ceph/src/boost/libs/property_map/include/boost/property_map/parallel/distributed_property_map.hpp

   1 // Copyright (C) 2004-2008 The Trustees of Indiana University.
   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 //  Authors: Douglas Gregor
   8 //           Nick Edmonds
   9 //           Andrew Lumsdaine
  10
  11 // The placement of this #include probably looks very odd relative to
  12 // the #ifndef/#define pair below. However, this placement is
  13 // extremely important to allow the various property map headers to be
  14 // included in any order.
  15 #include <boost/property_map/property_map.hpp>
  16
  17 #ifndef BOOST_PARALLEL_DISTRIBUTED_PROPERTY_MAP_HPP
  18 #define BOOST_PARALLEL_DISTRIBUTED_PROPERTY_MAP_HPP
  19
  20 #include <boost/assert.hpp>
  21 #include <boost/type_traits/is_base_and_derived.hpp>
  22 #include <boost/shared_ptr.hpp>
  23 #include <boost/weak_ptr.hpp>
  24 #include <boost/optional.hpp>
  25 #include <boost/property_map/parallel/process_group.hpp>
  26 #include <boost/function/function1.hpp>
  27 #include <vector>
  28 #include <set>
  29 #include <boost/property_map/parallel/basic_reduce.hpp>
  30 #include <boost/property_map/parallel/detail/untracked_pair.hpp>
  31 #include <boost/type_traits/is_same.hpp>
  32 #include <boost/property_map/parallel/local_property_map.hpp>
  33 #include <map>
  34 #include <boost/version.hpp>
  35 #include <boost/property_map/parallel/unsafe_serialize.hpp>
  36 #include <boost/multi_index_container.hpp>
  37 #include <boost/multi_index/hashed_index.hpp>
  38 #include <boost/multi_index/member.hpp>
  39 #include <boost/multi_index/sequenced_index.hpp>
  40
  41 // Serialization functions for constructs we use
  42 #include <boost/serialization/utility.hpp>
  43
  44 namespace boost { namespace parallel {
  45
  46 namespace detail {
  47   /**************************************************************************
  48    * Metafunction that degrades an Lvalue Property Map category tag to
  49    * a Read Write Property Map category tag.
  50    **************************************************************************/
  51   template<bool IsLvaluePropertyMap>
  52   struct make_nonlvalue_property_map
  53   {
  54     template<typename T> struct apply { typedef T type; };
  55   };
  56
  57   template<>
  58   struct make_nonlvalue_property_map<true>
  59   {
  60     template<typename>
  61     struct apply
  62     {
  63       typedef read_write_property_map_tag type;
  64     };
  65   };
  66
  67   /**************************************************************************
  68    * Performs a "put" on a property map so long as the property map is
  69    * a Writable Property Map or a mutable Lvalue Property Map. This
  70    * is required because the distributed property map's message
  71    * handler handles "put" messages even for a const property map,
  72    * although receipt of a "put" message is ill-formed.
  73    **************************************************************************/
  74   template<bool IsLvaluePropertyMap>
  75   struct maybe_put_in_lvalue_pm
  76   {
  77     template<typename PropertyMap, typename Key, typename Value>
  78     static inline void
  79     do_put(PropertyMap, const Key&, const Value&)
  80     { BOOST_ASSERT(false); }
  81   };
  82
  83   template<>
  84   struct maybe_put_in_lvalue_pm<true>
  85   {
  86     template<typename PropertyMap, typename Key, typename Value>
  87     static inline void
  88     do_put(PropertyMap pm, const Key& key, const Value& value)
  89     {
  90       using boost::put;
  91
  92       put(pm, key, value);
  93     }
  94   };
  95
  96   template<typename PropertyMap, typename Key, typename Value>
  97   inline void
  98   maybe_put_impl(PropertyMap pm, const Key& key, const Value& value,
  99                  writable_property_map_tag)
 100   {
 101     using boost::put;
 102
 103     put(pm, key, value);
 104   }
 105
 106   template<typename PropertyMap, typename Key, typename Value>
 107   inline void
 108   maybe_put_impl(PropertyMap pm, const Key& key, const Value& value,
 109                  lvalue_property_map_tag)
 110   {
 111     typedef typename property_traits<PropertyMap>::value_type value_type;
 112     typedef typename property_traits<PropertyMap>::reference reference;
 113     // DPG TBD: Some property maps are improperly characterized as
 114     // lvalue_property_maps, when in fact they do not provide true
 115     // references. The most typical example is those property maps
 116     // built from vector<bool> and its iterators, which deal with
 117     // proxies. We don't want to mischaracterize these as not having a
 118     // "put" operation, so we only consider an lvalue_property_map as
 119     // constant if its reference is const value_type&. In fact, this
 120     // isn't even quite correct (think of a
 121     // vector<bool>::const_iterator), but at present C++ doesn't
 122     // provide us with any alternatives.
