Hi all, I am having trouble with the following piece of code (I hacked apart one of the parallel HDF5 tutorial examples and changed the API to 1.8.4).
I am trying get each process to write to a different data set simultaneously (but all data sets are in the same file) using independent I/O. I suspect this may not be possible, but the documentation seems to say otherwise (see http://www.hdfgroup.org/HDF5/Tutor/pprog.html, at the bottom it says "Each process writes to a individual dataset."). I have enforced that the data sets are created collectively, but the simultaneous write fails. Do you all know why this does not work? The code is listed below. Cheers, Matt /* * This example writes data to the HDF5 file. * Number of processes is assumed to be 1 or multiples of 2 (up to 8) */ #include <stdlib.h> #include <stdio.h> #include <math.h> #include <assert.h> #include <mpi.h> #include <hdf5.h> #define H5FILE_NAME "SDS.h5" #define DATASETNAME "IntArray" #define NX 8 /* dataset dimensions */ #define NY 5 #define RANK 2 int main (int argc, char **argv) { /* * HDF5 APIs definitions */ hid_t file_id, dset_id, group_id; /* file and dataset identifiers */ hid_t filespace; /* file and memory dataspace identifiers */ hsize_t dimsf[] = {NX, NY}; /* dataset dimensions */ int *data; /* pointer to data buffer to write */ hid_t plist_id; /* property list identifier */ int i; herr_t status; char name[500]; /* * MPI variables */ int mpi_size, mpi_rank; MPI_Comm comm = MPI_COMM_WORLD; MPI_Info info = MPI_INFO_NULL; /* * Initialize MPI */ MPI_Init(&argc, &argv); MPI_Comm_size(comm, &mpi_size); MPI_Comm_rank(comm, &mpi_rank); /* * Initialize data buffer */ data = (int *) malloc(sizeof(int)*dimsf[0]* dimsf[1]); for (i=0; i < dimsf[0]*dimsf[1]; i++) { data[i] = mpi_rank; } /* * Set up file access property list with parallel I/O access */ plist_id = H5Pcreate(H5P_FILE_ACCESS); H5Pset_fapl_mpio(plist_id, comm, info); /* * Create a new file collectively and release property list identifier. */ file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id); H5Pclose(plist_id); /* * Create property list for collective dataset write. */ plist_id = H5Pcreate(H5P_DATASET_XFER); //H5Pset_dxpl_mpio(plist_id, H5FD_MPIO_COLLECTIVE); H5Pset_dxpl_mpio(plist_id, H5FD_MPIO_INDEPENDENT); /* * Create the dataspace for the dataset. */ filespace = H5Screate_simple(RANK, dimsf, NULL); for(i=0;i<mpi_size;++i) { MPI_Barrier(MPI_COMM_WORLD); sprintf(name,"node%d",i); dset_id = H5Dcreate(file_id, name, H5T_NATIVE_INT, filespace, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); H5Dclose(dset_id); MPI_Barrier(MPI_COMM_WORLD); } MPI_Barrier(MPI_COMM_WORLD); sprintf(name,"node%d",i); dset_id = H5Dopen(file_id, name, H5P_DEFAULT); status = H5Dwrite(dset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, plist_id, data); H5Dclose(dset_id); free(data); /* * Close/release resources. */ H5Sclose(filespace); H5Pclose(plist_id); H5Fclose(file_id); MPI_Finalize(); return 0; }
_______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
