以下例子来自https://computing.llnl.gov/tutorials/openMP/exercise.html网站

一、打印线程（Hello world）

C******************************************************************************

C FILE: omp_hello.f

C DESCRIPTION:

C   OpenMP Example - Hello World - Fortran Version

C   In this simple example, the master thread forks a parallel region.

C   All threads in the team obtain their unique thread number and print it.

C   The master thread only prints the total number of threads.  Two OpenMP

C   library routines are used to obtain the number of threads and each

C   thread's number.

C AUTHOR: Blaise Barney  5/99

C LAST REVISED:

C******************************************************************************

      PROGRAM HELLO

      INTEGER NTHREADS, TID, OMP_GET_NUM_THREADS, OMP_GET_THREAD_NUM

C     Fork a team of threads giving them their own copies of variables

!$OMP PARALLEL PRIVATE(NTHREADS, TID)

C     Obtain thread number

      TID = OMP_GET_THREAD_NUM()

      PRINT *, 'Hello World from thread = ', TID

C     Only master thread does this

      IF (TID .EQ. 0) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Number of threads = ', NTHREADS

      END IF

C     All threads join master thread and disband

!$OMP END PARALLEL

      END

二、循环（Loop work-sharing）

 C******************************************************************************

 C FILE: omp_workshare1.f

 C DESCRIPTION:

 C   OpenMP Example - Loop Work-sharing - Fortran Version

 C   In this example, the iterations of a loop are scheduled dynamically

 C   across the team of threads.  A thread will perform CHUNK iterations

 C   at a time before being scheduled for the next CHUNK of work.

 C AUTHOR: Blaise Barney  /

 C LAST REVISED: //

 C******************************************************************************

       PROGRAM WORKSHARE1

       INTEGER NTHREADS, TID, OMP_GET_NUM_THREADS,

      +  OMP_GET_THREAD_NUM, N, CHUNKSIZE, CHUNK, I

       PARAMETER (N=)

       PARAMETER (CHUNKSIZE=)

       REAL A(N), B(N), C(N)

 !     Some initializations

       DO I = , N

         A(I) = I * 1.0

         B(I) = A(I)

       ENDDO

       CHUNK = CHUNKSIZE

 !$OMP PARALLEL SHARED(A,B,C,NTHREADS,CHUNK) PRIVATE(I,TID)

       TID = OMP_GET_THREAD_NUM()

       IF (TID .EQ. ) THEN

         NTHREADS = OMP_GET_NUM_THREADS()

         PRINT *, 'Number of threads =', NTHREADS

       END IF

       PRINT *, 'Thread',TID,' starting...'

 !$OMP DO SCHEDULE(DYNAMIC,CHUNK)

       DO I = , N

         C(I) = A(I) + B(I)

         WRITE(*,) TID,I,C(I)

      FORMAT(' Thread',I2,': C(',I3,')=',F8.)

       ENDDO

 !$OMP END DO NOWAIT

       PRINT *, 'Thread',TID,' done.'

 !$OMP END PARALLEL

       END

三、Sections work-sharing

C******************************************************************************

C FILE: omp_workshare2.f

C DESCRIPTION:

C   OpenMP Example - Sections Work-sharing - Fortran Version

C   In this example, the OpenMP SECTION directive is used to assign

C   different array operations to each thread that executes a SECTION.

C AUTHOR: Blaise Barney  /

C LAST REVISED: //

C******************************************************************************

      PROGRAM WORKSHARE2

      INTEGER N, I, NTHREADS, TID, OMP_GET_NUM_THREADS,

     +        OMP_GET_THREAD_NUM

      PARAMETER (N=)

      REAL A(N), B(N), C(N), D(N)

!     Some initializations

      DO I = , N

        A(I) = I * 1.5

        B(I) = I + 22.35

        C(N) = 0.0

        D(N) = 0.0

      ENDDO

!$OMP PARALLEL SHARED(A,B,C,D,NTHREADS), PRIVATE(I,TID)

      TID = OMP_GET_THREAD_NUM()

      IF (TID .EQ. ) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Number of threads =', NTHREADS

      END IF

      PRINT *, 'Thread',TID,' starting...'

