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authorSverker Eriksson <[email protected]>2019-03-11 15:51:45 +0100
committerSverker Eriksson <[email protected]>2019-03-11 15:51:45 +0100
commit0d550c80d4f19cc432e7de056169695d436c02a0 (patch)
tree2955b3166a271465b4a9170a15f4f7c2adeffa76
parent2099dffc5894759eb4fb8375e968b93e26399347 (diff)
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erts: Fix ets:select table fixation leak at owner change
Symtom: ETS table remains fixed after finished ets:select* call. Problem: The decision to unfix table after a yielding ets:select* is based on table ownership, but ownership might have changed while ets:select* was yielding. Solution: Remember and pass along whether table was fixed when the traversal started.
-rw-r--r--erts/emulator/beam/erl_db.c72
-rw-r--r--erts/emulator/beam/erl_db_catree.c52
-rw-r--r--erts/emulator/beam/erl_db_hash.c116
-rw-r--r--erts/emulator/beam/erl_db_tree.c51
-rw-r--r--erts/emulator/beam/erl_db_util.h35
-rw-r--r--lib/stdlib/test/ets_SUITE.erl60
6 files changed, 268 insertions, 118 deletions
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 4132a54934..0a50af4d1a 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -81,14 +81,6 @@ static BIF_RETTYPE db_bif_fail(Process* p, Uint freason,
/* Get a key from any table structure and a tagged object */
#define TERM_GETKEY(tb, obj) db_getkey((tb)->common.keypos, (obj))
-
-/* How safe are we from double-hits or missed objects
-** when iterating without fixation? */
-enum DbIterSafety {
- ITER_UNSAFE, /* Must fixate to be safe */
- ITER_SAFE_LOCKED, /* Safe while table is locked, not between trap calls */
- ITER_SAFE /* No need to fixate at all */
-};
# define ITERATION_SAFETY(Proc,Tab) \
((IS_TREE_TABLE((Tab)->common.status) || IS_CATREE_TABLE((Tab)->common.status) \
|| ONLY_WRITER(Proc,Tab)) ? ITER_SAFE \
@@ -195,9 +187,6 @@ static int fixed_tabs_find(DbFixation* first, DbFixation* fix)
#define ERTS_RBT_WANT_DELETE
#define ERTS_RBT_WANT_FOREACH
#define ERTS_RBT_WANT_FOREACH_DESTROY
-#ifdef DEBUG
-# define ERTS_RBT_WANT_LOOKUP
-#endif
#define ERTS_RBT_UNDEF
#include "erl_rbtree.h"
@@ -2287,6 +2276,7 @@ static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1)
Eterm ret;
Eterm *tptr;
db_lock_kind_t kind = LCK_WRITE_REC;
+ enum DbIterSafety safety = ITER_SAFE;
CHECK_TABLES();
ASSERT(is_tuple(a1));
@@ -2296,10 +2286,11 @@ static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1)
DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
&ets_select_delete_continue_exp);
- cret = tb->common.meth->db_select_delete_continue(p,tb,a1,&ret);
+ cret = tb->common.meth->db_select_delete_continue(p,tb,a1,&ret,&safety);
- if(!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
- unfix_table_locked(p, tb, &kind);
+ if(!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+ ASSERT(erts_refc_read(&tb->common.fix_count,1));
+ unfix_table_locked(p, tb, &kind);
}
db_unlock(tb, kind);
@@ -2337,7 +2328,8 @@ BIF_RETTYPE ets_internal_select_delete_2(BIF_ALIST_2)
if (safety == ITER_UNSAFE) {
local_fix_table(tb);
}
- cret = tb->common.meth->db_select_delete(BIF_P, tb, BIF_ARG_1, BIF_ARG_2, &ret);
+ cret = tb->common.meth->db_select_delete(BIF_P, tb, BIF_ARG_1, BIF_ARG_2,
+ &ret, safety);
if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
fix_table_locked(BIF_P,tb);
@@ -2729,7 +2721,7 @@ ets_select3(Process* p, DbTable* tb, Eterm tid, Eterm ms, Sint chunk_size)
cret = tb->common.meth->db_select_chunk(p, tb, tid,
ms, chunk_size,
0 /* not reversed */,
- &ret);
+ &ret, safety);
if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
fix_table_locked(p, tb);
}
@@ -2756,7 +2748,8 @@ ets_select3(Process* p, DbTable* tb, Eterm tid, Eterm ms, Sint chunk_size)
}
-/* We get here instead of in the real BIF when trapping */
+/* Trap here from: ets_select_1/2/3
+ */
