From b0bd984ed620aeca1047f1f45692890eacb924be Mon Sep 17 00:00:00 2001 From: Dana Robinson <43805+derobins@users.noreply.github.com> Date: Fri, 22 Oct 2021 08:02:28 -0700 Subject: Removes the "try free" behavior from the skip lists (#1126) * Removes the "try free" behavior from the skip lists This was only used in the ID code when iterating and a callback could delete IDs. It is not used anywhere else in the library and is now pointless overhead. Also quiets the const warnings when returning stored elements. They only need to be const with respect to the skip list code, which should never modify them. The library can do whatever it wants with the elements it stored. * Formatted source --- src/H5SL.c | 666 ++++++++++++++++-------------------------------------- src/H5SLprivate.h | 4 - test/tskiplist.c | 208 ----------------- 3 files changed, 200 insertions(+), 678 deletions(-) diff --git a/src/H5SL.c b/src/H5SL.c index ba9721c..b4fbf99 100644 --- a/src/H5SL.c +++ b/src/H5SL.c @@ -36,13 +36,6 @@ * skip list. The implementation in that document hurts * performance, at least for integer keys. -NAF) * - * (Also, this implementation has a couple of home-grown - * optimizations, including setting the "update" vector to the - * actual 'forward' pointer to update, instead of the node - * containing the forward pointer -QAK - * -No longer uses update vector, as insertions/deletions are now - * always at level 0. -NAF) - * * (Note: This implementation does not have the information for * implementing the "Linear List Operations" (like insert/delete/ * search by position) in section 3.4 of "A Skip List Cookbook", @@ -71,25 +64,14 @@ /* Define the code template for searches for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_SEARCH_FOUND(SLIST, X, I) \ { \ - HDassert(!X->removed); \ - HGOTO_DONE(X->item); \ - } /* end block */ - -/* Define the code template for deferred removals for the "OP" in the - * H5SL_LOCATE macro */ -#define H5SL_LOCATE_SEARCH_DEFER_REMOVE_FOUND(SLIST, X, I) \ - { \ - HDassert(!X->removed); \ - X->removed = TRUE; \ HGOTO_DONE(X->item); \ - } /* end block */ + } /* Define the code template for finds for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_FIND_FOUND(SLIST, X, I) \ { \ - HDassert(!X->removed); \ HGOTO_DONE(X); \ - } /* end block */ + } /* Define a code template for comparing scalar keys for the "CMP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_SCALAR_CMP(SLIST, TYPE, PNODE, PKEY, HASHVAL) (*(TYPE *)((PNODE)->key) < *(TYPE *)PKEY) @@ -155,51 +137,19 @@ H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X->forward[_i], KEY, HASHVAL)) { \ X = X->forward[_i]; \ _count++; \ - } /* end while */ \ - } /* end for */ \ + } \ + } \ X = X->forward[0]; \ if (X != NULL && H5_GLUE3(H5SL_LOCATE_, CMP, _EQ)(SLIST, TYPE, X, KEY, HASHVAL)) { \ /* What to do when a node is found */ \ H5_GLUE3(H5SL_LOCATE_, OP, _FOUND)(SLIST, X, _i) \ - } /* end if */ \ - } - -/* Macro used to find node for operation, if there may be "removed" nodes in the - * list (whose keys cannot be read) */ -#define H5SL_LOCATE_SAFE(OP, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ - { \ - int _i; /* Local index variable */ \ - H5SL_node_t *_low = X; \ - H5SL_node_t *_high = NULL; \ - \ - H5_GLUE3(H5SL_LOCATE_, CMP, _HASHINIT) \ - (KEY, HASHVAL) for (_i = (int)SLIST->curr_level; _i >= 0; _i--) \ - { \ - X = _low->forward[_i]; \ - while (X != _high) { \ - if (!X->removed) { \ - if (H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X, KEY, HASHVAL)) \ - _low = X; \ - else \ - break; \ - } /* end if */ \ - X = X->forward[_i]; \ - } /* end while */ \ - _high = X; \ - if (X != NULL && H5_GLUE3(H5SL_LOCATE_, CMP, _EQ)(SLIST, TYPE, X, KEY, HASHVAL)) { \ - /* What to do when a node is found */ \ - H5_GLUE3(H5SL_LOCATE_, OP, _FOUND)(SLIST, X, _i) break; \ - } /* end if */ \ - } /* end for */ \ + } \ } /* Macro used to find node for operation */ #define H5SL_LOCATE(OP, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ { \ - if ((SLIST)->safe_iterating) \ - H5SL_LOCATE_SAFE(OP, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ - else \ - H5SL_LOCATE_OPT(OP, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ + H5SL_LOCATE_OPT(OP, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ } /* Macro used to grow a node by 1. Does not update pointers. LVL is the current @@ -225,13 +175,13 @@ if (NULL == (H5SL_fac_g = (H5FL_fac_head_t **)H5MM_realloc( \ (void *)H5SL_fac_g, H5SL_fac_nalloc_g * sizeof(H5FL_fac_head_t *)))) \ HGOTO_ERROR(H5E_SLIST, H5E_CANTALLOC, ERR, "memory allocation failed") \ - } /* end if */ \ + } \ \ /* Create the new factory */ \ H5SL_fac_g[H5SL_fac_nused_g] = \ H5FL_fac_init((1u << H5SL_fac_nused_g) * sizeof(H5SL_node_t *)); \ H5SL_fac_nused_g++; \ - } /* end if */ \ + } \ \ /* Allocate space for new forward pointers */ \ if (NULL == (_tmp = (H5SL_node_t **)H5FL_FAC_MALLOC(H5SL_fac_g[X->log_nalloc]))) \ @@ -239,7 +189,7 @@ H5MM_memcpy((void *)_tmp, (const void *)X->forward, (LVL + 1) * sizeof(H5SL_node_t *)); \ X->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[X->log_nalloc - 1], (void *)X->forward); \ X->forward = _tmp; \ - } /* end if */ \ + } \ \ X->level++; \ } @@ -260,7 +210,7 @@ H5MM_memcpy((void *)_tmp, (const void *)X->forward, (LVL) * sizeof(H5SL_node_t *)); \ X->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[X->log_nalloc + 1], (void *)X->forward); \ X->forward = _tmp; \ - } /* end if */ \ + } \ \ X->level--; \ } @@ -284,7 +234,7 @@ else { \ HDassert(_lvl < (size_t)SLIST->curr_level); \ X->forward[_lvl + 1] = PREV->forward[_lvl + 1]; \ - } /* end else */ \ + } \ PREV->forward[_lvl + 1] = X; \ } @@ -322,7 +272,7 @@ if (!_drop) \ _drop = X; \ break; \ - } /* end if */ \ + } \ \ /* Check if this node is the start of the next gap */ \ if (!_drop && !H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X->forward[_i], KEY, HASHVAL)) \ @@ -337,7 +287,7 @@ break; \ } \ X = X->forward[_i]; \ - } /* end for */ \ + } \ HDassert(!_drop->forward[_i] || \ !H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, _drop->forward[_i], KEY, HASHVAL)); \ \ @@ -350,7 +300,7 @@ /* Prepare to drop down */ \ X = _last = _drop; \ _next = _drop->forward[_i]; \ - } /* end for */ \ + } \ \ if (_next && H5_GLUE3(H5SL_LOCATE_, CMP, _EQ)(SLIST, TYPE, _next, KEY, HASHVAL)) \ HGOTO_ERROR(H5E_SLIST, H5E_CANTINSERT, NULL, "can't insert duplicate key") \ @@ -359,172 +309,167 @@ /* Macro used to remove node */ #define H5SL_REMOVE(CMP, SLIST, X, TYPE, KEY, HASHVAL) \ { \ - /* Check for deferred removal */ \ - if (SLIST->safe_iterating) \ - H5SL_LOCATE(SEARCH_DEFER_REMOVE, CMP, SLIST, X, TYPE, KEY, HASHVAL) \ - else { \ - H5SL_node_t *_last = X; /* Lowest node in the current gap */ \ - H5SL_node_t *_llast = X; /* Lowest node in the previous gap */ \ - H5SL_node_t *_next = NULL; /* Highest node in the currect gap */ \ - H5SL_node_t *_drop = NULL; /* Low node of the gap to drop into */ \ - H5SL_node_t *_ldrop = NULL; /* Low node of gap before the one to drop into */ \ - H5SL_node_t *_head = SLIST->header; /* Head of the skip list */ \ - int _count; /* Number of nodes in the current gap */ \ - int _i = (int)SLIST->curr_level; \ + H5SL_node_t *_last = X; /* Lowest node in the current gap */ \ + H5SL_node_t *_llast = X; /* Lowest node in the previous gap */ \ + H5SL_node_t *_next = NULL; /* Highest node in the currect gap */ \ + H5SL_node_t *_drop = NULL; /* Low node of the gap to drop into */ \ + H5SL_node_t *_ldrop = NULL; /* Low node of gap before the one to drop into */ \ + H5SL_node_t *_head = SLIST->header; /* Head of the skip list */ \ + int _count; /* Number of nodes in the current gap */ \ + int _i = (int)SLIST->curr_level; \ \ - if (_i < 0) \ - HGOTO_DONE(NULL); \ + if (_i < 0) \ + HGOTO_DONE(NULL); \ \ - H5_GLUE3(H5SL_LOCATE_, CMP, _HASHINIT) \ - (KEY, HASHVAL) \ + H5_GLUE3(H5SL_LOCATE_, CMP, _HASHINIT) \ + (KEY, HASHVAL) \ \ - /* Find the gap to drop in to at the highest level */ \ - while (X && (!X->key || H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X, KEY, HASHVAL))) \ - { \ - _llast = _last; \ - _last = X; \ - X = X->forward[_i]; \ - } \ - _next = X; \ + /* Find the gap to drop in to at the highest level */ \ + while (X && (!X->key || H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X, KEY, HASHVAL))) \ + { \ + _llast = _last; \ + _last = X; \ + X = X->forward[_i]; \ + } \ + _next = X; \ \ - /* Main loop */ \ - for (_i--; _i >= 0; _i--) { \ - /* Search for the node to drop into, also count the number of */ \ - /* nodes of height _i in this gap and keep track of of the node */ \ - /* before the one to drop into (_ldrop will become _llast, */ \ - /* _drop will become _last). */ \ - X = _ldrop = _last; \ - _drop = NULL; \ - for (_count = 0;; _count++) { \ - /* Terminate if this is the last node in the gap */ \ - if (X->forward[_i] == _next) { \ - if (!_drop) \ - _drop = X; \ - break; \ - } /* end if */ \ + /* Main loop */ \ + for (_i--; _i >= 0; _i--) { \ + /* Search for the node to drop into, also count the number of */ \ + /* nodes of height _i in this gap and keep track of of the node */ \ + /* before the one to drop into (_ldrop will become _llast, */ \ + /* _drop will become _last). */ \ + X = _ldrop = _last; \ + _drop = NULL; \ + for (_count = 0;; _count++) { \ + /* Terminate if this is the last node in the gap */ \ + if (X->forward[_i] == _next) { \ + if (!_drop) \ + _drop = X; \ + break; \ + } \ \ - /* If we have already found the node to drop into and there */ \ - /* is more than one node in this gap, we can stop searching */ \ - if (_drop) { \ - HDassert(_count >= 1); \ - _count = 2; \ - break; \ + /* If we have already found the node to drop into and there */ \ + /* is more than one node in this gap, we can stop searching */ \ + if (_drop) { \ + HDassert(_count >= 1); \ + _count = 2; \ + break; \ + } \ + else { /* !