eesupp/inc/GLOBAL_SUM.h

4c563c2ee9 Chri*0001 CBOP
                0002 C     !ROUTINE: GLOBAL_SUM.h
                0003 C     !INTERFACE:
                0004 C     include "GLOBAL_SUM.h"
                0005 C     !DESCRIPTION:
                0006 C     *==========================================================*
8d7d23bda2 Jean*0007 C     | GLOBAL\_SUM.h
                0008 C     | o Globals used by Fortran global sum routine.
4c563c2ee9 Chri*0009 C     *==========================================================*
aea29c8517 Alis*0010 C     | The global sum shared memory scheme uses global heap data|
                0011 C     | structures (.i.e COMMON blocks ). Each thread writes to  |
                0012 C     | an its own element of the shared memory array and then   |
                0013 C     | one thread reads all the entries and sums them. The sum  |
                0014 C     | result is then read by all threads.                      |
                0015 C     | Remember - you are working with regions of memory that   |
                0016 C     | are being updated concurrently by different threads.     |
                0017 C     | What happens, when it happens and who gets to see what   |
                0018 C     | happens at what stage depends on the computer systems    |
                0019 C     | memory model. Every computer has a different memory model|
                0020 C     | and they are never simple. In all current platforms it is|
                0021 C     | possible for one thread to see events happening in a     |
                0022 C     | different order from the order they are written in the   |
                0023 C     | code.                                                    |
                0024 C     | Unless you understand this it is not a good idea to      |
                0025 C     | make modifications te way these header files are setup or|
                0026 C     | the way the global sum routines work.                    |
4c563c2ee9 Chri*0027 C     *==========================================================*
                0028 CEOP
aea29c8517 Alis*0029
07ef6829ed Jean*0030       COMMON / GSUM_COMMON_R8 / phiGSR8, shareBufGSR8
                0031       Real*8  phiGSR8 (lShare8, 0:MAX_NO_THREADS )
4d45770d13 Jean*0032       Real*8  shareBufGSR8 ( nSx, nSy )
f8adb8fd4b Ed H*0033
07ef6829ed Jean*0034       COMMON / GSUM_COMMON_R4 / phiGSR4
                0035       Real*4  phiGSR4 (lShare4, 0:MAX_NO_THREADS )
f8adb8fd4b Ed H*0036
8d7d23bda2 Jean*0037       COMMON / GSUM_COMMON_I  / phiGSI
07ef6829ed Jean*0038       INTEGER phiGSI  (lShare4, 0:MAX_NO_THREADS )
f8adb8fd4b Ed H*0039
5237154b93 Jean*0040       COMMON / GLBSUM_VECTOR_RL / shareBufGSVec, shareGSVector
                0041       Real*8  shareBufGSVec( nSx, nSy, GSVec_size )
                0042       Real*8  shareGSVector( GSVec_size )
                0043
                0044       COMMON / GLBSUM_VECTOR_I / shareBufGSVecI, shareGSVectInt
                0045       INTEGER shareBufGSVecI( nSx, nSy, GSVec_size )
                0046       INTEGER shareGSVectInt( GSVec_size )
                0047 C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|