C $Header: /u/gcmpack/MITgcm/pkg/mdsio/mdsio_read_field.F,v 1.18 2014/08/12 17:38:11 jmc Exp $
C $Name: $
#include "MDSIO_OPTIONS.h"
CBOP
C !ROUTINE: MDS_READ_FIELD
C !INTERFACE:
SUBROUTINE MDS_READ_FIELD(
I fName,
I filePrec,
I useCurrentDir,
I arrType,
I kSize,kLo,kHi,
O fldRL, fldRS,
I irecord,
I myThid )
C !DESCRIPTION:
C Arguments:
C
C fName (string) :: base name for file to read
C filePrec (integer) :: number of bits per word in file (32 or 64)
C useCurrentDir(logic):: always read from the current directory (even if
C "mdsioLocalDir" is set)
C arrType (char(2)) :: which array (fldRL/RS) to read into, either "RL" or "RS"
C kSize (integer) :: size of third dimension: normally either 1 or Nr
C kLo (integer) :: 1rst vertical level (of array fldRL/RS) to read-in
C kHi (integer) :: last vertical level (of array fldRL/RS) to read-in
C fldRL ( RL ) :: array to read into if arrType="RL", fldRL(:,:,kSize,:,:)
C fldRS ( RS ) :: array to read into if arrType="RS", fldRS(:,:,kSize,:,:)
C irecord (integer) :: record number to read
C myIter (integer) :: time step number
C myThid (integer) :: thread identifier
C
C MDS_READ_FIELD first checks to see IF the file "fName" exists, then
C IF the file "fName.data" exists and finally the tiled files of the
C form "fName.xxx.yyy.data" exist. Currently, the meta-files are not
C read because it is difficult to parse files in fortran.
C The precision of the file is decsribed by filePrec, set either
C to floatPrec32 or floatPrec64. The char*(2) string arrType, either "RL"
C or "RS", selects which array is filled in, either fldRL or fldRS.
C (kSize,kLo,kHi) allows for both 2-D and 3-D arrays to be handled, with
C the option to only read and fill-in a sub-set of consecutive vertical
C levels (from kLo to kHi) ; (kSize,kLo,kHi)=(1,1,1) implies a 2-D model
C field and (kSize,kLo,kHi)=(Nr,1,Nr) implies a 3-D model field.
C irecord is the record number to be read and must be >= 1.
C The file data is stored in fldRL/RS *but* the overlaps are *not* updated,
C i.e., an exchange must be called.
C
C- Multi-threaded: Only Master thread does IO (and MPI calls) and put data
C to a shared buffer that any thread can get access to.
C- Convention regarding thread synchronisation (BARRIER):
C A per-thread (or per tile) partition of the 2-D shared-buffer (sharedLocBuf_r4/r8)
C is readily available => any access (e.g., by master-thread) to a portion
C owned by an other thread is put between BARRIER (protected).
C No thread partition exist for the 3-D shared buffer (shared3dBuf_r4/r8).
C Therefore, the 3-D buffer is considered to be owned by master-thread and
C any access by other than master thread is put between BARRIER (protected).
C
C Created: 03/16/99 adcroft@mit.edu
CEOP
C !USES:
IMPLICIT NONE
C Global variables / common blocks
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#ifdef ALLOW_EXCH2
#include "W2_EXCH2_SIZE.h"
#include "W2_EXCH2_TOPOLOGY.h"
#include "W2_EXCH2_PARAMS.h"
#endif /* ALLOW_EXCH2 */
#include "EEBUFF_SCPU.h"
#ifdef ALLOW_FIZHI
# include "fizhi_SIZE.h"
#endif /* ALLOW_FIZHI */
#include "MDSIO_BUFF_3D.h"
C !INPUT PARAMETERS:
CHARACTER*(*) fName
INTEGER filePrec
LOGICAL useCurrentDir
CHARACTER*(2) arrType
INTEGER kSize, kLo, kHi
INTEGER irecord
INTEGER myThid
C !OUTPUT PARAMETERS:
_RL fldRL(*)
_RS fldRS(*)
C !FUNCTIONS
INTEGER ILNBLNK
INTEGER MDS_RECLEN
LOGICAL MASTER_CPU_IO
EXTERNAL
EXTERNAL
EXTERNAL
C !LOCAL VARIABLES:
C bBij :: base shift in Buffer index for tile bi,bj
CHARACTER*(MAX_LEN_FNAM) dataFName,pfName
CHARACTER*(MAX_LEN_MBUF) msgBuf
LOGICAL exst
LOGICAL globalFile, fileIsOpen
LOGICAL iAmDoingIO
LOGICAL useExch2ioLayOut
INTEGER xSize, ySize
INTEGER iG,jG,bi,bj
INTEGER i1,i2,i,j,k,nNz
INTEGER irec,dUnit,IL,pIL
INTEGER length_of_rec
INTEGER bBij
INTEGER tNx, tNy, global_nTx
INTEGER tBx, tBy, iGjLoc, jGjLoc
#ifdef ALLOW_EXCH2
INTEGER tN
#endif /* ALLOW_EXCH2 */
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
C Set dimensions:
xSize = Nx
ySize = Ny
useExch2ioLayOut = .FALSE.
