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Container in distributed environment (rheolef-6.6).

Chapter
rheolef-6.6
array(2rheolef)                            rheolef-6.6                            array(2rheolef)

NAME array - container in distributed environment (rheolef-6.6)
SYNOPSYS STL-like vector container for a distributed memory machine model.
EXAMPLE A sample usage of the class is: int main(int argc, char**argv) { environment distributed(argc, argv); array<double> x(distributor(100), 3.14); dout << x << endl; } The array<T> interface is similar to those of the std::vector<T> with the addition of some communication features in the distributed case: write accesses with entry/assembly and read access with dis_at.
DISTRIBUTED WRITE ACCESS Loop on any dis_i that is not managed by the current processor: x.dis_entry (dis_i) = value; and then, after loop, perform all communication: x.dis_entry_assembly(); After this command, each value is stored in the array, available the processor associated to dis_i.
DISTRIBUTED READ ACCESS First, define the set of indexes: std::set<size_t> ext_idx_set; Then, loop on dis_i indexes that are not managed by the current processor: ext_idx_set.insert (dis_i); After the loop, performs the communications: x.set_dis_indexes (ext_idx_set); After this command, each values associated to the dis_i index, and that belongs to the index set, is now available also on the current processor as: value = x.dis_at (dis_i); For convenience, if dis_i is managed by the current processor, this function returns also the value.
NOTE The class takes two template parameters: one for the type T and the second for the memory model M, that could be either M=distributed or M=sequential. The two cases are associated to two diferent implementations, but proposes exactly the same interface. The sequential interface propose also a supplementary constructor: array<double,sequential> x(local_size, init_val); This constructor is a STL-like one but could be consufused in the distributed case, since there are two sizes: a local one and a global one. In that case, the use of the distribu‐ tor, as a generalization of the size concept, clarify the situation (see distributor(2)).
IMPLEMENTATION NOTE "scatter" via "get_dis_entry". "gather" via "dis_entry(dis_i) = value" or "dis_entry(dis_i) += value". Note that += applies when T=idx_set where idx_set is a wrapper class of std::set<size_t> ; the += oper‐ ator represents the union of a set. The operator= is used when T=double or others simple T types without algebra. If there is a conflict, i.e. several processes set the dis_i index, then the result of operator+= depends upon the order of the process at each run and is not deterministic. Such ambiguous behavior is not detected yet at run time.
IMPLEMENTATION template <class T, class A> class array<T,sequential,A> : public smart_pointer<array_rep<T,sequential,A> > { public: // typedefs: typedef array_rep<T,sequential,A> rep; typedef smart_pointer<rep> base; typedef sequential memory_type; typedef typename rep::size_type size_type; typedef typename rep::difference_type difference_type; typedef typename rep::value_type value_type; typedef typename rep::reference reference; typedef typename rep::dis_reference dis_reference; typedef typename rep::iterator iterator; typedef typename rep::const_reference const_reference; typedef typename rep::const_iterator const_iterator; // allocators: array (size_type loc_size = 0, const T& init_val = T(), const A& alloc = A()) ↲ ; void resize (size_type loc_size = 0, const T& init_val = T()); array (const distributor& ownership, const T& init_val = T(), const A& alloc = A()) ↲ ; void resize (const distributor& ownership, const T& init_val = T()); // local accessors & modifiers: A get_allocator() const { return base::data().get_allocator(); } size_type size () const { return base::data().size(); } size_type dis_size () const { return base::data().dis_size(); } const distributor& ownership() const { return base::data().ownership(); } const communicator& comm() const { return ownership().comm(); } reference operator[] (size_type i) { return base::data().operator[] (i); } const_reference operator[] (size_type i) const { return base::data().operator[] (i); } reference operator() (size_type i) { return base::data().operator[] (i); } const_reference operator() (size_type i) const { return base::data().operator[] (i); } const_reference dis_at (size_type dis_i) const { return operator[] (dis_i); } iterator begin() { return base::data().begin(); } const_iterator begin() const { return base::data().begin(); } iterator end() { return base::data().end(); } const_iterator end() const { return base::data().end(); } // global modifiers (for compatibility with distributed interface): dis_reference dis_entry (size_type dis_i) { return base::data().dis_entry(dis_i); } template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly (SetOp my_set_op = SetOp()) {} template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly_begin (SetOp my_set_op = SetOp()) {} template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly_end (SetOp my_set_op = SetOp()) {} void dis_entry_assembly_begin() {} void dis_entry_assembly_end() {} void dis_entry_assembly() {} void reset_dis_indexes() const {} template<class Set> void set_dis_indexes (const Set& ext_idx_set) const {} template<class Set> void append_dis_indexes (const Set& ext_idx_set) const {} template<class Set, class Map> void append_dis_entry (const Set& ext_idx_set, Map& ext_id ↲ x_map) const {} template<class Set, class Map> void get_dis_entry (const Set& ext_idx_set, Map& ext_id ↲ x_map) const {} // apply a partition: template<class RepSize> void repartition ( // old_numbering for *this const RepSize& partition, // old_ownership array<T,sequential,A>& new_array, // new_ownership (created) RepSize& old_numbering, // new_ownership RepSize& new_numbering) const // old_ownership { return base::data().repartition (partition, new_array, old_numbering, new_numbering ↲ ); } template<class RepSize> void permutation_apply ( // old_numbering for *this const RepSize& new_numbering, // old_ownership array<T,sequential,A>& new_array) const // new_ownership (already allocated) { return base::data().permutation_apply (new_numbering, new_array); } void reverse_permutation ( // old_ownership for *this=iol ↲ d2dis_inew array<size_type,sequential,A>& inew2dis_iold) const // new_ownership { base::data().reverse_permutation (inew2dis_iold.data()); } // i/o: odiststream& put_values (odiststream& ops) const { return base::data().put_values(ops); } idiststream& get_values (idiststream& ips) { return base::data().get_values(ips); } template <class GetFunction> idiststream& get_values (idiststream& ips, GetFunction get_element) { return base:: ↲ data().get_values(ips, get_element); } template <class PutFunction> odiststream& put_values (odiststream& ops, PutFunction put_element) const { return base:: ↲ data().put_values(ops, put_element); } void dump (std::string name) const { return base::data().dump(name); } };
IMPLEMENTATION template <class T, class A> class array<T,distributed,A> : public smart_pointer<array_rep<T,distributed,A> > { public: // typedefs: typedef array_rep<T,distributed,A> rep; typedef smart_pointer<rep> base; typedef distributed memory_type; typedef typename rep::size_type size_type; typedef typename rep::difference_type difference_type; typedef typename rep::value_type value_type; typedef typename rep::reference reference; typedef typename rep::dis_reference dis_reference; typedef typename rep::iterator iterator; typedef typename rep::const_reference const_reference; typedef typename rep::const_iterator const_iterator; typedef typename rep::scatter_map_type scatter_map_type; // allocators: array (const distributor& ownership = distributor(), const T& init_val = T(), const ↲ A& alloc = A()); void resize (const distributor& ownership = distributor(), const T& init_val = T()); // local accessors & modifiers: A get_allocator() const { return base::data().get_allocator(); } size_type size () const { return base::data().size(); } size_type dis_size () const { return base::data().dis_size(); } const distributor& ownership() const { return base::data().ownership(); } const communicator& comm() const { return base::data().comm(); } reference operator[] (size_type i) { return base::data().operator[] (i); } const_reference operator[] (size_type