ncdf4a13/libsrc/nc.c

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/*
 *      Copyright 1996, University Corporation for Atmospheric Research
 *      See netcdf/COPYRIGHT file for copying and redistribution conditions.
 */
/* $Id: nc.c,v 2.143 2006/01/28 20:01:19 ed Exp $ */

#include "nc.h"
#include "rnd.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "ncx.h"
#if defined(LOCKNUMREC) /* && _CRAYMPP */
#  include <mpp/shmem.h>
#  include <intrinsics.h>
#endif

/* list of open netcdf's */
static NC *NClist = NULL;

/* This is the default create format for nc_create and nc__create. */
int default_create_format = NC_FORMAT_CLASSIC;

/* These have to do with version numbers. */
#define MAGIC_NUM_LEN 4
#define VER_CLASSIC 1
#define VER_64BIT_OFFSET 2
#define VER_HDF5 3

static void
add_to_NCList(NC *ncp)
{
        assert(ncp != NULL);

        ncp->prev = NULL;
        if(NClist != NULL)
                NClist->prev = ncp;
        ncp->next = NClist;
        NClist = ncp;
}

static void
del_from_NCList(NC *ncp)
{
        assert(ncp != NULL);

        if(NClist == ncp)
        {
                assert(ncp->prev == NULL);
                NClist = ncp->next;
        }
        else
        {
                assert(ncp->prev != NULL);
                ncp->prev->next = ncp->next;
        }

        if(ncp->next != NULL)
                ncp->next->prev = ncp->prev;

        ncp->next = NULL;
        ncp->prev = NULL;
}


int
NC_check_id(int ncid, NC **ncpp)
{
        NC *ncp;

        if(ncid >= 0)
        {
                for(ncp = NClist; ncp != NULL; ncp = ncp->next)
                {
                        if(ncp->nciop->fd == ncid)
                        {
                                *ncpp = ncp;
                                return NC_NOERR; /* normal return */
                        }
                }
        }

        /* else, not found */
        return NC_EBADID;
}


static void
free_NC(NC *ncp)
{
        if(ncp == NULL)
                return;
        free_NC_dimarrayV(&ncp->dims);
        free_NC_attrarrayV(&ncp->attrs);
        free_NC_vararrayV(&ncp->vars);
#if _CRAYMPP && defined(LOCKNUMREC)
        shfree(ncp);
#else
        free(ncp);
#endif /* _CRAYMPP && LOCKNUMREC */
}


static NC *
new_NC(const size_t *chunkp)
{
        NC *ncp;

#if _CRAYMPP && defined(LOCKNUMREC)
        ncp = (NC *) shmalloc(sizeof(NC));
#else
        ncp = (NC *) malloc(sizeof(NC));
#endif /* _CRAYMPP && LOCKNUMREC */
        if(ncp == NULL)
                return NULL;
        (void) memset(ncp, 0, sizeof(NC));

        ncp->xsz = MIN_NC_XSZ;
        assert(ncp->xsz == ncx_len_NC(ncp,0));
        
        ncp->chunk = chunkp != NULL ? *chunkp : NC_SIZEHINT_DEFAULT;

        return ncp;
}


static NC *
dup_NC(const NC *ref)
{
        NC *ncp;

#if _CRAYMPP && defined(LOCKNUMREC)
        ncp = (NC *) shmalloc(sizeof(NC));
#else
        ncp = (NC *) malloc(sizeof(NC));
#endif /* _CRAYMPP && LOCKNUMREC */
        if(ncp == NULL)
                return NULL;
        (void) memset(ncp, 0, sizeof(NC));

        if(dup_NC_dimarrayV(&ncp->dims, &ref->dims) != NC_NOERR)
                goto err;
        if(dup_NC_attrarrayV(&ncp->attrs, &ref->attrs) != NC_NOERR)
                goto err;
        if(dup_NC_vararrayV(&ncp->vars, &ref->vars) != NC_NOERR)
                goto err;

        ncp->xsz = ref->xsz;
        ncp->begin_var = ref->begin_var;
        ncp->begin_rec = ref->begin_rec;
        ncp->recsize = ref->recsize;
        NC_set_numrecs(ncp, NC_get_numrecs(ref));
        return ncp;
err:
        free_NC(ncp);
        return NULL;
}


/*
 *  Verify that this is a user nc_type
 * Formerly
NCcktype()
 * Sense of the return is changed.
 */
int
nc_cktype(nc_type type)
{
        switch((int)type){
        case NC_BYTE:
        case NC_CHAR:
        case NC_SHORT:
        case NC_INT:
        case NC_FLOAT:
        case NC_DOUBLE:
                return(NC_NOERR);
        }
        return(NC_EBADTYPE);
}


/*
 * How many objects of 'type'
 * will fit into xbufsize?
 */
size_t
ncx_howmany(nc_type type, size_t xbufsize)
{
        switch(type){
        case NC_BYTE:
        case NC_CHAR:
                return xbufsize;
        case NC_SHORT:
                return xbufsize/X_SIZEOF_SHORT;
        case NC_INT:
                return xbufsize/X_SIZEOF_INT;
        case NC_FLOAT:
                return xbufsize/X_SIZEOF_FLOAT;
        case NC_DOUBLE:
                return xbufsize/X_SIZEOF_DOUBLE;
        }
        assert("ncx_howmany: Bad type" == 0);
        return(0);
}

