commit method
Mark a transaction committed, release its locks.
Implementation
void commit(TxnContext ctx) {
if (!ctx.isActive) return;
ctx.status = TxnStatus.committed;
_active.remove(ctx.txnId);
if (ctx.txnId > _lastCommitted) _lastCommitted = ctx.txnId;
lockManager.releaseAll(ctx.locks);
ctx.locks.clear();
}