NetCDF group,
Recently we are testing opendap with NetCDF.
Our code give segmentation vault, and we trace back this to NetCDF opendap.
The link we tried is:
http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.dailyavgs/pressure/air.1948.nc
We tried "ncdump -h …", which worked fine, but "ncdump -v air …" gave
segmentation fault.
We tried a simple c code, below, which give segmentation fault as well.
Has anyone seen this before?
Thanks,
Wei
---------
C - code:
#include <stdio.h>
#include <stdlib.h>
#include <netcdf.h>
int main(int *argc, char **argv)
{
char flnm[] =
"http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.dailyavgs/pressure/air.1948.nc";;
int status; /* error status */
int ncid; /* netCDF ID */
int varid; /* variable ID */
static size_t start[16];
static size_t count[16];
short *vals;
nc_type type; /* variable type */
int ndims; /* number of dims */
int dimids[NC_MAX_VAR_DIMS]; /* dimension IDs */
int natts; /* number of attributes */
int nvars, ngatts, unlimdimid;
size_t length, recs;
char recname[NC_MAX_NAME+1];
int n;
status = nc_open(flnm, NC_NOWRITE, &ncid);
/*
*if (status != NC_NOERR) handle_error(status);
*/
fprintf(stderr, "ncid = %d\n", ncid);
status = nc_inq(ncid, &ndims, &nvars, &ngatts, &unlimdimid);
status = nc_inq_varid(ncid, "air", &varid);
fprintf(stderr, "varid = %d\n", varid);
status = nc_inq_var(ncid, varid, 0, &type, &ndims, dimids,
&natts);
length = 1;
for(n = 0; n < ndims; ++n)
{
status = nc_inq_dim(ncid, dimids[n], recname, &count[n]);
fprintf(stderr, "dim %d: id = %d, name: <%s>, length = %ld\n",
n, dimids[n], recname, (long) count[n]);
length *= count[n];
start[n] = 0;
}
fprintf(stderr, "length = %ld\n", (long) length);
vals = (short *) malloc(length * sizeof(short));
/*read values*/
status = nc_get_vara(ncid, varid, start, count, vals);
fprintf(stderr, "vals[0] = %d\n", vals[0]);
free(vals);
return ( 0 );
}
Error message:
ncid = 65536
varid = 4
dim 0: id = 0, name: <time>, length = 366
dim 1: id = 2, name: <level>, length = 17
dim 2: id = 1, name: <lat>, length = 73
dim 3: id = 3, name: <lon>, length = 144
length = 65405664
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000008
0x000000010003163c in buildcachenode34 (nccomm=0x100f15c00,
constraint=0x102602650, varlist=0x102602490, cachep=0x7fff5fbfb148,
isprefetch=0) at cache.c:231
231 cache->cachesize -= node->xdrsize;
(gdb) where
#0 0x000000010003163c in buildcachenode34 (nccomm=0x100f15c00,
constraint=0x102602650, varlist=0x102602490, cachep=0x7fff5fbfb148,
isprefetch=0) at cache.c:231
#1 0x0000000100046998 in nc3d_getvarx (ncid=65536, varid=4,
startp=0x1004679e0, countp=0x100467960, stridep=0x10048b2a0, data=0x104000000,
dsttype0=3) at getvara3.c:192
#2 0x000000010004a9fb in NCD3_get_vara (ncid=65536, varid=4,
start=0x1004679e0, edges=0x100467960, value=0x104000000, memtype=3) at
ncd3dispatch.c:203
#3 0x0000000100008b90 in NC_get_vara (ncid=65536, varid=4, start=0x1004679e0,
edges=0x100467960, value=0x104000000, memtype=3) at var.c:172
#4 0x000000010000a7df in nc_get_vara (ncid=65536, varid=4, start=0x1004679e0,
edges=0x100467960, value=0x104000000) at var.c:939
#5 0x0000000100001ab2 in main ()
huangwei@xxxxxxxx
VETS/CISL
National Center for Atmospheric Research
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Boulder, CO 80307-3000 USA
(303) 497-8924