#define D_RNDUP(x, align) _RNDUP(x, (off_t)(align))

/*
 * Compute each variable's 'begin' offset,
 * update 'begin_rec' as well.
 */
static int
NC_begins(NC *ncp,
        size_t h_minfree, size_t v_align,
        size_t v_minfree, size_t r_align)
{
        size_t ii;
        int sizeof_off_t;
        off_t index = 0;
        NC_var **vpp;
        NC_var *last = NULL;

        if(v_align == NC_ALIGN_CHUNK)
                v_align = ncp->chunk;
        if(r_align == NC_ALIGN_CHUNK)
                r_align = ncp->chunk;

        if (fIsSet(ncp->flags, NC_64BIT_OFFSET)) {
          sizeof_off_t = 8;
        } else {
          sizeof_off_t = 4;
        }
        
        ncp->xsz = ncx_len_NC(ncp,sizeof_off_t);

        if(ncp->vars.nelems == 0) 
                return NC_NOERR;

        /* only (re)calculate begin_var if there is not sufficient space in header
           or start of non-record variables is not aligned as requested by valign */
        if (ncp->begin_var < ncp->xsz + h_minfree ||
            ncp->begin_var != D_RNDUP(ncp->begin_var, v_align) ) 
        {
          index = (off_t) ncp->xsz;
          ncp->begin_var = D_RNDUP(index, v_align);
          if(ncp->begin_var < index + h_minfree)
          {
            ncp->begin_var = D_RNDUP(index + (off_t)h_minfree, v_align);
          }
        }
        index = ncp->begin_var;

        /* loop thru vars, first pass is for the 'non-record' vars */
        vpp = ncp->vars.value;
        for(ii = 0; ii < ncp->vars.nelems ; ii++, vpp++)
        {
                if( IS_RECVAR(*vpp) )
                {
                        /* skip record variables on this pass */
                        continue;
                }
#if 0
fprintf(stderr, "    VAR %d %s: %ld\n", ii, (*vpp)->name->cp, (long)index);
#endif
                if( sizeof_off_t == 4 && (index > X_OFF_MAX || index < 0) ) 
                {
                    return NC_EVARSIZE;
                }
                (*vpp)->begin = index;
                index += (*vpp)->len;
        }

        /* only (re)calculate begin_rec if there is not sufficient
           space at end of non-record variables or if start of record
           variables is not aligned as requested by r_align */
        if (ncp->begin_rec < index + v_minfree ||
            ncp->begin_rec != D_RNDUP(ncp->begin_rec, r_align) )
        {
          ncp->begin_rec = D_RNDUP(index, r_align);
          if(ncp->begin_rec < index + v_minfree)
          {
            ncp->begin_rec = D_RNDUP(index + (off_t)v_minfree, r_align);
          }
        }
        index = ncp->begin_rec;

        ncp->recsize = 0;

        /* loop thru vars, second pass is for the 'record' vars */
        vpp = (NC_var **)ncp->vars.value;
        for(ii = 0; ii < ncp->vars.nelems; ii++, vpp++)
        {
                if( !IS_RECVAR(*vpp) )
                {
                        /* skip non-record variables on this pass */
                        continue;
                }

#if 0
fprintf(stderr, "    REC %d %s: %ld\n", ii, (*vpp)->name->cp, (long)index);
#endif
                if( sizeof_off_t == 4 && (index > X_OFF_MAX || index < 0) ) 
                {
                    return NC_EVARSIZE;
                }
                (*vpp)->begin = index;
                index += (*vpp)->len;
                /* check if record size must fit in 32-bits */
#if SIZEOF_OFF_T == SIZEOF_SIZE_T && SIZEOF_SIZE_T == 4
                if( ncp->recsize > X_UINT_MAX - (*vpp)->len )
                {
                    return NC_EVARSIZE;
                }
#endif
                ncp->recsize += (*vpp)->len;
                last = (*vpp);
        }

        /*
         * for special case of exactly one record variable, pack value
         */
        if(last != NULL && ncp->recsize == last->len)
                ncp->recsize = *last->dsizes * last->xsz;

        if(NC_IsNew(ncp))
                NC_set_numrecs(ncp, 0);
        return NC_NOERR;
}


/*
 * Read just the numrecs member.
 * (A relatively expensive way to do things.)
 */
int
read_numrecs(NC *ncp)
{
        int status = NC_NOERR;
        const void *xp = NULL;
        size_t nrecs = NC_get_numrecs(ncp);

        assert(!NC_indef(ncp));

#define NC_NUMRECS_OFFSET 4
#define NC_NUMRECS_EXTENT 4
        status = ncp->nciop->get(ncp->nciop,
                 NC_NUMRECS_OFFSET, NC_NUMRECS_EXTENT, 0, (void **)&xp);
                                        /* cast away const */
        if(status != NC_NOERR)
                return status;

        status = ncx_get_size_t(&xp, &nrecs);

