diff options
| -rw-r--r-- | erts/emulator/beam/erl_db.h | 2 | ||||
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.c | 246 | ||||
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.h | 4 |
3 files changed, 97 insertions, 155 deletions
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h index 1d26c49652..2f3c4a8e1b 100644 --- a/erts/emulator/beam/erl_db.h +++ b/erts/emulator/beam/erl_db.h @@ -267,7 +267,5 @@ erts_db_free_nt(ErtsAlcType_t type, void *ptr, Uint size) #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */ -#undef ERTS_DB_ALC_MEM_UPDATE_ - #endif /* #if defined(ERTS_WANT_DB_INTERNAL__) && !defined(ERTS_HAVE_DB_INTERNAL__) */ diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c index 16d97f05ee..82f03e458a 100644 --- a/erts/emulator/beam/erl_db_hash.c +++ b/erts/emulator/beam/erl_db_hash.c @@ -84,14 +84,6 @@ #include "erl_db_hash.h" -#ifdef MYDEBUG /* Will fail test case ets_SUITE:memory */ -# define IF_DEBUG(x) x -# define MY_ASSERT(x) ASSERT(x) -#else -# define IF_DEBUG(x) -# define MY_ASSERT(x) -#endif - /* * The following symbols can be manipulated to "tune" the linear hash array */ @@ -102,7 +94,7 @@ #define SEGSZ (1 << SEGSZ_EXP) #define SEGSZ_MASK (SEGSZ-1) -#define NSEG_1 2 /* Size of first segment table (must be at least 2) */ +#define NSEG_1 (ErtsSizeofMember(DbTableHash,first_segtab) / sizeof(struct segment*)) #define NSEG_2 256 /* Size of second segment table */ #define NSEG_INC 128 /* Number of segments to grow after that */ @@ -318,27 +310,21 @@ struct mp_info { /* A table segment */ struct segment { - HashDbTerm* buckets[SEGSZ]; -#ifdef MYDEBUG - int is_ext_segment; -#endif + HashDbTerm* buckets[1]; }; +#define SIZEOF_SEGMENT(N) \ + (offsetof(struct segment,buckets) + sizeof(HashDbTerm*)*(N)) -/* A segment that also contains a segment table */ -struct ext_segment { - struct segment s; /* The segment itself. Must be first */ - +/* An extended segment table */ +struct ext_segtab { + ErtsThrPrgrLaterOp lop; struct segment** prev_segtab; /* Used when table is shrinking */ - int nsegs; /* Size of segtab */ + int prev_nsegs; /* Size of prev_segtab */ + int nsegs; /* Size of this segtab */ struct segment* segtab[1]; /* The segment table */ }; -#define SIZEOF_EXTSEG(NSEGS) \ - (offsetof(struct ext_segment,segtab) + sizeof(struct segment*)*(NSEGS)) - -#if defined(DEBUG) || defined(VALGRIND) -# define EXTSEG(SEGTAB_PTR) \ - ((struct ext_segment*) (((char*)(SEGTAB_PTR)) - offsetof(struct ext_segment,segtab))) -#endif +#define SIZEOF_EXT_SEGTAB(NSEGS) \ + (offsetof(struct ext_segtab,segtab) + sizeof(struct segment*)*(NSEGS)) static ERTS_INLINE void SET_SEGTAB(DbTableHash* tb, @@ -348,41 +334,14 @@ static ERTS_INLINE void SET_SEGTAB(DbTableHash* tb, erts_smp_atomic_set_wb(&tb->segtab, (erts_aint_t) segtab); else erts_smp_atomic_set_nob(&tb->segtab, (erts_aint_t) segtab); -#ifdef VALGRIND - tb->top_ptr_to_segment_with_active_segtab = EXTSEG(segtab); -#endif } -/* How the table segments relate to each other: - - ext_segment: ext_segment: "plain" segment - #=================# #================# #=============# - | bucket[0] |<--+ +------->| bucket[256] | +->| bucket[512] | - | bucket[1] | | | | [257] | | | [513] | - : : | | : : | : : - | bucket[255] | | | | [511] | | | [767] | - |-----------------| | | |----------------| | #=============# - | prev_segtab=NULL| | | +--<---prev_segtab | | - | nsegs = 2 | | | | | nsegs = 256 | | -+->| segtab[0] -->-------+---|---|--<---segtab[0] |<-+ | -| | segtab[1] -->-----------+---|--<---segtab[1] | | | -| #=================# | | segtab[2] -->-----|--+ ext_segment: -| | : : | #================# -+----------------<---------------+ | segtab[255] ->----|----->| bucket[255*256]| - #================# | | | - | : : - | |----------------| - +----<---prev_segtab | - : : -*/ - /* ** Forward decl's (static functions) */ -static struct ext_segment* alloc_ext_seg(DbTableHash* tb, unsigned seg_ix, - struct segment** old_segtab); +static struct ext_segtab* alloc_ext_segtab(DbTableHash* tb, unsigned seg_ix); static int alloc_seg(DbTableHash *tb); static int free_seg(DbTableHash *tb, int free_records); static HashDbTerm* next(DbTableHash *tb, Uint *iptr, erts_smp_rwmtx_t** lck_ptr, @@ -666,9 +625,13 @@ int db_create_hash(Process *p, DbTable *tbl) erts_smp_atomic_init_nob(&tb->nactive, SEGSZ); erts_smp_atomic_init_nob(&tb->fixdel, (erts_aint_t)NULL); erts_smp_atomic_init_nob(&tb->segtab, (erts_aint_t)NULL); - SET_SEGTAB(tb, alloc_ext_seg(tb,0,NULL)->segtab); + SET_SEGTAB(tb, tb->first_segtab); tb->nsegs = NSEG_1; tb->nslots = SEGSZ; + tb->first_segtab[0] = (struct segment*) erts_db_alloc(ERTS_ALC_T_DB_SEG, + (DbTable *) tb, + SIZEOF_SEGMENT(SEGSZ)); + sys_memset(tb->first_segtab[0], 0, SIZEOF_SEGMENT(SEGSZ)); #ifdef ERTS_SMP erts_smp_atomic_init_nob(&tb->is_resizing, 0); @@ -2414,34 +2377,29 @@ static int analyze_pattern(DbTableHash *tb, Eterm pattern, return DB_ERROR_NONE; } -static struct ext_segment* alloc_ext_seg(DbTableHash* tb, unsigned seg_ix, - struct segment** old_segtab) +static struct ext_segtab* alloc_ext_segtab(DbTableHash* tb, unsigned seg_ix) { - int nsegs; - struct ext_segment* eseg; + struct segment** old_segtab = SEGTAB(tb); + int nsegs = 0; + struct ext_segtab* est; + ASSERT(seg_ix >= NSEG_1); switch (seg_ix) { - case 0: nsegs = NSEG_1; break; - case 1: nsegs = NSEG_2; break; - default: nsegs = seg_ix + NSEG_INC; break; - } - eseg = (struct ext_segment*) erts_db_alloc_fnf(ERTS_ALC_T_DB_SEG, - (DbTable *) tb, - SIZEOF_EXTSEG(nsegs)); - ASSERT(eseg != NULL); - sys_memset(&eseg->s, 0, sizeof(struct segment)); - IF_DEBUG(eseg->s.is_ext_segment = 1); - eseg->prev_segtab = old_segtab; - eseg->nsegs = nsegs; - if (old_segtab) { - ASSERT(nsegs > tb->nsegs); - sys_memcpy(eseg->segtab, old_segtab, tb->nsegs*sizeof(struct segment*)); - } + case NSEG_1: nsegs = NSEG_2; break; + default: nsegs = seg_ix + NSEG_INC; break; + } + ASSERT(nsegs > tb->nsegs); + est = (struct ext_segtab*) erts_db_alloc(ERTS_ALC_T_DB_SEG, + (DbTable *) tb, + SIZEOF_EXT_SEGTAB(nsegs)); + est->nsegs = nsegs; + est->prev_segtab = old_segtab; + est->prev_nsegs = tb->nsegs; + sys_memcpy(est->segtab, old_segtab, tb->nsegs*sizeof(struct segment*)); #ifdef DEBUG - sys_memset(&eseg->segtab[seg_ix], 0, (nsegs-seg_ix)*sizeof(struct segment*)); + sys_memset(&est->segtab[seg_ix], 