static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
{
Process *p = BIF_P;
@@ -2767,6 +2760,7 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
Eterm ret;
Eterm *tptr;
db_lock_kind_t kind = LCK_READ;
+ enum DbIterSafety safety = ITER_SAFE;
CHECK_TABLES();
@@ -2776,11 +2770,13 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
&ets_select_continue_exp);
- cret = tb->common.meth->db_select_continue(p, tb, a1,
- &ret);
+ cret = tb->common.meth->db_select_continue(p, tb, a1, &ret, &safety);
- if (!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
- unfix_table_locked(p, tb, &kind);
+ if (!DID_TRAP(p,ret)) {
+ if (safety != ITER_SAFE) {
+ ASSERT(erts_refc_read(&tb->common.fix_count,1));
+ unfix_table_locked(p, tb, &kind);
+ }
}
db_unlock(tb, kind);
@@ -2805,8 +2801,12 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
BIF_RETTYPE ets_select_1(BIF_ALIST_1)
{
return ets_select1(BIF_P, BIF_ets_select_1, BIF_ARG_1);
+ /* TRAP: ets_select_trap_1 */
}
+/*
+ * Common impl for select/1, select_reverse/1, match/1 and match_object/1
+ */
static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
{
BIF_RETTYPE result;
@@ -2814,7 +2814,7 @@ static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
int cret;
Eterm ret;
Eterm *tptr;
- enum DbIterSafety safety;
+ enum DbIterSafety safety, safety_copy;
CHECK_TABLES();
@@ -2839,7 +2839,8 @@ static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
local_fix_table(tb);
}
- cret = tb->common.meth->db_select_continue(p,tb, arg1, &ret);
+ safety_copy = safety;
+ cret = tb->common.meth->db_select_continue(p,tb, arg1, &ret, &safety_copy);
if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
fix_table_locked(p, tb);
@@ -2871,6 +2872,7 @@ BIF_RETTYPE ets_select_2(BIF_ALIST_2)
DbTable* tb;
DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_2);
return ets_select2(BIF_P, tb, BIF_ARG_1, BIF_ARG_2);
+ /* TRAP: ets_select_trap_1 */
}
static BIF_RETTYPE
@@ -2888,7 +2890,7 @@ ets_select2(Process* p, DbTable* tb, Eterm tid, Eterm ms)
local_fix_table(tb);
}
- cret = tb->common.meth->db_select(p, tb, tid, ms, 0, &ret);
+ cret = tb->common.meth->db_select(p, tb, tid, ms, 0, &ret, safety);
if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
fix_table_locked(p, tb);
@@ -2926,6 +2928,7 @@ static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1)
Eterm ret;
Eterm *tptr;
db_lock_kind_t kind = LCK_READ;
+ enum DbIterSafety safety = ITER_SAFE;
CHECK_TABLES();
@@ -2935,9 +2938,10 @@ static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1)
DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
&ets_select_count_continue_exp);
- cret = tb->common.meth->db_select_count_continue(p, tb, a1, &ret);
+ cret = tb->common.meth->db_select_count_continue(p, tb, a1, &ret, &safety);
- if (!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
+ if (!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+ ASSERT(erts_refc_read(&tb->common.fix_count,1));
unfix_table_locked(p, tb, &kind);
}
db_unlock(tb, kind);
@@ -2975,7 +2979,8 @@ BIF_RETTYPE ets_select_count_2(BIF_ALIST_2)
if (safety == ITER_UNSAFE) {
local_fix_table(tb);
}
- cret = tb->common.meth->db_select_count(BIF_P,tb, BIF_ARG_1, BIF_ARG_2, &ret);
+ cret = tb->common.meth->db_select_count(BIF_P,tb, BIF_ARG_1, BIF_ARG_2,
+ &ret, safety);
if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
fix_table_locked(BIF_P, tb);
@@ -3014,6 +3019,7 @@ static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1)
Eterm ret;
Eterm *tptr;
db_lock_kind_t kind = LCK_WRITE_REC;
+ enum DbIterSafety safety = ITER_SAFE;
CHECK_TABLES();
ASSERT(is_tuple(a1));
@@ -3023,9 +3029,10 @@ static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1)
DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
&ets_select_replace_continue_exp);
- cret = tb->common.meth->db_select_replace_continue(p,tb,a1,&ret);