        (void) ncp->nciop->rel(ncp->nciop, NC_NUMRECS_OFFSET, 0);

        if(status == NC_NOERR)
        {
                NC_set_numrecs(ncp, nrecs);
                fClr(ncp->flags, NC_NDIRTY);
        }

        return status;
}


/*
 * Write out just the numrecs member.
 * (A relatively expensive way to do things.)
 */
int
write_numrecs(NC *ncp)
{
        int status = NC_NOERR;
        void *xp = NULL;

        assert(!NC_readonly(ncp));
        assert(!NC_indef(ncp));

        status = ncp->nciop->get(ncp->nciop,
                 NC_NUMRECS_OFFSET, NC_NUMRECS_EXTENT, RGN_WRITE, &xp);
        if(status != NC_NOERR)
                return status;

        {
                const size_t nrecs = NC_get_numrecs(ncp);
                status = ncx_put_size_t(&xp, &nrecs);
        }

        (void) ncp->nciop->rel(ncp->nciop, NC_NUMRECS_OFFSET, RGN_MODIFIED);

        if(status == NC_NOERR)
                fClr(ncp->flags, NC_NDIRTY);

        return status;
}


/*
 * Read in the header
 * It is expensive.
 */
static int
read_NC(NC *ncp)
{
        int status = NC_NOERR;

        free_NC_dimarrayV(&ncp->dims);
        free_NC_attrarrayV(&ncp->attrs);
        free_NC_vararrayV(&ncp->vars);

        status = nc_get_NC(ncp);

        if(status == NC_NOERR)
                fClr(ncp->flags, NC_NDIRTY | NC_HDIRTY);

        return status;
}


/*
 * Write out the header
 */
static int
write_NC(NC *ncp)
{
        int status = NC_NOERR;

        assert(!NC_readonly(ncp));

        status = ncx_put_NC(ncp, NULL, 0, 0);

        if(status == NC_NOERR)
                fClr(ncp->flags, NC_NDIRTY | NC_HDIRTY);

        return status;
}


/*
 * Write the header or the numrecs if necessary.
 */
int
NC_sync(NC *ncp)
{
        assert(!NC_readonly(ncp));

        if(NC_hdirty(ncp))
        {
                return write_NC(ncp);
        }
        /* else */

        if(NC_ndirty(ncp))
        {
                return write_numrecs(ncp);
        }
        /* else */

        return NC_NOERR;
}


/*
 * Initialize the 'non-record' variables.
 */
static int
fillerup(NC *ncp)
{
        int status = NC_NOERR;
        size_t ii;
        NC_var **varpp;

        assert(!NC_readonly(ncp));
        assert(NC_dofill(ncp));

        /* loop thru vars */
        varpp = ncp->vars.value;
        for(ii = 0; ii < ncp->vars.nelems; ii++, varpp++)
        {
                if(IS_RECVAR(*varpp))
                {
                        /* skip record variables */
                        continue;
                }

                status = fill_NC_var(ncp, *varpp, 0);
                if(status != NC_NOERR)
                        break;
        }
        return status;
}

/* Begin endef */

/*
 */
static int
fill_added_recs(NC *gnu, NC *old)
{
        NC_var ** const gnu_varpp = (NC_var **)gnu->vars.value;

        const int old_nrecs = (int) NC_get_numrecs(old);
        int recno = 0;
        for(; recno < old_nrecs; recno++)
        {
                int varid = (int)old->vars.nelems;
                for(; varid < (int)gnu->vars.nelems; varid++)
                {
                        const NC_var *const gnu_varp = *(gnu_varpp + varid);
                        if(!IS_RECVAR(gnu_varp))
                        {
                                /* skip non-record variables */
                                continue;
                        }
                        /* else */
                        {
                        const int status = fill_NC_var(gnu, gnu_varp, recno);
                        if(status != NC_NOERR)
                                return status;
                        }
                }
        }

        return NC_NOERR;
}

/*
 */
static int
fill_added(NC *gnu, NC *old)
{
        NC_var ** const gnu_varpp = (NC_var **)gnu->vars.value;
        int varid = (int)old->vars.nelems;

        for(; varid < (int)gnu->vars.nelems; varid++)
        {
                const NC_var *const gnu_varp = *(gnu_varpp + varid);
                if(IS_RECVAR(gnu_varp))
                {
                        /* skip record variables */
                        continue;
                }
                /* else */
                {
                const int status = fill_NC_var(gnu, gnu_varp, 0);
                if(status != NC_NOERR)
                        return status;
                }
        }

        return NC_NOERR;
}


/*
 * Move the records "out". 
 * Fill as needed.
 */
static int
move_recs_r(NC *gnu, NC *old)
{
        int status;
        int recno;
        int varid;
        NC_var **gnu_varpp = (NC_var **)gnu->vars.value;
        NC_var **old_varpp = (NC_var **)old->vars.value;
        NC_var *gnu_varp;
        NC_var *old_varp;
        off_t gnu_off;
        off_t old_off;
        const size_t old_nrecs = NC_get_numrecs(old);
        
        /* Don't parallelize this loop */
        for(recno = (int)old_nrecs -1; recno >= 0; recno--)
        {
        /* Don't parallelize this loop */
        for(varid = (int)old->vars.nelems -1; varid >= 0; varid--)
        {
                gnu_varp = *(gnu_varpp + varid);
                if(!IS_RECVAR(gnu_varp))
                {
                        /* skip non-record variables on this pass */
                        continue;
                }
                /* else */