0, (nsegs-seg_ix)*sizeof(struct segment*)); #endif - eseg->segtab[seg_ix] = &eseg->s; - return eseg; + return est; } /* Extend table with one new segment @@ -2449,36 +2407,32 @@ static struct ext_segment* alloc_ext_seg(DbTableHash* tb, unsigned seg_ix, static int alloc_seg(DbTableHash *tb) { int seg_ix = tb->nslots >> SEGSZ_EXP; - - if (seg_ix+1 == tb->nsegs) { /* New segtab needed (extended segment) */ - struct segment** segtab = SEGTAB(tb); - struct ext_segment* seg = alloc_ext_seg(tb, seg_ix, segtab); - if (seg == NULL) return 0; - segtab[seg_ix] = &seg->s; - /* We don't use the new segtab until next call (see "shrink race") */ - } - else { /* Just a new plain segment */ - struct segment** segtab; - if (seg_ix == tb->nsegs) { /* Time to start use segtab from last call */ - struct ext_segment* eseg; - eseg = (struct ext_segment*) SEGTAB(tb)[seg_ix-1]; - MY_ASSERT(eseg!=NULL && eseg->s.is_ext_segment); - SET_SEGTAB(tb, eseg->segtab); - tb->nsegs = eseg->nsegs; - } - ASSERT(seg_ix < tb->nsegs); - segtab = SEGTAB(tb); - ASSERT(segtab[seg_ix] == NULL); - segtab[seg_ix] = (struct segment*) erts_db_alloc_fnf(ERTS_ALC_T_DB_SEG, - (DbTable *) tb, - sizeof(struct segment)); - if (segtab[seg_ix] == NULL) return 0; - sys_memset(segtab[seg_ix], 0, sizeof(struct segment)); - } + struct segment** segtab; + + if (seg_ix == tb->nsegs) { /* New segtab needed */ + struct ext_segtab* est = alloc_ext_segtab(tb, seg_ix); + SET_SEGTAB(tb, est->segtab); + tb->nsegs = est->nsegs; + } + ASSERT(seg_ix < tb->nsegs); + segtab = SEGTAB(tb); + segtab[seg_ix] = (struct segment*) erts_db_alloc(ERTS_ALC_T_DB_SEG, + (DbTable *) tb, + SIZEOF_SEGMENT(SEGSZ)); + sys_memset(segtab[seg_ix], 0, SIZEOF_SEGMENT(SEGSZ)); tb->nslots += SEGSZ; return 1; } +#ifdef ERTS_SMP +static void dealloc_ext_segtab(void* lop_data) +{ + struct ext_segtab* est = (struct ext_segtab*) lop_data; + + erts_free(ERTS_ALC_T_DB_SEG, est); +} +#endif + /* Shrink table by freeing the top segment ** free_records: 1=free any records in segment, 0=assume segment is empty */ @@ -2486,18 +2440,17 @@ static int free_seg(DbTableHash *tb, int free_records) { const int seg_ix = (tb->nslots >> SEGSZ_EXP) - 1; struct segment** const segtab = SEGTAB(tb); - struct ext_segment* const top = (struct ext_segment*) segtab[seg_ix]; - int bytes; + struct segment* const segp = segtab[seg_ix]; int nrecords = 0; - ASSERT(top != NULL); + ASSERT(segp != NULL); #ifndef DEBUG if (free_records) #endif { int i; for (i=0; i<SEGSZ; ++i) { - HashDbTerm* p = top->s.buckets[i]; + HashDbTerm* p = segp->buckets[i]; while(p != 0) { HashDbTerm* nxt = p->next; ASSERT(free_records); /* segment not empty as assumed? */ @@ -2507,53 +2460,46 @@ static int free_seg(DbTableHash *tb, int free_records) } } } - - /* The "shrink race": - * We must avoid deallocating an extended segment while its segtab may - * still be used by other threads. - * The trick is to stop use a segtab one call earlier. That is, stop use - * a segtab when the segment above it is deallocated. When the segtab is - * later deallocated, it has not been used for a very long time. - * It is even theoretically safe as we have