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authorErlang/OTP <[email protected]>2010-06-03 09:05:26 +0000
committerErlang/OTP <[email protected]>2010-06-03 09:05:26 +0000
commitfe22c51ffb9d71ca11d4bac71e1fcc82b6b6d977 (patch)
tree8bf9eef5ede7ff63acbda2882445b445c13f29f3 /erts/emulator
parentb770a19422f886d92a41eecee0a130d93bf42f80 (diff)
parentd6ed3417f87612b7a7c08e979d180e1d865482ba (diff)
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Merge branch 'pan/unregister_error' into dev
* pan/unregister_error: Add possibly missing process lock before unregistering oneself Keep process lock over trace of unregister OTP-8663 Unregister may crash VM Extreme combinations of register/unregister in a highly parallell SMP application could crash the VM. The error is corrected.
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/beam/erl_trace.c4
-rw-r--r--erts/emulator/beam/register.c37
2 files changed, 28 insertions, 13 deletions
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index 8addfcf5ad..381a182e39 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -1941,11 +1941,13 @@ trace_proc(Process *c_p, Process *t_p, Eterm what, Eterm data)
Eterm* hp;
int need;
+ ERTS_SMP_LC_ASSERT((erts_proc_lc_my_proc_locks(t_p) != 0) || erts_is_system_blocked(0));
if (is_internal_port(t_p->tracer_proc)) {
#define LOCAL_HEAP_SIZE (5+5)
DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
+
hp = local_heap;
mess = TUPLE4(hp, am_trace, t_p->id, what, data);
hp += 5;
@@ -2727,6 +2729,8 @@ trace_port(Port *t_p, Eterm what, Eterm data) {
Eterm mess;
Eterm* hp;
+ ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(t_p) || erts_is_system_blocked(0));
+
if (is_internal_port(t_p->tracer_proc)) {
#define LOCAL_HEAP_SIZE (5+5)
DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
diff --git a/erts/emulator/beam/register.c b/erts/emulator/beam/register.c
index 964c10a380..900ebcbbf7 100644
--- a/erts/emulator/beam/register.c
+++ b/erts/emulator/beam/register.c
@@ -476,8 +476,9 @@ int erts_unregister_name(Process *c_p,
* on c_prt.
*/
- if (!c_p)
+ if (!c_p) {
c_p_locks = 0;
+ }
current_c_p_locks = c_p_locks;
restart:
@@ -489,9 +490,15 @@ int erts_unregister_name(Process *c_p,
if (is_non_value(name)) {
/* Unregister current process name */
ASSERT(c_p);
- if (c_p->reg)
+#ifdef ERTS_SMP
+ if (current_c_p_locks != c_p_locks) {
+ erts_smp_proc_lock(c_p, c_p_locks);
+ current_c_p_locks = c_p_locks;
+ }
+#endif
+ if (c_p->reg) {
r.name = c_p->reg->name;
- else {
+ } else {
/* Name got unregistered while main lock was released */
res = 0;
goto done;
@@ -533,24 +540,25 @@ int erts_unregister_name(Process *c_p,
}
} else if (rp->p) {
- Process* p = rp->p;
+
#ifdef ERTS_SMP
erts_proc_safelock(c_p,
current_c_p_locks,
c_p_locks,
rp->p,
- 0,
+ (c_p == rp->p) ? current_c_p_locks : 0,
ERTS_PROC_LOCK_MAIN);
current_c_p_locks = c_p_locks;
#endif
- p->reg = NULL;
+ rp->p->reg = NULL;
+ if (IS_TRACED_FL(rp->p, F_TRACE_PROCS)) {
+ trace_proc(c_p, rp->p, am_unregister, r.name);
+ }
#ifdef ERTS_SMP
- if (rp->p != c_p)
+ if (rp->p != c_p) {
erts_smp_proc_unlock(rp->p, ERTS_PROC_LOCK_MAIN);
-#endif
- if (IS_TRACED_FL(p, F_TRACE_PROCS)) {
- trace_proc(c_p, p, am_unregister, r.name);
}
+#endif
}
hash_erase(&process_reg, (void*) &r);
res = 1;
@@ -560,14 +568,17 @@ int erts_unregister_name(Process *c_p,
reg_write_unlock();
if (c_prt != port) {
- if (port)
+ if (port) {
erts_smp_port_unlock(port);
- if (c_prt)
+ }
+ if (c_prt) {
erts_smp_port_lock(c_prt);
+ }
}
#ifdef ERTS_SMP
- if (c_p && !current_c_p_locks)
+ if (c_p && !current_c_p_locks) {
erts_smp_proc_lock(c_p, c_p_locks);
+ }
#endif
return res;
}