                /* else, a pre-existing variable */
                old_varp = *(old_varpp + varid);
                gnu_off = gnu_varp->begin + (off_t)(gnu->recsize * recno);
                old_off = old_varp->begin + (off_t)(old->recsize * recno);

                if(gnu_off == old_off)
                        continue;       /* nothing to do */

                assert(gnu_off > old_off);
        
                status = gnu->nciop->move(gnu->nciop, gnu_off, old_off,
                         old_varp->len, 0);

                if(status != NC_NOERR)
                        return status;
                
        }
        }

        NC_set_numrecs(gnu, old_nrecs);

        return NC_NOERR;
}


/*
 * Move the "non record" variables "out". 
 * Fill as needed.
 */
static int
move_vars_r(NC *gnu, NC *old)
{
        int status;
        int varid;
        NC_var **gnu_varpp = (NC_var **)gnu->vars.value;
        NC_var **old_varpp = (NC_var **)old->vars.value;
        NC_var *gnu_varp;
        NC_var *old_varp;
        off_t gnu_off;
        off_t old_off;
        
        /* Don't parallelize this loop */
        for(varid = (int)old->vars.nelems -1;
                 varid >= 0; varid--)
        {
                gnu_varp = *(gnu_varpp + varid);
                if(IS_RECVAR(gnu_varp))
                {
                        /* skip record variables on this pass */
                        continue;
                }
                /* else */

                old_varp = *(old_varpp + varid);
                gnu_off = gnu_varp->begin;
                old_off = old_varp->begin;
        
                if(gnu_off == old_off)
                        continue;       /* nothing to do */

                assert(gnu_off > old_off);

                status = gnu->nciop->move(gnu->nciop, gnu_off, old_off,
                         old_varp->len, 0);

                if(status != NC_NOERR)
                        return status;
                
        }

        return NC_NOERR;
}


/*
 * Given a valid ncp, return NC_EVARSIZE if any variable has a bad len 
 * (product of non-rec dim sizes too large), else return NC_NOERR.
 */
static int
NC_check_vlens(NC *ncp)
{
    NC_var **vpp;
    /* maximum permitted variable size (or size of one record's worth
       of a record variable) in bytes.  This is different for format 1
       and format 2. */
    size_t vlen_max;
    size_t ii;
    size_t large_vars_count;
    size_t rec_vars_count;
    int last;

    if(ncp->vars.nelems == 0) 
        return NC_NOERR;

    if ((ncp->flags & NC_64BIT_OFFSET) && sizeof(off_t) > 4) {
        /* CDF2 format and LFS */
        vlen_max = X_UINT_MAX - 3; /* "- 3" handles rounded-up size */
    } else {
        /* CDF1 format */
        vlen_max = X_INT_MAX - 3;
    }
    /* Loop through vars, first pass is for non-record variables.   */
    large_vars_count = 0;
    rec_vars_count = 0;
    vpp = ncp->vars.value;
    for (ii = 0; ii < ncp->vars.nelems; ii++, vpp++) {
        if( !IS_RECVAR(*vpp) ) {
            last = 0;
            if( NC_check_vlen(*vpp, vlen_max) == 0 ) {
                large_vars_count++;
                last = 1;
            }
        } else {
          rec_vars_count++;
        }
    }
    /* OK if last non-record variable size too large, since not used to 
       compute an offset */
    if( large_vars_count > 1) { /* only one "too-large" variable allowed */
      return NC_EVARSIZE;
    }
    /* and it has to be the last one */ 
    if( large_vars_count == 1 && last == 0) { 
      return NC_EVARSIZE;
    }
    if( rec_vars_count > 0 ) {
        /* and if it's the last one, there can't be any record variables */
        if( large_vars_count == 1 && last == 1) {
            return NC_EVARSIZE;
        }
        /* Loop through vars, second pass is for record variables.   */
        large_vars_count = 0;
        vpp = ncp->vars.value;
        for (ii = 0; ii < ncp->vars.nelems; ii++, vpp++) {
            if( IS_RECVAR(*vpp) ) {
                last = 0;
                if( NC_check_vlen(*vpp, vlen_max) == 0 ) {
                    large_vars_count++;
                    last = 1;
                }
            }
        }
        /* OK if last record variable size too large, since not used to 
           compute an offset */
        if( large_vars_count > 1) { /* only one "too-large" variable allowed */
            return NC_EVARSIZE;
        }
        /* and it has to be the last one */ 
        if( large_vars_count == 1 && last == 0) { 
            return NC_EVARSIZE;
        }
    }
    return NC_NOERR;
}


