schedule_type

The ways loop iterations can be divided among threads.

Declaración

Sintaxis

schedule_type
    = Static | Dynamic | Guided | Auto | Runtime

Values

Value

Meaning

Static

divide the iterations into chunks up front and assign them in order.

Dynamic

hand out a chunk whenever a thread becomes free.

Guided

like Dynamic, but with chunks that get smaller as the work runs out.

Auto

let the implementation choose.

Runtime

take the schedule from the environment at run time.

Valores devueltos

None.

Descripción

Static costs nothing at run time and is right when the iterations take similar time. The others pay for scheduling in exchange for balancing uneven work.

Ejemplos

An ASR text document that uses it:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "main" (Program
        :symtab (SymbolTable
          :id 1
          :symbols {
            "a" (Variable
              :parent_symtab 1
              :name "a"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
                :memory_space :Global
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "i" (Variable
              :parent_symtab 1
              :name "i"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "n" (Variable
              :parent_symtab 1
              :name "n"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "run" (Variable
              :parent_symtab 1
              :name "run"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Logical
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "total" (Variable
              :parent_symtab 1
              :name "total"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
          }
        )
        :name "main"
        :dependencies []
        :body [
          (OMPRegion
            :region :Parallel
            :clauses [
              (OMPPrivate
                :vars [
                  (Var
                    :v (SymbolRef 1 "i")
                  )
                ]
              )
              (OMPShared
                :vars [
                  (Var
                    :v (SymbolRef 1 "a")
                  )
                ]
              )
              (OMPFirstPrivate
                :vars [
                  (Var
                    :v (SymbolRef 1 "n")
                  )
                ]
              )
              (OMPNumThreads
                :num_threads (IntegerConstant
                  :n 4
                  :type (Integer
                    :kind 4
                  )
                  :intboz_type :Decimal
                )
              )
              (OMPIf
                :condition (Var
                  :v (SymbolRef 1 "run")
                )
              )
            ]
            :body [
              (OMPRegion
                :region :Do
                :clauses [
                  (OMPSchedule
                    :kind :Static
                    :chunk_size (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                  (OMPCollapse
                    :count (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                  (OMPReduction
                    :operator :ReduceAdd
                    :vars [
                      (Var
                        :v (SymbolRef 1 "total")
                      )
                    ]
                  )
                  (OMPLastPrivate
                    :vars [
                      (Var
                        :v (SymbolRef 1 "i")
                      )
                    ]
                  )
                  (OMPNowait)
                ]
                :body [
                  (DoLoop
                    :name nil
                    :head (do_loop_head
                      :v (Var
                        :v (SymbolRef 1 "i")
                      )
                      :start (IntegerConstant
                        :n 1
                        :type (Integer
                          :kind 4
                        )
                        :intboz_type :Decimal
                      )
                      :end (IntegerConstant
                        :n 3
                        :type (Integer
                          :kind 4
                        )
                        :intboz_type :Decimal
                      )
                      :increment (IntegerConstant
                        :n 1
                        :type (Integer
                          :kind 4
                        )
                        :intboz_type :Decimal
                      )
                    )
                    :body [
                      (Assignment
                        :target (Var
                          :v (SymbolRef 1 "total")
                        )
                        :value (IntegerBinOp
                          :left (Var
                            :v (SymbolRef 1 "total")
                          )
                          :op :Add
                          :right (Var
                            :v (SymbolRef 1 "i")
                          )
                          :type (Integer
                            :kind 4
                          )
                          :value nil
                        )
                        :overloaded nil
                        :realloc_lhs false
                        :move_allocation false
                      )
                    ]
                    :orelse []
                  )
                ]
                :exec_target :ExecAuto
              )
            ]
            :exec_target :ExecAuto
          )
          (OMPRegion
            :region :Target
            :clauses [
              (OMPMap
                :type :ToFrom
                :vars [
                  (Var
                    :v (SymbolRef 1 "a")
                  )
                ]
              )
              (OMPDevice
                :device (IntegerConstant
                  :n 0
                  :type (Integer
                    :kind 4
                  )
                  :intboz_type :Decimal
                )
              )
            ]
            :body [
              (OMPRegion
                :region :Teams
                :clauses [
                  (OMPNumTeams
                    :num_teams (IntegerConstant
                      :n 2
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                  (OMPThreadLimit
                    :thread_limit (IntegerConstant
                      :n 64
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :body [
                  (Assignment
                    :target (Var
                      :v (SymbolRef 1 "total")
                    )
                    :value (IntegerConstant
                      :n 0
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :overloaded nil
                    :realloc_lhs false
                    :move_allocation false
                  )
                ]
                :exec_target :ExecAuto
              )
            ]
            :exec_target :ExecAuto
          )
        ]
      )
    }
  )
  :items []
)

Ver también

OMPSchedule, OMPRegion