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-rw-r--r--database/engine/rrdenglocking.c241
1 files changed, 0 insertions, 241 deletions
diff --git a/database/engine/rrdenglocking.c b/database/engine/rrdenglocking.c
deleted file mode 100644
index a23abf307..000000000
--- a/database/engine/rrdenglocking.c
+++ /dev/null
@@ -1,241 +0,0 @@
-// SPDX-License-Identifier: GPL-3.0-or-later
-#include "rrdengine.h"
-
-struct page_cache_descr *rrdeng_create_pg_cache_descr(struct rrdengine_instance *ctx)
-{
- struct page_cache_descr *pg_cache_descr;
-
- pg_cache_descr = mallocz(sizeof(*pg_cache_descr));
- rrd_stat_atomic_add(&ctx->stats.page_cache_descriptors, 1);
- pg_cache_descr->page = NULL;
- pg_cache_descr->flags = 0;
- pg_cache_descr->prev = pg_cache_descr->next = NULL;
- pg_cache_descr->refcnt = 0;
- pg_cache_descr->waiters = 0;
- fatal_assert(0 == uv_cond_init(&pg_cache_descr->cond));
- fatal_assert(0 == uv_mutex_init(&pg_cache_descr->mutex));
-
- return pg_cache_descr;
-}
-
-void rrdeng_destroy_pg_cache_descr(struct rrdengine_instance *ctx, struct page_cache_descr *pg_cache_descr)
-{
- uv_cond_destroy(&pg_cache_descr->cond);
- uv_mutex_destroy(&pg_cache_descr->mutex);
- freez(pg_cache_descr);
- rrd_stat_atomic_add(&ctx->stats.page_cache_descriptors, -1);
-}
-
-/* also allocates page cache descriptor if missing */
-void rrdeng_page_descr_mutex_lock(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr)
-{
- unsigned long old_state, old_users, new_state, ret_state;
- struct page_cache_descr *pg_cache_descr = NULL;
- uint8_t we_locked;
-
- we_locked = 0;
- while (1) { /* spin */
- old_state = descr->pg_cache_descr_state;
- old_users = old_state >> PG_CACHE_DESCR_SHIFT;
-
- if (unlikely(we_locked)) {
- fatal_assert(old_state & PG_CACHE_DESCR_LOCKED);
- new_state = (1 << PG_CACHE_DESCR_SHIFT) | PG_CACHE_DESCR_ALLOCATED;
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- /* success */
- break;
- }
- continue; /* spin */
- }
- if (old_state & PG_CACHE_DESCR_LOCKED) {
- fatal_assert(0 == old_users);
- continue; /* spin */
- }
- if (0 == old_state) {
- /* no page cache descriptor has been allocated */
-
- if (NULL == pg_cache_descr) {
- pg_cache_descr = rrdeng_create_pg_cache_descr(ctx);
- }
- new_state = PG_CACHE_DESCR_LOCKED;
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, 0, new_state);
- if (0 == ret_state) {
- we_locked = 1;
- descr->pg_cache_descr = pg_cache_descr;
- pg_cache_descr->descr = descr;
- pg_cache_descr = NULL; /* make sure we don't free pg_cache_descr */
- /* retry */
- continue;
- }
- continue; /* spin */
- }
- /* page cache descriptor is already allocated */
- if (unlikely(!(old_state & PG_CACHE_DESCR_ALLOCATED))) {
- fatal("Invalid page cache descriptor locking state:%#lX", old_state);
- }
- new_state = (old_users + 1) << PG_CACHE_DESCR_SHIFT;
- new_state |= old_state & PG_CACHE_DESCR_FLAGS_MASK;
-
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- /* success */
- break;
- }
- /* spin */
- }
-
- if (pg_cache_descr) {
- rrdeng_destroy_pg_cache_descr(ctx, pg_cache_descr);
- }
- pg_cache_descr = descr->pg_cache_descr;
- uv_mutex_lock(&pg_cache_descr->mutex);
-}
-
-void rrdeng_page_descr_mutex_unlock(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr)
-{
- unsigned long old_state, new_state, ret_state, old_users;
- struct page_cache_descr *pg_cache_descr, *delete_pg_cache_descr = NULL;
- uint8_t we_locked;
-
- uv_mutex_unlock(&descr->pg_cache_descr->mutex);
-
- we_locked = 0;
- while (1) { /* spin */
- old_state = descr->pg_cache_descr_state;
- old_users = old_state >> PG_CACHE_DESCR_SHIFT;
-
- if (unlikely(we_locked)) {