/*
 *  End define mode.
 *  Common code for ncendef, ncclose(endef)
 *  Flushes I/O buffers.
 */
static int
NC_endef(NC *ncp,
        size_t h_minfree, size_t v_align,
        size_t v_minfree, size_t r_align)
{
        int status = NC_NOERR;

        assert(!NC_readonly(ncp));
        assert(NC_indef(ncp));

        status = NC_check_vlens(ncp);
        if(status != NC_NOERR)
            return status;
        status = NC_begins(ncp, h_minfree, v_align, v_minfree, r_align);
        if(status != NC_NOERR)
            return status;

        if(ncp->old != NULL)
        {
                /* a plain redef, not a create */
                assert(!NC_IsNew(ncp));
                assert(fIsSet(ncp->flags, NC_INDEF));
                assert(ncp->begin_rec >= ncp->old->begin_rec);
                assert(ncp->begin_var >= ncp->old->begin_var);

                if(ncp->vars.nelems != 0)
                {
                if(ncp->begin_rec > ncp->old->begin_rec)
                {
                        status = move_recs_r(ncp, ncp->old);
                        if(status != NC_NOERR)
                                return status;
                        if(ncp->begin_var > ncp->old->begin_var)
                        {
                                status = move_vars_r(ncp, ncp->old);
                                if(status != NC_NOERR)
                                        return status;
                        } 
                        /* else if (ncp->begin_var == ncp->old->begin_var) { NOOP } */
                }
                else
                {       /* Even if (ncp->begin_rec == ncp->old->begin_rec)
                           and     (ncp->begin_var == ncp->old->begin_var)
                           might still have added a new record variable */
                        if(ncp->recsize > ncp->old->recsize)
                        {
                                status = move_recs_r(ncp, ncp->old);
                                if(status != NC_NOERR)
                                      return status;
                        }
                }
                }
        }

        status = write_NC(ncp);
        if(status != NC_NOERR)
                return status;

        if(NC_dofill(ncp))
        {
                if(NC_IsNew(ncp))
                {
                        status = fillerup(ncp);
                        if(status != NC_NOERR)
                                return status;
                        
                }
                else if(ncp->vars.nelems > ncp->old->vars.nelems)
                {
                        status = fill_added(ncp, ncp->old);
                        if(status != NC_NOERR)
                                return status;
                        status = fill_added_recs(ncp, ncp->old);
                        if(status != NC_NOERR)
                                return status;
                }
        }

        if(ncp->old != NULL)
        {
                free_NC(ncp->old);
                ncp->old = NULL;
        }

        fClr(ncp->flags, NC_CREAT | NC_INDEF);

        return ncp->nciop->sync(ncp->nciop);
}

#ifdef LOCKNUMREC
static int
NC_init_pe(NC *ncp, int basepe) {
        if (basepe < 0 || basepe >= _num_pes()) {
                return NC_EINVAL; /* invalid base pe */
        }
        /* initialize common values */
        ncp->lock[LOCKNUMREC_VALUE] = 0;
        ncp->lock[LOCKNUMREC_LOCK] = 0;
        ncp->lock[LOCKNUMREC_SERVING] = 0;
        ncp->lock[LOCKNUMREC_BASEPE] =  basepe;
        return NC_NOERR;
}
#endif


/*
 * Compute the expected size of the file.
 */
int
NC_calcsize(NC *ncp, off_t *calcsizep)
{
        NC_var **vpp = (NC_var **)ncp->vars.value;
        NC_var *const *const end = &vpp[ncp->vars.nelems];
        NC_var *last_fix = NULL;        /* last "non-record" var */
        NC_var *last_rec = NULL;        /* last "record" var */
        /*NC_var *last_var;*/
        int status;
        int numrecvars = 0;     /* number of record variables */

        if(ncp->vars.nelems == 0) { /* no non-record variables and 
                                       no record variables */
            *calcsizep = ncp->xsz; /* size of header */
            return NC_NOERR;
        }

        for( /*NADA*/; vpp < end; vpp++) {
            status = NC_var_shape(*vpp, &ncp->dims);
            if(status != NC_NOERR)
                return status;
            if(IS_RECVAR(*vpp)) {
                last_rec = *vpp;
                numrecvars++;
            } else {
                last_fix = *vpp;
            }
        }

        if(numrecvars == 0) {
            assert(last_fix != NULL);
            *calcsizep = last_fix->begin + last_fix->len;
            /*last_var = last_fix;*/
        } else {       /* we have at least one record variable */
            *calcsizep = ncp->begin_rec + ncp->numrecs * ncp->recsize;
            /*last_var = last_rec;*/
        }

        return NC_NOERR;
}

/* Public */

int
nc__create(const char * path, int ioflags, size_t initialsz,
        size_t *chunksizehintp, int *ncid_ptr)
{
        return nc__create_mp(path, ioflags, initialsz, 0,
                chunksizehintp, ncid_ptr);
}

int
nc__create_mp(const char * path, int ioflags, size_t initialsz, int basepe,
        size_t *chunksizehintp, int *ncid_ptr)
{
        NC *ncp;
        int status;
        void *xp = NULL;
        int sizeof_off_t = 0;

#if ALWAYS_NC_SHARE /* DEBUG */
        fSet(ioflags, NC_SHARE);
#endif

        ncp = new_NC(chunksizehintp);
        if(ncp == NULL)
                return NC_ENOMEM;

#if defined(LOCKNUMREC) /* && _CRAYMPP */
        if (status = NC_init_pe(ncp, basepe)) {
                return status;
        }
#else
        /*
         * !_CRAYMPP, only pe 0 is valid
         */
        if(basepe != 0)
                return NC_EINVAL;
#endif

        assert(ncp->flags == 0);