 123     typedef is_same<const value_type&, reference> is_constant;
 124
 125     maybe_put_in_lvalue_pm<(!is_constant::value)>::do_put(pm, key, value);
 126   }
 127
 128   template<typename PropertyMap, typename Key, typename Value>
 129   inline void
 130   maybe_put_impl(PropertyMap, const Key&, const Value&, ...)
 131   { BOOST_ASSERT(false); }
 132
 133   template<typename PropertyMap, typename Key, typename Value>
 134   inline void
 135   maybe_put(PropertyMap pm, const Key& key, const Value& value)
 136   {
 137     maybe_put_impl(pm, key, value,
 138                    typename property_traits<PropertyMap>::category());
 139   }
 140 } // end namespace detail
 141
 142 /** The consistency model used by the distributed property map. */
 143 enum consistency_model {
 144   cm_forward = 1 << 0,
 145   cm_backward = 1 << 1,
 146   cm_bidirectional = cm_forward | cm_backward,
 147   cm_flush = 1 << 2,
 148   cm_reset = 1 << 3,
 149   cm_clear = 1 << 4
 150 };
 151
 152 /** Distributed property map adaptor.
 153  *
 154  *  The distributed property map adaptor is a property map whose
 155  *  stored values are distributed across multiple non-overlapping
 156  *  memory spaces on different processes. Values local to the current
 157  *  process are stored within a local property map and may be
 158  *  immediately accessed via @c get and @c put. Values stored on
 159  *  remote processes may also be access via @c get and @c put, but the
 160  *  behavior differs slightly:
 161  *
 162  *  - @c put operations update a local ghost cell and send a "put"
 163  *    message to the process that owns the value. The owner is free to
 164  *    update its own "official" value or may ignore the put request.
 165  *
 166  *  - @c get operations returns the contents of the local ghost
 167  *    cell. If no ghost cell is available, one is created using the
 168  *    default value provided by the "reduce" operation. See, e.g.,
 169  *    @ref basic_reduce and @ref property_reduce.
 170  *
 171  * Using distributed property maps requires a bit more care than using
 172  * local, sequential property maps. While the syntax and semantics are
 173  * similar, distributed property maps may contain out-of-date
 174  * information that can only be guaranteed to be synchronized by
 175  * calling the @ref synchronize function in all processes.
 176  *
 177  * To address the issue of out-of-date values, distributed property
 178  * maps are supplied with a reduction operation. The reduction
 179  * operation has two roles:
 180  *
 181  *   -# When a value is needed for a remote key but no value is
 182  *      immediately available, the reduction operation provides a
 183  *      suitable default. For instance, a distributed property map
 184  *      storing distances may have a reduction operation that returns
 185  *      an infinite value as the default, whereas a distributed
 186  *      property map for vertex colors may return white as the
 187  *      default.
 188  *
 189  *   -# When a value is received from a remote process, the process
 190  *      owning the key associated with that value must determine which
 191  *      value---the locally stored value, the value received from a
 192  *      remote process, or some combination of the two---will be
 193  *      stored as the "official" value in the property map. The
 194  *      reduction operation transforms the local and remote values
 195  *      into the "official" value to be stored.
 196  *
 197  * @tparam ProcessGroup the type of the process group over which the
 198  * property map is distributed and is also the medium for
 199  * communication.
 200  *
 201  * @tparam StorageMap the type of the property map that will
 202  * store values for keys local to this processor. The @c value_type of
 203  * this property map will become the @c value_type of the distributed
 204  * property map. The distributed property map models the same property
 205  * map concepts as the @c LocalPropertyMap, with one exception: a
 206  * distributed property map cannot be an LvaluePropertyMap (because
 207  * remote values are not addressable), and is therefore limited to
 208  * ReadWritePropertyMap.
