#include <config.h>
#include <string.h>
#include <isc/atomic.h>
#include <isc/buffer.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/platform.h>
#include <isc/print.h>
#include <isc/rwlock.h>
#include <isc/stats.h>
#include <isc/util.h>
#define ISC_STATS_MAGIC ISC_MAGIC('S', 't', 'a', 't')
#define ISC_STATS_VALID(x) ISC_MAGIC_VALID(x, ISC_STATS_MAGIC)
#ifndef ISC_STATS_USEMULTIFIELDS
#if defined(ISC_RWLOCK_USEATOMIC) && defined(ISC_PLATFORM_HAVEXADD) && !defined(ISC_PLATFORM_HAVEXADDQ)
#define ISC_STATS_USEMULTIFIELDS 1
#else
#define ISC_STATS_USEMULTIFIELDS 0
#endif
#endif
#if ISC_STATS_USEMULTIFIELDS
typedef struct {
isc_uint32_t hi;
isc_uint32_t lo;
} isc_stat_t;
#else
typedef isc_uint64_t isc_stat_t;
#endif
struct isc_stats {
unsigned int magic;
isc_mem_t *mctx;
int ncounters;
isc_mutex_t lock;
unsigned int references;
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_t counterlock;
#endif
isc_stat_t *counters;
isc_uint64_t *copiedcounters;
};
static isc_result_t
create_stats(isc_mem_t *mctx, int ncounters, isc_stats_t **statsp) {
isc_stats_t *stats;
isc_result_t result = ISC_R_SUCCESS;
REQUIRE(statsp != NULL && *statsp == NULL);
stats = isc_mem_get(mctx, sizeof(*stats));
if (stats == NULL)
return (ISC_R_NOMEMORY);
result = isc_mutex_init(&stats->lock);
if (result != ISC_R_SUCCESS)
goto clean_stats;
stats->counters = isc_mem_get(mctx, sizeof(isc_stat_t) * ncounters);
if (stats->counters == NULL) {
result = ISC_R_NOMEMORY;
goto clean_mutex;
}
stats->copiedcounters = isc_mem_get(mctx,
sizeof(isc_uint64_t) * ncounters);
if (stats->copiedcounters == NULL) {
result = ISC_R_NOMEMORY;
goto clean_counters;
}
#ifdef ISC_RWLOCK_USEATOMIC
result = isc_rwlock_init(&stats->counterlock, 0, 0);
if (result != ISC_R_SUCCESS)
goto clean_copiedcounters;
#endif
stats->references = 1;
memset(stats->counters, 0, sizeof(isc_stat_t) * ncounters);
stats->mctx = NULL;
isc_mem_attach(mctx, &stats->mctx);
stats->ncounters = ncounters;
stats->magic = ISC_STATS_MAGIC;
*statsp = stats;
return (result);
clean_counters:
isc_mem_put(mctx, stats->counters, sizeof(isc_stat_t) * ncounters);
#ifdef ISC_RWLOCK_USEATOMIC
clean_copiedcounters:
isc_mem_put(mctx, stats->copiedcounters,
sizeof(isc_stat_t) * ncounters);
#endif
clean_mutex:
DESTROYLOCK(&stats->lock);
clean_stats:
isc_mem_put(mctx, stats, sizeof(*stats));
return (result);
}
void
isc_stats_attach(isc_stats_t *stats, isc_stats_t **statsp) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(statsp != NULL && *statsp == NULL);
LOCK(&stats->lock);
stats->references++;
UNLOCK(&stats->lock);
*statsp = stats;
}
void
isc_stats_detach(isc_stats_t **statsp) {
isc_stats_t *stats;
REQUIRE(statsp != NULL && ISC_STATS_VALID(*statsp));
stats = *statsp;
*statsp = NULL;
LOCK(&stats->lock);
stats->references--;
UNLOCK(&stats->lock);
if (stats->references == 0) {
isc_mem_put(stats->mctx, stats->copiedcounters,
sizeof(isc_stat_t) * stats->ncounters);
isc_mem_put(stats->mctx, stats->counters,
sizeof(isc_stat_t) * stats->ncounters);
DESTROYLOCK(&stats->lock);
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_destroy(&stats->counterlock);
#endif
isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats));
}
}
int
isc_stats_ncounters(isc_stats_t *stats) {
REQUIRE(ISC_STATS_VALID(stats));
return (stats->ncounters);
}
static inline void
incrementcounter(isc_stats_t *stats, int counter) {
isc_int32_t prev;
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_read);
#endif
#if ISC_STATS_USEMULTIFIELDS
prev = isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].lo, 1);
if (prev == (isc_int32_t)0xffffffff)
isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].hi, 1);
#elif defined(ISC_PLATFORM_HAVEXADDQ)
UNUSED(prev);
isc_atomic_xaddq((isc_int64_t *)&stats->counters[counter], 1);
#else
UNUSED(prev);
stats->counters[counter]++;
#endif
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_read);
#endif
}
static inline void
decrementcounter(isc_stats_t *stats, int counter) {
isc_int32_t prev;
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_read);
#endif
#if ISC_STATS_USEMULTIFIELDS
prev = isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].lo, -1);
if (prev == 0)
isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].hi,
-1);
#elif defined(ISC_PLATFORM_HAVEXADDQ)
UNUSED(prev);
isc_atomic_xaddq((isc_int64_t *)&stats->counters[counter], -1);
#else
UNUSED(prev);
stats->counters[counter]--;
#endif
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_read);
#endif
}
static void
copy_counters(isc_stats_t *stats) {
int i;
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_write);
#endif
#if ISC_STATS_USEMULTIFIELDS
for (i = 0; i < stats->ncounters; i++) {
stats->copiedcounters[i] =
(isc_uint64_t)(stats->counters[i].hi) << 32 |
stats->counters[i].lo;
}
#else
UNUSED(i);
memcpy(stats->copiedcounters, stats->counters,
stats->ncounters * sizeof(isc_stat_t));
#endif
#ifdef ISC_RWLOCK_USEATOMIC
isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_write);
#endif
}
isc_result_t
isc_stats_create(isc_mem_t *mctx, isc_stats_t **statsp, int ncounters) {
REQUIRE(statsp != NULL && *statsp == NULL);
return (create_stats(mctx, ncounters, statsp));
}
void
isc_stats_increment(isc_stats_t *stats, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
incrementcounter(stats, (int)counter);
}
void
isc_stats_decrement(isc_stats_t *stats, isc_statscounter_t counter) {
REQUIRE(ISC_STATS_VALID(stats));
REQUIRE(counter < stats->ncounters);
decrementcounter(stats, (int)counter);
}
void
isc_stats_dump(isc_stats_t *stats, isc_stats_dumper_t dump_fn,
void *arg, unsigned int options)
{
int i;
REQUIRE(ISC_STATS_VALID(stats));
copy_counters(stats);
for (i = 0; i < stats->ncounters; i++) {
if ((options & ISC_STATSDUMP_VERBOSE) == 0 &&
stats->copiedcounters[i] == 0)
continue;
dump_fn((isc_statscounter_t)i, stats->copiedcounters[i], arg);
}
}