+ cret = tb->common.meth->db_select_replace_continue(p,tb,a1,&ret,&safety);
- if(!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
+ if(!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+ ASSERT(erts_refc_read(&tb->common.fix_count,1));
unfix_table_locked(p, tb, &kind);
}
@@ -3068,7 +3075,8 @@ BIF_RETTYPE ets_select_replace_2(BIF_ALIST_2)
if (safety == ITER_UNSAFE) {
local_fix_table(tb);
}
- cret = tb->common.meth->db_select_replace(BIF_P, tb, BIF_ARG_1, BIF_ARG_2, &ret);
+ cret = tb->common.meth->db_select_replace(BIF_P, tb, BIF_ARG_1, BIF_ARG_2,
+ &ret, safety);
if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
fix_table_locked(BIF_P,tb);
@@ -3120,7 +3128,7 @@ BIF_RETTYPE ets_select_reverse_3(BIF_ALIST_3)
}
cret = tb->common.meth->db_select_chunk(BIF_P,tb, BIF_ARG_1,
BIF_ARG_2, chunk_size,
- 1 /* reversed */, &ret);
+ 1 /* reversed */, &ret, safety);
if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
fix_table_locked(BIF_P, tb);
}
@@ -3165,7 +3173,7 @@ BIF_RETTYPE ets_select_reverse_2(BIF_ALIST_2)
local_fix_table(tb);
}
cret = tb->common.meth->db_select(BIF_P,tb, BIF_ARG_1, BIF_ARG_2,
- 1 /*reversed*/, &ret);
+ 1 /*reversed*/, &ret, safety);
if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
fix_table_locked(BIF_P, tb);
diff --git a/erts/emulator/beam/erl_db_catree.c b/erts/emulator/beam/erl_db_catree.c
index 75ac1c4a93..0402c6b7b4 100644
--- a/erts/emulator/beam/erl_db_catree.c
+++ b/erts/emulator/beam/erl_db_catree.c
@@ -116,24 +116,31 @@ static int db_erase_object_catree(DbTable *tbl, Eterm object,Eterm *ret);
static int db_slot_catree(Process *p, DbTable *tbl,
Eterm slot_term, Eterm *ret);
static int db_select_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, int reversed, Eterm *ret);
+ Eterm pattern, int reversed, Eterm *ret,
+ enum DbIterSafety);
static int db_select_count_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret, enum DbIterSafety);
static int db_select_chunk_catree(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
- int reversed, Eterm *ret);
+ int reversed, Eterm *ret, enum DbIterSafety);
static int db_select_continue_catree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_count_continue_catree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_delete_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety);
static int db_select_delete_continue_catree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_replace_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety);
static int db_select_replace_continue_catree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_take_catree(Process *, DbTable *, Eterm, Eterm *);
static void db_print_catree(fmtfn_t to, void *to_arg,
int show, DbTable *tbl);
@@ -1843,7 +1850,8 @@ static int db_slot_catree(Process *p, DbTable *tbl,
static int db_select_continue_catree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
int result;
CATreeRootIterator iter;
@@ -1856,7 +1864,8 @@ static int db_select_continue_catree(Process *p,
}
static int db_select_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, int reverse, Eterm *ret)
+ Eterm pattern, int reverse, Eterm *ret,
+ enum DbIterSafety safety)
{
int result;
CATreeRootIterator iter;
@@ -1871,7 +1880,8 @@ static int db_select_catree(Process *p, DbTable *tbl, Eterm tid,
static int db_select_count_continue_catree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
int result;
CATreeRootIterator iter;
@@ -1885,7 +1895,8 @@ static int db_select_count_continue_catree(Process *p,
}
static int db_select_count_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
int result;
CATreeRootIterator iter;
@@ -1899,7 +1910,8 @@ static int db_select_count_catree(Process *p, DbTable *tbl, Eterm tid,
static int db_select_chunk_catree(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
- int reversed, Eterm *ret)
+ int reversed, Eterm *ret,
+ enum DbIterSafety safety)
