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authorSverker Eriksson <[email protected]>2015-11-10 15:43:15 +0100
committerSverker Eriksson <[email protected]>2015-11-10 15:43:15 +0100
commit949de78331b9c4ecb9c628bb651cecb113790e2e (patch)
tree108bbaeb677a9f0445ca5580e2d6034be8f58161
parent1eeb980a3591b51f12363543b2ac9b0260ebd870 (diff)
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erts: Fix bug in setnode/2
that could lead strange things to happen when renaming a node with a name that already exist in node and dist tables. Problem: erts_set_this_node() is a bit brutal and does not handle the case when an old remote node name is reused as the new local node name. Solution: Treat erts_this_node and erts_this_dist_entry as all the others with correct reference counting.
-rw-r--r--erts/emulator/beam/bif.c1
-rw-r--r--erts/emulator/beam/dist.c14
-rw-r--r--erts/emulator/beam/erl_node_tables.c144
-rw-r--r--erts/emulator/test/distribution_SUITE_data/run.erl47
4 files changed, 95 insertions, 111 deletions
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 4e3a1cef69..6c61b0de6b 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -4231,6 +4231,7 @@ BIF_RETTYPE list_to_pid_1(BIF_ALIST_1)
goto bad;
enp = erts_find_or_insert_node(dep->sysname, dep->creation);
+ ASSERT(enp != erts_this_node);
etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
etp->header = make_external_pid_header(1);
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 5a0f8388f8..56a8633f85 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -2572,7 +2572,9 @@ int distribution_info(int to, void *arg) /* Called by break handler */
}
for (dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
- info_dist_entry(to, arg, dep, 0, 0);
+ if (dep != erts_this_dist_entry) {
+ info_dist_entry(to, arg, dep, 0, 0);
+ }
}
return(0);
@@ -3012,11 +3014,11 @@ BIF_RETTYPE nodes_1(BIF_ALIST_1)
erts_smp_rwmtx_rlock(&erts_dist_table_rwmtx);
- ASSERT(erts_no_of_not_connected_dist_entries >= 0);
+ ASSERT(erts_no_of_not_connected_dist_entries > 0);
ASSERT(erts_no_of_hidden_dist_entries >= 0);
ASSERT(erts_no_of_visible_dist_entries >= 0);
if(not_connected)
- length += erts_no_of_not_connected_dist_entries;
+ length += (erts_no_of_not_connected_dist_entries - 1);
if(hidden)
length += erts_no_of_hidden_dist_entries;
if(visible)
@@ -3038,8 +3040,10 @@ BIF_RETTYPE nodes_1(BIF_ALIST_1)
#endif
if(not_connected)
for(dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
- result = CONS(hp, dep->sysname, result);
- hp += 2;
+ if (dep != erts_this_dist_entry) {
+ result = CONS(hp, dep->sysname, result);
+ hp += 2;
+ }
}
if(hidden)
for(dep = erts_hidden_dist_entries; dep; dep = dep->next) {
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 865de1726d..a7d0511bf9 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -37,18 +37,18 @@ erts_smp_rwmtx_t erts_node_table_rwmtx;
DistEntry *erts_hidden_dist_entries;
DistEntry *erts_visible_dist_entries;
-DistEntry *erts_not_connected_dist_entries;
+DistEntry *erts_not_connected_dist_entries; /* including erts_this_dist_entry */
Sint erts_no_of_hidden_dist_entries;
Sint erts_no_of_visible_dist_entries;
-Sint erts_no_of_not_connected_dist_entries;
+Sint erts_no_of_not_connected_dist_entries; /* including erts_this_dist_entry */
DistEntry *erts_this_dist_entry;
ErlNode *erts_this_node;
char erts_this_node_sysname_BUFFER[256],
*erts_this_node_sysname = "uninitialized yet";
-static Uint node_entries;
-static Uint dist_entries;
+static Uint node_entries = 0;
+static Uint dist_entries = 0;
static int references_atoms_need_init = 1;
@@ -91,9 +91,6 @@ dist_table_alloc(void *dep_tmpl)
erts_smp_rwmtx_opt_t rwmtx_opt = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
- if(((DistEntry *) dep_tmpl) == erts_this_dist_entry)
- return dep_tmpl;
-
sysname = ((DistEntry *) dep_tmpl)->sysname;
chnl_nr = make_small((Uint) atom_val(sysname));
dep = (DistEntry *) erts_alloc(ERTS_ALC_T_DIST_ENTRY, sizeof(DistEntry));
@@ -132,7 +129,9 @@ dist_table_alloc(void *dep_tmpl)
/* Link in */
- /* All new dist entries are "not connected" */
+ /* All new dist entries are "not connected".
