Changes between Version 5 and Version 6 of CombiningOperations

Timestamp:

10/30/09 15:45:27 (3 weeks ago)

Author:

robl (IP: 130.202.135.164)

Comment:

feedback from wei-keng: c and fortran apis. no fortran bindings just yet for explicit.

CombiningOperations

@@ -24 +24 @@
 
 '''Explicit Method:''' The caller explicitly accesses multiple variables at once. New routines added to the library (e.g. ncmpi_put_mvara_all) 
-take a list of variables to access
-
-'''Implicit Method'''  The library accesses multiple variables implicitly. Several variable accesses can be "scheduled" with the
-nonblocking routines.   Then, when the application waits for completion of
-those accesses, the library will service them all in a single call.
+take a list of variables to access.  
 
 The function calls for the explicit method look like this:
@@ -44 +40 @@
 }}}
 
+Do note that we do not have Fortran bindings for these new routines in
+parallel-netcdf-1.1.0, but want very much to introduce Fortran bindings for
+this feature in a future release.  In the meantime, Fortran codes can use the
+implicit method (below).
+
+'''Implicit Method'''  The library accesses multiple variables implicitly. Several variable accesses can be "scheduled" with the
+nonblocking routines.   Then, when the application waits for completion of
+those accesses, the library will service them all in a single call.
+
+While it may not have had widespread use, parallel-netcdf has had a
+nonblocking interface for some time.  It looks a lot like the MPI non-blocking
+routines:
+
+In C:
+
+{{{
+ncmpi_iget_vara_all
+ncmpi_iput_vara_all
+ncmpi_wait
+ncmpi_waitall
+}}}
+
+In Fortran:
+{{{
+nfmpi_iget_vara_all
+nfmpi_iput_vara_all
+nfmpi_wait
+nfmpi_waitall
+}}}
+
+In the 'wait' and 'waitall' methods, the library actually batches up all
+outstanding nonblocking operations.  In this way, we can carry out this
+optimization without needing a thread.  
+
 == References ==