#ifdef ALLOW_EXCH2
IF ( W2_useE2ioLayOut ) THEN
xSize = exch2_global_Nx
ySize = exch2_global_Ny
useExch2ioLayOut = .TRUE.
ENDIF
#endif /* ALLOW_EXCH2 */
C Assume nothing
globalFile = .FALSE.
fileIsOpen = .FALSE.
IL = ILNBLNK( fName )
pIL = ILNBLNK( mdsioLocalDir )
nNz = 1 + kHi - kLo
C Only do I/O if I am the master thread (and mpi process 0 IF useSingleCpuIO):
iAmDoingIO = MASTER_CPU_IO(myThid)
C File name should not be too long:
C IL(+pIL if not useCurrentDir)(+5: '.data')(+8: bi,bj) =< MAX_LEN_FNAM
C and shorter enough to be written to msgBuf with other informations
IF ( useCurrentDir .AND. (90+IL).GT.MAX_LEN_MBUF ) THEN
WRITE(msgBuf,'(2A,2(I4,A))') 'MDS_READ_FIELD: ',
& 'Too long (IL=',IL,') file name:'
CALL PRINT_ERROR( msgBuf, myThid )
WRITE(errorMessageUnit,'(3A)')'file: >',fName(1:IL),'<'
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ELSEIF ( (90+IL+pIL).GT.MAX_LEN_MBUF ) THEN
WRITE(msgBuf,'(2A,2(I4,A))') 'MDS_READ_FIELD: ',
& 'Too long (pIL=',pIL,', IL=',IL,') pfix + file name:'
CALL PRINT_ERROR( msgBuf, myThid )
WRITE(errorMessageUnit,'(3A)')'pfix: >',mdsioLocalDir(1:pIL),'<'
WRITE(errorMessageUnit,'(3A)')'file: >',fName(1:IL),'<'
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C Record number must be >= 1
IF (irecord .LT. 1) THEN
WRITE(msgBuf,'(3A,I10)')
& ' MDS_READ_FIELD: file="', fName(1:IL), '"'
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(A,I9.8)')
& ' MDS_READ_FIELD: argument irecord = ',irecord
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: Invalid value for irecord'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C check for valid sub-set of levels:
IF ( kLo.LT.1 .OR. kHi.GT.kSize ) THEN
WRITE(msgBuf,'(3A,I10)')
& ' MDS_READ_FIELD: file="', fName(1:IL), '"'
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(3(A,I6))')
& ' MDS_READ_FIELD: arguments kSize=', kSize,
& ' , kLo=', kLo, ' , kHi=', kHi
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: invalid sub-set of levels'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C check for 3-D Buffer size:
IF ( .NOT.useSingleCpuIO .AND. nNz.GT.size3dBuf ) THEN
WRITE(msgBuf,'(3A,I10)')
& ' MDS_READ_FIELD: file="', fName(1:IL), '"'
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(3(A,I6))')
& ' MDS_READ_FIELD: Nb Lev to read =', nNz,
& ' >', size3dBuf, ' = buffer 3rd Dim'
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: buffer 3rd Dim. too small'
CALL PRINT_ERROR( msgBuf, myThid )
WRITE(msgBuf,'(A)')
& ' increase "size3dBuf" in "MDSIO_BUFF_3D.h" and recompile'
CALL PRINT_MESSAGE( msgBuf, errorMessageUnit,
& SQUEEZE_RIGHT, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C Only do I/O if I am the master thread
IF ( iAmDoingIO ) THEN
C Assign special directory
IF ( useCurrentDir .OR. pIL.EQ.0 ) THEN
pfName= fName
ELSE
WRITE(pfName,'(2a)') mdsioLocalDir(1:pIL), fName(1:IL)
ENDIF
pIL=ILNBLNK( pfName )
C Assign a free unit number as the I/O channel for this routine
CALL MDSFINDUNIT( dUnit, myThid )
C Check first for global file with simple name (ie. fName)
dataFName = fName
INQUIRE( file=dataFName, exist=exst )
IF (exst) THEN
IF ( debugLevel .GE. debLevB ) THEN
WRITE(msgBuf,'(A,A)')
& ' MDS_READ_FIELD: opening global file: ',dataFName(1:IL)
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
ENDIF
globalFile = .TRUE.
ENDIF
C If negative check for global file with MDS name (ie. fName.data)
IF (.NOT. globalFile) THEN
WRITE(dataFName,'(2a)') fName(1:IL),'.data'
INQUIRE( file=dataFName, exist=exst )
IF (exst) THEN
IF ( debugLevel .GE. debLevB ) THEN
WRITE(msgBuf,'(A,A)')
& ' MDS_READ_FIELD: opening global file: ',dataFName(1:IL+5)
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
ENDIF
globalFile = .TRUE.
ENDIF
ENDIF
C- endif iAmDoingIO
ENDIF
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
IF ( useSingleCPUIO ) THEN
C master thread of process 0, only, opens a global file
IF ( iAmDoingIO ) THEN
C If global file is visible to process 0, then open it here.
C Otherwise stop program.
IF ( globalFile) THEN
length_of_rec = MDS_RECLEN( filePrec, xSize*ySize, myThid )
OPEN( dUnit, file=dataFName, status='old',
& access='direct', recl=length_of_rec )
ELSE
WRITE(msgBuf,'(2A)')
& ' MDS_READ_FIELD: filename: ', dataFName(1:IL+5)
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
CALL PRINT_ERROR( msgBuf, myThid )
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: File does not exist'
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
CALL PRINT_ERROR( msgBuf, myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C- endif iAmDoingIO
ENDIF
DO k=kLo,kHi
C master thread of process 0, only, read from file
IF ( iAmDoingIO ) THEN
irec = 1 + k-kLo + (irecord-1)*nNz
IF (filePrec .EQ. precFloat32) THEN
READ(dUnit,rec=irec) ( xy_buffer_r4(i),i=1,xSize*ySize )
#ifdef _BYTESWAPIO
CALL MDS_BYTESWAPR4( xSize*ySize, xy_buffer_r4 )
#endif
ELSE
READ(dUnit,rec=irec) ( xy_buffer_r8(i),i=1,xSize*ySize )
#ifdef _BYTESWAPIO
CALL MDS_BYTESWAPR8( xSize*ySize, xy_buffer_r8 )
#endif
ENDIF
C- endif iAmDoingIO
ENDIF
C Wait for all thread to finish. This prevents other threads to continue
C to acces shared buffer while master thread is loading data into
CALL BAR2( myThid )
IF ( filePrec.EQ.precFloat32 ) THEN
CALL SCATTER_2D_R4(
U xy_buffer_r4,
O sharedLocBuf_r4,
I xSize, ySize,
I useExch2ioLayOut, .FALSE., myThid )
C All threads wait for Master to finish loading into shared buffer
CALL BAR2( myThid )
IF ( arrType.EQ.'RS' ) THEN
CALL MDS_PASS_R4TORS( sharedLocBuf_r4, fldRS,
I 0, 0, 1, k, kSize, 0, 0, .TRUE., myThid )
ELSEIF ( arrType.EQ.'RL' ) THEN
CALL MDS_PASS_R4TORL( sharedLocBuf_r4, fldRL,
I 0, 0, 1, k, kSize, 0, 0, .TRUE., myThid )
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for arrType'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
ELSEIF ( filePrec.EQ.precFloat64 ) THEN
CALL SCATTER_2D_R8(
U xy_buffer_r8,
O sharedLocBuf_r8,
I xSize, ySize,
I useExch2ioLayOut, .FALSE., myThid )
C All threads wait for Master to finish loading into shared buffer
CALL BAR2( myThid )
IF ( arrType.EQ.'RS' ) THEN
CALL MDS_PASS_R8TORS( sharedLocBuf_r8, fldRS,
I 0, 0, 1, k, kSize, 0, 0, .TRUE., myThid )
ELSEIF ( arrType.EQ.'RL' ) THEN
CALL MDS_PASS_R8TORL( sharedLocBuf_r8, fldRL,