 209  */
 210 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 211 class distributed_property_map
 212 {
 213  public:
 214   /// The key type of the property map.
 215   typedef typename property_traits<GlobalMap>::key_type key_type;
 216
 217   /// The value type of the property map.
 218   typedef typename property_traits<StorageMap>::value_type value_type;
 219   typedef typename property_traits<StorageMap>::reference  reference;
 220   typedef ProcessGroup                        process_group_type;
 221
 222  private:
 223   typedef distributed_property_map            self_type;
 224   typedef typename property_traits<StorageMap>::category local_category;
 225   typedef typename property_traits<StorageMap>::key_type local_key_type;
 226   typedef typename property_traits<GlobalMap>::value_type owner_local_pair;
 227   typedef typename ProcessGroup::process_id_type process_id_type;
 228
 229   enum property_map_messages {
 230     /** A request to store a value in a property map. The message
 231      * contains a std::pair<key, data>.
 232      */
 233     property_map_put,
 234
 235     /** A request to retrieve a particular value in a property
 236      *  map. The message contains a key. The owner of that key will
 237      *  reply with a value.
 238      */
 239     property_map_get,
 240
 241     /** A request to update values stored on a remote processor. The
 242      * message contains a vector of keys for which the source
 243      * requests updated values. This message will only be transmitted
 244      * during synchronization.
 245      */
 246     property_map_multiget,
 247
 248     /** A request to store values in a ghost cell. This message
 249      * contains a vector of key/value pairs corresponding to the
 250      * sequence of keys sent to the source processor.
 251      */
 252     property_map_multiget_reply,
 253
 254     /** The payload containing a vector of local key-value pairs to be
 255      * put into the remote property map. A key-value std::pair will be
 256      * used to store each local key-value pair.
 257      */
 258     property_map_multiput
 259   };
 260
 261   // Code from Joaquín M López Muñoz to work around unusual implementation of
 262   // std::pair in VC++ 10:
 263   template<typename First,typename Second>
 264   class pair_first_extractor {
 265     typedef std::pair<First,Second> value_type;
 266
 267     public:
 268     typedef First result_type;
 269     const result_type& operator()(const value_type& x) const {
 270       return x.first;
 271     }
 272
 273     result_type& operator()(value_type& x) const {
 274       return x.first;
 275     }
 276   };
 277
 278  public:
 279   /// The type of the ghost cells
 280   typedef multi_index::multi_index_container<
 281             std::pair<key_type, value_type>,
 282             multi_index::indexed_by<
 283               multi_index::sequenced<>,
 284               multi_index::hashed_unique<
 285                 pair_first_extractor<key_type, value_type>
 286               >
 287             >
 288           > ghost_cells_type;
 289
 290   /// Iterator into the ghost cells
 291   typedef typename ghost_cells_type::iterator iterator;
 292
 293   /// Key-based index into the ghost cells
 294   typedef typename ghost_cells_type::template nth_index<1>::type
 295     ghost_cells_key_index_type;
 296
 297   /// Iterator into the ghost cells (by key)
 298   typedef typename ghost_cells_key_index_type::iterator key_iterator;
 299
 300   /** The property map category.  A distributed property map cannot be
 301    * an Lvalue Property Map, because values on remote processes cannot
 302    * be addresses.
 303    */
 304   typedef typename detail::make_nonlvalue_property_map<
 305     (is_base_and_derived<lvalue_property_map_tag, local_category>::value
 306      || is_same<lvalue_property_map_tag, local_category>::value)>
 307     ::template apply<local_category>::type category;
 308
 309   /** Default-construct a distributed property map.  This function
 310    * creates an initialized property map that must be assigned to a
 311    * valid value before being used. It is only provided here because
 312    * property maps must be Default Constructible.
 313    */
 314   distributed_property_map() {}
 315
 316   /** Construct a distributed property map.  Builds a distributed
 317    * property map communicating over the given process group and using
 318    * the given local property map for storage. Since no reduction
 319    * operation is provided, the default reduction operation @c
 320    * basic_reduce<value_type> is used.
