diff options
| -rw-r--r-- | release_docs/RELEASE.txt | 6 | ||||
| -rw-r--r-- | src/H5I.c | 76 |
2 files changed, 72 insertions, 10 deletions
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt index e5b8c8b..0ee5583 100644 --- a/release_docs/RELEASE.txt +++ b/release_docs/RELEASE.txt @@ -117,6 +117,12 @@ Bug Fixes since HDF5-1.8.4 Library ------- + - Added a mechanism to the H5I interface to save returned object ID + structures for immediate re-use if needed. This addresses a + potential performance issue by delaying the case when the next ID to be + registered has grown so large that it wraps around and needs to be + checked to see if it is available for distribution. + (MAM - 2010/03/15 - 1730) - Files can now be concurrently opened more than once using the core file driver, as long as the backing store is used. (NAF - 2010/03/09) - Added support for H5O_COPY_EXPAND_EXT_LINK_FLAG to H5Ocopy. External @@ -62,6 +62,10 @@ /* Local Macros */ +/* Define the maximum number of returned ID structures to keep around + for re-use. */ +#define MAX_FREE_ID_STRUCTS 1000 + /* * Define the following macro for fast hash calculations (but limited * hash sizes) @@ -99,12 +103,14 @@ typedef struct H5I_id_info_t { /* ID type structure used */ typedef struct { unsigned count; /*# of times this type has been initialized*/ + unsigned free_count; /* # of available ID structures awaiting recycling */ unsigned reserved; /*# of IDs to reserve for constant IDs */ unsigned wrapped; /*whether the id count has wrapped around */ size_t hash_size; /*sizeof the hash table to store the IDs in */ unsigned ids; /*current number of IDs held */ unsigned nextid; /*ID to use for the next atom */ H5I_free_t free_func; /*release object method */ + H5I_id_info_t * next_id_ptr; /* pointer to head of available ID list */ H5I_id_info_t **id_list; /*pointer to an array of ptrs to IDs */ } H5I_id_type_t; @@ -832,7 +838,6 @@ H5I_register(H5I_type_t type, const void *object, hbool_t app_ref) { H5I_id_type_t *type_ptr; /*ptr to the type */ H5I_id_info_t *id_ptr; /*ptr to the new ID information */ - hid_t new_id; /*new ID */ unsigned hash_loc; /*new item's hash table location*/ hid_t next_id; /*next ID to check */ H5I_id_info_t *curr_id; /*ptr to the current atom */ @@ -847,26 +852,49 @@ H5I_register(H5I_type_t type, const void *object, hbool_t app_ref) type_ptr = H5I_id_type_list_g[type]; if(NULL == type_ptr || type_ptr->count <= 0) HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, FAIL, "invalid type") - if(NULL == (id_ptr = H5FL_MALLOC(H5I_id_info_t))) - HGOTO_ERROR(H5E_ATOM, H5E_NOSPACE, FAIL, "memory allocation failed") - /* Create the struct & it's ID */ - new_id = H5I_MAKE(type, type_ptr->nextid); - id_ptr->id = new_id; + /* If there is an available ID structure, use it. */ + if (type_ptr->next_id_ptr) { + + /* Use existing available ID struct */ + id_ptr = type_ptr->next_id_ptr; + + /* Remove struct from list of available ones */ + type_ptr->next_id_ptr = type_ptr->next_id_ptr->next; + + /* Decrease count of available ID structures */ + type_ptr->free_count--; + + /* If no available ID structure, then create a new id for use, and + * allocate a new struct to house it. */ + } else { + + /* Allocate new ID struct */ + if(NULL == (id_ptr = H5FL_MALLOC(H5I_id_info_t))) + HGOTO_ERROR(H5E_ATOM, H5E_NOSPACE, FAIL, "memory allocation failed") + + /* Make a new ID */ + id_ptr->id = H5I_MAKE(type, type_ptr->nextid); + + /* Increment nextid value */ + type_ptr->nextid++; + + } /* end if */ + + /* Fill in remaining fields of ID struct */ id_ptr->count = 1; /*initial reference count*/ id_ptr->app_count = !!app_ref; id_ptr->obj_ptr = object; id_ptr->next = NULL; /* hash bucket already full, prepend to front of chain */ - hash_loc = type_ptr->nextid % (unsigned)type_ptr->hash_size; + hash_loc = id_ptr->id % (unsigned)type_ptr->hash_size; if(type_ptr->id_list[hash_loc] != NULL) id_ptr->next = type_ptr->id_list[hash_loc]; /* Insert into the type */ type_ptr->id_list[hash_loc] = id_ptr; type_ptr->ids++; - type_ptr->nextid++; /* * This next section of code checks for the 'nextid' getting too large and @@ -917,7 +945,7 @@ H5I_register(H5I_type_t type, const void *object, hbool_t app_ref) } /* end if */ /* Set return value */ - ret_value = new_id; + ret_value = id_ptr->id; done: FUNC_LEAVE_NOAPI(ret_value) @@ -1251,6 +1279,7 @@ H5I_remove(hid_t id) H5I_id_type_t *type_ptr; /*ptr to the atomic type */ H5I_id_info_t *curr_id; /*ptr to the current atom */ H5I_id_info_t *last_id; /*ptr to the last atom */ + H5I_id_info_t *tmp_id_ptr; /*temp ptr to next atom */ H5I_type_t type; /*atom's atomic type */ unsigned hash_loc; /*atom's hash table location */ void * ret_value = NULL; /*return value */ @@ -1288,7 +1317,17 @@ H5I_remove(hid_t id) } /* (Casting away const OK -QAK) */ ret_value = (void *)curr_id->obj_ptr; - (void)H5FL_FREE(H5I_id_info_t, curr_id); + + /* If there's room, save the struct (and its ID) for future re-use */ + if (type_ptr->free_count < MAX_FREE_ID_STRUCTS) { + curr_id->next = type_ptr->next_id_ptr; + type_ptr->next_id_ptr = curr_id; + type_ptr->free_count++; + /* Otherwise, just toss it. */ + } else { + (void)H5FL_FREE(H5I_id_info_t, curr_id); + } /* end if */ + } else { /* couldn't find the ID in the proper place */ HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "invalid ID") @@ -1297,6 +1336,23 @@ H5I_remove(hid_t id) /* Decrement the number of IDs in the type */ (type_ptr->ids)--; + /* If there are no more IDs of this type, then we can free all available + ID strutures, and reset starting typeid and wrapped status. */ + if (type_ptr->ids == 0) { + + while (type_ptr->next_id_ptr) { + + tmp_id_ptr = type_ptr->next_id_ptr->next; + (void)H5FL_FREE(H5I_id_info_t, type_ptr->next_id_ptr); + type_ptr->next_id_ptr = tmp_id_ptr; + + } /* end while */ + + type_ptr->nextid = type_ptr->reserved; + type_ptr->wrapped = FALSE; + + } /* end if */ + done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5I_remove() */ |