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-rw-r--r--erts/emulator/beam/erl_db.h2
-rw-r--r--erts/emulator/beam/erl_db_hash.c246
-rw-r--r--erts/emulator/beam/erl_db_hash.h4
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;
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-13 17:23:33 +0000