netcdf-c/include/netcdf_aux.h
Dennis Heimbigner 751300ec59 Fix more memory leaks in netcdf-c library
This is a follow up to PR https://github.com/Unidata/netcdf-c/pull/1173

Sorry that it is so big, but leak suppression can be complex.

This PR fixes all remaining memory leaks -- as determined by
-fsanitize=address, and with the exceptions noted below.

Unfortunately. there remains a significant leak that I cannot
solve. It involves vlens, and it is unclear if the leak is
occurring in the netcdf-c library or the HDF5 library.

I have added a check_PROGRAM to the ncdump directory to show the
problem.  The program is called tst_vlen_demo.c To exercise it,
build the netcdf library with -fsanitize=address enabled. Then
go into ncdump and do a "make clean check".  This should build
tst_vlen_demo without actually executing it.  Then do the
command "./tst_vlen_demo" to see the output of the memory
checker.  Note the the lost malloc is deep in the HDF5 library
(in H5Tvlen.c).

I am temporarily working around this error in the following way.
1. I modified several test scripts to not execute known vlen tests
   that fail as described above.
2. Added an environment variable called NC_VLEN_NOTEST.
   If set, then those specific tests are suppressed.

This should mean that the --disable-utilities option to
./configure should not need to be set to get a memory leak clean
build.  This should allow for detection of any new leaks.

Note: I used an environment variable rather than a ./configure
option to control the vlen tests. This is because it is
temporary (I hope) and because it is a bit tricky for shell
scripts to access ./configure options.

Finally, as before, this only been tested with netcdf-4 and hdf5 support.
2018-11-15 10:00:38 -07:00

56 lines
1.4 KiB
C

/*********************************************************************
* Copyright 2010, UCAR/Unidata
* See netcdf/COPYRIGHT file for copying and redistribution conditions.
* $Id$
* $Header$
*********************************************************************/
#ifndef NCAUX_H
#define NCAUX_H
#define NCAUX_ALIGN_C 0
#define NCAUX_ALIGN_UNIFORM 1
#if defined(__cplusplus)
extern "C" {
#endif
/**
Reclaim the output tree of data from a call
to e.g. nc_get_vara or the input to e.g. nc_put_vara.
This recursively walks the top-level instances to
reclaim any nested data such as vlen or strings or such.
Assumes it is passed a pointer to count instances of xtype.
Reclaims any nested data.
WARNING: does not reclaim the top-level memory because
we do not know how it was allocated.
Should work for any netcdf format.
*/
EXTERNL int ncaux_reclaim_data(int ncid, int xtype, void* memory, size_t count);
EXTERNL int ncaux_begin_compound(int ncid, const char *name, int alignmode, void** tag);
EXTERNL int ncaux_end_compound(void* tag, nc_type* typeid);
EXTERNL int ncaux_abort_compound(void* tag);
EXTERNL int ncaux_add_field(void* tag, const char *name, nc_type field_type,
int ndims, const int* dimsizes);
/* Takes any type */
EXTERNL size_t ncaux_type_alignment(int xtype, int ncid);
/* Takes type classes only */
EXTERNL size_t ncaux_class_alignment(int ncclass);
#if defined(__cplusplus)
}
#endif
#endif /*NCAUX_H*/