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authorRickard Green <[email protected]>2018-03-21 17:34:38 +0100
committerRickard Green <[email protected]>2018-03-22 16:18:30 +0100
commit2dc14df8ce5d56df3974aa57a61b3c1a0bfd3149 (patch)
tree7107abb51be882bb34201279e8dedf7ec844bceb
parent4bc282d812cc2c49aa3e2d073e96c720f16aa270 (diff)
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Fix signal handling priority elevation
-rw-r--r--erts/emulator/beam/erl_process.c104
1 files changed, 66 insertions, 38 deletions
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 7969025f57..374583ec47 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -10501,6 +10501,8 @@ done:
return st;
}
+
+static void exit_permanent_prio_elevation(Process *c_p, erts_aint32_t state);
static void save_gc_task(Process *c_p, ErtsProcSysTask *st, int prio);
static void save_dirty_task(Process *c_p, ErtsProcSysTask *st);
@@ -10633,8 +10635,10 @@ execute_sys_tasks(Process *c_p, erts_aint32_t *statep, int in_reds)
reds, local_only);
reds -= sig_reds;
- if (state & ERTS_PSFLG_EXITING)
- goto perm_elevate_prio;
+ if (state & ERTS_PSFLG_EXITING) {
+ exit_permanent_prio_elevation(c_p, state);
+ break;
+ }
if (sig_res)
break;
@@ -10648,37 +10652,8 @@ execute_sys_tasks(Process *c_p, erts_aint32_t *statep, int in_reds)
st = NULL;
}
else {
- erts_aint32_t a;
-
state = erts_atomic32_read_nob(&c_p->state);
-
- perm_elevate_prio:
-
- /*
- * we are about to terminate; permanently elevate
- * prio in order to ensure high prio signal
- * handling...
- */
-
- a = state;
- while (1) {
- erts_aint32_t aprio, uprio, n, e;
- ASSERT(!(a & ERTS_PSFLG_FREE));
- aprio = ERTS_PSFLGS_GET_ACT_PRIO(a);
- uprio = ERTS_PSFLGS_GET_USR_PRIO(a);
- if (aprio >= uprio)
- break; /* user prio >= actual prio */
- /*
- * actual prio is higher than user prio; raise
- * user prio to actual prio...
- */
- n = e = a;
- n &= ~ERTS_PSFLGS_USR_PRIO_MASK;
- n |= aprio << ERTS_PSFLGS_USR_PRIO_OFFSET;
- a = erts_atomic32_cmpxchg_mb(&c_p->state, n, e);
- if (a == e)
- break;
- }
+ exit_permanent_prio_elevation(c_p, state);
}
break;
}
@@ -10730,12 +10705,15 @@ cleanup_sys_tasks(Process *c_p, erts_aint32_t in_state, int in_reds)
}
switch (st->type) {
+ case ERTS_PSTT_PRIO_SIG:
+ state = erts_atomic32_read_nob(&c_p->state);
+ exit_permanent_prio_elevation(c_p, state);
+ /* fall through... */
case ERTS_PSTT_GC_MAJOR:
case ERTS_PSTT_GC_MINOR:
case ERTS_PSTT_CPC:
case ERTS_PSTT_COHMQ:
case ERTS_PSTT_ETS_FREE_FIXATION:
- case ERTS_PSTT_PRIO_SIG:
st_res = am_false;
break;
case ERTS_PSTT_CLA:
@@ -10759,6 +10737,36 @@ cleanup_sys_tasks(Process *c_p, erts_aint32_t in_state, int in_reds)
return reds;
}
+static void
+exit_permanent_prio_elevation(Process *c_p, erts_aint32_t state)
+{
+ erts_aint32_t a;
+ /*
+ * we are about to terminate; permanently elevate
+ * prio in order to ensure high prio signal
+ * handling...
+ */
+ a = state;
+ while (1) {
+ erts_aint32_t aprio, uprio, n, e;
+ ASSERT(a & ERTS_PSFLG_EXITING);
+ ASSERT(!(a & ERTS_PSFLG_FREE));
+ aprio = ERTS_PSFLGS_GET_ACT_PRIO(a);
+ uprio = ERTS_PSFLGS_GET_USR_PRIO(a);
+ if (aprio >= uprio)
+ break; /* user prio >= actual prio */
+ /*
+ * actual prio is higher than user prio; raise
+ * user prio to actual prio...
+ */
+ n = e = a;
+ n &= ~ERTS_PSFLGS_USR_PRIO_MASK;
+ n |= aprio << ERTS_PSFLGS_USR_PRIO_OFFSET;
+ a = erts_atomic32_cmpxchg_mb(&c_p->state, n, e);
+ if (a == e)
+ break;
+ }
+}
void
erts_execute_dirty_system_task(Process *c_p)
@@ -12752,16 +12760,13 @@ erts_continue_exit_process(Process *p)
erts_set_gc_state(p, 1);
state = erts_atomic32_read_acqb(&p->state);
- if ((state & ERTS_PSFLG_SYS_TASKS)
- || p->dirty_sys_tasks
- ) {
+ if ((state & ERTS_PSFLG_SYS_TASKS) || p->dirty_sys_tasks) {
if (cleanup_sys_tasks(p, state, CONTEXT_REDS) >= CONTEXT_REDS/2)
goto yield;
}
#ifdef DEBUG
erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
- ASSERT(p->sys_task_qs == NULL);
ASSERT(ERTS_PROC_GET_DELAYED_GC_TASK_QS(p) == NULL);
ASSERT(p->dirty_sys_tasks == NULL);
erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
@@ -12873,7 +12878,30 @@ erts_continue_exit_process(Process *p)
? ERTS_PROC_SET_DIST_ENTRY(p, NULL)
: NULL);
- erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
+
+ /*
+ * It might show up signal prio elevation tasks until we
+ * have entered free state. Cleanup such tasks now.
+ */
+ state = erts_atomic32_read_acqb(&p->state);
+ if (!(state & ERTS_PSFLG_SYS_TASKS))
+ erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
+ else {
+ erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
+
+ do {
+ (void) cleanup_sys_tasks(p, state, CONTEXT_REDS);
+ state = erts_atomic32_read_acqb(&p->state);
+ } while (state & ERTS_PSFLG_SYS_TASKS);
+
+ erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
+ }
+
+#ifdef DEBUG
+ erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+ ASSERT(p->sys_task_qs == NULL);
+ erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
+#endif
if (dep) {
erts_do_net_exits(dep, (reason == am_kill) ? am_killed : reason);