+ * erts_this_dist_entry is also always included among "not connected"
+ */
dep->next = erts_not_connected_dist_entries;
if(erts_not_connected_dist_entries) {
ASSERT(erts_not_connected_dist_entries->prev == NULL);
@@ -149,9 +148,6 @@ dist_table_free(void *vdep)
{
DistEntry *dep = (DistEntry *) vdep;
- if(dep == erts_this_dist_entry)
- return;
-
ASSERT(is_nil(dep->cid));
ASSERT(dep->nlinks == NULL);
ASSERT(dep->node_links == NULL);
@@ -186,7 +182,7 @@ dist_table_free(void *vdep)
#endif
erts_free(ERTS_ALC_T_DIST_ENTRY, (void *) dep);
- ASSERT(dist_entries > 1);
+ ASSERT(dist_entries > 0);
dist_entries--;
}
@@ -306,7 +302,7 @@ static void try_delete_dist_entry(void *vdep)
* 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
+ * If refc reach -1, no one has used the entry since we
* set up the timer. Delete the entry.
*
* If refc reach 0, the entry is currently not in use
@@ -369,8 +365,7 @@ erts_dist_table_size(void)
ASSERT(dist_entries == (erts_no_of_visible_dist_entries
+ erts_no_of_hidden_dist_entries
- + erts_no_of_not_connected_dist_entries
- + 1 /* erts_this_dist_entry */));
+ + erts_no_of_not_connected_dist_entries));
#endif
res = (hash_table_sz(&erts_dist_table)
@@ -543,9 +538,6 @@ node_table_alloc(void *venp_tmpl)
{
ErlNode *enp;
- if(((ErlNode *) venp_tmpl) == erts_this_node)
- return venp_tmpl;
-
enp = (ErlNode *) erts_alloc(ERTS_ALC_T_NODE_ENTRY, sizeof(ErlNode));
node_entries++;
@@ -563,8 +555,7 @@ node_table_free(void *venp)
{
ErlNode *enp = (ErlNode *) venp;
- if(enp == erts_this_node)
- return;
+ ERTS_SMP_LC_ASSERT(enp != erts_this_node || erts_thr_progress_is_blocking());
erts_deref_dist_entry(enp->dist_entry);
#ifdef DEBUG
@@ -572,7 +563,7 @@ node_table_free(void *venp)
#endif
erts_free(ERTS_ALC_T_NODE_ENTRY, venp);
- ASSERT(node_entries > 1);
+ ASSERT(node_entries > 0);
node_entries--;
}
@@ -650,7 +641,7 @@ static void try_delete_node(void *venp)
* 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
+ * If refc reach -1, no one has used the entry since we
* set up the timer. Delete the entry.
*
* If refc reach 0, the entry is currently not in use
@@ -747,25 +738,20 @@ void erts_print_node_info(int to,
void
erts_set_this_node(Eterm sysname, Uint creation)
{
- erts_smp_rwmtx_rwlock(&erts_node_table_rwmtx);
- erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
+ ERTS_SMP_LC_ASSERT(erts_thr_progress_is_blocking());
+ ASSERT(erts_refc_read(&erts_this_dist_entry->refc, 2));
- (void) hash_erase(&erts_dist_table, (void *) erts_this_dist_entry);
- erts_this_dist_entry->sysname = sysname;
- erts_this_dist_entry->creation = creation;
- (void) hash_put(&erts_dist_table, (void *) erts_this_dist_entry);
+ if (erts_refc_dectest(&erts_this_node->refc, 0) == 0)
+ try_delete_node(erts_this_node);
- (void) hash_erase(&erts_node_table, (void *) erts_this_node);
- erts_this_node->sysname = sysname;
- erts_this_node->creation = creation;
- erts_this_node_sysname = erts_this_node_sysname_BUFFER;
- erts_snprintf(erts_this_node_sysname, sizeof(erts_this_node_sysname_BUFFER),
- "%T", sysname);
- (void) hash_put(&erts_node_table, (void *) erts_this_node);
+ if (erts_refc_dectest(&erts_this_dist_entry->refc, 0) == 0)
+ try_delete_dist_entry(erts_this_dist_entry);
- erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
