eesupp/inc/GLOBAL_SUM.h

C $Header: /u/gcmpack/MITgcm/eesupp/inc/GLOBAL_SUM.h,v 1.4 2004/03/27 03:51:50 edhill Exp $
C $Name:  $
CBOP
C     !ROUTINE: GLOBAL_SUM.h
C     !INTERFACE:
C     include "GLOBAL_SUM.h"
C     !DESCRIPTION:
C     *==========================================================*
C     | GLOBAL\_SUM.h                                             |
C     | o Globals used by Fortran global sum routine.            |
C     *==========================================================*
C     | The global sum shared memory scheme uses global heap data|
C     | structures (.i.e COMMON blocks ). Each thread writes to  |
C     | an its own element of the shared memory array and then   |
C     | one thread reads all the entries and sums them. The sum  |
C     | result is then read by all threads.                      |
C     | Remember - you are working with regions of memory that   |
C     | are being updated concurrently by different threads.     |
C     | What happens, when it happens and who gets to see what   |
C     | happens at what stage depends on the computer systems    |
C     | memory model. Every computer has a different memory model|
C     | and they are never simple. In all current platforms it is|
C     | possible for one thread to see events happening in a     |
C     | different order from the order they are written in the   |
C     | code.                                                    |
C     | Unless you understand this it is not a good idea to      |
C     | make modifications te way these header files are setup or|
C     | the way the global sum routines work.                    |
C     *==========================================================*
CEOP

      COMMON / GSUM_COMMON_R8 / phiGSRL, phiVGSRL
      Real*8  phiGSRL (lShare8, MAX_NO_THREADS )
      Real*8  phivGSRL(MAX_VGS, MAX_NO_THREADS )

      COMMON / GSUM_COMMON_R4 / phiGSRS, phiVGSRS
      Real*4  phiGSRS (lShare4, MAX_NO_THREADS )
      Real*4  phivGSRS(MAX_VGS, MAX_NO_THREADS )

      COMMON / GSUM_COMMON_I  / phiGSI, phiVGSI
      INTEGER phiGSI  (lShare4, MAX_NO_THREADS )
      INTEGER phivGSI (MAX_VGS, MAX_NO_THREADS )

CEH3 ;;; Local Variables: ***
CEH3 ;;; mode:fortran ***
CEH3 ;;; End: ***

1	C $Header: /u/gcmpack/MITgcm/eesupp/inc/GLOBAL_SUM.h,v 1.4 2004/03/27 03:51:50 edhill Exp $
2	C $Name: $
3	CBOP
4	C !ROUTINE: GLOBAL_SUM.h
5	C !INTERFACE:
6	C include "GLOBAL_SUM.h"
7	C !DESCRIPTION:
8	C ==========================================================
9	C \| GLOBAL\_SUM.h \|
10	C \| o Globals used by Fortran global sum routine. \|
11	C ==========================================================
12	C \| The global sum shared memory scheme uses global heap data\|
13	C \| structures (.i.e COMMON blocks ). Each thread writes to \|
14	C \| an its own element of the shared memory array and then \|
15	C \| one thread reads all the entries and sums them. The sum \|
16	C \| result is then read by all threads. \|
17	C \| Remember - you are working with regions of memory that \|
18	C \| are being updated concurrently by different threads. \|
19	C \| What happens, when it happens and who gets to see what \|
20	C \| happens at what stage depends on the computer systems \|
21	C \| memory model. Every computer has a different memory model\|
22	C \| and they are never simple. In all current platforms it is\|
23	C \| possible for one thread to see events happening in a \|
24	C \| different order from the order they are written in the \|
25	C \| code. \|
26	C \| Unless you understand this it is not a good idea to \|
27	C \| make modifications te way these header files are setup or\|
28	C \| the way the global sum routines work. \|
29	C ==========================================================
30	CEOP
31
32	COMMON / GSUM_COMMON_R8 / phiGSRL, phiVGSRL
33	Real*8 phiGSRL (lShare8, MAX_NO_THREADS )
34	Real*8 phivGSRL(MAX_VGS, MAX_NO_THREADS )
35
36	COMMON / GSUM_COMMON_R4 / phiGSRS, phiVGSRS
37	Real*4 phiGSRS (lShare4, MAX_NO_THREADS )
38	Real*4 phivGSRS(MAX_VGS, MAX_NO_THREADS )
39
40	COMMON / GSUM_COMMON_I / phiGSI, phiVGSI
41	INTEGER phiGSI (lShare4, MAX_NO_THREADS )
42	INTEGER phivGSI (MAX_VGS, MAX_NO_THREADS )
43
44	CEH3 ;;; Local Variables: ***
45	CEH3 ;;; mode:fortran ***
46	CEH3 ;;; End: ***
47