diff options
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.c | 66 |
1 files changed, 54 insertions, 12 deletions
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c index fdc82c8b88..e65d397cfb 100644 --- a/erts/emulator/beam/erl_db_hash.c +++ b/erts/emulator/beam/erl_db_hash.c @@ -105,7 +105,16 @@ #define NSEG_2 256 /* Size of second segment table */ #define NSEG_INC 128 /* Number of segments to grow after that */ -#define SEGTAB(tb) ((struct segment**)erts_smp_atomic_read_acqb(&(tb)->segtab)) +#ifdef ERTS_SMP +# define DB_USING_FINE_LOCKING(TB) (((TB))->common.type & DB_FINE_LOCKED) +#else +# define DB_USING_FINE_LOCKING(TB) 0 +#endif + +#define SEGTAB(tb) \ + (DB_USING_FINE_LOCKING(tb) \ + ? ((struct segment**) erts_smp_atomic_read_acqb(&(tb)->segtab)) \ + : ((struct segment**) erts_smp_atomic_read(&(tb)->segtab))) #define NACTIVE(tb) ((int)erts_smp_atomic_read(&(tb)->nactive)) #define NITEMS(tb) ((int)erts_smp_atomic_read(&(tb)->common.nitems)) @@ -122,7 +131,9 @@ */ static ERTS_INLINE Uint hash_to_ix(DbTableHash* tb, HashValue hval) { - Uint mask = erts_smp_atomic_read_acqb(&tb->szm); + Uint mask = (DB_USING_FINE_LOCKING(tb) + ? erts_smp_atomic_read_acqb(&tb->szm) + : erts_smp_atomic_read(&tb->szm)); Uint ix = hval & mask; if (ix >= erts_smp_atomic_read(&tb->nactive)) { ix &= mask>>1; @@ -2350,7 +2361,10 @@ static int alloc_seg(DbTableHash *tb) struct ext_segment* eseg; eseg = (struct ext_segment*) SEGTAB(tb)[seg_ix-1]; MY_ASSERT(eseg!=NULL && eseg->s.is_ext_segment); - erts_smp_atomic_set_relb(&tb->segtab, (erts_aint_t) eseg->segtab); + if (DB_USING_FINE_LOCKING(tb)) + erts_smp_atomic_set_relb(&tb->segtab, (erts_aint_t) eseg->segtab); + else + erts_smp_atomic_set(&tb->segtab, (erts_aint_t) eseg->segtab); tb->nsegs = eseg->nsegs; } ASSERT(seg_ix < tb->nsegs); @@ -2422,7 +2436,12 @@ static int free_seg(DbTableHash *tb, int free_records) MY_ASSERT(newtop->s.is_ext_segment); if (newtop->prev_segtab != NULL) { /* Time to use a smaller segtab */ - erts_smp_atomic_set_relb(&tb->segtab, (erts_aint_t)newtop->prev_segtab); + if (DB_USING_FINE_LOCKING(tb)) + erts_smp_atomic_set_relb(&tb->segtab, + (erts_aint_t)newtop->prev_segtab); + else + erts_smp_atomic_set(&tb->segtab, + (erts_aint_t) newtop->prev_segtab); tb->nsegs = seg_ix; ASSERT(tb->nsegs == EXTSEG(SEGTAB(tb))->nsegs); } @@ -2488,6 +2507,28 @@ static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2, return list; } +static ERTS_INLINE int +begin_resizing(DbTableHash* tb) +{ + if (DB_USING_FINE_LOCKING(tb)) + return !erts_smp_atomic_xchg(&tb->is_resizing, 1); + else { + if (erts_smp_atomic_read(&tb->is_resizing)) + return 0; + erts_smp_atomic_set(&tb->is_resizing, 1); + return 1; + } +} + +static ERTS_INLINE void +done_resizing(DbTableHash* tb) +{ + if (DB_USING_FINE_LOCKING(tb)) + erts_smp_atomic_set_relb(&tb->is_resizing, 0); + else + erts_smp_atomic_set(&tb->is_resizing, 0); +} + /* Grow table with one new bucket. ** Allocate new segment if needed. */ @@ -2500,9 +2541,8 @@ static void grow(DbTableHash* tb, int nactive) int from_ix; int szm; - if (erts_smp_atomic_xchg(&tb->is_resizing, 1)) { + if (!begin_resizing(tb)) return; /* already in progress */ - } if (NACTIVE(tb) != nactive) { goto abort; /* already done (race) */ } @@ -2534,9 +2574,12 @@ static void grow(DbTableHash* tb, int nactive) } erts_smp_atomic_inc(&tb->nactive); if (from_ix == 0) { - erts_smp_atomic_set_relb(&tb->szm, szm); + if (DB_USING_FINE_LOCKING(tb)) + erts_smp_atomic_set_relb(&tb->szm, szm); + else + erts_smp_atomic_set(&tb->szm, szm); } - erts_smp_atomic_set_relb(&tb->is_resizing, 0); + done_resizing(tb); /* Finally, let's split the bucket. We try to do it in a smart way to keep link order and avoid unnecessary updates of next-pointers */ @@ -2568,7 +2611,7 @@ static void grow(DbTableHash* tb, int nactive) return; abort: - erts_smp_atomic_set_relb(&tb->is_resizing, 0); + done_resizing(tb); } @@ -2577,9 +2620,8 @@ abort: */ static void shrink(DbTableHash* tb, int nactive) { - if (erts_smp_atomic_xchg(&tb->is_resizing, 1)) { + if (!begin_resizing(tb)) return; /* already in progress */ - } if (NACTIVE(tb) == nactive) { erts_smp_rwmtx_t* lck; int src_ix = nactive - 1; @@ -2626,7 +2668,7 @@ static void shrink(DbTableHash* tb, int nactive) } /*else already done */ - erts_smp_atomic_set_relb(&tb->is_resizing, 0); + done_resizing(tb); } |