I 0, 0, 1, k, kSize, 0, 0, .TRUE., myThid )
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for arrType'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for filePrec'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
ENDDO
c ENDDO k=kLo,kHi
IF ( iAmDoingIO ) THEN
CLOSE( dUnit )
ENDIF
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
C--- else .NOT.useSingleCpuIO
ELSE
C Wait for all thread to finish. This prevents other threads to continue
C to acces 3-D buffer while master thread is reading
c CALL BAR2( myThid )
C Only do I/O if I am the master thread
IF ( iAmDoingIO ) THEN
C If we are reading from a global file then we open it here
IF (globalFile) THEN
length_of_rec = MDS_RECLEN( filePrec, sNx, myThid )
OPEN( dUnit, file=dataFName, status='old',
& access='direct', recl=length_of_rec )
fileIsOpen=.TRUE.
ENDIF
C Loop over all tiles
DO bj=1,nSy
DO bi=1,nSx
bBij = sNx*sNy*nNz*( bi-1 + (bj-1)*nSx )
IF (globalFile) THEN
C--- Case of 1 Global file:
c IF (fileIsOpen) THEN
tNx = sNx
tNy = sNy
global_nTx = xSize/sNx
tBx = myXGlobalLo-1 + (bi-1)*sNx
tBy = myYGlobalLo-1 + (bj-1)*sNy
iGjLoc = 0
jGjLoc = 1
#ifdef ALLOW_EXCH2
IF ( useExch2ioLayOut ) THEN
tN = W2_myTileList(bi,bj)
c tNx = exch2_tNx(tN)
c tNy = exch2_tNy(tN)
c global_nTx = exch2_global_Nx/tNx
tBx = exch2_txGlobalo(tN) - 1
tBy = exch2_tyGlobalo(tN) - 1
IF ( exch2_mydNx(tN) .GT. xSize ) THEN
C- face x-size larger than glob-size : fold it
iGjLoc = 0
jGjLoc = exch2_mydNx(tN) / xSize
ELSEIF ( exch2_tNy(tN) .GT. ySize ) THEN
C- tile y-size larger than glob-size : make a long line
iGjLoc = exch2_mydNx(tN)
jGjLoc = 0
ELSE
C- default (face fit into global-IO-array)
iGjLoc = 0
jGjLoc = 1
ENDIF
ENDIF
#endif /* ALLOW_EXCH2 */
DO k=kLo,kHi
DO j=1,tNy
irec = 1 + ( tBx + (j-1)*iGjLoc )/sNx
& + ( tBy + (j-1)*jGjLoc )*global_nTx
& +( k-kLo + (irecord-1)*nNz )*global_nTx*ySize
i1 = bBij + 1 + (j-1)*sNx + (k-kLo)*sNx*sNy
i2 = bBij + j*sNx + (k-kLo)*sNx*sNy
IF ( filePrec.EQ.precFloat32 ) THEN
READ(dUnit,rec=irec) (shared3dBuf_r4(i),i=i1,i2)
ELSE
READ(dUnit,rec=irec) (shared3dBuf_r8(i),i=i1,i2)
ENDIF
C End of j,k loops
ENDDO
ENDDO
C end if fileIsOpen
c ENDIF
ELSE
C--- Case of 1 file per tile (globalFile=F):
C If we are reading from a tiled MDS file then we open each one here
iG=bi+(myXGlobalLo-1)/sNx
jG=bj+(myYGlobalLo-1)/sNy
WRITE(dataFName,'(2A,I3.3,A,I3.3,A)')
& pfName(1:pIL),'.',iG,'.',jG,'.data'
INQUIRE( file=dataFName, exist=exst )
C Of course, we only open the file if the tile is "active"
C (This is a place-holder for the active/passive mechanism
IF (exst) THEN
IF ( debugLevel .GE. debLevB ) THEN
WRITE(msgBuf,'(A,A)')
& ' MDS_READ_FIELD: opening file: ',dataFName(1:pIL+13)
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
ENDIF
length_of_rec = MDS_RECLEN( filePrec, sNx*sNy*nNz, myThid )
OPEN( dUnit, file=dataFName, status='old',
& access='direct', recl=length_of_rec )
fileIsOpen=.TRUE.
