boost/mpi/request.hpp

   1 // Copyright (C) 2006 Douglas Gregor <doug.gregor -at- gmail.com>.
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 /** @file request.hpp
   8  *
   9  *  This header defines the class @c request, which contains a request
  10  *  for non-blocking communication.
  11  */
  12 #ifndef BOOST_MPI_REQUEST_HPP
  13 #define BOOST_MPI_REQUEST_HPP
  14
  15 #include <boost/mpi/config.hpp>
  16 #include <boost/optional.hpp>
  17 #include <boost/shared_ptr.hpp>
  18 #include <boost/mpi/packed_iarchive.hpp>
  19
  20 namespace boost { namespace mpi {
  21
  22 class status;
  23 class communicator;
  24
  25 /**
  26  *  @brief A request for a non-blocking send or receive.
  27  *
  28  *  This structure contains information about a non-blocking send or
  29  *  receive and will be returned from @c isend or @c irecv,
  30  *  respectively.
  31  */
  32 class BOOST_MPI_DECL request
  33 {
  34  public:
  35   /**
  36    *  Constructs a NULL request.
  37    */
  38   request();
  39
  40   /**
  41    *  Wait until the communication associated with this request has
  42    *  completed, then return a @c status object describing the
  43    *  communication.
  44    */
  45   status wait();
  46
  47   /**
  48    *  Determine whether the communication associated with this request
  49    *  has completed successfully. If so, returns the @c status object
  50    *  describing the communication. Otherwise, returns an empty @c
  51    *  optional<> to indicate that the communication has not completed
  52    *  yet. Note that once @c test() returns a @c status object, the
  53    *  request has completed and @c wait() should not be called.
  54    */
  55   optional<status> test();
  56
  57   /**
  58    *  Cancel a pending communication, assuming it has not already been
  59    *  completed.
  60    */
  61   void cancel();
  62
  63  private:
  64   enum request_action { ra_wait, ra_test, ra_cancel };
  65   typedef optional<status> (*handler_type)(request* self,
  66                                            request_action action);
  67
  68   /**
  69    * INTERNAL ONLY
  70    *
  71    * Handles the non-blocking receive of a serialized value.
  72    */
  73   template<typename T>
  74   static optional<status>
  75   handle_serialized_irecv(request* self, request_action action);
  76
  77   /**
  78    * INTERNAL ONLY
  79    *
  80    * Handles the non-blocking receive of an array of  serialized values.
  81    */
  82   template<typename T>
  83   static optional<status>
  84   handle_serialized_array_irecv(request* self, request_action action);
  85
  86  public: // template friends are not portable
  87
  88   /// INTERNAL ONLY
  89   MPI_Request m_requests[2];
  90
  91   /// INTERNAL ONLY
  92   handler_type m_handler;
  93
  94   /// INTERNAL ONLY
  95   shared_ptr<void> m_data;
  96
  97   friend class communicator;
  98 };
  99
 100 } } // end namespace boost::mpi
 101
 102 #endif // BOOST_MPI_REQUEST_HPP