libgomp/testsuite/libgomp.fortran/omp_workshare1.f

   1 C******************************************************************************
   2 C FILE: omp_workshare1.f
   3 C DESCRIPTION:
   4 C   OpenMP Example - Loop Work-sharing - Fortran Version
   5 C   In this example, the iterations of a loop are scheduled dynamically
   6 C   across the team of threads.  A thread will perform CHUNK iterations
   7 C   at a time before being scheduled for the next CHUNK of work.
   8 C AUTHOR: Blaise Barney  5/99
   9 C LAST REVISED: 01/09/04
  10 C******************************************************************************
  11
  12       PROGRAM WORKSHARE1
  13
  14       INTEGER NTHREADS, TID, OMP_GET_NUM_THREADS,
  15      +  OMP_GET_THREAD_NUM, N, CHUNKSIZE, CHUNK, I
  16       PARAMETER (N=100)
  17       PARAMETER (CHUNKSIZE=10)
  18       REAL A(N), B(N), C(N)
  19
  20 !     Some initializations
  21       DO I = 1, N
  22         A(I) = I * 1.0
  23         B(I) = A(I)
  24       ENDDO
  25       CHUNK = CHUNKSIZE
  26
  27 !$OMP PARALLEL SHARED(A,B,C,NTHREADS,CHUNK) PRIVATE(I,TID)
  28
  29       TID = OMP_GET_THREAD_NUM()
  30       IF (TID .EQ. 0) THEN
  31         NTHREADS = OMP_GET_NUM_THREADS()
  32         PRINT *, 'Number of threads =', NTHREADS
  33       END IF
  34       PRINT *, 'Thread',TID,' starting...'
  35
  36 !$OMP DO SCHEDULE(DYNAMIC,CHUNK)
  37       DO I = 1, N
  38         C(I) = A(I) + B(I)
  39         WRITE(*,100) TID,I,C(I)
  40  100    FORMAT(' Thread',I2,': C(',I3,')=',F8.2)
  41       ENDDO
  42 !$OMP END DO NOWAIT
  43
  44       PRINT *, 'Thread',TID,' done.'
  45
  46 !$OMP END PARALLEL
  47
  48       END