!$OMP SECTIONS

!$OMP SECTION

      PRINT *, 'Thread',TID,' doing section 1'

      DO I = , N

         C(I) = A(I) + B(I)

         WRITE(*,) TID,I,C(I)

      FORMAT(' Thread',I2,': C(',I2,')=',F8.)

      ENDDO

!$OMP SECTION

      PRINT *, 'Thread',TID,' doing section 2'

      DO I = , N

         D(I) = A(I) * B(I)

         WRITE(*,) TID,I,D(I)

      ENDDO

!$OMP END SECTIONS NOWAIT

      PRINT *, 'Thread',TID,' done.'

!$OMP END PARALLEL

      END

四、Combined parallel loop reduction

C******************************************************************************

C FILE: omp_reduction.f

C DESCRIPTION:

C   OpenMP Example - Combined Parallel Loop Reduction - Fortran Version

C   This example demonstrates a sum reduction within a combined parallel loop

C   construct.  Notice that default data element scoping is assumed - there

C   are no clauses specifying shared or private variables.  OpenMP will

C   automatically make loop index variables private within team threads, and

C   global variables shared.

C AUTHOR: Blaise Barney  /

C LAST REVISED:

C******************************************************************************

      PROGRAM REDUCTION

      INTEGER I, N

      REAL A(), B(), SUM

!     Some initializations

      N =

      DO I = , N

        A(I) = I *1.0

        B(I) = A(I)

      ENDDO

      SUM = 0.0

!$OMP PARALLEL DO REDUCTION(+:SUM)

      DO I = , N

        SUM = SUM + (A(I) * B(I))

      ENDDO

      PRINT *, '   Sum = ', SUM

      END

五、Orphaned parallel loop reduction

C******************************************************************************

C FILE: omp_orphan.f

C DESCRIPTION:

C   OpenMP Example - Parallel region with an orphaned directive - Fortran

C   Version

C   This example demonstrates a dot product being performed by an orphaned

C   loop reduction construct.  Scoping of the reduction variable is critical.

C AUTHOR: Blaise Barney  /

C LAST REVISED:

C******************************************************************************

      PROGRAM ORPHAN

      COMMON /DOTDATA/ A, B, SUM

      INTEGER I, VECLEN

      PARAMETER (VECLEN = )

      REAL* A(VECLEN), B(VECLEN), SUM

      DO I=, VECLEN

         A(I) = 1.0 * I

         B(I) = A(I)

      ENDDO

      SUM = 0.0

!$OMP PARALLEL

      CALL DOTPROD

!$OMP END PARALLEL

      WRITE(*,*) "Sum = ", SUM

      END

      SUBROUTINE DOTPROD

      COMMON /DOTDATA/ A, B, SUM

      INTEGER I, TID, OMP_GET_THREAD_NUM, VECLEN

      PARAMETER (VECLEN = )

      REAL* A(VECLEN), B(VECLEN), SUM

      TID = OMP_GET_THREAD_NUM()

!$OMP DO REDUCTION(+:SUM)

      DO I=, VECLEN

         SUM = SUM + (A(I)*B(I))

         PRINT *, '  TID= ',TID,'I= ',I

      ENDDO

      RETURN

      END

六、Matrix multiply

C******************************************************************************

C FILE: omp_mm.f

C DESCRIPTION:

C   OpenMp Example - Matrix Multiply - Fortran Version

C   Demonstrates a matrix multiply using OpenMP. Threads share row iterations

C   according to a predefined chunk size.

