diff options
Diffstat (limited to 'usr.sbin/bind/lib/isc/stats.c')
| -rw-r--r-- | usr.sbin/bind/lib/isc/stats.c | 455 |
1 files changed, 0 insertions, 455 deletions
diff --git a/usr.sbin/bind/lib/isc/stats.c b/usr.sbin/bind/lib/isc/stats.c deleted file mode 100644 index 282c738b642..00000000000 --- a/usr.sbin/bind/lib/isc/stats.c +++ /dev/null @@ -1,455 +0,0 @@ -/* - * Copyright (C) Internet Systems Consortium, Inc. ("ISC") - * - * Permission to use, copy, modify, and/or distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH - * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY - * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, - * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM - * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE - * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - * PERFORMANCE OF THIS SOFTWARE. - */ - -/* $Id: stats.c,v 1.3 2020/01/09 13:47:14 florian Exp $ */ - -/*! \file */ - -#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/rwlock.h> -#include <isc/stats.h> -#include <isc/util.h> - -#if defined(ISC_PLATFORM_HAVESTDATOMIC) -#include <stdatomic.h> -#endif - -#define ISC_STATS_MAGIC ISC_MAGIC('S', 't', 'a', 't') -#define ISC_STATS_VALID(x) ISC_MAGIC_VALID(x, ISC_STATS_MAGIC) - -/*% - * Local macro confirming prescence of 64-bit - * increment and store operations, just to make - * the later macros simpler - */ -#if (defined(ISC_PLATFORM_HAVESTDATOMIC) && defined(ATOMIC_LONG_LOCK_FREE)) || \ - (defined(ISC_PLATFORM_HAVEXADDQ) && defined(ISC_PLATFORM_HAVEATOMICSTOREQ)) -#define ISC_STATS_HAVEATOMICQ 1 -#if (defined(ISC_PLATFORM_HAVESTDATOMIC) && defined(ATOMIC_LONG_LOCK_FREE)) -#define ISC_STATS_HAVESTDATOMICQ 1 -#endif -#else -#define ISC_STATS_HAVEATOMICQ 0 -#endif - -/*% - * Only lock the counters if 64-bit atomic operations are - * not available but cheap atomic lock operations are. - * On a modern 64-bit system this should never be the case. - * - * Normal locks are too expensive to be used whenever a counter - * is updated. - */ -#if !ISC_STATS_HAVEATOMICQ && defined(ISC_RWLOCK_HAVEATOMIC) -#define ISC_STATS_LOCKCOUNTERS 1 -#else -#define ISC_STATS_LOCKCOUNTERS 0 -#endif - -/*% - * If 64-bit atomic operations are not available but - * 32-bit operations are then split the counter into two, - * using the atomic operations to try to ensure that any carry - * from the low word is correctly carried into the high word. - * - * Otherwise, just rely on standard 64-bit data types - * and operations - */ -#if !ISC_STATS_HAVEATOMICQ && ((defined(ISC_PLATFORM_HAVESTDATOMIC) && defined(ATOMIC_INT_LOCK_FREE)) || defined(ISC_PLATFORM_HAVEXADD)) -#define ISC_STATS_USEMULTIFIELDS 1 -#if (defined(ISC_PLATFORM_HAVESTDATOMIC) && defined(ATOMIC_INT_LOCK_FREE)) -#define ISC_STATS_HAVESTDATOMIC 1 -#endif -#else -#define ISC_STATS_USEMULTIFIELDS 0 -#endif - -#if ISC_STATS_USEMULTIFIELDS -typedef struct { -#if defined(ISC_STATS_HAVESTDATOMIC) - atomic_int_fast32_t hi; - atomic_int_fast32_t lo; -#else - isc_uint32_t hi; - isc_uint32_t lo; -#endif -} isc_stat_t; -#else -#if defined(ISC_STATS_HAVESTDATOMICQ) -typedef atomic_int_fast64_t isc_stat_t; -#else -typedef isc_uint64_t isc_stat_t; -#endif -#endif - -struct isc_stats { - /*% Unlocked */ - unsigned int magic; - isc_mem_t *mctx; - int ncounters; - - isc_mutex_t lock; - unsigned int references; /* locked by lock */ - - /*% - * Locked by counterlock or unlocked if efficient rwlock is not - * available. - */ -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_t counterlock; -#endif - isc_stat_t *counters; - - /*% - * We don't want to lock the counters while we are dumping, so we first - * copy the current counter values into a local array. This buffer - * will be used as the copy destination. It's allocated on creation - * of the stats structure so that the dump operation won't fail due - * to memory allocation failure. - * XXX: this approach is weird for non-threaded build because the - * additional memory and the copy overhead could be avoided. We prefer - * simplicity here, however, under the assumption that this function - * should be only rarely called. - */ - 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; - } - -#if ISC_STATS_LOCKCOUNTERS - 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); - -#if ISC_STATS_LOCKCOUNTERS -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--; - - 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); - UNLOCK(&stats->lock); - DESTROYLOCK(&stats->lock); -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_destroy(&stats->counterlock); -#endif - isc_mem_putanddetach(&stats->mctx, stats, sizeof(*stats)); - return; - } - - UNLOCK(&stats->lock); -} - -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; - -#if ISC_STATS_LOCKCOUNTERS - /* - * We use a "read" lock to prevent other threads from reading the - * counter while we "writing" a counter field. The write access itself - * is protected by the atomic operation. - */ - isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_read); -#endif - -#if ISC_STATS_USEMULTIFIELDS -#if defined(ISC_STATS_HAVESTDATOMIC) - prev = atomic_fetch_add_explicit(&stats->counters[counter].lo, 1, - memory_order_relaxed); -#else - prev = isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].lo, 1); -#endif - /* - * If the lower 32-bit field overflows, increment the higher field. - * Note that it's *theoretically* possible that the lower field - * overlaps again before the higher field is incremented. It doesn't - * matter, however, because we don't read the value until - * isc_stats_copy() is called where the whole process is protected - * by the write (exclusive) lock. - */ - if (prev == (isc_int32_t)0xffffffff) { -#if defined(ISC_STATS_HAVESTDATOMIC) - atomic_fetch_add_explicit(&stats->counters[counter].hi, 1, - memory_order_relaxed); -#else - isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].hi, 1); -#endif - } -#elif ISC_STATS_HAVEATOMICQ - UNUSED(prev); -#if defined(ISC_STATS_HAVESTDATOMICQ) - atomic_fetch_add_explicit(&stats->counters[counter], 1, - memory_order_relaxed); -#else - isc_atomic_xaddq((isc_int64_t *)&stats->counters[counter], 1); -#endif -#else - UNUSED(prev); - stats->counters[counter]++; -#endif - -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_read); -#endif -} - -static inline void -decrementcounter(isc_stats_t *stats, int counter) { - isc_int32_t prev; - -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_read); -#endif - -#if ISC_STATS_USEMULTIFIELDS -#if defined(ISC_STATS_HAVESTDATOMIC) - prev = atomic_fetch_sub_explicit(&stats->counters[counter].lo, 1, - memory_order_relaxed); -#else - prev = isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].lo, -1); -#endif - if (prev == 0) { -#if defined(ISC_STATS_HAVESTDATOMIC) - atomic_fetch_sub_explicit(&stats->counters[counter].hi, 1, - memory_order_relaxed); -#else - isc_atomic_xadd((isc_int32_t *)&stats->counters[counter].hi, - -1); -#endif - } -#elif ISC_STATS_HAVEATOMICQ - UNUSED(prev); -#if defined(ISC_STATS_HAVESTDATOMICQ) - atomic_fetch_sub_explicit(&stats->counters[counter], 1, - memory_order_relaxed); -#else - isc_atomic_xaddq((isc_int64_t *)&stats->counters[counter], -1); -#endif -#else - UNUSED(prev); - stats->counters[counter]--; -#endif - -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_read); -#endif -} - -static void -copy_counters(isc_stats_t *stats) { - int i; - -#if ISC_STATS_LOCKCOUNTERS - /* - * We use a "write" lock before "reading" the statistics counters as - * an exclusive lock. - */ - isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_write); -#endif - - for (i = 0; i < stats->ncounters; i++) { -#if ISC_STATS_USEMULTIFIELDS - stats->copiedcounters[i] = - (isc_uint64_t)(stats->counters[i].hi) << 32 | - stats->counters[i].lo; -#elif ISC_STATS_HAVEATOMICQ -#if defined(ISC_STATS_HAVESTDATOMICQ) - stats->copiedcounters[i] = - atomic_load_explicit(&stats->counters[i], - memory_order_relaxed); -#else - /* use xaddq(..., 0) as an atomic load */ - stats->copiedcounters[i] = - (isc_uint64_t)isc_atomic_xaddq((isc_int64_t *)&stats->counters[i], 0); -#endif -#else - stats->copiedcounters[i] = stats->counters[i]; -#endif - } - -#if ISC_STATS_LOCKCOUNTERS - 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); - } -} - -void -isc_stats_set(isc_stats_t *stats, isc_uint64_t val, - isc_statscounter_t counter) -{ - REQUIRE(ISC_STATS_VALID(stats)); - REQUIRE(counter < stats->ncounters); - -#if ISC_STATS_LOCKCOUNTERS - /* - * We use a "write" lock before "reading" the statistics counters as - * an exclusive lock. - */ - isc_rwlock_lock(&stats->counterlock, isc_rwlocktype_write); -#endif - -#if ISC_STATS_USEMULTIFIELDS - stats->counters[counter].hi = (isc_uint32_t)((val >> 32) & 0xffffffff); - stats->counters[counter].lo = (isc_uint32_t)(val & 0xffffffff); -#elif ISC_STATS_HAVEATOMICQ -#if defined(ISC_STATS_HAVESTDATOMICQ) - atomic_store_explicit(&stats->counters[counter], val, - memory_order_relaxed); -#else - isc_atomic_storeq((isc_int64_t *)&stats->counters[counter], val); -#endif -#else - stats->counters[counter] = val; -#endif - -#if ISC_STATS_LOCKCOUNTERS - isc_rwlock_unlock(&stats->counterlock, isc_rwlocktype_write); -#endif -} |