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[svn-r5900] Purpose:

Browse Source 
Code cleanup/New Feature

Description:
    Improve the space allocation in the file by re-using freed space more
    effectively.

Platforms tested:
    FreeBSD 4.6 (sleipnir) w/serial & parallel
This commit is contained in:
Quincey Koziol 2002-08-27 14:59:12 -05:00
parent 44f3c84cc9
commit 966adccc59
2 changed files with 117 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
release_docs/RELEASE.txt
View File

@ -35,6 +35,8 @@ Bug Fixes since HDF5-1.4.0
Library
-------
* Partially fixed space allocation inefficiencies in the file by
improving our algorithms for re-using freed space. QAK - 2002/08/27
* Fixed data corruption problem which could occur when fill values were
written to a contiguously stored dataset in parallel. QAK - 2002/08/27
* Fixed metadata corruption problem which could occur when many objects

126
src/H5FD.c
View File

@ -35,6 +35,9 @@ static herr_t H5FD_init_interface(void);
static herr_t H5FD_free_cls(H5FD_class_t *cls);
static haddr_t H5FD_real_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size);
/* Declare a free list to manage the H5FD_free_t struct */
H5FL_DEFINE(H5FD_free_t);
/* Declare a PQ free list to manage the metadata accumulator buffer */
H5FL_BLK_DEFINE_STATIC(meta_accum);
@ -920,7 +923,7 @@ H5FD_close(H5FD_t *file)
nbytes += cur->size;
#endif
next = cur->next;
H5MM_xfree(cur);
H5FL_FREE(H5FD_free_t,cur);
}
file->fl[i]=NULL;
}
@ -1277,7 +1280,7 @@ H5FD_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size)
prev->next = cur->next;
else
file->fl[mapped_type] = cur->next;
H5MM_xfree(cur);
H5FL_FREE(H5FD_free_t,cur);
if (size==file->maxsize)
file->maxsize=0; /*unknown*/
HGOTO_DONE(ret_value);
@ -1329,7 +1332,7 @@ H5FD_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size)
prev->next = cur->next;
else
file->fl[mapped_type] = cur->next;
H5MM_xfree(cur);
H5FL_FREE(H5FD_free_t,cur);
if (size==file->maxsize)
file->maxsize=0; /*unknown*/
HGOTO_DONE(ret_value);
@ -1389,7 +1392,7 @@ H5FD_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size)
else {
/* Attempt to allocate memory for temporary node */
tmp = H5MM_malloc(sizeof(H5FD_free_t));
tmp = H5FL_ALLOC(H5FD_free_t,0);
#ifdef H5F_DEBUG
if (H5DEBUG(F)) {
HDfprintf(H5DEBUG(F),
@ -1407,7 +1410,7 @@ H5FD_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size)
} /* end if */
else {
/* no tail piece */
H5MM_xfree(tmp);
H5FL_FREE(H5FD_free_t,tmp);
} /* end else */
} /* end if */
else {
@ -1754,13 +1757,114 @@ H5FD_free(H5FD_t *file, H5FD_mem_t type, haddr_t addr, hsize_t size)
* driver deallocate the memory.
*/
if (mapped_type>=0) {
H5FD_free_t *cur = H5MM_malloc(sizeof(H5FD_free_t));
H5FD_free_t *curr; /* Current free block being inspected */
H5FD_free_t *prev; /* Previous free block being inspected */
cur->addr = addr;
cur->size = size;
cur->next = file->fl[mapped_type];
file->fl[mapped_type] = cur;
file->maxsize = MAX(file->maxsize, size);
/* Scan through the existing blocks for the mapped type to see if we can extend one */
curr=file->fl[mapped_type];
prev=NULL;
while(curr!=NULL) {
/* Check if the block to free adjoins the start of the current block */
if((addr+size)==curr->addr) {
/* Adjust the address and size of the block found */
curr->addr=addr;
curr->size+=size;
/* Break out of loop */
break;
} /* end if */
else {
/* Check if the block to free adjoins the end of the current block */
if((curr->addr+curr->size)==addr) {
/* Adjust the size of the block found */
curr->size+=size;
/* Break out of loop */
break;
} /* end if */
else {
/* Advance to next node in list */
prev=curr;
curr=curr->next;
} /* end else */
} /* end else */
} /* end while */
/* Check if we adjusted an existing block */
if(curr!=NULL) {
H5FD_free_t *merge_curr; /* Current free block for merging */
H5FD_free_t *merge_prev; /* Previous free block for merging */
/* Scan through the existing blocks for the mapped type to see if we can merge the block we just found */
merge_curr=file->fl[mapped_type];
merge_prev=NULL;
while(merge_curr!=NULL) {
/* Check if the found block adjoins the start of the current block */
if((curr->addr+curr->size)==merge_curr->addr) {
/* Adjust the size of the block found */
curr->size+=merge_curr->size;
/* Break out of loop */
break;
} /* end if */
else {
/* Check if the found block adjoins the end of the current block */
if((merge_curr->addr+merge_curr->size)==curr->addr) {
/* Adjust the address and size of the block found */
curr->addr=merge_curr->addr;
curr->size+=merge_curr->size;
/* Break out of loop */
break;
} /* end if */
else {
/* Advance to next node in list */
merge_prev=merge_curr;
merge_curr=merge_curr->next;
} /* end else */
} /* end else */
} /* end while */
/* Check if we merged a block out of existance */
if(merge_curr!=NULL) {
/* Check if there was a previous block in the list */
if(merge_prev!=NULL)
/* Eliminate the merged block from the list */
merge_prev->next=merge_curr->next;
/* No previous block, this must be the head of the list */
else
/* Eliminate the merged block from the list */
file->fl[mapped_type] = merge_curr->next;
/* Check for eliminating the block before the 'found' one */
if(merge_curr==prev)
prev=merge_prev;
/* Free the memory for the merged block */
H5FL_FREE(H5FD_free_t,merge_curr);
} /* end if */
/* Move the node found to the front, if it wasn't already there */
if(prev!=NULL) {
prev->next=curr->next;
curr->next = file->fl[mapped_type];
file->fl[mapped_type] = curr;
} /* end if */
} /* end if */
else {
/* Allocate a new node to hold the free block's information */
if(NULL==(curr = H5FL_ALLOC(H5FD_free_t,0)))
HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate node for free space info");
curr->addr = addr;
curr->size = size;
curr->next = file->fl[mapped_type];
file->fl[mapped_type] = curr;
} /* end else */
/* Check if we increased the size of the largest block on the list */
file->maxsize = MAX(file->maxsize, curr->size);
} else if (file->cls->free) {
if ((file->cls->free)(file, type, addr, size)<0)
HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, "driver free request failed");