Clauses in OpenMP/1

• Clauses for the “parallel” directive specify data association rules and conditional computation:

• default(private|shared|none)

  • default association for variables that are not mentioned in other clauses

• shared(list)

  • data in this list is accessible by all the threads and reference the same storage

• private(list)

  • data in this list are private to each thread.
  • A new storage location is created with that name and the contents of that storage are not available outside of the parallel region.
  • The data in this list are undefined at the entry to the parallel region

• firstprivate(list)

  • as for the private(list) clause with the addition that the contents are initialized from the variable with that name from outside of the parallel region

• lastprivate(list)

  • this is available only for work sharing constructs
  • a shared variable with that name is set to the last computed value of a thread private variable in the work sharing construct

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