i) const { return base::data().operator[] (i); } reference operator() (size_type i) { return base::data().operator[] (i); } const_reference operator() (size_type i) const { return base::data().operator[] (i); } iterator begin() { return base::data().begin(); } const_iterator begin() const { return base::data().begin(); } iterator end() { return base::data().end(); } const_iterator end() const { return base::data().end(); } // global accessor: template<class Set, class Map> void append_dis_entry (const Set& ext_idx_set, Map& ext_idx_map) const { base::data().app ↲ end_dis_entry (ext_idx_set, ext_idx_map); } template<class Set, class Map> void get_dis_entry (const Set& ext_idx_set, Map& ext_idx_map) const { base::data().get ↲ _dis_entry (ext_idx_set, ext_idx_map); } template<class Set> void append_dis_indexes (const Set& ext_idx_set) const { base::data().append_dis_indexes ↲ (ext_idx_set); } void reset_dis_indexes() const { base::data().reset_dis_indexes(); } template<class Set> void set_dis_indexes (const Set& ext_idx_set) const { base::data().set_dis_indexes (ex ↲ t_idx_set); } const T& dis_at (size_type dis_i) const { return base::data().dis_at (dis_i); } // get all external pairs (dis_i, values): const scatter_map_type& get_dis_map_entries() const { return base::data().get_dis_map_ent ↲ ries(); } // global modifiers (for compatibility with distributed interface): dis_reference dis_entry (size_type dis_i) { return base::data().dis_entry(dis_i); } template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly_begin (SetOp my_set_op = SetOp()) { base::data().dis_entry_assemb ↲ ly_begin (my_set_op); } template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly_end (SetOp my_set_op = SetOp()) { base::data().dis_entry_assemb ↲ ly_end (my_set_op); } template<class SetOp = typename default_set_op<T>::type> void dis_entry_assembly (SetOp my_set_op = SetOp()) { base::data().dis_entry_assemb ↲ ly (my_set_op); } void dis_entry_assembly_begin() { base::data().template dis_entry_assembly_begin<typename ↲ default_set_op<T>::type>(); } void dis_entry_assembly_end() { base::data().template dis_entry_assembly_end<typename d ↲ efault_set_op<T>::type>(); } void dis_entry_assembly() { dis_entry_assembly_begin(); dis_entry_assembly_end(); } // apply a partition: template<class RepSize> void repartition ( // old_numbering for *this const RepSize& partition, // old_ownership array<T,distributed>& new_array, // new_ownership (created) RepSize& old_numbering, // new_ownership RepSize& new_numbering) const // old_ownership { return base::data().repartition (partition.data(), new_array.data(), old_numbering. ↲ data(), new_numbering.data()); } template<class RepSize> void permutation_apply ( // old_numbering for *this const RepSize& new_numbering, // old_ownership array<T,distributed,A>& new_array) const // new_ownership (already allocated) { base::data().permutation_apply (new_numbering.data(), new_array.data()); } void reverse_permutation ( // old_ownership for *this=iol ↲ d2dis_inew array<size_type,distributed,A>& inew2dis_iold) const // new_ownership { base::data().reverse_permutation (inew2dis_iold.data()); } // i/o: odiststream& put_values (odiststream& ops) const { return base::data().put_values(ops); } idiststream& get_values (idiststream& ips) { return base::data().get_values(ips); } void dump (std::string name) const { return base::data().dump(name); } template <class GetFunction> idiststream& get_values (idiststream& ips, GetFunction get_element) { return base:: ↲ data().get_values(ips, get_element); } template <class PutFunction> odiststream& put_values (odiststream& ops, PutFunction put_element) const { return base:: ↲ data().put_values(ops, put_element); } template <class PutFunction, class A2> odiststream& permuted_put_values ( odiststream& ops, const array<size_type,distributed,A2>& perm, PutFunction pu ↲ t_element) const { return base::data().pe ↲ rmuted_put_values (ops, perm.data(), put_element); } };
SEE ALSO distributor(2)
rheolef-6.6 rheolef-6.6 array(2rheolef)
This manual Reference Other manuals
array(2rheolef) referred by conop3(3NCARG) | field(2rheolef) | hstopr(3NCARG) | index_set(7rheolef) | pair_set(7rheolef)
refer to distributor(2rheolef)