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Use spinlock for reference counting. ()

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vkalintiris 2024-02-01 16:36:17 +02:00 • committed by GitHub
parent a25ff1b401
commit 2e459de7ec
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1 changed files with 24 additions and 20 deletions

44
src/database/engine/metric.c
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@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-3.0-or-later
#include "metric.h"
#include "cache.h"
#include "libnetdata/locks/locks.h"
#include "rrddiskprotocol.h"
typedef int32_t REFCOUNT;
@ -16,6 +17,8 @@ struct metric {
uint32_t latest_update_every_s; // the latest data collection frequency
pid_t writer;
uint8_t partition;
SPINLOCK refcount_spinlock;
REFCOUNT refcount;
// THIS IS allocated with malloc()
@ -131,17 +134,17 @@ static inline time_t mrg_metric_get_first_time_s_smart(MRG *mrg __maybe_unused,
}
static inline REFCOUNT metric_acquire(MRG *mrg __maybe_unused, METRIC *metric) {
spinlock_lock(&metric->refcount_spinlock);
if (metric->refcount >= 0)
metric->refcount += 1;
else
fatal("METRIC: refcount is %d (negative) during acquire", metric->refcount);
REFCOUNT refcount = metric->refcount;
spinlock_unlock(&metric->refcount_spinlock);
size_t partition = metric->partition;
REFCOUNT expected = __atomic_load_n(&metric->refcount, __ATOMIC_RELAXED);
REFCOUNT refcount;
do {
if(expected < 0)
fatal("METRIC: refcount is %d (negative) during acquire", metric->refcount);
refcount = expected + 1;
} while(!__atomic_compare_exchange_n(&metric->refcount, &expected, refcount, false, __ATOMIC_RELAXED, __ATOMIC_RELAXED));
if(refcount == 1)
__atomic_add_fetch(&mrg->index[partition].stats.entries_referenced, 1, __ATOMIC_RELAXED);
@ -151,17 +154,17 @@ static inline REFCOUNT metric_acquire(MRG *mrg __maybe_unused, METRIC *metric) {
}
static inline bool metric_release_and_can_be_deleted(MRG *mrg __maybe_unused, METRIC *metric) {
spinlock_lock(&metric->refcount_spinlock);
if (metric->refcount <= 0)
fatal("METRIC: refcount is %d (zero or negative) during release", metric->refcount);
metric->refcount -= 1;
REFCOUNT refcount = metric->refcount;
spinlock_unlock(&metric->refcount_spinlock);
size_t partition = metric->partition;
REFCOUNT expected = __atomic_load_n(&metric->refcount, __ATOMIC_RELAXED);
REFCOUNT refcount;
do {
if(expected <= 0)
fatal("METRIC: refcount is %d (zero or negative) during release", metric->refcount);
refcount = expected - 1;
} while(!__atomic_compare_exchange_n(&metric->refcount, &expected, refcount, false, __ATOMIC_RELAXED, __ATOMIC_RELAXED));
if(unlikely(!refcount))
__atomic_sub_fetch(&mrg->index[partition].stats.entries_referenced, 1, __ATOMIC_RELAXED);
@ -223,6 +226,7 @@ static inline METRIC *metric_add_and_acquire(MRG *mrg, MRG_ENTRY *entry, bool *r
metric->writer = 0;
metric->refcount = 0;
metric->partition = partition;
spinlock_init(&metric->refcount_spinlock);
metric_acquire(mrg, metric);
*PValue = metric;