_drop */ \ + /* Check if this node is the start of the next gap */ \ + if (!H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X->forward[_i], KEY, HASHVAL)) { \ + _drop = X; \ + /* Again check if we can stop searching */ \ + if (_count) { \ + _count = 2; \ + break; \ + } \ } \ - else { /* !_drop */ \ - /* Check if this node is the start of the next gap */ \ - if (!H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, X->forward[_i], KEY, HASHVAL)) { \ - _drop = X; \ - /* Again check if we can stop searching */ \ - if (_count) { \ - _count = 2; \ - break; \ - } /* end if */ \ - } /* end if */ \ - else \ - _ldrop = X; \ - } /* end else */ \ + else \ + _ldrop = X; \ + } \ \ - /* No need to check the last node in the gap if there are */ \ - /* 3, as there cannot be a fourth */ \ - if (_count == 2) { \ - if (!_drop) \ - _drop = X->forward[_i]; \ - break; \ - } /* end if */ \ - X = X->forward[_i]; \ - } /* end for */ \ - HDassert(_count >= 1 && _count <= 3); \ - HDassert(!_drop->forward[_i] || \ - !H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, _drop->forward[_i], KEY, HASHVAL)); \ + /* No need to check the last node in the gap if there are */ \ + /* 3, as there cannot be a fourth */ \ + if (_count == 2) { \ + if (!_drop) \ + _drop = X->forward[_i]; \ + break; \ + } \ + X = X->forward[_i]; \ + } \ + HDassert(_count >= 1 && _count <= 3); \ + HDassert(!_drop->forward[_i] || \ + !H5_GLUE3(H5SL_LOCATE_, CMP, _CMP)(SLIST, TYPE, _drop->forward[_i], KEY, HASHVAL)); \ \ - /* Check if we need to adjust node heights */ \ - if (_count == 1) { \ - /* Check if we are in the first gap */ \ - if (_llast == _last) { \ - /* We are in the first gap, count the number of nodes */ \ - /* of height _i in the next gap. We need only check */ \ - /* onenode to see if we should promote the first node */ \ - /* in the next gap */ \ - _llast = _next->forward[_i + 1]; \ + /* Check if we need to adjust node heights */ \ + if (_count == 1) { \ + /* Check if we are in the first gap */ \ + if (_llast == _last) { \ + /* We are in the first gap, count the number of nodes */ \ + /* of height _i in the next gap. We need only check */ \ + /* onenode to see if we should promote the first node */ \ + /* in the next gap */ \ + _llast = _next->forward[_i + 1]; \ \ - /* Demote the separator node */ \ - H5SL_DEMOTE(_next, _last) \ + /* Demote the separator node */ \ + H5SL_DEMOTE(_next, _last) \ \ - /* If there are 2 or more nodes, promote the first */ \ - if (_next->forward[_i]->forward[_i] != _llast) { \ - X = _next->forward[_i]; \ - H5SL_PROMOTE(SLIST, X, _last, NULL) \ - } \ - else if (!_head->forward[_i + 1]) { \ - /* shrink the header */ \ - HDassert(_i == SLIST->curr_level - 1); \ - HDassert((size_t)SLIST->curr_level == _head->level); \ + /* If there are 2 or more nodes, promote the first */ \ + if (_next->forward[_i]->forward[_i] != _llast) { \ + X = _next->forward[_i]; \ + H5SL_PROMOTE(SLIST, X, _last, NULL) \ + } \ + else if (!_head->forward[_i + 1]) { \ + /* shrink the header */ \ + HDassert(_i == SLIST->curr_level - 1); \ + HDassert((size_t)SLIST->curr_level == _head->level); \ \ - H5SL_SHRINK(_head, (size_t)(_i + 1)) \ - SLIST->curr_level--; \ - } /* end else */ \ + H5SL_SHRINK(_head, (size_t)(_i + 1)) \ + SLIST->curr_level--; \ } \ - else { \ - /* We are not in the first gap, count the number of */ \ - /* nodes of height _i in the previous gap. Note we */ \ - /* "look ahead" in this loop so X has the value of the */ \ - /* last node in the previous gap. */ \ - X = _llast->forward[_i]; \ - for (_count = 1; _count < 3 && X->forward[_i] != _last; _count++) \ - X = X->forward[_i]; \ - HDassert(X->forward[_i] == _last); \ + } \ + else { \ + /* We are not in the first gap, count the number of */ \ + /* nodes of height _i in the previous gap. Note we */ \ + /* "look ahead" in this loop so X has the value of the */ \ + /* last node in the previous gap. */ \ + X = _llast->forward[_i]; \ + for (_count = 1; _count < 3 && X->forward[_i] != _last; _count++) \ + X = X->forward[_i]; \ + HDassert(X->forward[_i] == _last); \ \ - /* Demote the separator node */ \ - H5SL_DEMOTE(_last, _llast) \ + /* Demote the separator node */ \ + H5SL_DEMOTE(_last, _llast) \ \ - /* If there are 2 or more nodes, promote the last */ \ - if (_count >= 2) \ - H5SL_PROMOTE(SLIST, X, _llast, NULL) \ - else if (!_head->forward[_i + 1]) { \ - /* shrink the header */ \ - HDassert(_i == SLIST->curr_level - 1); \ - HDassert((size_t)SLIST->curr_level == _head->level); \ + /* If there are 2 or more nodes, promote the last */ \ + if (_count >= 2) \ + H5SL_PROMOTE(SLIST, X, _llast, NULL) \ + else if (!