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authorRickard Green <[email protected]>2015-06-10 18:08:12 +0200
committerRickard Green <[email protected]>2015-06-10 18:08:12 +0200
commitf35bbd90e3b6a9151169f6df716e56086eeb379e (patch)
treec963ef1e019c1ab859c9ef769d44b1bf64681efd /erts/emulator/beam/erl_node_tables.c
parent98ea0ed0985d1e9788b235de996befb8d6344abd (diff)
parentfe1c0d26d4e6180b79fc8497b827ac2ef1f471d5 (diff)
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Merge branch 'rickard/delayed-delete-node/OTP-12802'
* rickard/delayed-delete-node/OTP-12802: Delayed node table GC
Diffstat (limited to 'erts/emulator/beam/erl_node_tables.c')
-rw-r--r--erts/emulator/beam/erl_node_tables.c202
1 files changed, 171 insertions, 31 deletions
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 964d830fc1..0950d7e7ef 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -51,6 +51,9 @@ static Uint dist_entries;
static int references_atoms_need_init = 1;
+static ErtsMonotonicTime orig_node_tab_delete_delay;
+static ErtsMonotonicTime node_tab_delete_delay;
+
/* -- The distribution table ---------------------------------------------- */
#ifdef DEBUG
@@ -290,21 +293,46 @@ DistEntry *erts_find_dist_entry(Eterm sysname)
return res;
}
-void erts_delete_dist_entry(DistEntry *dep)
+static void try_delete_dist_entry(void *vdep)
+{
+ DistEntry *dep = (DistEntry *) vdep;
+ erts_aint_t refc;
+
+ erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
+ /*
+ * Another thread might have looked up this dist entry after
+ * we decided to delete it (refc became zero). If so, the other
+ * thread incremented refc twice. Once for the new reference
+ * and once for this thread.
+ *
+ * If refc reach -1, noone has used the entry since we
+ * set up the timer. Delete the entry.
+ *
+ * If refc reach 0, the entry is currently not in use
+ * but has been used since we set up the timer. Set up a
+ * new timer.
+ *
+ * If refc > 0, the entry is in use. Keep the entry.
+ */
+ refc = erts_refc_dectest(&dep->refc, -1);
+ if (refc == -1)
+ (void) hash_erase(&erts_dist_table, (void *) dep);
+ erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
+
+ if (refc == 0)
+ erts_schedule_delete_dist_entry(dep);
+}
+
+void erts_schedule_delete_dist_entry(DistEntry *dep)
{
ASSERT(dep != erts_this_dist_entry);
- if(dep != erts_this_dist_entry) {
- erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
- /*
- * Another thread might have looked up this dist entry after
- * we decided to delete it (refc became zero). If so, the other
- * thread incremented refc twice. Once for the new reference
- * and once for this thread. Therefore, delete dist entry if
- * refc is 0 or -1 after a decrement.
- */
- if (erts_refc_dectest(&dep->refc, -1) <= 0)
- (void) hash_erase(&erts_dist_table, (void *) dep);
- erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
+ if (dep != erts_this_dist_entry) {
+ if (node_tab_delete_delay == 0)
+ try_delete_dist_entry((void *) dep);
+ else if (node_tab_delete_delay > 0)
+ erts_start_timer_callback(node_tab_delete_delay,
+ try_delete_dist_entry,
+ (void *) dep);
}
}
@@ -609,21 +637,46 @@ ErlNode *erts_find_or_insert_node(Eterm sysname, Uint creation)
return res;
}
-void erts_delete_node(ErlNode *enp)
+static void try_delete_node(void *venp)
+{
+ ErlNode *enp = (ErlNode *) venp;
+ erts_aint_t refc;
+
+ erts_smp_rwmtx_rwlock(&erts_node_table_rwmtx);
+ /*
+ * Another thread might have looked up this node after we
+ * decided to delete it (refc became zero). If so, the other
+ * thread incremented refc twice. Once for the new reference
+ * and once for this thread.
+ *
+ * If refc reach -1, noone has used the entry since we
+ * set up the timer. Delete the entry.
+ *
+ * If refc reach 0, the entry is currently not in use
+ * but has been used since we set up the timer. Set up a
+ * new timer.
+ *
+ * If refc > 0, the entry is in use. Keep the entry.
