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authorRickard Green <[email protected]>2016-01-13 18:33:42 +0100
committerRickard Green <[email protected]>2016-01-20 11:10:37 +0100
commitdc8e62f33ad0ca7a772ec74d67b6d3e157f639b4 (patch)
treedfb9c44328ba358c34678d557941a13b79e3d281 /erts/emulator
parent858c6f7fa44f7b2dc363b359198d6522dd60e914 (diff)
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Introduce time warp safe replacement for safe_fixed option
The new time warp safe option is safe_fixed_monotonic_time which gives erlang:monotonic_time(). The safe_fixed option was also slightly changed. It now gives erlang:timestamp() instead of erlang:now(). This has however not been documented, so it is considered a compatible change. The above effects both ets, and dets. This commit also include the bugfix OTP-13239 for dets:info(Tab, safe_fixed). The timestamp in the result returned by dets:info(Tab, safe_fixed) was unintentionally broken as a result of the time API rewrites in OTP 18.0.
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/beam/erl_db.c46
-rw-r--r--erts/emulator/beam/erl_db_util.h5
-rw-r--r--erts/emulator/beam/erl_time_sup.c47
-rw-r--r--erts/emulator/beam/sys.h4
4 files changed, 78 insertions, 24 deletions
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 878ee32b47..645f9e3c28 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -1376,7 +1376,6 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
status |= DB_ORDERED_SET;
status &= ~(DB_SET | DB_BAG | DB_DUPLICATE_BAG);
}
- /*TT*/
else if (is_tuple(val)) {
Eterm *tp = tuple_val(val);
if (arityval(tp[0]) == 2) {
@@ -3466,10 +3465,10 @@ static void fix_table_locked(Process* p, DbTable* tb)
#endif
erts_refc_inc(&tb->common.ref,1);
fix = tb->common.fixations;
- if (fix == NULL) {
- get_now(&(tb->common.megasec),
- &(tb->common.sec),
- &(tb->common.microsec));
+ if (fix == NULL) {
+ tb->common.time.monotonic
+ = erts_get_monotonic_time(ERTS_PROC_GET_SCHDATA(p));
+ tb->common.time.offset = erts_get_time_offset();
}
else {
for (; fix != NULL; fix = fix->next) {
@@ -3731,6 +3730,7 @@ static int free_table_cont(Process *p,
static Eterm table_info(Process* p, DbTable* tb, Eterm What)
{
Eterm ret = THE_NON_VALUE;
+ int use_monotonic;
if (What == am_size) {
ret = make_small(erts_smp_atomic_read_nob(&tb->common.nitems));
@@ -3788,7 +3788,10 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
ret = am_true;
else
ret = am_false;
- } else if (What == am_atom_put("safe_fixed",10)) {
+ } else if ((use_monotonic
+ = ERTS_IS_ATOM_STR("safe_fixed_monotonic_time",
+ What))
+ || ERTS_IS_ATOM_STR("safe_fixed", What)) {
#ifdef ERTS_SMP
erts_smp_mtx_lock(&tb->common.fixlock);
#endif
@@ -3797,7 +3800,19 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
Eterm *hp;
Eterm tpl, lst;
DbFixation *fix;
- need = 7;
+ Sint64 mtime;
+
+ need = 3;
+ if (use_monotonic) {
+ mtime = (Sint64) tb->common.time.monotonic;
+ mtime += ERTS_MONOTONIC_OFFSET_NATIVE;
+ if (!IS_SSMALL(mtime))
+ need += ERTS_SINT64_HEAP_SIZE(mtime);
+ }
+ else {
+ mtime = 0;
+ need += 4;
+ }
for (fix = tb->common.fixations; fix != NULL; fix = fix->next) {
need += 5;
}
@@ -3809,11 +3824,18 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
lst = CONS(hp,tpl,lst);
hp += 2;
}
- tpl = TUPLE3(hp,
- make_small(tb->common.megasec),
- make_small(tb->common.sec),
- make_small(tb->common.microsec));
- hp += 4;
+ if (use_monotonic)
+ tpl = (IS_SSMALL(mtime)
+ ? make_small(mtime)
+ : erts_sint64_to_big(mtime, &hp));
+ else {
+ Uint ms, s, us;
+ erts_make_timestamp_value(&ms, &s, &us,