_head->forward[_i + 1]) { \ + /* shrink the header */ \ + HDassert(_i == SLIST->curr_level - 1); \ + HDassert((size_t)SLIST->curr_level == _head->level); \ \ - H5SL_SHRINK(_head, (size_t)(_i + 1)) \ - SLIST->curr_level--; \ - } /* end else */ \ - } /* end else */ \ - } /* end if */ \ + H5SL_SHRINK(_head, (size_t)(_i + 1)) \ + SLIST->curr_level--; \ + } \ + } \ + } \ \ - /* Prepare to drop down */ \ - _llast = _ldrop; \ - _last = _drop; \ - _next = _drop->forward[_i]; \ - } /* end for */ \ + /* Prepare to drop down */ \ + _llast = _ldrop; \ + _last = _drop; \ + _next = _drop->forward[_i]; \ + } \ \ - /* Check if we've found the node */ \ - if (_next && H5_GLUE3(H5SL_LOCATE_, CMP, _EQ)(SLIST, TYPE, _next, KEY, HASHVAL)) { \ - void *tmp = _next->item; \ - X = _next; \ + /* Check if we've found the node */ \ + if (_next && H5_GLUE3(H5SL_LOCATE_, CMP, _EQ)(SLIST, TYPE, _next, KEY, HASHVAL)) { \ + void *tmp = _next->item; \ + X = _next; \ \ - /* If the node has a height > 0, swap it with its (lower) */ \ - /* neighbor */ \ - if (X->level) { \ - X = X->backward; \ - _next->key = X->key; \ - _next->item = X->item; \ - _next->hashval = X->hashval; \ - } /* end if */ \ - HDassert(!X->level); \ + /* If the node has a height > 0, swap it with its (lower) */ \ + /* neighbor */ \ + if (X->level) { \ + X = X->backward; \ + _next->key = X->key; \ + _next->item = X->item; \ + _next->hashval = X->hashval; \ + } \ + HDassert(!X->level); \ \ - /* Remove the node */ \ - X->backward->forward[0] = X->forward[0]; \ - if (SLIST->last == X) \ - SLIST->last = X->backward; \ - else \ - X->forward[0]->backward = X->backward; \ - SLIST->nobjs--; \ - X->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[0], X->forward); \ - X = H5FL_FREE(H5SL_node_t, X); \ + /* Remove the node */ \ + X->backward->forward[0] = X->forward[0]; \ + if (SLIST->last == X) \ + SLIST->last = X->backward; \ + else \ + X->forward[0]->backward = X->backward; \ + SLIST->nobjs--; \ + X->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[0], X->forward); \ + X = H5FL_FREE(H5SL_node_t, X); \ \ - HGOTO_DONE(tmp); \ - } /* end if */ \ - } /* end else */ \ + HGOTO_DONE(tmp); \ + } \ } /* Macro used to search for node */ @@ -542,7 +487,6 @@ struct H5SL_node_t { size_t level; /* The level of this node */ size_t log_nalloc; /* log2(Number of slots allocated in forward) */ uint32_t hashval; /* Hash value for key (only for strings, currently) */ - hbool_t removed; /* Whether the node is "removed" (actual removal deferred) */ struct H5SL_node_t **forward; /* Array of forward pointers from this node */ struct H5SL_node_t * backward; /* Backward pointer from this node */ }; @@ -558,8 +502,6 @@ struct H5SL_t { size_t nobjs; /* Number of active objects in skip list */ H5SL_node_t *header; /* Header for nodes in skip list */ H5SL_node_t *last; /* Pointer to last node in skip list */ - hbool_t safe_iterating; /* Whether a routine is "safely" iterating over the list and removals should be - deferred */ }; /* Static functions */ @@ -651,11 +593,11 @@ H5SL_term_package(void) for (i = 0; i < H5SL_fac_nused_g; i++) { ret = H5FL_fac_term(H5SL_fac_g[i]); HDassert(ret >= 0); - } /* end if */ + } H5SL_fac_nused_g = 0; n++; - } /* end if */ + } /* Free the list of factories */ if (H5SL_fac_g) { @@ -663,12 +605,12 @@ H5SL_term_package(void) H5SL_fac_nalloc_g = 0; n++; - } /* end if */ + } /* Mark the interface as uninitialized */ if (0 == n) H5_PKG_INIT_VAR = FALSE; - } /* end if */ + } FUNC_LEAVE_NOAPI(n) } /* H5SL_term_package() */ @@ -711,11 +653,10 @@ H5SL__new_node(void *item, const void *key, uint32_t hashval) ret_value->item = item; ret_value->level = 0; ret_value->hashval = hashval; - ret_value->removed = FALSE; if (NULL == (ret_value->forward = (H5SL_node_t **)H5FL_FAC_MALLOC(H5SL_fac_g[0]))) { ret_value = H5FL_FREE(H5SL_node_t, ret_value); HGOTO_ERROR(H5E_SLIST, H5E_NOSPACE, NULL, "memory allocation failed") - } /* end if */ + } ret_value->log_nalloc = 0; done: @@ -805,7 +746,7 @@ H5SL__insert_common(H5SL_t *slist, void *item, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* 'key' must not have been found in existing list, if we get here */ @@ -880,15 +821,22 @@ H5SL__release_common(H5SL_t *slist, H5SL_operator_t op, void *op_data) while (node) { next_node = node->forward[0]; - /* Call callback, if one is given */ + /* Call callback, if one is given. + * + * Ignoring const here is fine as we only need the value to be const + * with respect to the list code, which should never modify the + * elements. The library code that is making use of the skip list + * container can do what it likes with the elements. + */ + H5_GCC_CLANG_DIAG_OFF("cast-qual") if (op) - /* Casting away const OK -QAK */ (void)(op)(node->item, (void *)node->key, op_data); + H5_GCC_CLANG_DIAG_ON("cast-qual") node->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[node->log_nalloc], node->forward); node = H5FL_FREE(H5SL_node_t, node); node = next_node; - } /* end while */ + } /* Reset the header pointers */ slist->header->forward = @@ -1001,9 +949,8 @@ H5SL_create(H5SL_type_t type, H5SL_cmp_t cmp) new_slist->cmp = cmp; /* Set the dynamic internal fields */ - new_slist->curr_level = -1; - new_slist->nobjs = 0; - new_slist->safe_iterating = FALSE; + new_slist->curr_level = -1; + new_slist->nobjs = 0; /* Allocate the header node */ if (NULL == (header = H5SL__new_node(NULL, NULL, (uint32_t)ULONG_MAX))) @@ -1027,7 +974,7 @@ done: if (ret_value == NULL) { if (new_slist != NULL) new_slist = H5FL_FREE(H5SL_t, new_slist); - } /* end if */ + } FUNC_LEAVE_NOAPI(ret_value) } /* end H5SL_create() */ @@ -1058,9 +1005,6 @@ H5SL_count(H5SL_t *slist) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -1099,9 +1043,6 @@ H5SL_insert(H5SL_t *slist, void *item, const void *key) HDassert(slist); HDassert(key); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -1148,9 +1089,6 @@ H5SL_add(H5SL_t *slist, void *item, const void *key) HDassert(slist); HDassert(key); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -1242,7 +1180,7 @@ H5SL_remove(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } done: FUNC_LEAVE_NOAPI(ret_value) @@ -1281,9 +1219,6 @@ H5SL_remove_first(H5SL_t *slist) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Assign level */ H5_CHECK_OVERFLOW(slist->curr_level, int, size_t); level = (size_t)slist->curr_level; @@ -1345,12 +1280,12 @@ H5SL_remove_first(H5SL_t *slist) H5SL_SHRINK(head, level) slist->curr_level--; - } /* end else */ + } } else break; - } /* end for */ - } /* end if */ + } + } done: FUNC_LEAVE_NOAPI(ret_value) @@ -1436,7 +1371,7 @@ H5SL_search(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* 'key' must not have been found in list, if we get here */ ret_value = NULL; @@ -1480,9 +1415,6 @@ H5SL_less(H5SL_t *slist, const void *key) HDassert(slist); HDassert(key); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -1531,7 +1463,7 @@ H5SL_less(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* An exact match for 'key' must not have been found in list, if we get here */ /* Check for a node with a key that is less than the given 'key' */ @@ -1541,13 +1473,13 @@ H5SL_less(H5SL_t *slist, const void *key) ret_value = slist->last->item; else ret_value = NULL; - } /* end if */ + } else { if (x->backward != slist->header) ret_value = x->backward->item; else ret_value = NULL; - } /* end else */ + } done: FUNC_LEAVE_NOAPI(ret_value) @@ -1588,9 +1520,6 @@ H5SL_greater(H5SL_t *slist, const void *key) HDassert(slist); HDassert(key); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -1639,7 +1568,7 @@ H5SL_greater(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* An exact match for 'key' must not have been found in list, if we get here */ /* ('x' must be the next node with a key greater than the 'key', or NULL) */ @@ -1734,7 +1663,7 @@ H5SL_find(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* 'key' must not have been found in list, if we get here */ ret_value = NULL; @@ -1826,7 +1755,7 @@ H5SL_below(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* An exact match for 'key' must not have been found in list, if we get here */ /* Check for a node with a key that is less than the given 'key' */ @@ -1836,13 +1765,13 @@ H5SL_below(H5SL_t *slist, const void *key) ret_value = slist->last; else ret_value = NULL; - } /* end if */ + } else { if (x->backward != slist->header) ret_value = x->backward; else ret_value = NULL; - } /* end else */ + } done: FUNC_LEAVE_NOAPI(ret_value) @@ -1931,7 +1860,7 @@ H5SL_above(H5SL_t *slist, const void *key) default: HDassert(0 && "Unknown skiplist type!"); - } /* end switch */ + } /* An exact match for 'key' must not have been found in list, if we get here */ /* ('x' must be the next node with a key greater than the 'key', or NULL) */ @@ -1971,9 +1900,6 @@ H5SL_first(H5SL_t *slist) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2007,9 +1933,6 @@ H5SL_next(H5SL_node_t *slist_node) /* Check args */ HDassert(slist_node); - /* Not currently supported */ - HDassert(!slist_node->removed); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2043,9 +1966,6 @@ H5SL_prev(H5SL_node_t *slist_node) /* Check args */ HDassert(slist_node); - /* Not currently supported */ - HDassert(!slist_node->removed); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2080,9 +2000,6 @@ H5SL_last(H5SL_t *slist) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2116,9 +2033,6 @@ H5SL_item(H5SL_node_t *slist_node) /* Check args */ HDassert(slist_node); - /* Not currently supported */ - HDassert(!slist_node->removed); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2179,15 +2093,21 @@ H5SL_iterate(H5SL_t *slist, H5SL_operator_t op, void *op_data) /* Protect against the node being deleted by the callback */ next = node->forward[0]; - /* Call the iterator callback */ - /* Casting away const OK -QAK */ - if (!node->removed) - if ((ret_value = (op)(node->item, (void *)node->key, op_data)) != 0) - break; + /* Call the iterator callback + * + * Ignoring const here is fine as we only need the value to be const + * with respect to the list