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mdbx: упрощение page_alloc_slowpath().
Упрощение за счет удаления проверки флага `MDBX_ALLOC_GC`, который всегда взведен при вызове page_alloc_slowpath().
This commit is contained in:
Леонид Юрьев (Leonid Yuriev)
parent
3e05d1a427
commit
f73cd7a491
92
src/core.c
92
src/core.c
@ -5394,6 +5394,7 @@ static txnid_t find_oldest_reader(MDBX_env *const env, const txnid_t steady) {
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MDBX_lockinfo *const lck = env->me_lck_mmap.lck;
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if (unlikely(lck == NULL /* exclusive without-lck mode */)) {
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eASSERT(env, env->me_lck == (void *)&env->x_lckless_stub);
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env->me_lck->mti_readers_refresh_flag.weak = nothing_changed;
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return env->me_lck->mti_oldest_reader.weak = steady;
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}
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@ -6623,6 +6624,14 @@ static int gc_cursor_init(MDBX_cursor *mc, MDBX_txn *txn) {
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return cursor_init(mc, txn, FREE_DBI);
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}
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__hot static bool is_already_reclaimed(const MDBX_txn *txn, txnid_t id) {
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const size_t len = MDBX_PNL_GETSIZE(txn->tw.lifo_reclaimed);
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for (size_t i = 1; i <= len; ++i)
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if (txn->tw.lifo_reclaimed[i] == id)
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return true;
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return false;
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}
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static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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char flags) {
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#if MDBX_ENABLE_PROFGC
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@ -6642,11 +6651,9 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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prof->spe_counter += 1;
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#endif /* MDBX_ENABLE_PROFGC */
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eASSERT(env, flags & MDBX_ALLOC_GC);
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eASSERT(env, num == 0 || !(flags & MDBX_ALLOC_SLOT));
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eASSERT(env, num > 0 || !(flags & MDBX_ALLOC_NEW));
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eASSERT(env, (flags & (MDBX_ALLOC_SLOT | MDBX_ALLOC_RESERVE |
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MDBX_ALLOC_BACKLOG)) == 0 ||
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(flags & MDBX_ALLOC_GC));
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eASSERT(env, (flags & (MDBX_ALLOC_SLOT | MDBX_ALLOC_RESERVE |
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MDBX_ALLOC_BACKLOG)) == 0 ||
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(flags & MDBX_ALLOC_NEW) == 0);
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@ -6654,9 +6661,12 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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txn->mt_next_pgno - MDBX_ENABLE_REFUND));
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pgno_t pgno = 0, *range = nullptr;
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size_t re_len = MDBX_PNL_GETSIZE(txn->tw.relist);
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size_t newnext, re_len = MDBX_PNL_GETSIZE(txn->tw.relist);
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if (num > 1) {
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eASSERT(env, !(flags & MDBX_ALLOC_SLOT));
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eASSERT(env, (txn->mt_flags & MDBX_TXN_FROZEN_RE) == 0);
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if (unlikely(txn->mt_flags & MDBX_TXN_FROZEN_RE))
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goto no_gc;
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#if MDBX_ENABLE_PROFGC
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prof->xpages += 1;
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#endif /* MDBX_ENABLE_PROFGC */
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@ -6672,13 +6682,12 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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}
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}
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} else {
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eASSERT(env, (flags & (MDBX_ALLOC_SLOT | MDBX_ALLOC_RESERVE)) ||
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MDBX_PNL_GETSIZE(txn->tw.relist) == 0);
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eASSERT(env,
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(flags & (MDBX_ALLOC_SLOT | MDBX_ALLOC_RESERVE)) || re_len == 0);
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}
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//---------------------------------------------------------------------------
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if (likely(flags & MDBX_ALLOC_GC)) {
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if (unlikely(!is_gc_usable(txn)))
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goto no_gc;
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@ -6695,12 +6704,9 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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if (unlikely(ret.err != MDBX_SUCCESS))
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goto fail;
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retry_gc_refresh_oldest:;
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retry_gc_refresh_oldest:;
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txnid_t oldest = txn_oldest_reader(txn);
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if (unlikely(!oldest))
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goto no_gc;
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retry_gc_have_oldest:
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retry_gc_have_oldest:
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if (unlikely(oldest >= txn->mt_txnid)) {
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ERROR("unexpected/invalid oldest-readed txnid %" PRIaTXN
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" for current-txnid %" PRIaTXN,
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@ -6710,7 +6716,7 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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}
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const txnid_t detent = oldest + 1;
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txnid_t last = 0;
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txnid_t id = 0;
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bool should_scan = false;
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MDBX_cursor_op op = MDBX_FIRST;
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if (flags & MDBX_ALLOC_LIFO) {