ELSE
fileIsOpen=.FALSE.
WRITE(msgBuf,'(4A)') ' MDS_READ_FIELD: filename: ',
& fName(1:IL),' , ', dataFName(1:pIL+13)
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
CALL PRINT_ERROR( msgBuf, myThid )
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: Files DO not exist'
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
& SQUEEZE_RIGHT, myThid)
CALL PRINT_ERROR( msgBuf, myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
irec = irecord
i1 = bBij + 1
i2 = bBij + sNx*sNy*nNz
IF ( filePrec.EQ.precFloat32 ) THEN
READ(dUnit,rec=irec) (shared3dBuf_r4(i),i=i1,i2)
ELSE
READ(dUnit,rec=irec) (shared3dBuf_r8(i),i=i1,i2)
ENDIF
C here We close the tiled MDS file
IF ( fileIsOpen ) THEN
CLOSE( dUnit )
fileIsOpen = .FALSE.
ENDIF
C--- End Global File / tile-file cases
ENDIF
C End of bi,bj loops
ENDDO
ENDDO
C If global file was opened then close it
IF (fileIsOpen .AND. globalFile) THEN
CLOSE( dUnit )
fileIsOpen = .FALSE.
ENDIF
#ifdef _BYTESWAPIO
IF ( filePrec.EQ.precFloat32 ) THEN
CALL MDS_BYTESWAPR4( sNx*sNy*nNz*nSx*nSy, shared3dBuf_r4 )
ELSE
CALL MDS_BYTESWAPR8( sNx*sNy*nNz*nSx*nSy, shared3dBuf_r8 )
ENDIF
#endif
C- endif iAmDoingIO
ENDIF
C All threads wait for Master to finish reading into shared buffer
CALL BAR2( myThid )
C--- Copy from 3-D buffer to fldRL/RS (multi-threads):
IF ( filePrec.EQ.precFloat32 ) THEN
IF ( arrType.EQ.'RS' ) THEN
CALL MDS_PASS_R4TORS( shared3dBuf_r4, fldRS,
I 0, 0, nNz, kLo, kSize, 0, 0, .TRUE., myThid )
ELSEIF ( arrType.EQ.'RL' ) THEN
CALL MDS_PASS_R4TORL( shared3dBuf_r4, fldRL,
I 0, 0, nNz, kLo, kSize, 0, 0, .TRUE., myThid )
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for arrType'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
ELSEIF ( filePrec.EQ.precFloat64 ) THEN
IF ( arrType.EQ.'RS' ) THEN
CALL MDS_PASS_R8TORS( shared3dBuf_r8, fldRS,
I 0, 0, nNz, kLo, kSize, 0, 0, .TRUE., myThid )
ELSEIF ( arrType.EQ.'RL' ) THEN
CALL MDS_PASS_R8TORL( shared3dBuf_r8, fldRL,
I 0, 0, nNz, kLo, kSize, 0, 0, .TRUE., myThid )
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for arrType'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
ELSE
WRITE(msgBuf,'(A)')
& ' MDS_READ_FIELD: illegal value for filePrec'
CALL PRINT_ERROR( msgBuf, myThid )
CALL ALL_PROC_DIE( myThid )
STOP 'ABNORMAL END: S/R MDS_READ_FIELD'
ENDIF
C Wait for all threads to finish getting data from 3-D shared buffer.
C This prevents the master-thread to change the buffer content before
C every one got his data.
CALL BAR2( myThid )
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
C if useSingleCpuIO / else / end
ENDIF
RETURN
END