eesupp/inc/BAR2.h

048ce7bdb7 Chri*0001 C
4c563c2ee9 Chri*0002 CBOP
                0003 C     !ROUTINE: BAR2.h
                0004 C     !INTERFACE:
                0005 C     include "BAR2.h"
                0006 C     !DESCRIPTION:
                0007 C     *==========================================================*
                0008 C     | BAR2.h
                0009 C     | o Globals used by BAR2 Fortran barrier routine.
                0010 C     |==========================================================*
                0011 C     | These variables support a simple Fortran shared memory
                0012 C     | barrier routine. They do busy waiting, that is the
                0013 C     | thread that is waiting sits in a tight loop reading
                0014 C     | some memory location and waiting for all other threads.
                0015 C     | On some systems this is sometimes a good method to use.
                0016 C     | On the T3E memory is not shared so the routine should
                0017 C     | use the T3E "eureka" barriers. On CRAY and NEC there are
                0018 C     | hardware barriers that are accessed through a compiler
                0019 C     | directives. Finally proper multi-threading compilers
                0020 C     | support barrier compile directives - sometimes these
                0021 C     | are good, sometimes they are lousy.
                0022 C     |  The barrier mechanism is used as follows
                0023 C     |  1. In the single-threaded part of the code
2b4c849245 Ed H*0024 C     |     CALL BAR2\_INIT
4c563c2ee9 Chri*0025 C     |     on CRAY, NEC this routine does nothing
                0026 C     |     on T3E there is no single-threaded code
                0027 C     |        but there may be barrier initialisation -
                0028 C     |        need to check.
                0029 C     |  2. When we need to synchronize everybody just
                0030 C     |     CALL BAR2( myThid )
                0031 C     |     where myThid is myThreadId
2b4c849245 Ed H*0032 C     |     on CRAY, NEC FBAR will just do C\$DIR BARRIER
4c563c2ee9 Chri*0033 C     |     or CALL BARRIER or the like.
                0034 C     |     on T3E FBAR does CALL BARRIER(...) or something
                0035 C     |     need to check this.
                0036 C     *==========================================================*
                0037 CEOP
048ce7bdb7 Chri*0038       COMMON /BAR2_BUFFER_I/
                0039      &  BAR2_level,
                0040      &  BAR2_barrierCount,
                0041      &  BAR2_spinsCount, BAR2_spinsMax, BAR2_spinsMin
                0042       INTEGER BAR2_level(cacheLineSize/4,MAX_NO_THREADS)
                0043       INTEGER BAR2_barrierCount(cacheLineSize/4,MAX_NO_THREADS)
                0044       INTEGER BAR2_spinsCount(cacheLineSize/4,MAX_NO_THREADS)
                0045       INTEGER BAR2_spinsMax(cacheLineSize/4,MAX_NO_THREADS)
                0046       INTEGER BAR2_spinsMin(cacheLineSize/4,MAX_NO_THREADS)
                0047
                0048       COMMON /BAR2_L/ bar2CollectStatistics
                0049       LOGICAL bar2CollectStatistics