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@ -6722,20 +6728,20 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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}
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}
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/* Begin lookup backward from oldest reader */
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last = detent - 1;
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id = detent - 1;
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op = MDBX_SET_RANGE;
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} else if (txn->tw.last_reclaimed) {
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/* Continue lookup forward from last-reclaimed */
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last = txn->tw.last_reclaimed + 1;
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if (last >= detent)
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goto no_gc;
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id = txn->tw.last_reclaimed + 1;
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if (id >= detent)
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goto depleted_gc;
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op = MDBX_SET_RANGE;
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}
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next_gc:;
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next_gc:;
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MDBX_val key;
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key.iov_base = &last;
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key.iov_len = sizeof(last);
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key.iov_base = &id;
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key.iov_len = sizeof(id);
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#if MDBX_ENABLE_PROFGC
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prof->rsteps += 1;
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@ -6756,26 +6762,22 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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ret.err = MDBX_CORRUPTED;
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goto fail;
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}
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last = unaligned_peek_u64(4, key.iov_base);
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id = unaligned_peek_u64(4, key.iov_base);
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if (flags & MDBX_ALLOC_LIFO) {
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op = MDBX_PREV;
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if (last >= detent)
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goto next_gc;
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/* skip IDs of records that already reclaimed */
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for (size_t i = MDBX_PNL_GETSIZE(txn->tw.lifo_reclaimed); i > 0; --i)
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if (txn->tw.lifo_reclaimed[i] == last)
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if (id >= detent || is_already_reclaimed(txn, id))
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goto next_gc;
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} else {
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op = MDBX_NEXT;
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if (unlikely(last >= detent))
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if (unlikely(id >= detent))
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goto depleted_gc;
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}
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/* Reading next GC record */
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MDBX_val data;
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MDBX_page *const mp = recur.mc_pg[recur.mc_top];
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if (unlikely((ret.err = node_read(&recur,
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page_node(mp, recur.mc_ki[recur.mc_top]),
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if (unlikely(
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(ret.err = node_read(&recur, page_node(mp, recur.mc_ki[recur.mc_top]),
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&data, mp)) != MDBX_SUCCESS))
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goto fail;
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@ -6798,7 +6800,8 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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/* Stop reclaiming to avoid large/overflow the page list.
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* This is a rare case while search for a continuously multi-page region
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* in a large database.
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* https://web.archive.org/web/https://github.com/erthink/libmdbx/issues/123 */
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* https://web.archive.org/web/https://github.com/erthink/libmdbx/issues/123
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*/
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NOTICE("stop reclaiming to avoid PNL overflow: %zu (current) + %zu "
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"(chunk) -> %zu",
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MDBX_PNL_GETSIZE(txn->tw.relist), gc_len,
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@ -6807,9 +6810,9 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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}
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/* Remember ID of readed GC record */
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txn->tw.last_reclaimed = last;
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txn->tw.last_reclaimed = id;
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if (flags & MDBX_ALLOC_LIFO) {
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ret.err = txl_append(&txn->tw.lifo_reclaimed, last);
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ret.err = txl_append(&txn->tw.lifo_reclaimed, id);
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if (unlikely(ret.err != MDBX_SUCCESS))
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goto fail;
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}
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@ -6818,12 +6821,11 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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ret.err = pnl_need(&txn->tw.relist, gc_len);
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if (unlikely(ret.err != MDBX_SUCCESS))
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goto fail;
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txn->tw.relist = txn->tw.relist;
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if (LOG_ENABLED(MDBX_LOG_EXTRA)) {
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DEBUG_EXTRA("readed GC-pnl txn %" PRIaTXN " root %" PRIaPGNO
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" len %zu, PNL",
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last, txn->mt_dbs[FREE_DBI].md_root, gc_len);
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id, txn->mt_dbs[FREE_DBI].md_root, gc_len);
