diff options
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.c | 152 | ||||
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.h | 3 |
2 files changed, 88 insertions, 67 deletions
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c index 23074766e8..d55e110e10 100644 --- a/erts/emulator/beam/erl_db_hash.c +++ b/erts/emulator/beam/erl_db_hash.c @@ -149,20 +149,14 @@ static ERTS_INLINE Uint hash_to_ix(DbTableHash* tb, HashValue hval) return ix; } -/* Remember a slot containing a pseudo-deleted item - * 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) + +static ERTS_INLINE int link_fixdel(DbTableHash* tb, + FixedDeletion* fixd, + erts_aint_t fixated_by_me) { erts_aint_t was_next; erts_aint_t exp_next; - FixedDeletion* fixd = (FixedDeletion*) erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL, - (DbTable *) tb, - sizeof(FixedDeletion)); - ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion)); - fixd->slot = ix; + was_next = erts_atomic_read_acqb(&tb->fixdel); do { /* Lockless atomic insertion in linked list: */ if (NFIXED(tb) <= fixated_by_me) { @@ -179,6 +173,21 @@ static ERTS_INLINE int add_fixed_deletion(DbTableHash* tb, int ix, return 1; } +/* Remember a slot containing a pseudo-deleted item + * Return false if we got raced by unfixing thread + * and the object should be deleted for real. + */ +static int add_fixed_deletion(DbTableHash* tb, int ix, + erts_aint_t fixated_by_me) +{ + FixedDeletion* fixd = (FixedDeletion*) erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL, + (DbTable *) tb, + sizeof(FixedDeletion)); + ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion)); + fixd->slot = ix; + fixd->all = 0; + return link_fixdel(tb, fixd, fixated_by_me); +} static ERTS_INLINE int is_pseudo_deleted(HashDbTerm* p) @@ -579,54 +588,61 @@ SWord db_unfix_table_hash(DbTableHash *tb) SWord work = 0; ERTS_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&tb->common.rwlock) - || (erts_lc_rwmtx_is_rlocked(&tb->common.rwlock) - && !tb->common.is_thread_safe)); + || (erts_lc_rwmtx_is_rlocked(&tb->common.rwlock) + && !tb->common.is_thread_safe)); restart: fixdel = (FixedDeletion*) erts_atomic_xchg_mb(&tb->fixdel, - (erts_aint_t) NULL); - while (fixdel != NULL) { - FixedDeletion *fx = fixdel; - int ix = fx->slot; - HashDbTerm **bp; - HashDbTerm *b; - HashDbTerm *free_us = NULL; - erts_rwmtx_t* lck = WLOCK_HASH(tb,ix); - - if (IS_FIXED(tb)) { /* interrupted by fixer */ - WUNLOCK_HASH(lck); - restore_fixdel(tb,fixdel); - if (!IS_FIXED(tb)) { - goto restart; /* unfixed again! */ - } - return work; - } - if (ix < NACTIVE(tb)) { - bp = &BUCKET(tb, ix); - b = *bp; - - while (b != NULL) { - if (is_pseudo_deleted(b)) { - HashDbTerm* nxt = b->next; - b->next = free_us; - free_us = b; - work++; - b = *bp = nxt; - } else { - bp = &b->next; - b = b->next; - } - } - } - /* else slot has been joined and purged by shrink() */ - WUNLOCK_HASH(lck); - free_term_list(tb, free_us); - fixdel = fx->next; - erts_db_free(ERTS_ALC_T_DB_FIX_DEL, - (DbTable *) tb, - (void *) fx, - sizeof(FixedDeletion)); - ERTS_ETS_MISC_MEM_ADD(-sizeof(FixedDeletion)); - work++; + (erts_aint_t) NULL); + while (fixdel) { + FixedDeletion *free_me; + + do { + HashDbTerm **bp; + HashDbTerm *b; + HashDbTerm *free_us = NULL; + erts_rwmtx_t* lck; + + lck = WLOCK_HASH(tb, fixdel->slot); + + if (IS_FIXED(tb)) { /* interrupted by fixer */ + WUNLOCK_HASH(lck); + restore_fixdel(tb,fixdel); + if (!IS_FIXED(tb)) { + goto restart; /* unfixed again! */ + } + return work; + } + if (fixdel->slot < NACTIVE(tb)) { + bp = &BUCKET(tb, fixdel->slot); + b = *bp; + + while (b != NULL) { + if (is_pseudo_deleted(b)) { + HashDbTerm* nxt = b->next; + b->next = free_us; + free_us = b; + work++; + b = *bp = nxt; + } else { + bp = &b->next; + b = b->next; + } + } + } + /* else slot has been joined and purged by shrink() */ + WUNLOCK_HASH(lck); + free_term_list(tb, free_us); + + }while (fixdel->all && fixdel->slot-- > 0); + + free_me = fixdel; + fixdel = fixdel->next; + erts_db_free(ERTS_ALC_T_DB_FIX_DEL, + (DbTable *) tb, + (void *) free_me, + sizeof(FixedDeletion)); + ERTS_ETS_MISC_MEM_ADD(-sizeof(FixedDeletion)); + work++; } /* ToDo: Maybe try grow/shrink the table as well */ @@ -2306,20 +2322,24 @@ void db_initialize_hash(void) static SWord db_mark_all_deleted_hash(DbTable *tbl, SWord reds) { DbTableHash *tb = &tbl->hash; - HashDbTerm* list; + FixedDeletion* fixdel; int i; ERTS_LC_ASSERT(IS_TAB_WLOCKED(tb)); + fixdel = erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL, + (DbTable *) tb, + sizeof(FixedDeletion)); + ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion)); + fixdel->slot = NACTIVE(tb) - 1; + fixdel->all = 1; + link_fixdel(tb, fixdel, 0); + for (i = 0; i < NACTIVE(tb); i++) { - if ((list = BUCKET(tb,i)) != NULL) { - add_fixed_deletion(tb, i, 0); - do { - list->pseudo_deleted = 1; - list = list->next; - }while(list != NULL); - reds--; - } + HashDbTerm* b; + for (b = BUCKET(tb,i); b; b = b->next) + b->pseudo_deleted = 1; + --reds; } erts_atomic_set_nob(&tb->common.nitems, 0); return reds < 0 ? 0 : reds; /* ToDo: Yield! */ diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h index 127512e1fe..d48343378d 100644 --- a/erts/emulator/beam/erl_db_hash.h +++ b/erts/emulator/beam/erl_db_hash.h @@ -24,7 +24,8 @@ #include "erl_db_util.h" /* DbTerm & DbTableCommon */ typedef struct fixed_deletion { - int slot; + UWord slot : sizeof(UWord)*8 - 1; + UWord all : 1; struct fixed_deletion *next; } FixedDeletion; |