C AUTHOR: Blaise Barney

C LAST REVISED: // Blaise Barney

C******************************************************************************

      PROGRAM MATMULT

      INTEGER  NRA, NCA, NCB, TID, NTHREADS, I, J, K, CHUNK,

     +         OMP_GET_NUM_THREADS, OMP_GET_THREAD_NUM

C     number of rows in matrix A

      PARAMETER (NRA=)

C     number of columns in matrix A

      PARAMETER (NCA=)

C     number of columns in matrix B

      PARAMETER (NCB=)

      REAL* A(NRA,NCA), B(NCA,NCB), C(NRA,NCB)

C     Set loop iteration chunk size

      CHUNK = 

C     Spawn a parallel region explicitly scoping all variables

!$OMP PARALLEL SHARED(A,B,C,NTHREADS,CHUNK) PRIVATE(TID,I,J,K)

      TID = OMP_GET_THREAD_NUM()

      IF (TID .EQ. ) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Starting matrix multiple example with', NTHREADS,

     +           'threads'

        PRINT *, 'Initializing matrices'

      END IF

C     Initialize matrices

!$OMP DO SCHEDULE(STATIC, CHUNK)

      DO  I=, NRA

        DO  J=, NCA

          A(I,J) = (I-)+(J-)

    CONTINUE

!$OMP DO SCHEDULE(STATIC, CHUNK)

      DO  I=, NCA

        DO  J=, NCB

          B(I,J) = (I-)*(J-)

    CONTINUE

!$OMP DO SCHEDULE(STATIC, CHUNK)

      DO  I=, NRA

        DO  J=, NCB

          C(I,J) =

    CONTINUE

C     Do matrix multiply sharing iterations on outer loop

C     Display who does which iterations for demonstration purposes

      PRINT *, 'Thread', TID, 'starting matrix multiply...'

!$OMP DO SCHEDULE(STATIC, CHUNK)

      DO  I=, NRA

      PRINT *, 'Thread', TID, 'did row', I

        DO  J=, NCB

          DO  K=, NCA

            C(I,J) = C(I,J) + A(I,K) * B(K,J)

    CONTINUE

C     End of parallel region

!$OMP END PARALLEL

C     Print results

      PRINT *, '******************************************************'

      PRINT *, 'Result Matrix:'

      DO  I=, NRA

        DO  J=, NCB

          WRITE(*,) C(I,J)

        FORMAT(2x,f8.,$)

        CONTINUE

          PRINT *, ' '

        CONTINUE

      PRINT *, '******************************************************'

      PRINT *, 'Done.'

      END

七、Get and print environment information

C******************************************************************************

C FILE: omp_getEnvInfo.f

C DESCRIPTION:

C   OpenMP Example - Get Environment Information - Fortran Version

C   The master thread queries and prints selected environment information.

C AUTHOR: Blaise Barney  /

C LAST REVISED: //

C******************************************************************************

      PROGRAM GETINFO

      INTEGER NTHREADS, TID, OMP_GET_NUM_THREADS,

     +  OMP_GET_THREAD_NUM, OMP_GET_NUM_PROCS, OMP_GET_MAX_THREADS,

     +  OMP_IN_PARALLEL, OMP_GET_DYNAMIC, OMP_GET_NESTED,

     +  PROCS, MAXT

C     These are for AIX compilations

C     INTEGER INPAR, DYNAMIC, NESTED

C     These are for non-AIX compilations

      LOGICAL INPAR, DYNAMIC, NESTED

C     Start parallel region

!$OMP PARALLEL PRIVATE(NTHREADS, TID)

C     Obtain thread number

      TID = OMP_GET_THREAD_NUM()

C     Only master thread does this

      IF (TID .EQ. ) THEN

        PRINT *, 'Thread',tid,'getting environment information'

C     Get environment information

        PROCS = OMP_GET_NUM_PROCS()

        NTHREADS = OMP_GET_NUM_THREADS()

        MAXT = OMP_GET_MAX_THREADS()

        INPAR = OMP_IN_PARALLEL()

