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Fix the memory ordering for the isc stats to be acquire-release

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(cherry picked from commit 4ffd4cd4f6)
This commit is contained in:
Witold Kręcicki
2019-06-13 11:01:12 +02:00
committed by Ondřej Surý
parent 27be7a8bd1
commit 3559b32dcc
1 changed files with 8 additions and 14 deletions
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22
lib/isc/stats.c
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@@ -108,17 +108,14 @@ isc_stats_increment(isc_stats_t *stats, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
atomic_fetch_add_explicit(&stats->counters[counter], 1,
memory_order_relaxed);
atomic_fetch_add_relaxed(&stats->counters[counter], 1);
}
void
isc_stats_decrement(isc_stats_t *stats, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
atomic_fetch_sub_explicit(&stats->counters[counter], 1,
memory_order_relaxed);
atomic_fetch_sub_release(&stats->counters[counter], 1);
}
void
@@ -129,8 +126,7 @@ isc_stats_dump(isc_stats_t *stats, isc_stats_dumper_t dump_fn, void *arg,
REQUIRE(ISC_STATS_VALID(stats));
for (i = 0; i < stats->ncounters; i++) {
uint32_t counter = atomic_load_explicit(&stats->counters[i],
memory_order_relaxed);
uint32_t counter = atomic_load_acquire(&stats->counters[i]);
if ((options & ISC_STATSDUMP_VERBOSE) == 0 && counter == 0) {
continue;
}
@@ -143,8 +139,7 @@ isc_stats_set(isc_stats_t *stats, uint64_t val, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
atomic_store_explicit(&stats->counters[counter], val,
memory_order_relaxed);
atomic_store_release(&stats->counters[counter], val);
}
void
@@ -154,13 +149,13 @@ isc_stats_update_if_greater(isc_stats_t *stats, isc_statscounter_t counter,
REQUIRE(counter < stats->ncounters);
isc_statscounter_t curr_value =
atomic_load_relaxed(&stats->counters[counter]);
atomic_load_acquire(&stats->counters[counter]);
do {
if (curr_value >= value) {
break;
}
} while (!atomic_compare_exchange_strong(&stats->counters[counter],
&curr_value, value));
} while (!atomic_compare_exchange_weak_acq_rel(
&stats->counters[counter], &curr_value, value));
}
isc_statscounter_t
@@ -168,6 +163,5 @@ isc_stats_get_counter(isc_stats_t *stats, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
return (atomic_load_explicit(&stats->counters[counter],
memory_order_relaxed));
return (atomic_load_acquire(&stats->counters[counter]));
}