{
int result;
CATreeRootIterator iter;
@@ -1915,7 +1927,8 @@ static int db_select_chunk_catree(Process *p, DbTable *tbl, Eterm tid,
static int db_select_delete_continue_catree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
DbTreeStack stack;
TreeDbTerm * stack_array[STACK_NEED];
@@ -1931,7 +1944,8 @@ static int db_select_delete_continue_catree(Process *p,
}
static int db_select_delete_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
DbTreeStack stack;
TreeDbTerm * stack_array[STACK_NEED];
@@ -1948,7 +1962,8 @@ static int db_select_delete_catree(Process *p, DbTable *tbl, Eterm tid,
}
static int db_select_replace_catree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety_p)
{
int result;
CATreeRootIterator iter;
@@ -1961,7 +1976,8 @@ static int db_select_replace_catree(Process *p, DbTable *tbl, Eterm tid,
}
static int db_select_replace_continue_catree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret)
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety* safety_p)
{
int result;
CATreeRootIterator iter;
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index a2690f6d6a..fac4703620 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -404,26 +404,31 @@ static int db_slot_hash(Process *p, DbTable *tbl,
static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
- int reverse, Eterm *ret);
+ int reverse, Eterm *ret, enum DbIterSafety);
static int db_select_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, int reverse, Eterm *ret);
+ Eterm pattern, int reverse, Eterm *ret,
+ enum DbIterSafety);
static int db_select_continue_hash(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret, enum DbIterSafety);
static int db_select_count_continue_hash(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
-
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety);
static int db_select_delete_continue_hash(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret, enum DbIterSafety);
static int db_select_replace_continue_hash(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_take_hash(Process *, DbTable *, Eterm, Eterm *);
static void db_print_hash(fmtfn_t to,
@@ -535,7 +540,7 @@ DbTableMethod db_hash =
db_select_chunk_hash,
db_select_hash,
db_select_delete_hash,
- db_select_continue_hash, /* hmm continue_hash? */
+ db_select_continue_hash,
db_select_delete_continue_hash,
db_select_count_hash,
db_select_count_continue_hash,
@@ -1209,6 +1214,7 @@ struct traverse_context_t_
DbTableHash* tb;
Eterm tid;
Eterm* prev_continuation_tptr;
+ enum DbIterSafety safety;
};
@@ -1476,11 +1482,11 @@ static ERTS_INLINE int on_simple_trap(Export* trap_function,
BUMP_ALL_REDS(ctx->p);
if (IS_USMALL(0, got)) {
- hp = HAllocX(ctx->p, base_halloc_sz + 5, ERTS_MAGIC_REF_THING_SIZE);
+ hp = HAllocX(ctx->p, base_halloc_sz + 6, ERTS_MAGIC_REF_THING_SIZE);
egot = make_small(got);
}
else {
- hp = HAllocX(ctx->p, base_halloc_sz + BIG_UINT_HEAP_SIZE + 5,
+ hp = HAllocX(ctx->p, base_halloc_sz + BIG_UINT_HEAP_SIZE + 6,
ERTS_MAGIC_REF_THING_SIZE);
egot = uint_to_big(got, hp);
hp += BIG_UINT_HEAP_SIZE;
@@ -1497,12 +1503,13 @@ static ERTS_INLINE int on_simple_trap(Export* trap_function,
mpb = ctx->prev_continuation_tptr[3];
}
- continuation = TUPLE4(
+ continuation = TUPLE5(
hp,
ctx->tid,
make_small(slot_ix),
mpb,
- egot);
+ egot,
+ make_small(ctx->safety));
ERTS_BIF_PREP_TRAP1(*ret, trap_function, ctx->p, continuation);
return DB_ERROR_NONE;
}
@@ -1512,17 +1519,18 @@ static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
Eterm* tid_ptr,
Sint* slot_ix_p,
Binary** mpp,
- Sint* got_p)
+ Sint* got_p,
+ enum DbIterSafety* safety_p)
{
Eterm* tptr;
ASSERT(is_tuple(continuation));
tptr = tuple_val(continuation);
- if (arityval(*tptr) != 4)
+ if (*tptr != make_arityval(5))
return 1;
- if (! is_small(tptr[2]) || !(is_big(tptr[4]) || is_small(tptr[4]))) {
