vchoi_fork

[svn-r8923] Purpose:
To add a special section of codes for collective-chunk IO tests.

Description:
The current patch of collective chunk IO support in HDF5 can only handle
some special("however, can cover many applications") cases,
Inside source code, we did a careful checking to make sure other cases would
not fall into this category and would not use collective IO.
We also would like to test whether those collective conditions were met in our
test programs.
The current parallel HDF5 handled those collective IO requests in a special way.
If the library finds it cannot do collective IO, it will silently change to independent IO.
So basically there is no better way to check whether the library is doing what it should do without "hacking" into HDF5 source codes for the purpose of testing. But the "hacking" should not affect library work and should be easily pulled out after we get more general collective IO algorithm to work.

With Quincey's suggestion, we used HDF5 property APIs to finish the job.
Solution:
The approach includes three parts:
1) In the test program, insert a property inside data transfer property list.
   Set a default value for this property.
2) Inside H5Dio.c, when the library finds that it cannot do collective IO with chunking storage, it will change the default value.
3) Then the test program will recheck the value after H5Dwrite or H5Dread to evaluate whether
the current collective IO case is doing the right thing.

Note: The test won't stop after it finds that the library is not doing the right thing and probably it will finish normally. The current approach is that the test program just printed out an error message. It should be changed later.
Platforms tested:o
copper,arabica,eirene

Misc. update: