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authorErlang/OTP <[email protected]>2015-07-08 20:31:18 +0200
committerErlang/OTP <[email protected]>2015-07-08 20:31:18 +0200
commit86a121c5e59ab891b51ba8f28b705659d84e7330 (patch)
treee623b3d6290dab2640d53a97b2275378acf583b4
parentf90a1c457fce5bb4ebc81729bae7c91f82f23e1d (diff)
parent9b44550e9f1b8bf49d447152625f5b3999649034 (diff)
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Merge branch 'rickard/read_corrected_time/OTP-12894' into maint-18
* rickard/read_corrected_time/OTP-12894: Avoid unnecessary copying of data when retrieving corrected monotonic time
-rw-r--r--erts/emulator/beam/erl_time_sup.c85
1 files changed, 41 insertions, 44 deletions
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 7f8f560681..7327e0b48c 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -124,7 +124,11 @@ typedef struct {
typedef struct {
ErtsMonotonicCorrectionInstance prev;
- ErtsMonotonicCorrectionInstance curr;
+ ErtsMonotonicCorrectionInstance curr;
+} ErtsMonotonicCorrectionInstances;
+
+typedef struct {
+ ErtsMonotonicCorrectionInstances insts;
ErtsMonotonicDriftData drift;
ErtsMonotonicTime last_check;
int short_check_interval;
@@ -272,27 +276,24 @@ static ERTS_INLINE ErtsMonotonicTime
read_corrected_time(int os_drift_corrected)
{
ErtsMonotonicTime os_mtime;
- ErtsMonotonicCorrectionData cdata;
- ErtsMonotonicCorrectionInstance *cip;
+ ErtsMonotonicCorrectionInstance ci;
erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
os_mtime = erts_os_monotonic_time();
- cdata = time_sup.inf.c.parmon.cdata;
-
- erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
-
- if (os_mtime >= cdata.curr.os_mtime)
- cip = &cdata.curr;
+ if (os_mtime >= time_sup.inf.c.parmon.cdata.insts.curr.os_mtime)
+ ci = time_sup.inf.c.parmon.cdata.insts.curr;
else {
- if (os_mtime < cdata.prev.os_mtime)
+ if (os_mtime < time_sup.inf.c.parmon.cdata.insts.prev.os_mtime)
erl_exit(ERTS_ABORT_EXIT,
"OS monotonic time stepped backwards\n");
- cip = &cdata.prev;
+ ci = time_sup.inf.c.parmon.cdata.insts.prev;
}
- return calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+ return calc_corrected_erl_mtime(os_mtime, &ci, NULL,
os_drift_corrected);
}
@@ -360,9 +361,8 @@ check_time_correction(void *vesdp)
{
int init_drift_adj = !vesdp;
ErtsSchedulerData *esdp = (ErtsSchedulerData *) vesdp;
- ErtsMonotonicCorrectionData cdata;
ErtsMonotonicCorrection new_correction;
- ErtsMonotonicCorrectionInstance *cip;
+ ErtsMonotonicCorrectionInstance ci;
ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime,
erl_stime, time_offset, timeout_pos;
Uint timeout;
@@ -373,16 +373,15 @@ check_time_correction(void *vesdp)
erts_os_times(&os_mtime, &os_stime);
- cdata = time_sup.inf.c.parmon.cdata;
+ ci = time_sup.inf.c.parmon.cdata.insts.curr;
erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
- if (os_mtime < cdata.curr.os_mtime)
+ if (os_mtime < ci.os_mtime)
erl_exit(ERTS_ABORT_EXIT,
"OS monotonic time stepped backwards\n");
- cip = &cdata.curr;
- erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, &mdiff,
+ erl_mtime = calc_corrected_erl_mtime(os_mtime, &ci, &mdiff,
os_drift_corrected);
time_offset = get_time_offset();
erl_stime = erl_mtime + time_offset;
@@ -397,7 +396,7 @@ check_time_correction(void *vesdp)
time_sup.inf.c.shadow_offset = 0;
}
- new_correction = cip->correction;
+ new_correction = ci.correction;
if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE
&& (sdiff < -2*time_sup.r.o.adj.small_diff
@@ -408,7 +407,7 @@ check_time_correction(void *vesdp)
set_time_offset(time_offset);
schedule_send_time_offset_changed_notifications(time_offset);
begin_short_intervals = 1;
- if (cdata.curr.correction.error != 0) {
+ if (ci.correction.error != 0) {
set_new_correction = 1;
new_correction.error = 0;
}
@@ -425,12 +424,12 @@ check_time_correction(void *vesdp)
time_sup.inf.c.shadow_offset -= sdiff;
sdiff = 0;
begin_short_intervals = 1;
- if (cdata.curr.correction.error != 0) {
+ if (ci.correction.error != 0) {
set_new_correction = 1;
new_correction.error = 0;