+ if (!is_small(tptr[2]) || !(is_big(tptr[4]) || is_small(tptr[4]))
+ || !is_small(tptr[5]))
return 1;
- }
*tptr_ptr = tptr;
*tid_ptr = tptr[1];
@@ -1534,6 +1542,7 @@ static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
else {
*got_p = unsigned_val(tptr[4]);
}
+ *safety_p = signed_val(tptr[5]);
return 0;
}
@@ -1657,32 +1666,34 @@ static int select_chunk_on_trap(traverse_context_t* ctx_base,
if (ctx->base.prev_continuation_tptr == NULL) {
Eterm tid = ctx->base.tid;
/* First time we're trapping */
- hp = HAllocX(ctx->base.p, 7 + ERTS_MAGIC_REF_THING_SIZE,
+ hp = HAllocX(ctx->base.p, 8 + ERTS_MAGIC_REF_THING_SIZE,
ERTS_MAGIC_REF_THING_SIZE);
if (is_atom(tid))
tid = erts_db_make_tid(ctx->base.p, &ctx->base.tb->common);
mpb = erts_db_make_match_prog_ref(ctx->base.p, *mpp, &hp);
- continuation = TUPLE6(
+ continuation = TUPLE7(
hp,
tid,
make_small(slot_ix),
make_small(ctx->chunk_size),
mpb,
ctx->match_list,
- make_small(got));
+ make_small(got),
+ make_small(ctx->base.safety));
*mpp = NULL; /* otherwise the caller will destroy it */
}
else {
/* Not the first time we're trapping; reuse continuation terms */
- hp = HAlloc(ctx->base.p, 7);
- continuation = TUPLE6(
+ hp = HAlloc(ctx->base.p, 8);
+ continuation = TUPLE7(
hp,
ctx->base.prev_continuation_tptr[1],
make_small(slot_ix),
ctx->base.prev_continuation_tptr[3],
ctx->base.prev_continuation_tptr[4],
ctx->match_list,
- make_small(got));
+ make_small(got),
+ make_small(ctx->base.safety));
}
ERTS_BIF_PREP_TRAP1(*ret, &ets_select_continue_exp, ctx->base.p,
continuation);
@@ -1690,14 +1701,14 @@ static int select_chunk_on_trap(traverse_context_t* ctx_base,
}
static int db_select_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern,
- int reverse, Eterm *ret)
+ int reverse, Eterm *ret, enum DbIterSafety safety)
{
- return db_select_chunk_hash(p, tbl, tid, pattern, 0, reverse, ret);
+ return db_select_chunk_hash(p, tbl, tid, pattern, 0, reverse, ret, safety);
}
static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
- int reverse, Eterm *ret)
+ int reverse, Eterm *ret, enum DbIterSafety safety)
{
select_chunk_context_t ctx;
@@ -1709,6 +1720,7 @@ static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
ctx.base.tb = &tbl->hash;
ctx.base.tid = tid;
ctx.base.prev_continuation_tptr = NULL;
+ ctx.base.safety = safety;
ctx.hp = NULL;
ctx.chunk_size = chunk_size;
ctx.match_list = NIL;
@@ -1784,10 +1796,11 @@ int select_chunk_continue_on_loop_ended(traverse_context_t* ctx_base,
}
/*
- * This is called when select traps
+ * This is called when ets:select/1/2/3 traps
+ * and for ets:select/1 with user continuation term.
*/
static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
- Eterm* ret)
+ Eterm* ret, enum DbIterSafety* safety_p)
{
select_chunk_context_t ctx;
Eterm* tptr;
@@ -1803,7 +1816,13 @@ static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
ASSERT(is_tuple(continuation));
tptr = tuple_val(continuation);
- if (arityval(*tptr) != 6)
+ /*
+ * 6-tuple is select/1 user continuation term
+ * 7-tuple is select trap continuation
+ */
+ if (*tptr == make_arityval(7) && is_small(tptr[7]))
+ *safety_p = signed_val(tptr[7]);
+ else if (*tptr != make_arityval(6))
goto badparam;
if (!is_small(tptr[2]) || !is_small(tptr[3]) ||
@@ -1831,6 +1850,7 @@ static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
ctx.base.tb = &tbl->hash;
ctx.base.tid = tid;
ctx.base.prev_continuation_tptr = tptr;
+ ctx.base.safety = *safety_p;
ctx.hp = NULL;
ctx.chunk_size = chunk_size;
ctx.match_list = match_list;
@@ -1891,7 +1911,8 @@ static int select_count_on_trap(traverse_context_t* ctx,
}
static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
traverse_context_t ctx;
Sint iterations_left = MAX_SELECT_COUNT_ITERATIONS;
@@ -1905,6 +1926,7 @@ static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
ctx.tb = &tbl->hash;
ctx.tid = tid;
ctx.prev_continuation_tptr = NULL;
