From dc8e62f33ad0ca7a772ec74d67b6d3e157f639b4 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Wed, 13 Jan 2016 18:33:42 +0100 Subject: 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. --- erts/emulator/beam/erl_db.c | 46 ++++++++++++++++++++++++++++---------- erts/emulator/beam/erl_db_util.h | 5 ++++- erts/emulator/beam/erl_time_sup.c | 47 ++++++++++++++++++++++++++++++--------- erts/emulator/beam/sys.h | 4 ++++ 4 files changed, 78 insertions(+), 24 deletions(-) (limited to 'erts/emulator') 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, µ_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)); -- cgit v1.2.3