        /* Apply default create format. */
        if (default_create_format == NC_FORMAT_64BIT)
          ioflags |= NC_64BIT_OFFSET;

        if (fIsSet(ioflags, NC_64BIT_OFFSET)) {
          fSet(ncp->flags, NC_64BIT_OFFSET);
          sizeof_off_t = 8;
        } else {
          sizeof_off_t = 4;
        }

        assert(ncp->xsz == ncx_len_NC(ncp,sizeof_off_t));
        
        status = ncio_create(path, ioflags,
                initialsz,
                0, ncp->xsz, &ncp->chunk,
                &ncp->nciop, &xp);
        if(status != NC_NOERR)
        {
                /* translate error status */
                if(status == EEXIST)
                        status = NC_EEXIST;
                goto unwind_alloc;
        }

        fSet(ncp->flags, NC_CREAT);

        if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
        {
                /*
                 * NC_SHARE implies sync up the number of records as well.
                 * (File format version one.)
                 * Note that other header changes are not shared
                 * automatically.  Some sort of IPC (external to this package)
                 * would be used to trigger a call to nc_sync().
                 */
                fSet(ncp->flags, NC_NSYNC);
        }

        status = ncx_put_NC(ncp, &xp, sizeof_off_t, ncp->xsz);
        if(status != NC_NOERR)
                goto unwind_ioc;

        add_to_NCList(ncp);

        if(chunksizehintp != NULL)
                *chunksizehintp = ncp->chunk;
        *ncid_ptr = ncp->nciop->fd;
        return NC_NOERR;

unwind_ioc:
        (void) ncio_close(ncp->nciop, 1); /* N.B.: unlink */
        ncp->nciop = NULL;
        /*FALLTHRU*/
unwind_alloc:
        free_NC(ncp);
        return status;
}

/* This function sets a default create flag that will be logically
   or'd to whatever flags are passed into nc_create for all future
   calls to nc_create.
   Valid default create flags are NC_64BIT_OFFSET, NC_CLOBBER,
   NC_LOCK, NC_SHARE. */
int
nc_set_default_format(int format, int *old_formatp)
{
    /* Return existing format if desired. */
    if (old_formatp)
      *old_formatp = default_create_format;

    /* Make sure only valid format is set. */
#ifdef USE_NETCDF4
    if (format != NC_FORMAT_CLASSIC && format != NC_FORMAT_64BIT &&
        format != NC_FORMAT_NETCDF4 && format != NC_FORMAT_NETCDF4_CLASSIC)
      return NC_EINVAL;
#else
    if (format != NC_FORMAT_CLASSIC && format != NC_FORMAT_64BIT)
      return NC_EINVAL;
#endif
    default_create_format = format;
    return NC_NOERR;
}

int
nc_create(const char * path, int ioflags, int *ncid_ptr)
{
        return nc__create(path, ioflags, 0, NULL, ncid_ptr);
}

int
nc__open(const char * path, int ioflags,
        size_t *chunksizehintp, int *ncid_ptr)
{
        return nc__open_mp(path, ioflags, 0,
                chunksizehintp, ncid_ptr);
}

int
nc__open_mp(const char * path, int ioflags, int basepe,
        size_t *chunksizehintp, int *ncid_ptr)
{
        NC *ncp;
        int status;

#if ALWAYS_NC_SHARE /* DEBUG */
        fSet(ioflags, NC_SHARE);
#endif

        ncp = new_NC(chunksizehintp);
        if(ncp == NULL)
                return NC_ENOMEM;

#if defined(LOCKNUMREC) /* && _CRAYMPP */
        if (status = NC_init_pe(ncp, basepe)) {
                return status;
        }
#else
        /*
         * !_CRAYMPP, only pe 0 is valid
         */
        if(basepe != 0)
                return NC_EINVAL;
#endif

        status = ncio_open(path, ioflags,
                0, 0, &ncp->chunk,
                &ncp->nciop, 0);
        if(status)
                goto unwind_alloc;

        assert(ncp->flags == 0);

        if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
        {
                /*
                 * NC_SHARE implies sync up the number of records as well.
                 * (File format version one.)
                 * Note that other header changes are not shared
                 * automatically.  Some sort of IPC (external to this package)
                 * would be used to trigger a call to nc_sync().
                 */
                fSet(ncp->flags, NC_NSYNC);
        }

        status = nc_get_NC(ncp);
        if(status != NC_NOERR)
                goto unwind_ioc;

        add_to_NCList(ncp);

        if(chunksizehintp != NULL)
                *chunksizehintp = ncp->chunk;
        *ncid_ptr = ncp->nciop->fd;
        return NC_NOERR;

unwind_ioc:
        (void) ncio_close(ncp->nciop, 0);
        ncp->nciop = NULL;
        /*FALLTHRU*/
unwind_alloc:
        free_NC(ncp);
        return status;
}

int
nc_open(const char * path, int ioflags, int *ncid_ptr)
{
        return nc__open(path, ioflags, NULL, ncid_ptr);
}


int
nc__enddef(int ncid,
        size_t h_minfree, size_t v_align,
        size_t v_minfree, size_t r_align)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(!NC_indef(ncp))
                return(NC_ENOTINDEFINE);

        return (NC_endef(ncp, h_minfree, v_align, v_minfree, r_align));
}

int
nc_enddef(int ncid)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(!NC_indef(ncp))
                return(NC_ENOTINDEFINE);