 321    */
 322   distributed_property_map(const ProcessGroup& pg, const GlobalMap& global,
 323                            const StorageMap& pm)
 324     : data(new data_t(pg, global, pm, basic_reduce<value_type>(), false))
 325   {
 326     typedef handle_message<basic_reduce<value_type> > Handler;
 327
 328     data->ghost_cells.reset(new ghost_cells_type());
 329     Handler handler(data);
 330     data->process_group.replace_handler(handler, true);
 331     data->process_group.template get_receiver<Handler>()
 332       ->setup_triggers(data->process_group);
 333   }
 334
 335   /** Construct a distributed property map.  Builds a distributed
 336    * property map communicating over the given process group and using
 337    * the given local property map for storage. The given @p reduce
 338    * parameter is used as the reduction operation.
 339    */
 340   template<typename Reduce>
 341   distributed_property_map(const ProcessGroup& pg, const GlobalMap& global,
 342                            const StorageMap& pm,
 343                            const Reduce& reduce);
 344
 345   ~distributed_property_map();
 346
 347   /// Set the reduce operation of the distributed property map.
 348   template<typename Reduce>
 349   void set_reduce(const Reduce& reduce);
 350
 351   // Set the consistency model for the distributed property map
 352   void set_consistency_model(int model);
 353
 354   // Get the consistency model
 355   int get_consistency_model() const { return data->model; }
 356
 357   // Set the maximum number of ghost cells that we are allowed to
 358   // maintain. If 0, all ghost cells will be retained.
 359   void set_max_ghost_cells(std::size_t max_ghost_cells);
 360
 361   // Clear out all ghost cells
 362   void clear();
 363
 364   // Reset the values in all ghost cells to the default value
 365   void reset();
 366
 367   // Flush all values destined for remote processors
 368   void flush();
 369
 370   reference operator[](const key_type& key) const
 371   {
 372     owner_local_pair p = get(data->global, key);
 373
 374     if (p.first == process_id(data->process_group)) {
 375       return data->storage[p.second];
 376     } else {
 377       return cell(key);
 378     }
 379   }
 380
 381   process_group_type process_group() const
 382   {
 383     return data->process_group.base();
 384   }
 385
 386   StorageMap&       base()       { return data->storage; }
 387   const StorageMap& base() const { return data->storage; }
 388
 389   /** Sends a "put" request.
 390    * \internal
 391    *
 392    */
 393   void
 394   request_put(process_id_type p, const key_type& k, const value_type& v) const
 395   {
 396     send(data->process_group, p, property_map_put,
 397          boost::parallel::detail::make_untracked_pair(k, v));
 398   }
 399
 400   /** Access the ghost cell for the given key.
 401    * \internal
 402    */
 403   value_type& cell(const key_type& k, bool request_if_missing = true) const;
 404
 405   /** Perform synchronization
 406    * \internal
 407    */
 408   void do_synchronize();
 409
 410   const GlobalMap& global() const { return data->global; }
 411   GlobalMap&       global()       { return data->global; }
 412
 413   struct data_t
 414   {
 415     data_t(const ProcessGroup& pg, const GlobalMap& global,
 416            const StorageMap& pm, const function1<value_type, key_type>& dv,
 417            bool has_default_resolver)
 418       : process_group(pg), global(global), storage(pm),
 419         ghost_cells(), max_ghost_cells(1000000), get_default_value(dv),
 420         has_default_resolver(has_default_resolver), model(cm_forward) { }
 421
 422     /// The process group
 423     ProcessGroup process_group;
 424
 425     /// A mapping from the keys of this property map to the global
 426     /// descriptor.
 427     GlobalMap global;
 428
 429     /// Local property map
 430     StorageMap storage;
 431
 432     /// The ghost cells
 433     shared_ptr<ghost_cells_type> ghost_cells;
 434
 435     /// The maximum number of ghost cells we are permitted to hold. If
 436     /// zero, we are permitted to have an infinite number of ghost
 437     /// cells.
 438     std::size_t max_ghost_cells;
 439
 440     /// Default value for remote ghost cells, as defined by the
 441     /// reduction operation.
 442     function1<value_type, key_type> get_default_value;
 443
 444     /// True if this resolver is the "default" resolver, meaning that
 445     /// we should not be able to get() a default value; it needs to be
 446     /// request()ed first.
 447     bool has_default_resolver;
 448
 449     // Current consistency model
 450     int model;
 451
 452     // Function that resets all of the ghost cells to their default
 453     // values. It knows the type of the resolver, so we can eliminate
 454     // a large number of calls through function pointers.