        DYNAMIC = OMP_GET_DYNAMIC()

        NESTED = OMP_GET_NESTED()

C     Print environment information

        PRINT *, 'Number of processors = ', PROCS

        PRINT *, 'Number of threads = ', NTHREADS

        PRINT *, 'Max threads = ', MAXT

        PRINT *, 'In parallel? = ', INPAR

        PRINT *, 'Dynamic threads enabled? = ', DYNAMIC

        PRINT *, 'Nested parallelism supported? = ', NESTED

      END IF

C     Done

!$OMP END PARALLEL

      END

八、Programs with bugs

（1)omp_bug1.f 

C******************************************************************************

C FILE: omp_bug1.f

C DESCRIPTION:

C   This example attempts to show use of the PARALLEL DO construct.  However

C   it will generate errors at compile time.  Try to determine what is causing

C   the error.  See omp_bug1fix.f for a corrected version.

C AUTHOR: Blaise Barney  /

C LAST REVISED:

C******************************************************************************

      PROGRAM WORKSHARE3

      INTEGER TID, OMP_GET_THREAD_NUM, N, I, CHUNKSIZE, CHUNK

      PARAMETER (N=)

      PARAMETER (CHUNKSIZE=)

      REAL A(N), B(N), C(N)

!     Some initializations

      DO I = , N

        A(I) = I * 1.0

        B(I) = A(I)

      ENDDO

      CHUNK = CHUNKSIZE

!$OMP  PARALLEL DO SHARED(A,B,C,CHUNK)

!$OMP& PRIVATE(I,TID)

!$OMP& SCHEDULE(STATIC,CHUNK)

      TID = OMP_GET_THREAD_NUM()

      DO I = , N

         C(I) = A(I) + B(I)

         PRINT *,'TID= ',TID,'I= ',I,'C(I)= ',C(I)

      ENDDO

!$OMP  END PARALLEL DO

      END

（2）omp_bug1fix.f 

C******************************************************************************

C FILE: omp_bug1fix.f

C DESCRIPTION:

C   This is a corrected version of the omp_bug1fix.f example. Corrections

C   include removing all statements between the PARALLEL DO construct and

C   the actual DO loop, and introducing logic to preserve the ability to

C   query a thread's id and print it from inside the DO loop.

C AUTHOR: Blaise Barney  /

C LAST REVISED:

C******************************************************************************

      PROGRAM WORKSHARE4

      INTEGER TID, OMP_GET_THREAD_NUM, N, I, CHUNKSIZE, CHUNK

      PARAMETER (N=)

      PARAMETER (CHUNKSIZE=)

      REAL A(N), B(N), C(N)

      CHARACTER FIRST_TIME

!     Some initializations

      DO I = , N

        A(I) = I * 1.0

        B(I) = A(I)

      ENDDO

      CHUNK = CHUNKSIZE

      FIRST_TIME = 'Y'

!$OMP  PARALLEL DO SHARED(A,B,C,CHUNK)

!$OMP& PRIVATE(I,TID)

!$OMP& SCHEDULE(STATIC,CHUNK)

!$OMP& FIRSTPRIVATE(FIRST_TIME) 

      DO I = , N

         IF (FIRST_TIME .EQ. 'Y') THEN

            TID = OMP_GET_THREAD_NUM()

            FIRST_TIME = 'N'

         ENDIF

         C(I) = A(I) + B(I)

         PRINT *,'TID= ',TID,'I= ',I,'C(I)= ',C(I)

      ENDDO

!$OMP  END PARALLEL DO

      END

（3）omp_bug2.f 

C******************************************************************************

C FILE: omp_bug2.f

C DESCRIPTION:

C   Another OpenMP program with a bug

C AUTHOR: Blaise Barney  //

C LAST REVISED:

C******************************************************************************

      PROGRAM BUG2

      INTEGER NTHREADS, I, TID, OMP_GET_NUM_THREADS,

     +        OMP_GET_THREAD_NUM

      REAL* TOTAL

C     Spawn parallel region

!$OMP PARALLEL 

C     Obtain thread number

      TID = OMP_GET_THREAD_NUM()

C     Only master thread does this

      IF (TID .EQ. ) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Number of threads = ', NTHREADS

      END IF

      PRINT *, 'Thread ',TID,'is starting...'