+ tb->common.time.monotonic,
+ tb->common.time.offset);
+ tpl = TUPLE3(hp, make_small(ms), make_small(s), make_small(us));
+ hp += 4;
+ }
ret = TUPLE2(hp, tpl, lst);
} else {
ret = am_false;
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 1ccdc0305b..0903a40460 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -229,7 +229,10 @@ typedef struct db_table_common {
DbTableMethod* meth; /* table methods */
erts_smp_atomic_t nitems; /* Total number of items in table */
erts_smp_atomic_t memory_size;/* Total memory size. NOTE: in bytes! */
- Uint megasec,sec,microsec; /* Last fixation time */
+ struct { /* Last fixation time */
+ ErtsMonotonicTime monotonic;
+ ErtsMonotonicTime offset;
+ } time;
DbFixation* fixations; /* List of processes who have done safe_fixtable,
"local" fixations not included. */
/* All 32-bit fields */
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 7327e0b48c..2c87b8e81c 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -1747,6 +1747,39 @@ erts_get_monotonic_time(ErtsSchedulerData *esdp)
return mtime;
}
+ErtsMonotonicTime
+erts_get_time_offset(void)
+{
+ return get_time_offset();
+}
+
+static ERTS_INLINE void
+make_timestamp_value(Uint* megasec, Uint* sec, Uint* microsec,
+ ErtsMonotonicTime mtime, ErtsMonotonicTime offset)
+{
+ ErtsMonotonicTime stime, as;
+ Uint ms;
+
+ stime = ERTS_MONOTONIC_TO_USEC(mtime + offset);
+
+ as = stime / ERTS_MONOTONIC_TIME_MEGA;
+ *megasec = ms = (Uint) (stime / ERTS_MONOTONIC_TIME_TERA);
+ *sec = (Uint) (as - (((ErtsMonotonicTime) ms)
+ * ERTS_MONOTONIC_TIME_MEGA));
+ *microsec = (Uint) (stime - as*ERTS_MONOTONIC_TIME_MEGA);
+
+ ASSERT(((ErtsMonotonicTime) ms)*ERTS_MONOTONIC_TIME_TERA
+ + ((ErtsMonotonicTime) *sec)*ERTS_MONOTONIC_TIME_MEGA
+ + *microsec == stime);
+}
+
+void
+erts_make_timestamp_value(Uint* megasec, Uint* sec, Uint* microsec,
+ ErtsMonotonicTime mtime, ErtsMonotonicTime offset)
+{
+ make_timestamp_value(megasec, sec, microsec, mtime, offset);
+}
+
void
get_sys_now(Uint* megasec, Uint* sec, Uint* microsec)
{
@@ -2220,22 +2253,14 @@ BIF_RETTYPE time_offset_1(BIF_ALIST_1)
BIF_RETTYPE timestamp_0(BIF_ALIST_0)
{
Eterm *hp, res;
- ErtsMonotonicTime stime, mtime, all_sec, offset;
+ ErtsMonotonicTime mtime, offset;
Uint mega_sec, sec, micro_sec;
mtime = time_sup.r.o.get_time();
offset = get_time_offset();
update_last_mtime(ERTS_PROC_GET_SCHDATA(BIF_P), mtime);
- stime = ERTS_MONOTONIC_TO_USEC(mtime + offset);
- all_sec = stime / ERTS_MONOTONIC_TIME_MEGA;
- mega_sec = (Uint) (stime / ERTS_MONOTONIC_TIME_TERA);
- sec = (Uint) (all_sec - (((ErtsMonotonicTime) mega_sec)
- * ERTS_MONOTONIC_TIME_MEGA));
- micro_sec = (Uint) (stime - all_sec*ERTS_MONOTONIC_TIME_MEGA);
-
- ASSERT(((ErtsMonotonicTime) mega_sec)*ERTS_MONOTONIC_TIME_TERA
- + ((ErtsMonotonicTime) sec)*ERTS_MONOTONIC_TIME_MEGA
- + micro_sec == stime);
+
+ make_timestamp_value(&mega_sec, &sec, &micro_sec, mtime, offset);
/*
* Mega seconds is the only value that potentially
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index ec94e3a596..03e30573de 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -819,6 +819,10 @@ int local_to_univ(Sint *year, Sint *month, Sint *day,
void get_now(Uint*, Uint*, Uint*);
struct ErtsSchedulerData_;
ErtsMonotonicTime erts_get_monotonic_time(struct ErtsSchedulerData_ *);
+ErtsMonotonicTime erts_get_time_offset(void);
+void
+erts_make_timestamp_value(Uint* megasec, Uint* sec, Uint* microsec,
+ ErtsMonotonicTime mtime, ErtsMonotonicTime offset);
void get_sys_now(Uint*, Uint*, Uint*);
void set_break_quit(void (*)(void), void (*)(void));