[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 950316: netCDF library

Hi Yuji,

> Hello!  A few months ago I sent you a mail asking whether there 
> is Windows-based netCDF library.  At that time I had a negative 
> answer.  
> The problem is memory allocation.  It seems that the netCDF 
> library allocates memory, but does not release anywhere.  This 
> may cause memory leak. 

No that's not actually the problem.  Every netCDF malloc() call has a
corresponding free() that's called by the time an open netCDF file is
closed.  The circumstances we know of that cause memory leaks occur under
(for us) unusual error conditions when not much memory is available, for
example when malloc() fails repeatedly.  The netCDF library doesn't recover
well after a malloc() call has failed, and may not free all the memory
previously allocated before the malloc() failure.

> I have asked many people what I must do.  A person said I can 
> release the allocated memory in the library itself and also in 
> my application. 
> Though I read the document of the library, I don't know what to 
> do.
> I would very much appreciate your help.

Although we don't port code to Windows platforms, we know of a company in
Europe that successfully ported the netCDF library to Windows NT, in the
form of an easy-to-use DLL library.  They said the work was in making the
library reentrant.  Currently it is not reentrant, since, for example,
global variables are used to return information about errors and to control
error handling.

Although we have asked for a copy of the modified sources for their DLL
library version, we haven't received the necessary modifications yet.

We don't have any Windows programmers here and so must rely on the community
for this port, so I'm sorry to say we can't be of much more help.

______________________________________________________________________________

Russ Rew                                                UCAR Unidata Program
address@hidden                                          P.O. Box 3000
http://www.unidata.ucar.edu/                          Boulder, CO 80307-3000
______________________________________________________________________________