!$OMP BARRIER

C     Do some work

      TOTAL = 0.0

!$OMP DO SCHEDULE(DYNAMIC,)

      DO I=,

        TOTAL = TOTAL + I * 1.0

      END DO

      WRITE(*,) TID,TOTAL

   FORMAT('Thread',I2,' is done! Total= ',E12.)

!$OMP END PARALLEL

      END

（4）omp_bug3.f 

C******************************************************************************

C FILE: omp_bug3.f

C DESCRIPTION:

C   Run time bug

C AUTHOR: Blaise Barney  //

C LAST REVISED: //

C******************************************************************************

      PROGRAM BUG3

      INTEGER N, I, NTHREADS, TID, SECTION, OMP_GET_NUM_THREADS,

     +        OMP_GET_THREAD_NUM

      PARAMETER (N=)

      REAL A(N), B(N), C(N)

C     Some initializations

      DO I = , N

        A(I) = I * 1.0

        B(I) = A(I)

      ENDDO

!$OMP PARALLEL PRIVATE(C,I,TID,SECTION)

      TID = OMP_GET_THREAD_NUM()

      IF (TID .EQ. ) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Number of threads = ', NTHREADS

      END IF

C     Use barriers for clean output

!$OMP BARRIER

      PRINT *, 'Thread ',TID,' starting...'

!$OMP BARRIER

!$OMP SECTIONS

!$OMP SECTION

      SECTION =

      DO I = , N

         C(I) = A(I) * B(I)

      ENDDO

      CALL PRINT_RESULTS(C, TID, SECTION)

!$OMP SECTION

      SECTION =

      DO I = , N

         C(I) = A(I) + B(I)

      ENDDO

      CALL PRINT_RESULTS(C, TID, SECTION)

!$OMP END SECTIONS 

C     Use barrier for clean output

!$OMP BARRIER

      PRINT *, 'Thread',tid,' exiting...'

!$OMP END PARALLEL

      END

      SUBROUTINE PRINT_RESULTS(C, TID, SECTION)

      INTEGER TID, SECTION, N, I, J

      PARAMETER (N=)

      REAL C(N)

      J =

C     Use critical for clean output

!$OMP CRITICAL

      PRINT *, ' '

      PRINT *, 'Thread',TID,' did section',SECTION

      DO I=, N

        WRITE(*,) C(I)

     FORMAT(E12.,$)

        J = J +

        IF (J .EQ. ) THEN

          PRINT *, ' '

          J =

        END IF

      END DO

      PRINT *, ' '

!$OMP END CRITICAL

!$OMP BARRIER

      PRINT *,'Thread',TID,' done and synchronized'

      END SUBROUTINE PRINT_RESULTS

(4)omp_bug4.f 

C******************************************************************************

C FILE: omp_bug4.f

C DESCRIPTION:

C   This very simple program causes a segmentation fault.

C AUTHOR: Blaise Barney  //

C LAST REVISED:

C******************************************************************************

      PROGRAM BUG4

      INTEGER N, NTHREADS, TID, I, J, OMP_GET_NUM_THREADS,

     +        OMP_GET_THREAD_NUM

      PARAMETER(N=)

      REAL* A(N,N)

C     Fork a team of threads with explicit variable scoping

!$OMP PARALLEL SHARED(NTHREADS) PRIVATE(I,J,TID,A)

C     Obtain/print thread info

      TID = OMP_GET_THREAD_NUM()

      IF (TID .EQ. ) THEN

        NTHREADS = OMP_GET_NUM_THREADS()

        PRINT *, 'Number of threads = ', NTHREADS

      END IF

      PRINT *, 'Thread',TID,' starting...'