- erts_smp_rwmtx_rwunlock(&erts_node_table_rwmtx);
+ erts_this_node = NULL; /* to make sure refc is bumped for this node */
+ erts_this_node = erts_find_or_insert_node(sysname, creation);
+ erts_this_dist_entry = erts_this_node->dist_entry;
+ erts_refc_inc(&erts_this_dist_entry->refc, 2);
}
Uint
@@ -782,6 +768,7 @@ void erts_init_node_tables(int dd_sec)
{
erts_smp_rwmtx_opt_t rwmtx_opt = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
HashFunctions f;
+ ErlNode node_tmpl;
if (dd_sec == ERTS_NODE_TAB_DELAY_GC_INFINITY)
node_tab_delete_delay = (ErtsMonotonicTime) -1;
@@ -793,16 +780,21 @@ void erts_init_node_tables(int dd_sec)
rwmtx_opt.type = ERTS_SMP_RWMTX_TYPE_FREQUENT_READ;
rwmtx_opt.lived = ERTS_SMP_RWMTX_LONG_LIVED;
+ erts_smp_rwmtx_init_opt(&erts_node_table_rwmtx, &rwmtx_opt, "node_table");
+ erts_smp_rwmtx_init_opt(&erts_dist_table_rwmtx, &rwmtx_opt, "dist_table");
+
f.hash = (H_FUN) dist_table_hash;
f.cmp = (HCMP_FUN) dist_table_cmp;
f.alloc = (HALLOC_FUN) dist_table_alloc;
f.free = (HFREE_FUN) dist_table_free;
-
- erts_this_dist_entry = erts_alloc(ERTS_ALC_T_DIST_ENTRY, sizeof(DistEntry));
- dist_entries = 1;
-
hash_init(ERTS_ALC_T_DIST_TABLE, &erts_dist_table, "dist_table", 11, f);
+ f.hash = (H_FUN) node_table_hash;
+ f.cmp = (HCMP_FUN) node_table_cmp;
+ f.alloc = (HALLOC_FUN) node_table_alloc;
+ f.free = (HFREE_FUN) node_table_free;
+ hash_init(ERTS_ALC_T_NODE_TABLE, &erts_node_table, "node_table", 11, f);
+
erts_hidden_dist_entries = NULL;
erts_visible_dist_entries = NULL;
erts_not_connected_dist_entries = NULL;
@@ -810,69 +802,23 @@ void erts_init_node_tables(int dd_sec)
erts_no_of_visible_dist_entries = 0;
erts_no_of_not_connected_dist_entries = 0;
- erts_this_dist_entry->next = NULL;
- erts_this_dist_entry->prev = NULL;
- erts_refc_init(&erts_this_dist_entry->refc, 1); /* erts_this_node */
-
- erts_smp_rwmtx_init_opt_x(&erts_this_dist_entry->rwmtx,
- &rwmtx_opt,
- "dist_entry",
- make_small(ERST_INTERNAL_CHANNEL_NO));
- erts_this_dist_entry->sysname = am_Noname;
- erts_this_dist_entry->cid = NIL;
- erts_this_dist_entry->connection_id = 0;
- erts_this_dist_entry->status = 0;
- erts_this_dist_entry->flags = 0;
- erts_this_dist_entry->version = 0;
-
- erts_smp_mtx_init_x(&erts_this_dist_entry->lnk_mtx,
- "dist_entry_links",
- make_small(ERST_INTERNAL_CHANNEL_NO));
- erts_this_dist_entry->node_links = NULL;
- erts_this_dist_entry->nlinks = NULL;
- erts_this_dist_entry->monitors = NULL;
-
- erts_smp_mtx_init_x(&erts_this_dist_entry->qlock,
- "dist_entry_out_queue",
- make_small(ERST_INTERNAL_CHANNEL_NO));
- erts_this_dist_entry->qflgs = 0;
- erts_this_dist_entry->qsize = 0;
- erts_this_dist_entry->out_queue.first = NULL;
- erts_this_dist_entry->out_queue.last = NULL;
- erts_this_dist_entry->suspended = NULL;
-
- erts_this_dist_entry->finalized_out_queue.first = NULL;
- erts_this_dist_entry->finalized_out_queue.last = NULL;
- erts_smp_atomic_init_nob(&erts_this_dist_entry->dist_cmd_scheduled, 0);
- erts_port_task_handle_init(&erts_this_dist_entry->dist_cmd);
- erts_this_dist_entry->send = NULL;
- erts_this_dist_entry->cache = NULL;
-
- (void) hash_put(&erts_dist_table, (void *) erts_this_dist_entry);
+ node_tmpl.sysname = am_Noname;
+ node_tmpl.creation = 0;
+ erts_this_node = hash_put(&erts_node_table, &node_tmpl);