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for (size_t i = gc_len; i; i--)
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DEBUG_EXTRA_PRINT(" %" PRIaPGNO, gc_pnl[i]);
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DEBUG_EXTRA_PRINT(", next_pgno %u\n", txn->mt_next_pgno);
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@ -6847,7 +6849,7 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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if (MDBX_ENABLE_REFUND && re_len &&
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unlikely(MDBX_PNL_MOST(txn->tw.relist) == txn->mt_next_pgno - 1)) {
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/* Refund suitable pages into "unallocated" space */
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if (txn_refund(txn))
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txn_refund(txn);
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re_len = MDBX_PNL_GETSIZE(txn->tw.relist);
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}
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eASSERT(env, re_len == MDBX_PNL_GETSIZE(txn->tw.relist));
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@ -6875,7 +6877,7 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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flags &= ~MDBX_ALLOC_COALESCE;
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}
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scan:
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scan:
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eASSERT(env, should_scan);
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if (re_len >= num) {
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eASSERT(env, MDBX_PNL_LAST(txn->tw.relist) < txn->mt_next_pgno &&
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@ -6895,7 +6897,7 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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if (ret.err == MDBX_SUCCESS)
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goto next_gc;
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depleted_gc:
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depleted_gc:
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ret.err = MDBX_NOTFOUND;
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if (should_scan)
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goto scan;
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@ -6910,12 +6912,11 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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* - extend the database file. */
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/* Will use new pages from the map if nothing is suitable in the GC. */
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pgno = txn->mt_next_pgno;
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const size_t newnext = num + pgno;
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newnext = (pgno = txn->mt_next_pgno) + num;
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/* Does reclaiming stopped at the last steady point? */
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const meta_ptr_t recent = meta_recent(env, &txn->tw.troika);
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const meta_ptr_t prefer_steady = meta_prefer_steady(env, &txn->tw.troika);
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/* does reclaiming stopped at the last steady point? */
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if (recent.ptr_c != prefer_steady.ptr_c && prefer_steady.is_steady &&
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detent == prefer_steady.txnid + 1) {
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DEBUG("gc-kick-steady: recent %" PRIaTXN "-%s, steady %" PRIaTXN
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@ -6979,16 +6980,14 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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}
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}
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if (env->me_lck_mmap.lck &&
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unlikely(true ==
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atomic_load32(&env->me_lck_mmap.lck->mti_readers_refresh_flag,
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if (unlikely(true == atomic_load32(&env->me_lck->mti_readers_refresh_flag,
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mo_AcquireRelease))) {
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oldest = txn_oldest_reader(txn);
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if (oldest >= detent)
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goto retry_gc_have_oldest;
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}
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/* avoid kick lagging reader(s) if is enough unallocated space
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/* Avoid kick lagging reader(s) if is enough unallocated space
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* at the end of database file. */
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if ((flags & MDBX_ALLOC_NEW) && newnext <= txn->mt_end_pgno) {
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eASSERT(env, range == nullptr);
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@ -7000,7 +6999,6 @@ static pgr_t page_alloc_slowpath(const MDBX_cursor *mc, const size_t num,
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if (oldest >= detent)
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goto retry_gc_have_oldest;
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}
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}
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//---------------------------------------------------------------------------
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@ -7011,8 +7009,7 @@ no_gc:
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}
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/* Will use new pages from the map if nothing is suitable in the GC. */
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pgno = txn->mt_next_pgno;
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const size_t newnext = num + pgno;
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newnext = (pgno = txn->mt_next_pgno) + num;
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if (newnext <= txn->mt_end_pgno)
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goto done;
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@ -7055,6 +7052,7 @@ done:
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eASSERT(env, (txn->mt_flags & MDBX_TXN_FROZEN_RE) == 0);
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eASSERT(env, pgno == *range);
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eASSERT(env, pgno + num <= txn->mt_next_pgno && pgno >= NUM_METAS);
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eASSERT(env, re_len == MDBX_PNL_GETSIZE(txn->tw.relist));
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/* Cutoff allocated pages from tw.relist */
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#if MDBX_PNL_ASCENDING
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for (const pgno_t *const end = re_list + re_len - num; range <= end;
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