Assertion `ncp->head != ((void *)0)' failed.

[Liu, Jaln]

Hi Dr. Liao,

Thank you. Other ncmpi call works fine, like  ncmpi_get_vara_float and ncmpi_get_vara_float_all,

>Also, I am seeing this line in your codes:
>        nb_temp_in[rank]=calloc(varasize,sizeof(float));

Yes, it should be `nb_temp'.

I wonder can we use ncmpi_iget_vara() on the same variable but different starts&lengths. From the sample program, it is used for multiple variables.

Jialin
________________________________________
From: parallel-netcdf-bounces at lists.mcs.anl.gov [parallel-netcdf-bounces at lists.mcs.anl.gov] on behalf of Wei-keng Liao [wkliao at ece.northwestern.edu]
Sent: Wednesday, February 13, 2013 1:28 PM
To: parallel-netcdf at lists.mcs.anl.gov
Subject: Re: Assertion `ncp->head != ((void *)0)' failed.

Hi, Jialin,

I suspect it is because the call to ncmpi_iget_vara() failed.
Please check the return values of all your ncmpi_ calls.
It may tell you if you got an error before you would like to continue.

Also, I am seeing this line in your codes:
>        nb_temp_in[rank]=calloc(varasize,sizeof(float));

But you are using nb_temp[rank] in ncmpi_iget_vara()


Wei-keng

On Feb 13, 2013, at 12:13 PM, Liu, Jaln wrote:

> Hi,
>
> When I run the codes below, I got an error " Assertion `ncp->head != ((void *)0)' failed."
> (I looked into the source codes, I saw a operation of checking Id, seems each request should be checked and matched with the file handle? I don't know the reason)
>
>        float ** nb_temp;
>        nb_temp=malloc(nprocs*sizeof(float *));
>        int * request=calloc(nprocs, sizeof(int));
>        int * status=calloc(nprocs,sizeof(int));
>        mpi_start[1]=rank*5;//starts on other dimensions are specified to 0.
>        int varasize=100*10*NLAT*NLON;
>        nb_temp_in[rank]=calloc(varasize,sizeof(float));
>
>        ncmpi_iget_vara(ncid, temp_varid, mpi_start,mpi_count,nb_temp[rank],varasize,MPI_FLOAT,&(request[rank]);
>
>        ncmpi_wait_all(ncid, nprocs, request, status);
>
> A detailed return is in the attachment,
>
> Can you please tell me what's wrong with the codes?
> I appreciate it.
>
> Jialin
> <56034.e>