+ /* +1 for erts_this_node */
+ erts_refc_init(&erts_this_node->refc, 1);
- f.hash = (H_FUN) node_table_hash;
- f.cmp = (HCMP_FUN) node_table_cmp;
- f.alloc = (HALLOC_FUN) node_table_alloc;
- f.free = (HFREE_FUN) node_table_free;
-
- hash_init(ERTS_ALC_T_NODE_TABLE, &erts_node_table, "node_table", 11, f);
+ ASSERT(erts_this_node->dist_entry != NULL);
+ erts_this_dist_entry = erts_this_node->dist_entry;
+ /* +1 for erts_this_dist_entry */
+ /* +1 for erts_this_node->dist_entry */
+ erts_refc_init(&erts_this_dist_entry->refc, 2);
- erts_this_node = erts_alloc(ERTS_ALC_T_NODE_ENTRY, sizeof(ErlNode));
- node_entries = 1;
- erts_refc_init(&erts_this_node->refc, 1); /* The system itself */
- erts_this_node->sysname = am_Noname;
- erts_this_node->creation = 0;
- erts_this_node->dist_entry = erts_this_dist_entry;
erts_this_node_sysname = erts_this_node_sysname_BUFFER;
erts_snprintf(erts_this_node_sysname, sizeof(erts_this_node_sysname_BUFFER),
"%T", erts_this_node->sysname);
- (void) hash_put(&erts_node_table, (void *) erts_this_node);
-
- erts_smp_rwmtx_init_opt(&erts_node_table_rwmtx, &rwmtx_opt, "node_table");
- erts_smp_rwmtx_init_opt(&erts_dist_table_rwmtx, &rwmtx_opt, "dist_table");
-
references_atoms_need_init = 1;
}
@@ -1410,6 +1356,10 @@ setup_reference_table(void)
SYSTEM_REF,
TUPLE2(&heap[0], AM_system, am_undefined));
+ insert_dist_entry(erts_this_dist_entry,
+ SYSTEM_REF,
+ TUPLE2(&heap[0], AM_system, am_undefined),
+ erts_this_node->creation);
UnUseTmpHeapNoproc(3);
max = erts_ptab_max(&erts_proc);
diff --git a/erts/emulator/test/distribution_SUITE_data/run.erl b/erts/emulator/test/distribution_SUITE_data/run.erl
index f5169e160c..d5ed139369 100644
--- a/erts/emulator/test/distribution_SUITE_data/run.erl
+++ b/erts/emulator/test/distribution_SUITE_data/run.erl
@@ -30,16 +30,19 @@ from(H, [_ | T]) -> from(H, T);
from(H, []) -> [].
start() ->
- net_kernel:start([fideridum,shortnames]),
- {ok, Node} = slave:start(host(), heppel),
- P = spawn(Node, a, b, []),
- B1 = term_to_binary(P),
- N1 = node(P),
- ok = net_kernel:stop(),
- N2 = node(P),
- io:format("~w~n", [N1 == N2]),
+ Result = do_it(),
+
+ %% Do GCs and node_and_dist_references
+ %% in an attempt to crash the VM (without OTP-13076 fix)
+ lists:foreach(fun(P) -> erlang:garbage_collect(P) end,
+ processes()),
+ erts_debug:set_internal_state(available_internal_state, true),
+ erts_debug:get_internal_state(node_and_dist_references),
+
+ io:format("~w~n", [Result]),
+
if
- N1 == N2 ->
+ Result ->
init:stop();
true ->
%% Make sure that the io:format/2 output is really written
@@ -47,3 +50,29 @@ start() ->
erlang:yield(),
init:stop()
end.
+
+
+do_it() ->
+ {ok, _} = net_kernel:start([fideridum,shortnames]),
+ {ok, Node} = slave:start(host(), heppel),
+ P = spawn(Node, net_kernel, stop, []),
+ B1 = term_to_binary(P),
+ N1 = node(P),
+ ok = net_kernel:stop(),
+ N2 = node(P),
+
+ %% OTP-13076
+ %% Restart distribution with same node name as previous remote node
+ %% Repeat to wrap around creation
+ Result = lists:foldl(fun(_, Acc) ->
+ timer:sleep(2), % give net_kernel:stop() time to take effect :-(
+ {ok, _} = net_kernel:start([heppel,shortnames]),
+ N3 = node(P),
+ ok = net_kernel:stop(),
+ N4 = node(P),
+ Acc and (N3 =:= N1) and (N4 =:= N1)
+ end,
+ (N2 =:= N1),
+ lists:seq(1,3)),
+
+ Result.