        /* return(NC_endef(ncp, 0, 4096, 0, 4096)); */
        return (NC_endef(ncp, 0, 1, 0, 1));
}


int
nc_close(int ncid)
{
        int status = NC_NOERR;
        NC *ncp; 

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(NC_indef(ncp))
        {
                status = NC_endef(ncp, 0, 1, 0, 1); /* TODO: defaults */
                if(status != NC_NOERR )
                {
                        (void) nc_abort(ncid);
                        return status;
                }
        }
        else if(!NC_readonly(ncp))
        {
                status = NC_sync(ncp);
        }

        /* 
         * If file opened for writing and file size is different from
         * what it should be (due to previous use of NOFILL mode),
         * change it to correct size, as reported by NC_calcsize().
         */
        {
            off_t filesize;     /* current size of open file */
            off_t calcsize;     /* calculated file size, from header */
            status = ncio_filesize(ncp->nciop, &filesize);
            if(status != ENOERR)
                return status;
            status = NC_calcsize(ncp, &calcsize);
            if(status != NC_NOERR)
                return status;
            if(filesize < calcsize && !NC_readonly(ncp)) {
                status = ncio_pad_length(ncp->nciop, calcsize);
                if(status != ENOERR)
                    return status;
            }
            
        }

        (void) ncio_close(ncp->nciop, 0);
        ncp->nciop = NULL;

        del_from_NCList(ncp);

        free_NC(ncp);

        return status;
}


int
nc_delete(const char * path)
{
        return nc_delete_mp(path, 0);
}

int
nc_delete_mp(const char * path, int basepe)
{
        NC *ncp;
        int status;
        size_t chunk = 512;

        ncp = new_NC(&chunk);
        if(ncp == NULL)
                return NC_ENOMEM;
        
#if defined(LOCKNUMREC) /* && _CRAYMPP */
        if (status = NC_init_pe(ncp, basepe)) {
                return status;
        }
#else
        /*
         * !_CRAYMPP, only pe 0 is valid
         */
        if(basepe != 0)
                return NC_EINVAL;
#endif
        status = ncio_open(path, NC_NOWRITE,
                0, 0, &ncp->chunk,
                &ncp->nciop, 0);
        if(status)
                goto unwind_alloc;

        assert(ncp->flags == 0);

        status = nc_get_NC(ncp);
        if(status != NC_NOERR)
        {
                /* Not a netcdf file, don't delete */
                /* ??? is this the right semantic? what if it was just too big? */
                (void) ncio_close(ncp->nciop, 0);
        }
        else
        {
                /* ncio_close does the unlink */
                status = ncio_close(ncp->nciop, 1); /* ncio_close does the unlink */
        }

        ncp->nciop = NULL;
unwind_alloc:
        free_NC(ncp);
        return status;
}


/*
 * In data mode, same as ncclose.
 * In define mode, restore previous definition.
 * In create, remove the file.
 */
int
nc_abort(int ncid)
{
        int status;
        NC *ncp;
        int doUnlink = 0;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        doUnlink = NC_IsNew(ncp);

        if(ncp->old != NULL)
        {
                /* a plain redef, not a create */
                assert(!NC_IsNew(ncp));
                assert(fIsSet(ncp->flags, NC_INDEF));
                free_NC(ncp->old);
                ncp->old = NULL;
                fClr(ncp->flags, NC_INDEF);
        }
        else if(!NC_readonly(ncp))
        {
                status = NC_sync(ncp);
                if(status != NC_NOERR)
                        return status;
        }


        (void) ncio_close(ncp->nciop, doUnlink);
        ncp->nciop = NULL;

        del_from_NCList(ncp);

        free_NC(ncp);

        return NC_NOERR;
}


int
nc_redef(int ncid)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(NC_readonly(ncp))
                return NC_EPERM;

        if(NC_indef(ncp))
                return NC_EINDEFINE;

        
        if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
        {
                /* read in from disk */
                status = read_NC(ncp);
                if(status != NC_NOERR)
                        return status;
        }

        ncp->old = dup_NC(ncp);
        if(ncp->old == NULL)
                return NC_ENOMEM;

        fSet(ncp->flags, NC_INDEF);

        return NC_NOERR;
}


int
nc_inq(int ncid,
        int *ndimsp,
        int *nvarsp,
        int *nattsp,
        int *xtendimp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(ndimsp != NULL)
                *ndimsp = (int) ncp->dims.nelems;
        if(nvarsp != NULL)
                *nvarsp = (int) ncp->vars.nelems;
        if(nattsp != NULL)
                *nattsp = (int) ncp->attrs.nelems;
        if(xtendimp != NULL)
                *xtendimp = find_NC_Udim(&ncp->dims, NULL);

        return NC_NOERR;
}

int 
nc_inq_ndims(int ncid, int *ndimsp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(ndimsp != NULL)
                *ndimsp = (int) ncp->dims.nelems;

        return NC_NOERR;
}

int 
nc_inq_nvars(int ncid, int *nvarsp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(nvarsp != NULL)
                *nvarsp = (int) ncp->vars.nelems;

        return NC_NOERR;
}

int 
nc_inq_natts(int ncid, int *nattsp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(nattsp != NULL)
                *nattsp = (int) ncp->attrs.nelems;