 455     void (data_t::*reset)();
 456
 457     // Clear out all ghost cells
 458     void clear();
 459
 460     // Flush all values destined for remote processors
 461     void flush();
 462
 463     // Send out requests to "refresh" the values of ghost cells that
 464     // we're holding.
 465     void refresh_ghost_cells();
 466
 467   private:
 468     template<typename Resolver> void do_reset();
 469
 470     friend class distributed_property_map;
 471   };
 472   friend struct data_t;
 473
 474   shared_ptr<data_t> data;
 475
 476  private:
 477   // Prunes the least recently used ghost cells until we have @c
 478   // max_ghost_cells or fewer ghost cells.
 479   void prune_ghost_cells() const;
 480
 481   /** Handles incoming messages.
 482    *
 483    * This function object is responsible for handling all incoming
 484    * messages for the distributed property map.
 485    */
 486   template<typename Reduce>
 487   struct handle_message
 488   {
 489     explicit handle_message(const shared_ptr<data_t>& data,
 490                             const Reduce& reduce = Reduce())
 491       : data_ptr(data), reduce(reduce) { }
 492
 493     void operator()(process_id_type source, int tag);
 494
 495     /// Individual message handlers
 496     void
 497     handle_put(int source, int tag,
 498                const boost::parallel::detail::untracked_pair<key_type, value_type>& data,
 499                trigger_receive_context);
 500
 501     value_type
 502     handle_get(int source, int tag, const key_type& data,
 503                trigger_receive_context);
 504
 505     void
 506     handle_multiget(int source, int tag,
 507                     const std::vector<key_type>& data,
 508                     trigger_receive_context);
 509
 510     void
 511     handle_multiget_reply
 512       (int source, int tag,
 513        const std::vector<boost::parallel::detail::untracked_pair<key_type, value_type> >& msg,
 514        trigger_receive_context);
 515
 516     void
 517     handle_multiput
 518       (int source, int tag,
 519        const std::vector<unsafe_pair<local_key_type, value_type> >& data,
 520        trigger_receive_context);
 521
 522     void setup_triggers(process_group_type& pg);
 523
 524   private:
 525     weak_ptr<data_t> data_ptr;
 526     Reduce reduce;
 527   };
 528
 529   /* Sets up the next stage in a multi-stage synchronization, for
 530      bidirectional consistency. */
 531   struct on_synchronize
 532   {
 533     explicit on_synchronize(const shared_ptr<data_t>& data) : data_ptr(data) { }
 534
 535     void operator()();
 536
 537   private:
 538     weak_ptr<data_t> data_ptr;
 539   };
 540 };
 541
 542 /* An implementation helper macro for the common case of naming
 543    distributed property maps with all of the normal template
 544    parameters. */
 545 #define PBGL_DISTRIB_PMAP                                       \
 546   distributed_property_map<ProcessGroup, GlobalMap, StorageMap>
 547
 548 /* Request that the value for the given remote key be retrieved in
 549    the next synchronization round. */
 550 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 551 inline void
 552 request(const PBGL_DISTRIB_PMAP& pm,
 553         typename PBGL_DISTRIB_PMAP::key_type const& key)
 554 {
 555   if (get(pm.data->global, key).first != process_id(pm.data->process_group))
 556     pm.cell(key, false);
 557 }
 558
 559 /** Get the value associated with a particular key.  Retrieves the
 560  * value associated with the given key. If the key denotes a
 561  * locally-owned object, it returns the value from the local property
 562  * map; if the key denotes a remotely-owned object, retrieves the
 563  * value of the ghost cell for that key, which may be the default
 564  * value provided by the reduce operation.
 565  *
 566  * Complexity: For a local key, O(1) get operations on the underlying
 567  * property map. For a non-local key, O(1) accesses to the ghost cells.
 568  */
 569 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 570 inline
 571 typename PBGL_DISTRIB_PMAP::value_type
 572 get(const PBGL_DISTRIB_PMAP& pm,
 573     typename PBGL_DISTRIB_PMAP::key_type const& key)
 574 {
 575   using boost::get;
 576
 577   typename property_traits<GlobalMap>::value_type p =
 578     get(pm.data->global, key);
 579
 580   if (p.first == process_id(pm.data->process_group)) {
 581     return get(pm.data->storage, p.second);
 582   } else {
 583     return pm.cell(key);
 584   }
 585 }
 586
 587 /** Put a value associated with the given key into the property map.
