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mdbx: рефакторинг txn_renew() транзакций с вычленением txn_basal_start().

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This commit is contained in:
Леонид Юрьев (Leonid Yuriev)
2025-01-15 00:49:30 +03:00
parent 314b8ce1f0
commit 2c3b36da64
3 changed files with 81 additions and 62 deletions
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63
src/txn.c
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@@ -70,6 +70,19 @@ int txn_abort(MDBX_txn *txn) {
return txn_end(txn, TXN_END_ABORT | TXN_END_SLOT | TXN_END_FREE);
}
static bool txn_check_overlapped(lck_t *const lck, const uint32_t pid, const uintptr_t tid) {
const size_t snap_nreaders = atomic_load32(&lck->rdt_length, mo_AcquireRelease);
for (size_t i = 0; i < snap_nreaders; ++i) {
if (atomic_load32(&lck->rdt[i].pid, mo_Relaxed) == pid &&
unlikely(atomic_load64(&lck->rdt[i].tid, mo_Relaxed) == tid)) {
const txnid_t txnid = safe64_read(&lck->rdt[i].txnid);
if (txnid >= MIN_TXNID && txnid <= MAX_TXNID)
return true;
}
}
return false;
}
int txn_renew(MDBX_txn *txn, unsigned flags) {
MDBX_env *const env = txn->env;
int rc;
@@ -90,17 +103,9 @@ int txn_renew(MDBX_txn *txn, unsigned flags) {
/* not recovery mode */ env->stuck_meta >= 0))
return MDBX_BUSY;
lck_t *const lck = env->lck_mmap.lck;
if (lck && (env->flags & MDBX_NOSTICKYTHREADS) == 0 && (globals.runtime_flags & MDBX_DBG_LEGACY_OVERLAP) == 0) {
const size_t snap_nreaders = atomic_load32(&lck->rdt_length, mo_AcquireRelease);
for (size_t i = 0; i < snap_nreaders; ++i) {
if (atomic_load32(&lck->rdt[i].pid, mo_Relaxed) == env->pid &&
unlikely(atomic_load64(&lck->rdt[i].tid, mo_Relaxed) == tid)) {
const txnid_t txnid = safe64_read(&lck->rdt[i].txnid);
if (txnid >= MIN_TXNID && txnid <= MAX_TXNID)
return MDBX_TXN_OVERLAPPING;
}
}
}
if (lck && !(env->flags & MDBX_NOSTICKYTHREADS) && !(globals.runtime_flags & MDBX_DBG_LEGACY_OVERLAP) &&
txn_check_overlapped(lck, env->pid, tid))
return MDBX_TXN_OVERLAPPING;
/* Not yet touching txn == env->basal_txn, it may be active */
jitter4testing(false);
@@ -118,41 +123,9 @@ int txn_renew(MDBX_txn *txn, unsigned flags) {
}
#endif /* Windows */
txn->wr.troika = meta_tap(env);
const meta_ptr_t head = meta_recent(env, &txn->wr.troika);
uint64_t timestamp = 0;
while ("workaround for https://libmdbx.dqdkfa.ru/dead-github/issues/269") {
rc = coherency_fetch_head(txn, head, &timestamp);
if (likely(rc == MDBX_SUCCESS))
break;
if (unlikely(rc != MDBX_RESULT_TRUE))
goto bailout;
}
eASSERT(env, meta_txnid(head.ptr_v) == txn->txnid);
txn->txnid = safe64_txnid_next(txn->txnid);
if (unlikely(txn->txnid > MAX_TXNID)) {
rc = MDBX_TXN_FULL;
ERROR("txnid overflow, raise %d", rc);
rc = txn_basal_start(txn, flags);
if (unlikely(rc != MDBX_SUCCESS))
goto bailout;
}
tASSERT(txn, txn->dbs[FREE_DBI].flags == MDBX_INTEGERKEY);
tASSERT(txn, check_table_flags(txn->dbs[MAIN_DBI].flags));
txn->flags = flags;
txn->nested = nullptr;
txn->wr.loose_pages = nullptr;
txn->wr.loose_count = 0;
#if MDBX_ENABLE_REFUND
txn->wr.loose_refund_wl = 0;
#endif /* MDBX_ENABLE_REFUND */
MDBX_PNL_SETSIZE(txn->wr.retired_pages, 0);
txn->wr.spilled.list = nullptr;
txn->wr.spilled.least_removed = 0;
txn->wr.gc.time_acc = 0;
txn->wr.gc.last_reclaimed = 0;
if (txn->wr.gc.retxl)
MDBX_PNL_SETSIZE(txn->wr.gc.retxl, 0);
env->txn = txn;
}
txn->front_txnid = txn->txnid + ((flags & (MDBX_WRITEMAP | MDBX_RDONLY)) == 0);