+ ctx.safety = safety;
return match_traverse(
&ctx,
@@ -1917,7 +1939,8 @@ static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
* This is called when select_count traps
*/
static int db_select_count_continue_hash(Process* p, DbTable* tbl,
- Eterm continuation, Eterm* ret)
+ Eterm continuation, Eterm* ret,
+ enum DbIterSafety* safety_p)
{
traverse_context_t ctx;
Eterm* tptr;
@@ -1928,7 +1951,8 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl,
Sint chunk_size = 0;
*ret = NIL;
- if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+ if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+ &got, safety_p)) {
*ret = NIL;
return DB_ERROR_BADPARAM;
}
@@ -1940,6 +1964,7 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl,
ctx.tb = &tbl->hash;
ctx.tid = tid;
ctx.prev_continuation_tptr = tptr;
+ ctx.safety = *safety_p;
return match_traverse_continue(
&ctx, chunk_size,
@@ -2033,7 +2058,8 @@ static int select_delete_on_trap(traverse_context_t* ctx_base,
}
static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
select_delete_context_t ctx;
Sint chunk_size = 0;
@@ -2046,6 +2072,7 @@ static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
ctx.base.tb = &tbl->hash;
ctx.base.tid = tid;
ctx.base.prev_continuation_tptr = NULL;
+ ctx.base.safety = safety;
ctx.fixated_by_me = ctx.base.tb->common.is_thread_safe ? 0 : 1;
ctx.last_pseudo_delete = (Uint) -1;
ctx.free_us = NULL;
@@ -2062,7 +2089,8 @@ static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
* This is called when select_delete traps
*/
static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
- Eterm continuation, Eterm* ret)
+ Eterm continuation, Eterm* ret,
+ enum DbIterSafety* safety_p)
{
select_delete_context_t ctx;
Eterm* tptr;
@@ -2072,7 +2100,8 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
Sint slot_ix;
Sint chunk_size = 0;
- if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+ if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+ &got, safety_p)) {
*ret = NIL;
return DB_ERROR_BADPARAM;
}
@@ -2084,6 +2113,7 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
ctx.base.tb = &tbl->hash;
ctx.base.tid = tid;
ctx.base.prev_continuation_tptr = tptr;
+ ctx.base.safety = *safety_p;
ctx.fixated_by_me = ONLY_WRITER(p, ctx.base.tb) ? 0 : 1;
ctx.last_pseudo_delete = (Uint) -1;
ctx.free_us = NULL;
@@ -2164,7 +2194,9 @@ static int select_replace_on_trap(traverse_context_t* ctx,
slot_ix, got, mpp, ret);
}
-static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Eterm *ret)
+static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid,
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
traverse_context_t ctx;
Sint chunk_size = 0;
@@ -2194,7 +2226,9 @@ static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pat
/*
* This is called when select_replace traps
*/
-static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret)
+static int db_select_replace_continue_hash(Process* p, DbTable* tbl,
+ Eterm continuation, Eterm* ret,
+ enum DbIterSafety* safety_p)
{
traverse_context_t ctx;
Eterm* tptr;
@@ -2205,7 +2239,8 @@ static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm conti
Sint chunk_size = 0;
*ret = NIL;
- if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+ if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+ &got, safety_p)) {
*ret = NIL;
return DB_ERROR_BADPARAM;
}
@@ -2218,6 +2253,7 @@ static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm conti
ctx.tb = &tbl->hash;
ctx.tid = tid;
ctx.prev_continuation_tptr = tptr;
+ ctx.safety = *safety_p;
return match_traverse_continue(
&ctx, chunk_size,
diff --git a/erts/emulator/beam/erl_db_tree.c b/erts/emulator/beam/erl_db_tree.c
index fe57348700..f9ba04f399 100644
--- a/erts/emulator/beam/erl_db_tree.c
+++ b/erts/emulator/beam/erl_db_tree.c
@@ -397,24 +397,31 @@ static int db_erase_object_tree(DbTable *tbl, Eterm object,Eterm *ret);