 588  * When the key denotes a locally-owned object, this operation updates
 589  * the underlying local property map. Otherwise, the local ghost cell
 590  * is updated and a "put" message is sent to the processor owning this
 591  * key.
 592  *
 593  * Complexity: For a local key, O(1) put operations on the underlying
 594  * property map. For a nonlocal key, O(1) accesses to the ghost cells
 595  * and will send O(1) messages of size O(sizeof(key) + sizeof(value)).
 596  */
 597 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 598 void
 599 put(const PBGL_DISTRIB_PMAP& pm,
 600     typename PBGL_DISTRIB_PMAP::key_type const & key,
 601     typename PBGL_DISTRIB_PMAP::value_type const & value)
 602 {
 603   using boost::put;
 604
 605   typename property_traits<GlobalMap>::value_type p =
 606     get(pm.data->global, key);
 607
 608   if (p.first == process_id(pm.data->process_group)) {
 609     put(pm.data->storage, p.second, value);
 610   } else {
 611     if (pm.data->model & cm_forward)
 612       pm.request_put(p.first, key, value);
 613
 614     pm.cell(key, false) = value;
 615   }
 616 }
 617
 618 /** Put a value associated with a given key into the local view of the
 619  * property map. This operation is equivalent to @c put, but with one
 620  * exception: no message will be sent to the owning processor in the
 621  * case of a remote update. The effect is that any value written via
 622  * @c local_put for a remote key may be overwritten in the next
 623  * synchronization round.
 624  */
 625 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 626 void
 627 local_put(const PBGL_DISTRIB_PMAP& pm,
 628           typename PBGL_DISTRIB_PMAP::key_type const & key,
 629           typename PBGL_DISTRIB_PMAP::value_type const & value)
 630 {
 631   using boost::put;
 632
 633   typename property_traits<GlobalMap>::value_type p =
 634     get(pm.data->global, key);
 635
 636   if (p.first == process_id(pm.data->process_group))
 637     put(pm.data->storage, p.second, value);
 638   else pm.cell(key, false) = value;
 639 }
 640
 641 /** Cache the value associated with the given remote key. If the key
 642  *  is local, ignore the operation. */
 643 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 644 inline void
 645 cache(const PBGL_DISTRIB_PMAP& pm,
 646       typename PBGL_DISTRIB_PMAP::key_type const & key,
 647       typename PBGL_DISTRIB_PMAP::value_type const & value)
 648 {
 649   typename ProcessGroup::process_id_type id = get(pm.data->global, key).first;
 650
 651   if (id != process_id(pm.data->process_group)) pm.cell(key, false) = value;
 652 }
 653
 654 /// Synchronize the property map.
 655 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 656 void
 657 synchronize(PBGL_DISTRIB_PMAP& pm)
 658 {
 659   pm.do_synchronize();
 660 }
 661
 662 /// Create a distributed property map.
 663 template<typename ProcessGroup, typename GlobalMap, typename StorageMap>
 664 inline distributed_property_map<ProcessGroup, GlobalMap, StorageMap>
 665 make_distributed_property_map(const ProcessGroup& pg, GlobalMap global,
 666                               StorageMap storage)
 667 {
 668   typedef distributed_property_map<ProcessGroup, GlobalMap, StorageMap>
 669     result_type;
 670   return result_type(pg, global, storage);
 671 }
 672
 673 /**
 674  * \overload
 675  */
 676 template<typename ProcessGroup, typename GlobalMap, typename StorageMap,
 677          typename Reduce>
 678 inline distributed_property_map<ProcessGroup, GlobalMap, StorageMap>
 679 make_distributed_property_map(const ProcessGroup& pg, GlobalMap global,
 680                               StorageMap storage, Reduce reduce)
 681 {
 682   typedef distributed_property_map<ProcessGroup, GlobalMap, StorageMap>
 683     result_type;
 684   return result_type(pg, global, storage, reduce);
 685 }
 686
 687 } } // end namespace boost::parallel
 688
 689 #include <boost/property_map/parallel/impl/distributed_property_map.ipp>
 690
 691 #undef PBGL_DISTRIB_PMAP
 692
 693 #endif // BOOST_PARALLEL_DISTRIBUTED_PROPERTY_MAP_HPP