diff options
Diffstat (limited to 'src/H5MF.c')
| -rw-r--r-- | src/H5MF.c | 155 |
1 files changed, 134 insertions, 21 deletions
@@ -11,10 +11,13 @@ * Purpose: File memory management functions. * * Modifications: - * * Robb Matzke, 5 Aug 1997 * Added calls to H5E. * + * Robb Matzke, 8 Jun 1998 + * Implemented a very simple free list which is not persistent and which + * is lossy. + * *------------------------------------------------------------------------- */ #include <H5private.h> @@ -27,6 +30,7 @@ /* Is the interface initialized? */ static intn interface_initialize_g = FALSE; #define INTERFACE_INIT NULL + /*------------------------------------------------------------------------- * Function: H5MF_alloc @@ -53,7 +57,12 @@ static intn interface_initialize_g = FALSE; herr_t H5MF_alloc(H5F_t *f, intn op, hsize_t size, haddr_t *addr/*out*/) { - haddr_t tmp_addr; + haddr_t tmp_addr; + intn i, found, status; + hsize_t n; + H5MF_free_t blk; + hsize_t thresh = f->shared->access_parms->threshold; + hsize_t align = f->shared->access_parms->alignment; FUNC_ENTER(H5MF_alloc, FAIL); @@ -63,30 +72,114 @@ H5MF_alloc(H5F_t *f, intn op, hsize_t size, haddr_t *addr/*out*/) assert(size > 0); assert(addr); +#if 0 + HDfprintf (stderr, "A %Hu\n", size); +#endif + + /* Fail if we don't have write access */ if (0==(f->intent & H5F_ACC_RDWR)) { HRETURN_ERROR (H5E_RESOURCE, H5E_CANTINIT, FAIL, "file is read-only"); } /* - * Eventually we'll maintain a free list(s) and try to satisfy requests - * from there. But for now we just allocate more memory from the end of - * the file. + * Try to satisfy the request from the free list. We prefer exact matches + * to partial matches, so if we find an exact match then we break out of + * the loop immediately, otherwise we keep looking for an exact match. */ - if (H5F_low_extend(f->shared->lf, f->shared->access_parms, op, - size, addr/*out*/) < 0) { - HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, - "low level mem management failed"); + for (i=0, found=-1; i<f->shared->fl_nfree; i++) { + if ((status=H5F_low_alloc(f->shared->lf, op, align, thresh, size, + f->shared->fl_free+i, addr/*out*/))>0) { + /* Exact match found */ + found = i; + break; + } else if (0==status) { + /* Partial match */ + found = i; + } } - /* Convert from absolute to relative */ - addr->offset -= f->shared->base_addr.offset; - - /* Did we extend the size of the hdf5 data? */ - tmp_addr = *addr; - H5F_addr_inc(&tmp_addr, size); - if (H5F_addr_gt(&tmp_addr, &(f->shared->hdf5_eof))) { - f->shared->hdf5_eof = tmp_addr; + + if (found>=0 && + (status=H5F_low_alloc (f->shared->lf, op, align, thresh, size, + f->shared->fl_free+found, addr/*out*/))>0) { + /* + * We found an exact match. Remove that block from the free list and + * use it to satisfy the request. + */ + --(f->shared->fl_nfree); + HDmemmove (f->shared->fl_free+found, f->shared->fl_free+found+1, + (f->shared->fl_nfree-found) * sizeof(H5MF_free_t)); + + } else if (found>=0 && status==0) { + /* + * We found a free block which is larger than the requested size. + * Return the unused parts of the free block to the free list. + */ + blk = f->shared->fl_free[found]; + --f->shared->fl_nfree; + HDmemmove (f->shared->fl_free+found, f->shared->fl_free+found+1, + (f->shared->fl_nfree-found) * sizeof(H5MF_free_t)); + if (H5F_addr_gt (addr, &(blk.addr))) { + /* Free the first part of the free block */ + n = addr->offset - blk.addr.offset; + H5MF_free (f, &(blk.addr), n); + blk.addr = *addr; + blk.size -= n; + } + + if (blk.size > size) { + /* Free the second part of the free block */ + H5F_addr_inc (&(blk.addr), size); + blk.size -= size; + H5MF_free (f, &(blk.addr), blk.size); + } + + } else { + /* + * No suitable free block was found. Allocate space from the end of + * the file. We don't know about alignment at this point, so we + * allocate enough space to align the data also. + */ + if (size>=thresh) { + blk.size = size + align - 1; + } else { + blk.size = size; + } + if (H5F_low_extend(f->shared->lf, f->shared->access_parms, op, + blk.size, &(blk.addr)/*out*/) < 0) { + HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, + "low level mem management failed"); + } + + /* Convert from absolute to relative */ + blk.addr.offset -= f->shared->base_addr.offset; + + /* Did we extend the size of the hdf5 data? */ + tmp_addr = blk.addr; + H5F_addr_inc(&tmp_addr, blk.size); + if (H5F_addr_gt(&tmp_addr, &(f->shared->hdf5_eof))) { + f->shared->hdf5_eof = tmp_addr; + } + + if ((status=H5F_low_alloc (f->shared->lf, op, align, thresh, size, + &blk, addr/*out*/))>0) { + /* Exact match */ + } else if (0==status) { + /* Partial match */ + if (H5F_addr_gt (addr, &(blk.addr))) { + n = addr->offset - blk.addr.offset; + H5MF_free (f, &(blk.addr), n); + blk.addr = *addr; + blk.size -= n; + } + if (blk.size > size) { + H5F_addr_inc (&(blk.addr), size); + blk.size -= size; + H5MF_free (f, &(blk.addr), blk.size); + } + } } + FUNC_LEAVE(SUCCEED); } @@ -111,8 +204,10 @@ H5MF_alloc(H5F_t *f, intn op, hsize_t size, haddr_t *addr/*out*/) *------------------------------------------------------------------------- */ herr_t -H5MF_free(H5F_t __unused__ *f, const haddr_t *addr, hsize_t size) +H5MF_free(H5F_t *f, const haddr_t *addr, hsize_t size) { + int i; + FUNC_ENTER(H5MF_free, FAIL); /* check arguments */ @@ -121,11 +216,29 @@ H5MF_free(H5F_t __unused__ *f, const haddr_t *addr, hsize_t size) HRETURN(SUCCEED); assert(!H5F_addr_zerop(addr)); + /* + * Insert this free block into the free list without attempting to + * combine it with other free blocks. If the list is overfull then + * remove the smallest free block. + */ + if (f->shared->fl_nfree>=H5MF_NFREE) { + for (i=0; i<H5MF_NFREE; i++) { + if (f->shared->fl_free[i].size<size) { #ifdef H5MF_DEBUG - fprintf(stderr, "H5MF_free: lost %lu bytes of file storage\n", - (unsigned long) size); + fprintf(stderr, "H5MF_free: lost %lu bytes of file storage\n", + (unsigned long) f->shared->fl_free[i].size); #endif - + f->shared->fl_free[i].addr = *addr; + f->shared->fl_free[i].size = size; + break; + } + } + } else { + i = f->shared->fl_nfree++; + f->shared->fl_free[i].addr = *addr; + f->shared->fl_free[i].size = size; + } + FUNC_LEAVE(SUCCEED); } |