[ET Trac] [Einstein Toolkit] #2112: move CCTK_MyHost and friends into flesh

[Einstein Toolkit]

#2112: move CCTK_MyHost and friends into flesh
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  Reporter:  rhaas        |       Owner:                     
      Type:  enhancement  |      Status:  new                
  Priority:  minor        |   Milestone:                     
 Component:  Cactus       |     Version:  development version
Resolution:               |    Keywords:  Carpet PUGH driver 
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Comment (by rhaas):

 I attach a sample code using mmap. Note that it is not bulletproof. The
 bug that exists is that if there are more than one independent Cactus runs
 on the same node (eg on your workstation while running testsuites) then
 they all compete for the same shared memory section and only one of them
 will get it.

 To avoid it one needs some name for the shared memory section that is
 unique to the simulation. This is quite hard to do and I am somewhat sure
 that it is not always possible. One cannot for example choose the name of
 the executable or the name of the parfile since neither one needs to be
 unique. So it is the opposite problem the Erik mentioned on a BG since the
 problem with the mmap approach is to limit the mapping to just the
 processes in the current run.

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Ticket URL: <https://trac.einsteintoolkit.org/ticket/2112#comment:5>
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