what's dummy Pstream for??

quaintchewster · March 4, 2012, 12:55

I tried compiling OF 2.1.0 on a cluster with its native MPI. The make system of OpenFoam is really puzzeling. And I was confused by the dummy Pstream.

I think dummy Pstream was designed for serial running. But why libOpenFoam.so is forced to be linked with dummy version libPstream.so ? How this libOpenFoam.so with the dummy Pstream code can do parallel running??

wyldckat · March 4, 2012, 13:54

Greetings quaintchewster,

It's simple: the dummy Pstream acts as a place holder, sort-of of a stub. This way it's possible to have a single OpenFOAM installation that can easily work with any number of MPI libraries/toolboxes as you want to, without having to recompile the whole OpenFOAM source code.

For example, if you were conducting experiments to compare several MPI libraries, such as Open-MPI 1.4.3 and 1.5.3 vs MPICH2 1.4.1, you would then have the following folders in "$FOAM_LIBBIN":

dummy
openmpi-1.4.3
openmpi-1.5.3
mpich2-1.4.1

Inside each one you will then have a dedicated Pstream library, along with other MPI dependent libraries.

For more about how wmake works: OpenFoam Installation in Redhat Enterprise linux 5 - post #22
For more about how the OpenFOAM works on the shell: Advanced tips for working with the OpenFOAM shell environment

Best regards,
Bruno

quaintchewster · March 4, 2012, 14:29

wyldckat

Thank you !!
If only I read these a week ago. It took me so much time to make it.

March 4, 2012, 12:55	what's dummy Pstream for??	#1
quaintchewster New Member Kun Qu Join Date: Nov 2010 Posts: 5 Rep Power: 16	I tried compiling OF 2.1.0 on a cluster with its native MPI. The make system of OpenFoam is really puzzeling. And I was confused by the dummy Pstream. I think dummy Pstream was designed for serial running. But why libOpenFoam.so is forced to be linked with dummy version libPstream.so ? How this libOpenFoam.so with the dummy Pstream code can do parallel running??

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March 4, 2012, 13:54		#2
wyldckat Retired Super Moderator Bruno Santos Join Date: Mar 2009 Location: Lisbon, Portugal Posts: 10,981 Blog Entries: 45 Rep Power: 128	Greetings quaintchewster, It's simple: the dummy Pstream acts as a place holder, sort-of of a stub. This way it's possible to have a single OpenFOAM installation that can easily work with any number of MPI libraries/toolboxes as you want to, without having to recompile the whole OpenFOAM source code. For example, if you were conducting experiments to compare several MPI libraries, such as Open-MPI 1.4.3 and 1.5.3 vs MPICH2 1.4.1, you would then have the following folders in "$FOAM_LIBBIN": dummy openmpi-1.4.3 openmpi-1.5.3 mpich2-1.4.1 Inside each one you will then have a dedicated Pstream library, along with other MPI dependent libraries. For more about how wmake works: OpenFoam Installation in Redhat Enterprise linux 5 - post #22 For more about how the OpenFOAM works on the shell: Advanced tips for working with the OpenFOAM shell environment Best regards, Bruno lakeat and vivek05 like this. __________________ OpenFOAM: FAQ \| Getting started Forum: How to get help, to post code/output and forum guide Read this before sending me PM

March 4, 2012, 14:29		#3
quaintchewster New Member Kun Qu Join Date: Nov 2010 Posts: 5 Rep Power: 16	wyldckat Thank you !! If only I read these a week ago. It took me so much time to make it.