    void submit(BOOST_THREAD_FWD_REF(Closure) closure)
+    {
+      work w((boost::forward<Closure>(closure)));
+      submit(boost::move(w));
+    }
+
+//    size_t num_pending_closures() const
+//    {
+//      return ex->num_pending_closures();
+//    }
+
+    /**
+     * \par Effects
+     * Try to execute one task.
+     *
+     * \par Returns
+     * Whether a task has been executed.
+     *
+     * \par Throws
+     * Whatever the current task constructor throws or the task() throws.
+     */
+    bool try_executing_one() { return ex->try_executing_one(); }
+
+    /**
+     * \par Requires
+     * This must be called from an scheduled task.
+     *
+     * \par Effects
+     * reschedule functions until pred()
+     */
+    template <typename Pred>
+    bool reschedule_until(Pred const& pred)
+    {
+      do {
+        //schedule_one_or_yield();
+        if ( ! try_executing_one())
+        {
+          return false;
+        }
+      } while (! pred());
+      return true;
+    }
+
+  };
+  }
+  using executors::executor_ref;
+  using executors::generic_executor_ref;
+}
+
+#include <boost/config/abi_suffix.hpp>
+
+#endif
+#endif