C     Each thread works on its own private copy of the array

      DO I=,N

        DO J=,N

          A(J,I) = TID + I + J

        END DO

      END DO

C     For confirmation

      PRINT *, 'Thread',TID,'done. Last element=',A(N,N)

C     All threads join master thread and disband

!$OMP END PARALLEL

      END

(5)omp_bug4fix.f 

#!/bin/csh

#******************************************************************************

# FILE: omp_bug4fix

# DESCRIPTION:

#   This script is used to set the thread stack size limit to accomodate

#   the omp_bug4 example. The example code requires @16MB per thread. For

#   safety, this script sets the stack limit to 20MB. Note that the way

#   to do this differs between architectures.

# AUTHOR: Blaise Barney  //

# LAST REVISED:

#*****************************************************************************/

# This is for all systems

limit stacksize unlimited

# This is for IBM AIX systems

setenv XLSMPOPTS "stack=20000000"

# This is for Linux systems

setenv KMP_STACKSIZE 

# This is for HP/Compaq Tru64 systems

setenv MP_STACK_SIZE 

# Now call the executable - change the name to match yours

omp_bug4

(6)omp_bug5.f 

C******************************************************************************

C FILE: omp_bug5.f

C DESCRIPTION:

C   Using SECTIONS, two threads initialize their own array and then add

C   it to the other's array, however a deadlock occurs.

C AUTHOR: Blaise Barney  //

C LAST REVISED:

C******************************************************************************

      PROGRAM BUG5

      INTEGER* LOCKA, LOCKB

      INTEGER NTHREADS, TID, I,

     +        OMP_GET_NUM_THREADS, OMP_GET_THREAD_NUM

      PARAMETER (N=)

      REAL A(N), B(N), PI, DELTA

      PARAMETER (PI=3.1415926535)

      PARAMETER (DELTA=.)

C     Initialize the locks

      CALL OMP_INIT_LOCK(LOCKA)

      CALL OMP_INIT_LOCK(LOCKB)

C     Fork a team of threads giving them their own copies of variables

!$OMP PARALLEL SHARED(A, B, NTHREADS, LOCKA, LOCKB) PRIVATE(TID)

C     Obtain thread number and number of threads

      TID = OMP_GET_THREAD_NUM()

!$OMP MASTER

      NTHREADS = OMP_GET_NUM_THREADS()

      PRINT *, 'Number of threads = ', NTHREADS

!$OMP END MASTER

      PRINT *, 'Thread', TID, 'starting...'

!$OMP BARRIER

!$OMP SECTIONS

!$OMP SECTION

      PRINT *, 'Thread',TID,' initializing A()'

      CALL OMP_SET_LOCK(LOCKA)

      DO I = , N

         A(I) = I * DELTA

      ENDDO

      CALL OMP_SET_LOCK(LOCKB)

      PRINT *, 'Thread',TID,' adding A() to B()'

      DO I = , N

         B(I) = B(I) + A(I)

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKB)

      CALL OMP_UNSET_LOCK(LOCKA)

!$OMP SECTION

      PRINT *, 'Thread',TID,' initializing B()'

      CALL OMP_SET_LOCK(LOCKB)

      DO I = , N

         B(I) = I * PI

      ENDDO

      CALL OMP_SET_LOCK(LOCKA)

      PRINT *, 'Thread',TID,' adding B() to A()'

      DO I = , N

         A(I) = A(I) + B(I)

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKA)

      CALL OMP_UNSET_LOCK(LOCKB)

!$OMP END SECTIONS NOWAIT

      PRINT *, 'Thread',TID,' done.'