+ */
+ refc = erts_refc_dectest(&enp->refc, -1);
+ if (refc == -1)
+ (void) hash_erase(&erts_node_table, (void *) enp);
+ erts_smp_rwmtx_rwunlock(&erts_node_table_rwmtx);
+
+ if (refc == 0)
+ erts_schedule_delete_node(enp);
+}
+
+void erts_schedule_delete_node(ErlNode *enp)
{
ASSERT(enp != erts_this_node);
- if(enp != erts_this_node) {
- erts_smp_rwmtx_rwlock(&erts_node_table_rwmtx);
- /*
- * Another thread might have looked up this node after we
- * decided to delete it (refc became zero). If so, the other
- * thread incremented refc twice. Once for the new reference
- * and once for this thread. Therefore, delete node if refc
- * is 0 or -1 after a decrement.
- */
- if (erts_refc_dectest(&enp->refc, -1) <= 0)
- (void) hash_erase(&erts_node_table, (void *) enp);
- erts_smp_rwmtx_rwunlock(&erts_node_table_rwmtx);
+ if (enp != erts_this_node) {
+ if (node_tab_delete_delay == 0)
+ try_delete_node((void *) enp);
+ else if (node_tab_delete_delay > 0)
+ erts_start_timer_callback(node_tab_delete_delay,
+ try_delete_node,
+ (void *) enp);
}
}
@@ -651,7 +704,7 @@ static void print_node(void *venp, void *vpndp)
erts_print(pndp->to, pndp->to_arg, " %d", enp->creation);
#ifdef DEBUG
erts_print(pndp->to, pndp->to_arg, " (refc=%ld)",
- erts_refc_read(&enp->refc, 1));
+ erts_refc_read(&enp->refc, 0));
#endif
pndp->no_sysname++;
}
@@ -714,11 +767,28 @@ erts_set_this_node(Eterm sysname, Uint creation)
}
-void erts_init_node_tables(void)
+Uint
+erts_delayed_node_table_gc(void)
+{
+ if (node_tab_delete_delay < 0)
+ return (Uint) ERTS_NODE_TAB_DELAY_GC_INFINITY;
+ if (node_tab_delete_delay == 0)
+ return (Uint) 0;
+ return (Uint) ((node_tab_delete_delay-1)/1000 + 1);
+}
+
+void erts_init_node_tables(int dd_sec)
{
erts_smp_rwmtx_opt_t rwmtx_opt = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
HashFunctions f;
+ if (dd_sec == ERTS_NODE_TAB_DELAY_GC_INFINITY)
+ node_tab_delete_delay = (ErtsMonotonicTime) -1;
+ else
+ node_tab_delete_delay = ((ErtsMonotonicTime) dd_sec)*1000;
+
+ orig_node_tab_delete_delay = node_tab_delete_delay;
+
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
rwmtx_opt.lived = ERTS_SMP_RWMTX_LONG_LIVED;
@@ -847,6 +917,7 @@ static Eterm AM_dist_references;
static Eterm AM_node_references;
static Eterm AM_system;
static Eterm AM_timer;
+static Eterm AM_delayed_delete_timer;
static void setup_reference_table(void);
static Eterm reference_table_term(Uint **hpp, Uint *szp);
@@ -881,8 +952,10 @@ typedef struct dist_referrer_ {
int heap_ref;
int node_ref;
int ctrl_ref;
+ int system_ref;
Eterm id;
Uint creation;
+ Uint id_heap[ID_HEAP_SIZE];
} DistReferrer;
typedef struct {
@@ -931,6 +1004,7 @@ erts_get_node_and_dist_references(struct process *proc)
INIT_AM(node_references);
INIT_AM(timer);
INIT_AM(system);
+ INIT_AM(delayed_delete_timer);
references_atoms_need_init = 0;
}
@@ -988,17 +1062,25 @@ insert_dist_referrer(ReferredDist *referred_dist,
sizeof(DistReferrer));
drp->next = referred_dist->referrers;
referred_dist->referrers = drp;
- drp->id = id;
+ if(IS_CONST(id))
+ drp->id = id;
+ else {
+ Uint *hp = &drp->id_heap[0];
+ ASSERT(is_tuple(id));
+ drp->id = copy_struct(id, size_object(id), &hp, NULL);
+ }
drp->creation = creation;
drp->heap_ref = 0;
drp->node_ref = 0;
drp->ctrl_ref = 0;
+ drp->system_ref = 0;
}
switch (type) {
case NODE_REF: drp->node_ref++; break;
case CTRL_REF: drp->ctrl_ref++; break;
case HEAP_REF: drp->heap_ref++; break;
+ case SYSTEM_REF: drp->system_ref++; break;
default: ASSERT(0);
}
}
@@ -1261,6 +1343,33 @@ insert_sys_msg(Eterm from, Eterm to, Eterm msg, ErlHeapFragment *bp)
#endif
static void
+insert_delayed_delete_node(void *state,
+ ErtsMonotonicTime timeout_pos,
+ void *vnp)
+{
+ DeclareTmpHeapNoproc(heap,3);
+ UseTmpHeapNoproc(3);
+ insert_node((ErlNode *) vnp,
+ SYSTEM_REF,
+ TUPLE2(&heap[0], AM_system, AM_delayed_delete_timer));
+ UnUseTmpHeapNoproc(3);
+}
+
+static void
+insert_delayed_delete_dist_entry(void *state,
+ ErtsMonotonicTime timeout_pos,
+ void *vdep)
+{
+ DeclareTmpHeapNoproc(heap,3);
+ UseTmpHeapNoproc(3);
+ insert_dist_entry((DistEntry *) vdep,
+ SYSTEM_REF,
+ TUPLE2(&heap[0], AM_system, AM_delayed_delete_timer),
+ 0);
+ UnUseTmpHeapNoproc(3);
+}
+
+static void
setup_reference_table(void)
{
ErlHeapFragment *hfp;
@@ -1288,6 +1397,13 @@ setup_reference_table(void)
/* Go through the hole system, and build a table of all references
to ErlNode and DistEntry structures */
+ erts_debug_callback_timer_foreach(try_delete_node,
+ insert_delayed_delete_node,
+ NULL);
+ erts_debug_callback_timer_foreach(try_delete_dist_entry,
+ insert_delayed_delete_dist_entry,
+ NULL);
+
UseTmpHeapNoproc(3);
insert_node(erts_this_node,
SYSTEM_REF,
@@ -1601,7 +1717,7 @@ reference_table_term(Uint **hpp, Uint *szp)
tup = MK_2TUP(referred_nodes[i].node->sysname,
MK_UINT(referred_nodes[i].node->creation));
- tup = MK_3TUP(tup, MK_UINT(erts_refc_read(&referred_nodes[i].node->refc, 1)), nril);
+ tup = MK_3TUP(tup, MK_UINT(erts_refc_read(&referred_nodes[i].node->refc, 0)), nril);
nl = MK_CONS(tup, nl);
}
@@ -1624,6 +1740,10 @@ reference_table_term(Uint **hpp, Uint *szp)
tup = MK_2TUP(AM_heap, MK_UINT(drp->heap_ref));
drl = MK_CONS(tup, drl);
}
+ if(drp->system_ref) {
+ tup = MK_2TUP(AM_system, MK_UINT(drp->system_ref));
+ drl = MK_CONS(tup, drl);
+ }
if (is_internal_pid(drp->id)) {
ASSERT(!drp->node_ref);
@@ -1633,6 +1753,14 @@ reference_table_term(Uint **hpp, Uint *szp)
ASSERT(drp->ctrl_ref && !drp->node_ref);
tup = MK_2TUP(AM_port, drp->id);
}
+ else if (is_tuple(drp->id)) {
+ Eterm *t;
+ ASSERT(drp->system_ref && !drp->node_ref
+ && !drp->ctrl_ref && !drp->heap_ref);
+ t = tuple_val(drp->id);
+ ASSERT(2 == arityval(t[0]));
+ tup = MK_2TUP(t[1], t[2]);
+ }
else {
ASSERT(!drp->ctrl_ref && drp->node_ref);
ASSERT(is_atom(drp->id));
@@ -1650,7 +1778,7 @@ reference_table_term(Uint **hpp, Uint *szp)
/* DistList = [{Dist, Refc, ReferenceIdList}] */
tup = MK_3TUP(referred_dists[i].dist->sysname,
- MK_UINT(erts_refc_read(&referred_dists[i].dist->refc, 1)),
+ MK_UINT(erts_refc_read(&referred_dists[i].dist->refc, 0)),
dril);
dl = MK_CONS(tup, dl);
}
@@ -1705,3 +1833,15 @@ delete_reference_table(void)
}
}
+void
+erts_debug_test_node_tab_delayed_delete(Sint64 millisecs)
+{
+ erts_smp_thr_progress_block();
+
+ if (millisecs < 0)
+ node_tab_delete_delay = orig_node_tab_delete_delay;
+ else
+ node_tab_delete_delay = millisecs;
+
+ erts_smp_thr_progress_unblock();
+}