static int db_slot_tree(Process *p, DbTable *tbl,
Eterm slot_term, Eterm *ret);
static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, int reversed, Eterm *ret);
+ Eterm pattern, int reversed, Eterm *ret,
+ enum DbIterSafety);
static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret, enum DbIterSafety);
static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
- int reversed, Eterm *ret);
+ int reversed, Eterm *ret, enum DbIterSafety);
static int db_select_continue_tree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_count_continue_tree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety);
static int db_select_delete_continue_tree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret);
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety);
static int db_select_replace_continue_tree(Process *p, DbTable *tbl,
- Eterm continuation, Eterm *ret);
+ Eterm continuation, Eterm *ret,
+ enum DbIterSafety*);
static int db_take_tree(Process *, DbTable *, Eterm, Eterm *);
static void db_print_tree(fmtfn_t to, void *to_arg,
int show, DbTable *tbl);
@@ -1160,7 +1167,8 @@ int db_select_continue_tree_common(Process *p,
static int db_select_continue_tree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
DbTableTree *tb = &tbl->tree;
return db_select_continue_tree_common(p, &tb->common,
@@ -1297,7 +1305,8 @@ int db_select_tree_common(Process *p, DbTable *tb,
}
static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, int reverse, Eterm *ret)
+ Eterm pattern, int reverse, Eterm *ret,
+ enum DbIterSafety safety)
{
return db_select_tree_common(p, tbl, tid,
pattern, reverse, ret, &tbl->tree, NULL);
@@ -1408,7 +1417,8 @@ int db_select_count_continue_tree_common(Process *p,
static int db_select_count_continue_tree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
DbTableTree *tb = &tbl->tree;
return db_select_count_continue_tree_common(p, tbl,
@@ -1527,7 +1537,8 @@ int db_select_count_tree_common(Process *p, DbTable *tb,
}
static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
DbTableTree *tb = &tbl->tree;
return db_select_count_tree_common(p, tbl,
@@ -1704,7 +1715,7 @@ int db_select_chunk_tree_common(Process *p, DbTable *tb,
static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
Eterm pattern, Sint chunk_size,
int reverse,
- Eterm *ret)
+ Eterm *ret, enum DbIterSafety safety)
{
DbTableTree *tb = &tbl->tree;
return db_select_chunk_tree_common(p, tbl,
@@ -1813,7 +1824,8 @@ int db_select_delete_continue_tree_common(Process *p,
static int db_select_delete_continue_tree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
DbTableTree *tb = &tbl->tree;
ASSERT(!erts_atomic_read_nob(&tb->is_stack_busy));
@@ -1942,7 +1954,8 @@ int db_select_delete_tree_common(Process *p, DbTable *tbl,
}
static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
DbTableTree *tb = &tbl->tree;
return db_select_delete_tree_common(p, tbl, tid, pattern, ret,
@@ -2052,7 +2065,8 @@ int db_select_replace_continue_tree_common(Process *p,
static int db_select_replace_continue_tree(Process *p,
DbTable *tbl,
Eterm continuation,
- Eterm *ret)
+ Eterm *ret,
+ enum DbIterSafety* safety_p)
{
return db_select_replace_continue_tree_common(p, tbl, continuation, ret,
&tbl->tree, NULL);
@@ -2177,7 +2191,8 @@ int db_select_replace_tree_common(Process *p, DbTable *tbl,
}
static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
- Eterm pattern, Eterm *ret)
+ Eterm pattern, Eterm *ret,
+ enum DbIterSafety safety)
{
return db_select_replace_tree_common(p, tbl, tid, pattern, ret,
&tbl->tree, NULL);
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index e1af9210ea..e3d3c0e804 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -101,6 +101,14 @@ typedef struct {
} u;
} DbUpdateHandle;
+/* How safe are we from double-hits or missed objects
+ * when iterating without fixation?