by then rehashed the entire - * segment, seizing *all* locks, so there cannot exist any retarded threads - * still hanging in BUCKET macro with an old segtab pointer. - * For this to work, we must of course allocate a new segtab one call - * earlier in alloc_seg() as well. And this is also the reason why - * the minimum size of the first segtab is 2 and not 1 (NSEG_1). - */ - if (seg_ix == tb->nsegs-1 || seg_ix==0) { /* Dealloc extended segment */ - MY_ASSERT(top->s.is_ext_segment); - ASSERT(segtab != top->segtab || seg_ix==0); - bytes = SIZEOF_EXTSEG(top->nsegs); - } - else { /* Dealloc plain segment */ - struct ext_segment* newtop = (struct ext_segment*) segtab[seg_ix-1]; - MY_ASSERT(!top->s.is_ext_segment); - - if (segtab == newtop->segtab) { /* New top segment is extended */ - MY_ASSERT(newtop->s.is_ext_segment); - if (newtop->prev_segtab != NULL) { - /* Time to use a smaller segtab */ - SET_SEGTAB(tb, newtop->prev_segtab); - tb->nsegs = seg_ix; - ASSERT(tb->nsegs == EXTSEG(SEGTAB(tb))->nsegs); - } - else { - ASSERT(NSEG_1 > 2 && seg_ix==1); - } - } - bytes = sizeof(struct segment); + if (seg_ix >= NSEG_1) { + struct ext_segtab* est = ErtsContainerStruct_(segtab,struct ext_segtab,segtab); + + if (seg_ix == est->prev_nsegs) { /* Dealloc extended segtab */ + ASSERT(est->prev_segtab != NULL); + SET_SEGTAB(tb, est->prev_segtab); + tb->nsegs = est->prev_nsegs; + +#ifdef ERTS_SMP + if (!tb->common.is_thread_safe) { + /* + * Table is doing a graceful shrink operation and we must avoid + * deallocating this segtab while it may still be read by other + * threads. Schedule deallocation with thread progress to make + * sure no lingering threads are still hanging in BUCKET macro + * with an old segtab pointer. + */ + Uint sz = SIZEOF_EXT_SEGTAB(est->nsegs); + ASSERT(sz == ERTS_ALC_DBG_BLK_SZ(est)); + ERTS_DB_ALC_MEM_UPDATE_(tb, sz, 0); + erts_schedule_thr_prgr_later_cleanup_op(dealloc_ext_segtab, + est, + &est->lop, + sz); + } + else +#endif + erts_db_free(ERTS_ALC_T_DB_SEG, (DbTable*)tb, est, + SIZEOF_EXT_SEGTAB(est->nsegs)); + } + else { + + } } + erts_db_free(ERTS_ALC_T_DB_SEG, (DbTable *)tb, segp, SIZEOF_SEGMENT(SEGSZ)); - erts_db_free(ERTS_ALC_T_DB_SEG, (DbTable *)tb, - (void*)top, bytes); #ifdef DEBUG - if (seg_ix > 0) { - segtab[seg_ix] = NULL; - } else { - SET_SEGTAB(tb, NULL); - } + if (seg_ix < tb->nsegs) + SEGTAB(tb)[seg_ix] = NULL; #endif tb->nslots -= SEGSZ; ASSERT(tb->nslots >= 0); diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h index 081ff8fafc..2d9b5e308a 100644 --- a/erts/emulator/beam/erl_db_hash.h +++ b/erts/emulator/beam/erl_db_hash.h @@ -51,6 +51,7 @@ typedef struct db_table_hash { DbTableCommon common; erts_smp_atomic_t segtab; /* The segment table (struct segment**) */ + struct segment* first_segtab[1]; erts_smp_atomic_t szm; /* current size mask. */ /* SMP: nslots and nsegs are protected by is_resizing or table write lock */ @@ -64,9 +65,6 @@ typedef struct db_table_hash { erts_smp_atomic_t is_resizing; /* grow/shrink in progress */ DbTableHashFineLocks* locks; #endif -#ifdef VALGRIND - struct ext_segment* top_ptr_to_segment_with_active_segtab; -#endif } DbTableHash; |