diff options
Diffstat (limited to 'erts/emulator/beam/erl_db_hash.c')
-rw-r--r-- | erts/emulator/beam/erl_db_hash.c | 76 |
1 files changed, 42 insertions, 34 deletions
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c index 81b0c4465c..cff65f244d 100644 --- a/erts/emulator/beam/erl_db_hash.c +++ b/erts/emulator/beam/erl_db_hash.c @@ -148,8 +148,11 @@ static ERTS_INLINE Uint hash_to_ix(DbTableHash* tb, HashValue hval) } /* Remember a slot containing a pseudo-deleted item (INVALID_HASH) -*/ -static ERTS_INLINE void add_fixed_deletion(DbTableHash* tb, int ix) + * Return false if we got raced by unfixing thread + * and the object should be deleted for real. + */ +static ERTS_INLINE int add_fixed_deletion(DbTableHash* tb, int ix, + erts_aint_t fixated_by_me) { erts_aint_t was_next; erts_aint_t exp_next; @@ -160,12 +163,18 @@ static ERTS_INLINE void add_fixed_deletion(DbTableHash* tb, int ix) fixd->slot = ix; was_next = erts_smp_atomic_read_acqb(&tb->fixdel); do { /* Lockless atomic insertion in linked list: */ - exp_next = was_next; + if (NFIXED(tb) <= fixated_by_me) { + erts_db_free(ERTS_ALC_T_DB_FIX_DEL, (DbTable*)tb, + fixd, sizeof(FixedDeletion)); + return 0; /* raced by unfixer */ + } + exp_next = was_next; fixd->next = (FixedDeletion*) exp_next; - was_next = erts_smp_atomic_cmpxchg_relb(&tb->fixdel, - (erts_aint_t) fixd, - exp_next); + was_next = erts_smp_atomic_cmpxchg_mb(&tb->fixdel, + (erts_aint_t) fixd, + exp_next); }while (was_next != exp_next); + return 1; } @@ -460,9 +469,6 @@ static ERTS_INLINE void try_shrink(DbTableHash* tb) } } -#define EQ_REL(x,y,y_base) \ - (is_same(x,NULL,y,y_base) || (is_not_both_immed((x),(y)) && eq_rel((x),NULL,(y),y_base))) - /* Is this a live object (not pseodo-deleted) with the specified key? */ static ERTS_INLINE int has_live_key(DbTableHash* tb, HashDbTerm* b, @@ -472,7 +478,7 @@ static ERTS_INLINE int has_live_key(DbTableHash* tb, HashDbTerm* b, else { Eterm itemKey = GETKEY(tb, b->dbterm.tpl); ASSERT(!is_header(itemKey)); - return EQ_REL(key, itemKey, b->dbterm.tpl); + return EQ(key, itemKey); } } @@ -485,7 +491,7 @@ static ERTS_INLINE int has_key(DbTableHash* tb, HashDbTerm* b, else { Eterm itemKey = GETKEY(tb, b->dbterm.tpl); ASSERT(!is_header(itemKey)); - return EQ_REL(key, itemKey, b->dbterm.tpl); + return EQ(key, itemKey); } } @@ -607,8 +613,8 @@ void db_unfix_table_hash(DbTableHash *tb) || (erts_smp_lc_rwmtx_is_rlocked(&tb->common.rwlock) && !tb->common.is_thread_safe)); restart: - fixdel = (FixedDeletion*) erts_smp_atomic_xchg_acqb(&tb->fixdel, - (erts_aint_t) NULL); + fixdel = (FixedDeletion*) erts_smp_atomic_xchg_mb(&tb->fixdel, + (erts_aint_t) NULL); while (fixdel != NULL) { FixedDeletion *fx = fixdel; int ix = fx->slot; @@ -1142,9 +1148,9 @@ int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret) while(b != 0) { if (has_live_key(tb,b,key,hval)) { --nitems_diff; - if (nitems_diff == -1 && IS_FIXED(tb)) { + if (nitems_diff == -1 && IS_FIXED(tb) + && add_fixed_deletion(tb, ix, 0)) { /* Pseudo remove (no need to keep several of same key) */ - add_fixed_deletion(tb, ix); b->hvalue = INVALID_HASH; } else { *bp = b->next; @@ -1196,9 +1202,8 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret) ++nkeys; if (db_eq(&tb->common,object, &b->dbterm)) { --nitems_diff; - if (nkeys==1 && IS_FIXED(tb)) { /* Pseudo remove */ - add_fixed_deletion(tb,ix); - b->hvalue = INVALID_HASH; + if (nkeys==1 && IS_FIXED(tb) && add_fixed_deletion(tb,ix,0)) { + b->hvalue = INVALID_HASH; /* Pseudo remove */ bp = &b->next; b = b->next; } else { @@ -1820,14 +1825,17 @@ static int db_select_delete_hash(Process *p, int did_erase = 0; if (db_match_dbterm(&tb->common, p, mpi.mp, 0, &(*current)->dbterm, NULL, 0) == am_true) { + HashDbTerm *del; if (NFIXED(tb) > fixated_by_me) { /* fixated by others? */ if (slot_ix != last_pseudo_delete) { - add_fixed_deletion(tb, slot_ix); - last_pseudo_delete = slot_ix; + if (!add_fixed_deletion(tb, slot_ix, fixated_by_me)) + goto do_erase; + last_pseudo_delete = slot_ix; } (*current)->hvalue = INVALID_HASH; } else { - HashDbTerm *del = *current; + do_erase: + del = *current; *current = (*current)->next; free_term(tb, del); did_erase = 1; @@ -1931,14 +1939,17 @@ static int db_select_delete_continue_hash(Process *p, int did_erase = 0; if (db_match_dbterm(&tb->common, p, mp, 0, &(*current)->dbterm, NULL, 0) == am_true) { + HashDbTerm *del; if (NFIXED(tb) > fixated_by_me) { /* fixated by others? */ if (slot_ix != last_pseudo_delete) { - add_fixed_deletion(tb, slot_ix); + if (!add_fixed_deletion(tb, slot_ix, fixated_by_me)) + goto do_erase; last_pseudo_delete = slot_ix; } (*current)->hvalue = INVALID_HASH; } else { - HashDbTerm *del = *current; + do_erase: + del = *current; *current = (*current)->next; free_term(tb, del); did_erase = 1; @@ -2089,9 +2100,9 @@ static int db_take_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret) *ret = get_term_list(p, tb, key, hval, b, &bend); while (b != bend) { --nitems_diff; - if (nitems_diff == -1 && IS_FIXED(tb)) { + if (nitems_diff == -1 && IS_FIXED(tb) + && add_fixed_deletion(tb, ix, 0)) { /* Pseudo remove (no need to keep several of same key) */ - add_fixed_deletion(tb, ix); bp = &b->next; b->hvalue = INVALID_HASH; b = b->next; @@ -2131,7 +2142,7 @@ int db_mark_all_deleted_hash(DbTable *tbl) for (i = 0; i < NACTIVE(tb); i++) { if ((list = BUCKET(tb,i)) != NULL) { - add_fixed_deletion(tb, i); + add_fixed_deletion(tb, i, 0); do { list->hvalue = INVALID_HASH; list = list->next; @@ -2190,11 +2201,11 @@ static void db_print_hash(int to, void *to_arg, int show, DbTable *tbl) erts_print(to, to_arg, "*"); if (tb->common.compress) { Eterm key = GETKEY(tb, list->dbterm.tpl); - erts_print(to, to_arg, "key=%R", key, list->dbterm.tpl); + erts_print(to, to_arg, "key=%T", key); } else { - Eterm obj = make_tuple_rel(list->dbterm.tpl,list->dbterm.tpl); - erts_print(to, to_arg, "%R", obj, list->dbterm.tpl); + Eterm obj = make_tuple(list->dbterm.tpl); + erts_print(to, to_arg, "%T", obj); } if (list->next != 0) erts_print(to, to_arg, ","); @@ -2885,9 +2896,6 @@ Ldone: handle->dbterm = &b->dbterm; handle->flags = flags; handle->new_size = b->dbterm.size; -#if HALFWORD_HEAP - handle->abs_vec = NULL; -#endif handle->lck = lck; return 1; } @@ -2908,8 +2916,8 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle) ASSERT((&b->dbterm == handle->dbterm) == !(tb->common.compress && handle->flags & DB_MUST_RESIZE)); if (handle->flags & DB_NEW_OBJECT && cret != DB_ERROR_NONE) { - if (IS_FIXED(tb)) { - add_fixed_deletion(tb, hash_to_ix(tb, b->hvalue)); + if (IS_FIXED(tb) && add_fixed_deletion(tb, hash_to_ix(tb, b->hvalue), + 0)) { b->hvalue = INVALID_HASH; } else { *bp = b->next; |