}
}
- else if (cdata.curr.correction.error == 0) {
+ else if (ci.correction.error == 0) {
if (sdiff < -time_sup.r.o.adj.small_diff) {
set_new_correction = 1;
if (sdiff < -time_sup.r.o.adj.large_diff)
@@ -446,9 +445,9 @@ check_time_correction(void *vesdp)
new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
}
}
- else if (cdata.curr.correction.error > 0) {
+ else if (ci.correction.error > 0) {
if (sdiff < 0) {
- if (cdata.curr.correction.error != ERTS_TCORR_ERR_LARGE_ADJ
+ if (ci.correction.error != ERTS_TCORR_ERR_LARGE_ADJ
&& sdiff < -time_sup.r.o.adj.large_diff) {
new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
set_new_correction = 1;
@@ -466,9 +465,9 @@ check_time_correction(void *vesdp)
new_correction.error = 0;
}
}
- else /* if (cdata.curr.correction.error < 0) */ {
+ else /* if (ci.correction.error < 0) */ {
if (0 < sdiff) {
- if (cdata.curr.correction.error != -ERTS_TCORR_ERR_LARGE_ADJ
+ if (ci.correction.error != -ERTS_TCORR_ERR_LARGE_ADJ
&& time_sup.r.o.adj.large_diff < sdiff) {
new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
set_new_correction = 1;
@@ -631,8 +630,8 @@ check_time_correction(void *vesdp)
#ifdef ERTS_TIME_CORRECTION_PRINT
print_correction(set_new_correction,
sdiff,
- cip->correction.error,
- cip->correction.drift,
+ ci.correction.error,
+ ci.correction.drift,
new_correction.error,
new_correction.drift,
timeout);
@@ -644,7 +643,7 @@ check_time_correction(void *vesdp)
os_mtime = erts_os_monotonic_time();
/* Save previous correction instance */
- time_sup.inf.c.parmon.cdata.prev = *cip;
+ time_sup.inf.c.parmon.cdata.insts.prev = ci;
/*
* Current correction instance begin when
@@ -657,15 +656,15 @@ check_time_correction(void *vesdp)
* next OS monotonic time using previous
* correction.
*/
- erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ erl_mtime = calc_corrected_erl_mtime(os_mtime, &ci, NULL,
os_drift_corrected);
/*
* Save new current correction instance.
*/
- time_sup.inf.c.parmon.cdata.curr.erl_mtime = erl_mtime;
- time_sup.inf.c.parmon.cdata.curr.os_mtime = os_mtime;
- time_sup.inf.c.parmon.cdata.curr.correction = new_correction;
+ time_sup.inf.c.parmon.cdata.insts.curr.erl_mtime = erl_mtime;
+ time_sup.inf.c.parmon.cdata.insts.curr.os_mtime = os_mtime;
+ time_sup.inf.c.parmon.cdata.insts.curr.correction = new_correction;
erts_smp_rwmtx_rwunlock(&time_sup.inf.c.parmon.rwmtx);
}
@@ -784,24 +783,22 @@ static ErtsMonotonicTime
finalize_corrected_time_offset(ErtsSystemTime *stimep)
{
ErtsMonotonicTime os_mtime;
- ErtsMonotonicCorrectionData cdata;
- ErtsMonotonicCorrectionInstance *cip;
+ ErtsMonotonicCorrectionInstance ci;
int os_drift_corrected = time_sup.r.o.os_corrected_monotonic_time;
erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
erts_os_times(&os_mtime, stimep);
- cdata = time_sup.inf.c.parmon.cdata;
+ ci = time_sup.inf.c.parmon.cdata.insts.curr;
erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
- if (os_mtime < cdata.curr.os_mtime)
+ if (os_mtime < ci.os_mtime)
erl_exit(ERTS_ABORT_EXIT,
"OS monotonic time stepped backwards\n");
- cip = &cdata.curr;
- return calc_corrected_erl_mtime(os_mtime, cip, NULL,
+ return calc_corrected_erl_mtime(os_mtime, &ci, NULL,
os_drift_corrected);
}
@@ -1128,13 +1125,13 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
cdatap->drift.intervals[0].time.sys = time_sup.inf.c.sinit;
cdatap->drift.intervals[0].time.mon = time_sup.inf.c.minit;
- cdatap->curr.correction.drift = 0;
- cdatap->curr.correction.error = 0;
- cdatap->curr.erl_mtime = ERTS_MONOTONIC_BEGIN;
- cdatap->curr.os_mtime = time_sup.inf.c.minit;
+ cdatap->insts.curr.correction.drift = 0;
+ cdatap->insts.curr.correction.error = 0;
+ cdatap->insts.curr.erl_mtime = ERTS_MONOTONIC_BEGIN;
+ cdatap->insts.curr.os_mtime = time_sup.inf.c.minit;
cdatap->last_check = time_sup.inf.c.minit;
cdatap->short_check_interval = ERTS_INIT_SHORT_INTERVAL_COUNTER;
- cdatap->prev = cdatap->curr;
+ cdatap->insts.prev = cdatap->insts.curr;
if (!time_sup.r.o.os_corrected_monotonic_time)
time_sup.r.o.get_time = get_corrected_time;