!$OMP END PARALLEL

      END

(7)omp_bug5fix.f 

C******************************************************************************

C FILE: omp_bug5fix.f

C DESCRIPTION:

C   The problem in omp_bug5.f is that the first thread acquires locka and then

C   tries to get lockb before releasing locka. Meanwhile, the second thread

C   has acquired lockb and then tries to get locka before releasing lockb.

C   This solution overcomes the deadlock by using locks correctly.

C AUTHOR: Blaise Barney  //

C LAST REVISED:

C******************************************************************************

      PROGRAM BUG5

      INTEGER* LOCKA, LOCKB

      INTEGER NTHREADS, TID, I,

     +        OMP_GET_NUM_THREADS, OMP_GET_THREAD_NUM

      PARAMETER (N=)

      REAL A(N), B(N), PI, DELTA

      PARAMETER (PI=3.1415926535)

      PARAMETER (DELTA=.)

C     Initialize the locks

      CALL OMP_INIT_LOCK(LOCKA)

      CALL OMP_INIT_LOCK(LOCKB)

C     Fork a team of threads giving them their own copies of variables

!$OMP PARALLEL SHARED(A, B, NTHREADS, LOCKA, LOCKB) PRIVATE(TID)

C     Obtain thread number and number of threads

      TID = OMP_GET_THREAD_NUM()

!$OMP MASTER

      NTHREADS = OMP_GET_NUM_THREADS()

      PRINT *, 'Number of threads = ', NTHREADS

!$OMP END MASTER

      PRINT *, 'Thread', TID, 'starting...'

!$OMP BARRIER

!$OMP SECTIONS

!$OMP SECTION

      PRINT *, 'Thread',TID,' initializing A()'

      CALL OMP_SET_LOCK(LOCKA)

      DO I = , N

         A(I) = I * DELTA

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKA)

      CALL OMP_SET_LOCK(LOCKB)

      PRINT *, 'Thread',TID,' adding A() to B()'

      DO I = , N

         B(I) = B(I) + A(I)

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKB)

!$OMP SECTION

      PRINT *, 'Thread',TID,' initializing B()'

      CALL OMP_SET_LOCK(LOCKB)

      DO I = , N

         B(I) = I * PI

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKB)

      CALL OMP_SET_LOCK(LOCKA)

      PRINT *, 'Thread',TID,' adding B() to A()'

      DO I = , N

         A(I) = A(I) + B(I)

      ENDDO

      CALL OMP_UNSET_LOCK(LOCKA)

!$OMP END SECTIONS NOWAIT

      PRINT *, 'Thread',TID,' done.'

!$OMP END PARALLEL

      END

(8)omp_bug6.f 

C******************************************************************************

C FILE: omp_bug6.f

C DESCRIPTION:

C   This program compiles and runs fine, but produces the wrong result.

C   Compare to omp_orphan.f.

C AUTHOR: Blaise Barney  /

C LAST REVISED: //

C******************************************************************************

      PROGRAM ORPHAN

      COMMON /DOTDATA/ A, B

      INTEGER I, VECLEN

      REAL* SUM

      PARAMETER (VECLEN = )

      REAL* A(VECLEN), B(VECLEN)

      DO I=, VECLEN

         A(I) = 1.0 * I

         B(I) = A(I)

      ENDDO

      SUM = 0.0

!$OMP PARALLEL SHARED (SUM)

      CALL DOTPROD

!$OMP END PARALLEL

      WRITE(*,*) "Sum = ", SUM

      END

      SUBROUTINE DOTPROD

      COMMON /DOTDATA/ A, B

      INTEGER I, TID, OMP_GET_THREAD_NUM, VECLEN

c     REAL* SUM

      PARAMETER (VECLEN = )

      REAL* A(VECLEN), B(VECLEN)

      TID = OMP_GET_THREAD_NUM()

!$OMP DO REDUCTION(+:SUM)

      DO I=, VECLEN

         SUM = SUM + (A(I)*B(I))

         PRINT *, '  TID= ',TID,'I= ',I

      ENDDO

      RETURN

      END

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