code, which should never modify the + * elements. The library code that is making use of the skip list + * container can do what it likes with the elements. + */ + H5_GCC_CLANG_DIAG_OFF("cast-qual") + if ((ret_value = (op)(node->item, (void *)node->key, op_data)) != 0) + break; + H5_GCC_CLANG_DIAG_ON("cast-qual") /* Advance to next node */ node = next; - } /* end while */ + } FUNC_LEAVE_NOAPI(ret_value) } /* end H5SL_iterate() */ @@ -2222,9 +2142,6 @@ H5SL_release(H5SL_t *slist) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2274,9 +2191,6 @@ H5SL_free(H5SL_t *slist, H5SL_operator_t op, void *op_data) /* Check args */ HDassert(slist); - /* Not currently supported */ - HDassert(!slist->safe_iterating); - /* Check internal consistency */ /* (Pre-condition) */ @@ -2290,186 +2204,6 @@ done: /*-------------------------------------------------------------------------- NAME - H5SL_try_free_safe - PURPOSE - Makes the supplied callback on all nodes in the skip list, freeing each - node that the callback returns TRUE for. - USAGE - herr_t PURPOSE(slist,op,opdata) - H5SL_t *slist; IN/OUT: Pointer to skip list to release nodes - H5SL_try_free_op_t op; IN: Callback function to try to free item & key - void *op_data; IN/OUT: Pointer to application data for callback - - RETURNS - Returns non-negative on success, negative on failure. - DESCRIPTION - Makes the supplied callback on all nodes in the skip list, freeing each - node that the callback returns TRUE for. The iteration is performed in - a safe manner, such that the callback can call H5SL_remove(), - H5SL_search(), H5SL_find(), and H5SL_iterate() on nodes in this - skiplist, except H5SL_remove() may not be call on *this* node. - GLOBAL VARIABLES - COMMENTS, BUGS, ASSUMPTIONS - This function is written to be most efficient when most nodes are - removed from the skiplist, as it rebuilds the nodes afterwards. - EXAMPLES - REVISION LOG ---------------------------------------------------------------------------*/ -herr_t -H5SL_try_free_safe(H5SL_t *slist, H5SL_try_free_op_t op, void *op_data) -{ - H5SL_node_t *node, *next_node, *last_node; /* Pointers to skip list nodes */ - htri_t op_ret; - herr_t ret_value = SUCCEED; - - FUNC_ENTER_NOAPI_NOINIT - - /* Check args */ - HDassert(slist); - HDassert(op); - - /* Not currently supported */ - HDassert(!slist->safe_iterating); - - /* Check internal consistency */ - /* (Pre-condition) */ - - /* Mark skip list as safe iterating, so nodes aren't freed out from under - * us */ - slist->safe_iterating = TRUE; - - /* Iterate over skip list nodes, making the callback for each and marking - * them as removed if requested by the callback */ - node = slist->header->forward[0]; - while (node) { - /* Check if the node was already removed */ - if (!node->removed) { - /* Call callback */ - /* Casting away const OK -NAF */ - if ((op_ret = (op)(node->item, (void *)node->key, op_data)) < 0) - HGOTO_ERROR(H5E_SLIST, H5E_CALLBACK, FAIL, "callback operation failed") - - /* Check if op indicated that the node should be removed */ - if (op_ret) - /* Mark the node as removed */ - node->removed = TRUE; - } /* end if */ - - /* Advance node */ - node = node->forward[0]; - } /* end while */ - - /* Reset safe_iterating */ - slist->safe_iterating = FALSE; - - /* Iterate over nodes, freeing ones marked as removed */ - node = slist->header->forward[0]; - last_node = slist->header; - while (node) { - /* Save next node */ - next_node = node->forward[0]; - - /* Check if the node was marked as removed */ - if (node->removed) { - /* Remove the node */ - node->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[node->log_nalloc], node->forward); - node = H5FL_FREE(H5SL_node_t, node); - slist->nobjs--; - } /* end if */ - else { - /* Update backwards and forwards[0] pointers, and set the level to - * 0. Since the list is flattened we must rebuild the skiplist - * afterwards. */ - /* Set level to 0. Note there is no need to preserve - * node->forward[0] since it was cached above and will always be - * updated later. */ - if (node->level > 0) { - node->forward = - (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[node->log_nalloc], (void *)node->forward); - if (NULL == (node->forward = (H5SL_node_t **)H5FL_FAC_MALLOC(H5SL_fac_g[0]))) - HGOTO_ERROR(H5E_SLIST, H5E_CANTALLOC, FAIL, "memory allocation failed") - node->log_nalloc = 0; - node->level = 0; - } /* end if */ - - /* Update pointers */ - last_node->forward[0] = node; - node->backward = last_node; - last_node = node; - } /* end else */ - - /* Advance node */ - node = next_node; - } /* end while */ - - /* Final pointer update */ - last_node->forward[0] = NULL; - slist->last = last_node; - - /* Demote skip list to level 0 */ - if (slist->curr_level > 0) { - HDassert(slist->header->level == (size_t)slist->curr_level); - - node = slist->header->forward[0]; - slist->header->forward = (H5SL_node_t **)H5FL_FAC_FREE(H5SL_fac_g[slist->header->log_nalloc], - (void *)slist->header->forward); - if (NULL == (slist->header->forward = (H5SL_node_t **)H5FL_FAC_MALLOC(H5SL_fac_g[0]))) - HGOTO_ERROR(H5E_SLIST, H5E_CANTALLOC, FAIL, "memory allocation failed") - slist->header->forward[0] = node; - slist->header->log_nalloc = 0; - slist->header->level = 0; - } /* end if */ - - /* Check if there are any nodes left */ - if (slist->nobjs > 0) { - int i; - - HDassert(slist->header->forward[0]); - - /* Set skiplist level to 0 */ - slist->curr_level = 0; - - /* Rebuild the forward arrays */ - for (i = 0; slist->curr_level >= i; i++) { - HDassert(slist->curr_level == i); - - /* Promote every third node this level until we run out of nodes */ - node = last_node = slist->header; - while (1) { - /* Check second node in gap, if not present, no need to promote - * further this level. */ - HDassert(node->forward[i]); - node = node->forward[i]->forward[i]; - if (!node) - break; - - /* Check third and fourth node in gap, if either is not present, - * no need to promote further this level. */ - node = node->forward[i]; - if (!node || !node->forward[i]) - break; - - /* Promote the third node in the gap */ - H5SL_PROMOTE(slist, node, last_node, FAIL) - last_node = node; - } /* end while */ - } /* end for */ - } /* end if */ - else { - HDassert(!slist->header->forward[0]); - HDassert(slist->last == slist->header); - HDassert(slist->nobjs == 0); - - /* Reset the skiplist level */ - slist->curr_level = -1; - } /* end else */ - -done: - FUNC_LEAVE_NOAPI(ret_value) -} /* end H5SL_try_free_safe() */ - -/*-------------------------------------------------------------------------- - NAME H5SL_destroy PURPOSE Close a skip list, deallocating it and freeing all its nodes. diff --git a/src/H5SLprivate.h b/src/H5SLprivate.h index c9e1147..be6f7b6 100644 --- a/src/H5SLprivate.h +++ b/src/H5SLprivate.h @@ -60,9 +60,6 @@ typedef int (*H5SL_cmp_t)(const void *key1, const void *key2); /* Typedef for iteration operations */ typedef herr_t (*H5SL_operator_t)(void *item, void *key, void *operator_data /*in,out*/); -/* Typedef for H5SL_try_free_safe operation callback */ -typedef htri_t (*H5SL_try_free_op_t)(void *item, void *key, void *operator_data /*in,out*/); - /********************/ /* Private routines */ /********************/ @@ -86,7 +83,6 @@ H5_DLL void * H5SL_item(H5SL_node_t *slist_node); H5_DLL herr_t H5SL_iterate(H5SL_t *slist, H5SL_operator_t op, void *op_data); H5_DLL herr_t H5SL_release(H5SL_t *slist); H5_DLL herr_t H5SL_free(H5SL_t *slist, H5SL_operator_t op, void *op_data); -H5_DLL herr_t H5SL_try_free_safe(H5SL_t *slist, H5SL_try_free_op_t op, void *op_data); H5_DLL herr_t H5SL_close(H5SL_t *slist); H5_DLL herr_t H5SL_destroy(H5SL_t *slist, H5SL_operator_t op, void *op_data); H5_DLL int H5SL_term_interface(void); diff --git a/test/tskiplist.c b/test/tskiplist.c index 4bf9b11..31b5cff 100644 --- a/test/tskiplist.c +++ b/test/tskiplist.c @@ -1165,213 +1165,6 @@ test_skiplist_free(void) /**************************************************************** ** -** test_skiplist_try_free_safe(): Test H5SL (skip list) code. -** Tests 'try_free_safe' operation in skip lists. -** -****************************************************************/ -/* Macro definitions */ -#define TEST_TFS_MAX_NOBJS 100 -#define TEST_TFS_MIN_NOBJS 5 -#define TEST_TFS_NITER 50 - -/* Structure to hold the list of objects */ -typedef struct { - H5SL_t * slist; /* Skiplist holding the objects */ - struct test_tfs_obj_t *list; /* Linear list of objects */ - int nobjs; /* Number of objects in list */ - int nobjs_rem; /* Number of objects in list that have not been freed */ -} test_tfs_list_t; - -/* Structure for an object */ -typedef struct test_tfs_obj_t { - int idx; /* Index (key) for this object */ - int nfrees; /* Number of times this object has been freed */ -} test_tfs_obj_t; - -/* op_data struct for H5SL_iterate() */ -typedef struct test_tfs_it_ud_t { - test_tfs_list_t *obj_list; /* List of objects */ - int last_idx; /* Index of last object visited in iteration */ - int ncalls; /* Number of times this callback was called */ -} test_tfs_it_ud_t; - -/* iterate callback */ -static herr_t -test_tfs_iter(void *_obj, void *key, void *_udata) -{ - test_tfs_obj_t * obj = (test_tfs_obj_t *)_obj; - test_tfs_it_ud_t *udata = (test_tfs_it_ud_t *)_udata; - - /* Check consistency */ - CHECK_PTR_EQ((void *)&obj->idx, key, "obj->idx"); - CHECK_PTR_EQ(obj, &udata->obj_list->list[obj->idx], "obj_list->list[obj->idx]"); - - /* Increment number of calls */ - udata->ncalls++; - - /* Verify we were given the correct object */ - do { - udata->last_idx++; - } while (udata->obj_list->list[udata->last_idx].nfrees != 0); - VERIFY(udata->last_idx, obj->idx, "H5SL_iterate"); - - return 0; -} /* end test_tfs_iter() */ - -/* try_free_safe callback */ -static htri_t -test_tfs_free(void *_obj, void *key, void *_obj_list) -{ - test_tfs_obj_t * obj = (test_tfs_obj_t *)_obj; - test_tfs_list_t *obj_list = (test_tfs_list_t *)_obj_list; - test_tfs_it_ud_t iter_ud; - int nrems, rem_idx, i, j; - test_tfs_obj_t * obj_ret; - herr_t ret; /* return value */ - htri_t ret_value; - - /* Check consistency */ - CHECK_PTR_EQ((void *)&obj->idx, key, "obj->idx"); - CHECK_PTR_EQ(obj, &obj_list->list[obj->idx], "obj_list->list[obj->idx]"); - - /* Mark this object as freed (to make sure it isn't recursively freed, that - * is not something we support, we will undo this if we decide later not to - * free the object) */ - obj->nfrees++; - obj_list->nobjs_rem--; - - /* Decide how many objects to remove */ - nrems = (int)(HDrandom() % (long)3); - - /* Remove objects */ - for (i = 0; i < nrems; i++) - /* Check nobjs_rem */ - if (obj_list->nobjs_rem > 0) { - /* Remove a random object from the list */ - rem_idx = (int)(HDrandom() % (long)obj_list->nobjs_rem); - - /* Scan the list, finding the rem_idx'th object that has not been - * freed */ - for (j = 0; j < obj_list->nobjs; j++) - if (obj_list->list[j].nfrees == 0) { - if (rem_idx == 0) - break; - else - rem_idx--; - } /* end if */ - if (j == obj_list->nobjs) - ERROR("invalid obj_list"); - else { - /* Remove the object */ - obj_ret = (test_tfs_obj_t *)H5SL_remove(obj_list->slist, &j); - CHECK_PTR(obj_ret, "H5SL_remove"); - obj_ret->nfrees++; - obj_list->nobjs_rem--; - } /* end else */ - } /* end if */ - - /* Mark this object as not freed so we know to expect it in the iterate call - */ - obj->nfrees--; - obj_list->nobjs_rem++; - - /* Iterate over skip list (maybe) */ - if (HDrandom() % (long)5) { - iter_ud.obj_list = obj_list; - iter_ud.last_idx = -1; - iter_ud.ncalls = 0; - ret = H5SL_iterate(obj_list->slist, test_tfs_iter, &iter_ud); - CHECK(ret, FAIL, "H5SL_iterate"); - VERIFY(iter_ud.ncalls, obj_list->nobjs_rem, "H5SL_iterate"); - } /* end if */ - - /* Verify nobjs_rem is non-negative */ - if (obj_list->nobjs_rem < 0) - ERROR("invalid nobjs_rem"); - - /* Decide whether this object should be freed */ - if (HDrandom() % (long)2) { - /* Free the object */ - ret_value = TRUE; - obj->nfrees++; - obj_list->nobjs_rem--; - } /* end if */ - else - /* Do not free the object */ - ret_value = FALSE; - - return ret_value; -} /* end test_tfs_free() */ - -/* Test function */ -static void -test_skiplist_try_free_safe(void) -{ - test_tfs_list_t obj_list; - test_tfs_obj_t list[TEST_TFS_MAX_NOBJS]; - int i, j; - int nobjs_found; - hsize_t count; - herr_t ret; /* Generic return value */ - - /* Output message about test being performed */ - MESSAGE(7, ("Testing Skip List 'Try Free Safe' Operation\n")); - - /* Create a skip list */ - obj_list.slist = H5SL_create(H5SL_TYPE_INT, NULL); - CHECK_PTR(obj_list.slist, "H5SL_create"); - - /* Init obj_list.list */ - obj_list.list = list; - for (j = 0; j < TEST_TFS_MAX_NOBJS; j++) - list[j].idx = j; - - for (i = 0; i < TEST_TFS_NITER; i++) { - /* Build object list */ - obj_list.nobjs = obj_list.nobjs_rem = - (int)(TEST_TFS_MIN_NOBJS + (HDrandom() % (long)(TEST_TFS_MAX_NOBJS - TEST_TFS_MIN_NOBJS + 1))); - for (j = 0; j < obj_list.nobjs; j++) { - list[j].nfrees = 0; - ret = H5SL_insert(obj_list.slist, &list[j], &list[j].idx); - CHECK(ret, FAIL, "H5SL_insert"); - } /* end for */ - - /* Call H5S_try_free_safe() - free most of the items in the skip list in - * a safe manner */ - ret = H5SL_try_free_safe(obj_list.slist, test_tfs_free, &obj_list); - CHECK(ret, FAIL, "H5SL_try_free_safe"); - - /* Verify list */ - nobjs_found = 0; - for (j = 0; j < obj_list.nobjs; j++) - if (list[j].nfrees == 0) - nobjs_found++; - else - VERIFY(list[j].nfrees, (long)1, "list[j].nfrees"); - - /* Verify number of objects */ - VERIFY(obj_list.nobjs_rem, nobjs_found, "obj_list.nobjs_rem"); - count = H5SL_count(obj_list.slist); - VERIFY(count, (size_t)nobjs_found, "H5SL_count"); - - /* Release the skip list, forcibly freeing all nodes (will not make - * callbacks) */ - ret = H5SL_release(obj_list.slist); - CHECK(ret, FAIL, "H5SL_release"); - - /* Verify number of objects is 0 */ - count = H5SL_count(obj_list.slist); - VERIFY(count, (size_t)0, "H5SL_count"); - } /* end for */ - - /* Close the skip list */ - ret = H5SL_close(obj_list.slist); - CHECK(ret, FAIL, "H5SL_close"); - -} /* end test_skiplist_try_free_safe() */ - -/**************************************************************** -** ** test_skiplist_less(): Test H5SL (skip list) code. ** Tests 'less' operation in skip lists. ** @@ -1796,7 +1589,6 @@ test_skiplist(void) test_skiplist_add(); /* Test 'add' operation */ test_skiplist_destroy(); /* Test 'destroy' operation */ test_skiplist_free(); /* Test 'free' operation */ - test_skiplist_try_free_safe(); /* Test 'try_free_safe' operation */ test_skiplist_less(); /* Test 'less' operation */ test_skiplist_greater(); /* Test 'greater' operation */ test_skiplist_below(); /* Test 'below' operation */ -- cgit v0.12