+ */
+enum DbIterSafety {
+ ITER_UNSAFE, /* Must fixate to be safe */
+ ITER_SAFE_LOCKED, /* Safe while table is locked, not between trap calls */
+ ITER_SAFE /* No need to fixate at all */
+};
typedef struct db_table_method
{
@@ -150,44 +158,53 @@ typedef struct db_table_method
Eterm pattern,
Sint chunk_size,
int reverse,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety);
int (*db_select)(Process* p,
DbTable* tb, /* [in out] */
Eterm tid,
Eterm pattern,
int reverse,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety);
int (*db_select_delete)(Process* p,
DbTable* tb, /* [in out] */
Eterm tid,
Eterm pattern,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety);
int (*db_select_continue)(Process* p,
DbTable* tb, /* [in out] */
Eterm continuation,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety*);
int (*db_select_delete_continue)(Process* p,
DbTable* tb, /* [in out] */
Eterm continuation,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety*);
int (*db_select_count)(Process* p,
DbTable* tb, /* [in out] */
Eterm tid,
Eterm pattern,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety);
int (*db_select_count_continue)(Process* p,
DbTable* tb, /* [in out] */
Eterm continuation,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety*);
int (*db_select_replace)(Process* p,
DbTable* tb, /* [in out] */
Eterm tid,
Eterm pattern,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety);
int (*db_select_replace_continue)(Process* p,
DbTable* tb, /* [in out] */
Eterm continuation,
- Eterm* ret);
+ Eterm* ret,
+ enum DbIterSafety*);
int (*db_take)(Process *, DbTable *, Eterm, Eterm *);
SWord (*db_delete_all_objects)(Process* p, DbTable* db, SWord reds);
diff --git a/lib/stdlib/test/ets_SUITE.erl b/lib/stdlib/test/ets_SUITE.erl
index 7703198c4c..8561491d50 100644
--- a/lib/stdlib/test/ets_SUITE.erl
+++ b/lib/stdlib/test/ets_SUITE.erl
@@ -56,6 +56,7 @@
-export([t_match_spec_run/1]).
-export([t_bucket_disappears/1]).
-export([t_named_select/1]).
+-export([select_fixtab_owner_change/1]).
-export([otp_5340/1]).
-export([otp_6338/1]).
-export([otp_6842_select_1000/1]).
@@ -130,7 +131,7 @@ all() ->
t_insert_list, t_test_ms, t_select_delete, t_select_replace,
t_select_replace_next_bug,
t_ets_dets, memory, t_select_reverse, t_bucket_disappears,
- t_named_select,
+ t_named_select, select_fixtab_owner_change,
select_fail, t_insert_new, t_repair_continuation,
otp_5340, otp_6338, otp_6842_select_1000, otp_7665,
select_mbuf_trapping,
@@ -249,7 +250,64 @@ t_named_select_do(Opts) ->
verify_etsmem(EtsMem).
+%% Verify select and friends release fixtab as they should
+%% even when owneship is changed between traps.
+select_fixtab_owner_change(_Config) ->
+ T = ets:new(xxx, [protected]),
+ NKeys = 2000,
+ [ets:insert(T,{K,K band 7}) || K <- lists:seq(1,NKeys)],
+ %% Buddy and Papa will ping-pong table ownership between them
+ %% and the aim is to give Buddy the table when he is
+ %% in the middle of a yielding select* call.
+ {Buddy,_} = spawn_opt(fun() -> sfoc_buddy_loop(T, 1, undefined) end,
+ [link,monitor]),
+
+ sfoc_papa_loop(T, Buddy),
+
+ receive {'DOWN', _, process, Buddy, _} -> ok end,
+ ets:delete(T),
+ ok.
+
+sfoc_buddy_loop(T, I, State0) ->
+ receive
+ {'ETS-TRANSFER', T, Papa, _} ->
+ ets:give_away(T, Papa, State0),
+ case State0 of
+ done ->
+ ok;
+ _ ->
+ State1 = sfoc_traverse(T, I, State0),
+ %% Verify no fixation left
+ {I, false} = {I, ets:info(T, safe_fixed_monotonic_time)},
+ sfoc_buddy_loop(T, I+1, State1)
+ end
+ end.
+
+sfoc_papa_loop(T, Buddy) ->
+ ets:give_away(T, Buddy, "Catch!"),
+ receive
+ {'ETS-TRANSFER', T, Buddy, State} ->
+ case State of
+ done ->
+ ok;
+ _ ->
+ sfoc_papa_loop(T, Buddy)
+ end
+ end.
+
+sfoc_traverse(T, 1, S) ->
+ ets:select(T, [{{'$1',7}, [], ['$1']}]), S;
+sfoc_traverse(T, 2, S) ->
+ 0 = ets:select_count(T, [{{'$1',7}, [], [false]}]), S;
+sfoc_traverse(T, 3, _) ->
+ Limit = ets:info(T, size) div 2,
+ {_, Continuation} = ets:select(T, [{{'$1',7}, [], ['$1']}],
+ Limit),
+ Continuation;
+sfoc_traverse(_T, 4, Continuation) ->
+ _ = ets:select(Continuation),
+ done.
%% Check ets:match_spec_run/2.
t_match_spec_run(Config) when is_list(Config) ->