- fatal_assert(0 == old_users);
-
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, 0);
- if (old_state == ret_state) {
- /* success */
- rrdeng_destroy_pg_cache_descr(ctx, delete_pg_cache_descr);
- return;
- }
- continue; /* spin */
- }
- if (old_state & PG_CACHE_DESCR_LOCKED) {
- fatal_assert(0 == old_users);
- continue; /* spin */
- }
- fatal_assert(old_state & PG_CACHE_DESCR_ALLOCATED);
- pg_cache_descr = descr->pg_cache_descr;
- /* caller is the only page cache descriptor user and there are no pending references on the page */
- if ((old_state & PG_CACHE_DESCR_DESTROY) && (1 == old_users) &&
- !pg_cache_descr->flags && !pg_cache_descr->refcnt) {
- fatal_assert(!pg_cache_descr->waiters);
-
- new_state = PG_CACHE_DESCR_LOCKED;
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- we_locked = 1;
- delete_pg_cache_descr = pg_cache_descr;
- descr->pg_cache_descr = NULL;
- /* retry */
- continue;
- }
- continue; /* spin */
- }
- fatal_assert(old_users > 0);
- new_state = (old_users - 1) << PG_CACHE_DESCR_SHIFT;
- new_state |= old_state & PG_CACHE_DESCR_FLAGS_MASK;
-
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- /* success */
- break;
- }
- /* spin */
- }
-}
-
-/*
- * Tries to deallocate page cache descriptor. If it fails, it postpones deallocation by setting the
- * PG_CACHE_DESCR_DESTROY flag which will be eventually cleared by a different context after doing
- * the deallocation.
- */
-void rrdeng_try_deallocate_pg_cache_descr(struct rrdengine_instance *ctx, struct rrdeng_page_descr *descr)
-{
- unsigned long old_state, new_state, ret_state, old_users;
- struct page_cache_descr *pg_cache_descr = NULL;
- uint8_t just_locked, can_free, must_unlock;
-
- just_locked = 0;
- can_free = 0;
- must_unlock = 0;
- while (1) { /* spin */
- old_state = descr->pg_cache_descr_state;
- old_users = old_state >> PG_CACHE_DESCR_SHIFT;
-
- if (unlikely(just_locked)) {
- fatal_assert(0 == old_users);
-
- must_unlock = 1;
- just_locked = 0;
- /* Try deallocate if there are no pending references on the page */
- if (!pg_cache_descr->flags && !pg_cache_descr->refcnt) {
- fatal_assert(!pg_cache_descr->waiters);
-
- descr->pg_cache_descr = NULL;
- can_free = 1;
- /* success */
- continue;
- }
- continue; /* spin */
- }
- if (unlikely(must_unlock)) {
- fatal_assert(0 == old_users);
-
- if (can_free) {
- /* success */
- new_state = 0;
- } else {
- new_state = old_state | PG_CACHE_DESCR_DESTROY;
- new_state &= ~PG_CACHE_DESCR_LOCKED;
- }
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- /* unlocked */
- if (can_free)
- rrdeng_destroy_pg_cache_descr(ctx, pg_cache_descr);
- return;
- }
- continue; /* spin */
- }
- if (!(old_state & PG_CACHE_DESCR_ALLOCATED)) {
- /* don't do anything */
- return;
- }
- if (old_state & PG_CACHE_DESCR_LOCKED) {
- fatal_assert(0 == old_users);
- continue; /* spin */
- }
- /* caller is the only page cache descriptor user */
- if (0 == old_users) {
- new_state = old_state | PG_CACHE_DESCR_LOCKED;
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- just_locked = 1;
- pg_cache_descr = descr->pg_cache_descr;
- /* retry */
- continue;
- }
- continue; /* spin */
- }
- if (old_state & PG_CACHE_DESCR_DESTROY) {
- /* don't do anything */
- return;
- }
- /* plant PG_CACHE_DESCR_DESTROY so that other contexts eventually free the page cache descriptor */
- new_state = old_state | PG_CACHE_DESCR_DESTROY;
-
- ret_state = ulong_compare_and_swap(&descr->pg_cache_descr_state, old_state, new_state);
- if (old_state == ret_state) {
- /* success */
- return;
- }
- /* spin */
- }
-} \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 09:49:26 +0000