Atomic Update

• Optimization of mutual exclusion for a certain cases

  • Not structured, applies to following statement
  • Enables fast implementation on some HW
    • Others will use critical sections

C$OMP PARALLEL

……

C$OMP ATOMIC

A(i) = A(i) + Alocal

……

C$OMP END PARALLEL

#pragma omp parallel {

……

#pragma omp atomic

A[i] += Alocal

}

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