        return NC_NOERR;
}

int 
nc_inq_unlimdim(int ncid, int *xtendimp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(xtendimp != NULL)
                *xtendimp = find_NC_Udim(&ncp->dims, NULL);

        return NC_NOERR;
}


int
nc_sync(int ncid)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(NC_indef(ncp))
                return NC_EINDEFINE;

        if(NC_readonly(ncp))
        {
                return read_NC(ncp);
        }
        /* else, read/write */

        status = NC_sync(ncp);
        if(status != NC_NOERR)
                return status;

        return ncp->nciop->sync(ncp->nciop);
}


int
nc_set_fill(int ncid,
        int fillmode, int *old_mode_ptr)
{
        int status;
        NC *ncp;
        int oldmode;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        if(NC_readonly(ncp))
                return NC_EPERM;

        oldmode = fIsSet(ncp->flags, NC_NOFILL) ? NC_NOFILL : NC_FILL;

        if(fillmode == NC_NOFILL)
        {
                fSet(ncp->flags, NC_NOFILL);
        }
        else if(fillmode == NC_FILL)
        {
                if(fIsSet(ncp->flags, NC_NOFILL))
                {
                        /*
                         * We are changing back to fill mode
                         * so do a sync
                         */
                        status = NC_sync(ncp);
                        if(status != NC_NOERR)
                                return status;
                }
                fClr(ncp->flags, NC_NOFILL);
        }
        else
        {
                return NC_EINVAL; /* Invalid fillmode */
        }

        if(old_mode_ptr != NULL)
                *old_mode_ptr = oldmode;

        return NC_NOERR;
}

#ifdef LOCKNUMREC

/* create function versions of the NC_*_numrecs macros */
size_t NC_get_numrecs(const NC *ncp) {
        shmem_t numrec;
        shmem_short_get(&numrec, (shmem_t *) ncp->lock + LOCKNUMREC_VALUE, 1,
                ncp->lock[LOCKNUMREC_BASEPE]);
        return (size_t) numrec;
}

void NC_set_numrecs(NC *ncp, size_t nrecs) {
        shmem_t numrec = (shmem_t) nrecs;
        /* update local value too */
        ncp->lock[LOCKNUMREC_VALUE] = (ushmem_t) numrec;
        shmem_short_put((shmem_t *) ncp->lock + LOCKNUMREC_VALUE, &numrec, 1,
                ncp->lock[LOCKNUMREC_BASEPE]);
}

void NC_increase_numrecs(NC *ncp, size_t nrecs) {
        /* this is only called in one place that's already protected
         * by a lock ... so don't worry about it */
        if (nrecs > NC_get_numrecs(ncp))
                NC_set_numrecs(ncp, nrecs);
}

#endif /* LOCKNUMREC */

/* everyone in communicator group will be executing this */
/*ARGSUSED*/
int
nc_set_base_pe(int ncid, int pe)
{
#if _CRAYMPP && defined(LOCKNUMREC)
        int status;
        NC *ncp;
        shmem_t numrecs;

        if ((status = NC_check_id(ncid, &ncp)) != NC_NOERR) {
                return status;
        }
        if (pe < 0 || pe >= _num_pes()) {
                return NC_EINVAL; /* invalid base pe */
        }

        numrecs = (shmem_t) NC_get_numrecs(ncp);

        ncp->lock[LOCKNUMREC_VALUE] = (ushmem_t) numrecs;

        /* update serving & lock values for a "smooth" transition */
        /* note that the "real" server will being doing this as well */
        /* as all the rest in the group */
        /* must have syncronization before & after this step */
        shmem_short_get(
                (shmem_t *) ncp->lock + LOCKNUMREC_SERVING,
                (shmem_t *) ncp->lock + LOCKNUMREC_SERVING,
                1, ncp->lock[LOCKNUMREC_BASEPE]);

        shmem_short_get(
                (shmem_t *) ncp->lock + LOCKNUMREC_LOCK,
                (shmem_t *) ncp->lock + LOCKNUMREC_LOCK,
                1, ncp->lock[LOCKNUMREC_BASEPE]);

        /* complete transition */
        ncp->lock[LOCKNUMREC_BASEPE] = (ushmem_t) pe;

#endif /* _CRAYMPP && LOCKNUMREC */
        return NC_NOERR;
}

/*ARGSUSED*/
int
nc_inq_base_pe(int ncid, int *pe)
{
#if _CRAYMPP && defined(LOCKNUMREC)
        int status;
        NC *ncp;

        if ((status = NC_check_id(ncid, &ncp)) != NC_NOERR) {
                return status;
        }

        *pe = (int) ncp->lock[LOCKNUMREC_BASEPE];
#else
        /*
         * !_CRAYMPP, only pe 0 is valid
         */
        *pe = 0;
#endif /* _CRAYMPP && LOCKNUMREC */
        return NC_NOERR;
}

int
nc_inq_format(int ncid, int *formatp)
{
        int status;
        NC *ncp;

        status = NC_check_id(ncid, &ncp); 
        if(status != NC_NOERR)
                return status;

        /* only need to check for netCDF-3 variants, since this is never called for netCDF-4 
           files */
        *formatp = fIsSet(ncp->flags, NC_64BIT_OFFSET) ? NC_FORMAT_64BIT 
            : NC_FORMAT_CLASSIC; 
        return NC_NOERR;
}

---