chore: get rid of redundant argument

Signed-off-by: Roman Gershman <roman@dragonflydb.io>

Author: romange

src/server/engine_shard.cc

@@ -614,14 +614,11 @@ void EngineShard::PollExecution(const char* context, Transaction* trans) {
     continuation_trans_ = nullptr;
   }
 
-  string dbg_id;
   bool update_stats = false;
 
-  auto run = [this, &dbg_id, &update_stats](Transaction* tx, bool is_ooo) -> bool /* keep */ {
-    dbg_id = VLOG_IS_ON(1) ? tx->DebugId() : "";
-    bool concluding = tx->RunInShard(this, is_ooo);
+  auto run = [this, &update_stats](Transaction* tx, bool is_ooo) -> bool /* concluding */ {
     update_stats = true;
-    return !concluding;
+    return tx->RunInShard(this, is_ooo);
   };
 
   // Check the currently running transaction, we have to handle it first until it concludes
@@ -632,9 +629,7 @@ void EngineShard::PollExecution(const char* context, Transaction* trans) {
 
     if ((is_self && disarmed) || continuation_trans_->DisarmInShard(sid)) {
       auto bc = continuation_trans_->GetNamespace().GetBlockingController(shard_id_);
-      if (bool keep = run(continuation_trans_, false); !keep) {
-        // if this holds, we can remove this check altogether.
-        DCHECK(continuation_trans_ == nullptr);
+      if (bool concludes = run(continuation_trans_, false); concludes) {
         continuation_trans_ = nullptr;
       }
       if (bc && bc->HasAwakedTransaction()) {
@@ -677,25 +672,28 @@ void EngineShard::PollExecution(const char* context, Transaction* trans) {
     DCHECK_LT(committed_txid_, txid);  //  strictly increasing when processed via txq
     committed_txid_ = txid;
 
-    if (bool keep = run(head, false); keep)
+    DCHECK(!continuation_trans_);  // while() check above ensures this.
+    if (bool concludes = run(head, false); !concludes) {
       continuation_trans_ = head;
+    }
   }
 
   // If we disarmed, but didn't find ourselves in the loop, run now.
   if (trans && disarmed) {
     DCHECK(trans != head);
     DCHECK(trans_mask & (Transaction::OUT_OF_ORDER | Transaction::SUSPENDED_Q));
+    CHECK(trans != continuation_trans_);
 
     bool is_ooo = trans_mask & Transaction::OUT_OF_ORDER;
-    bool keep = run(trans, is_ooo);
-    if (is_ooo && !keep) {
+    bool concludes = run(trans, is_ooo);
+    if (is_ooo && concludes) {
       stats_.tx_ooo_total++;
     }
 
     // If the transaction concluded, it must remove itself from the tx queue.
     // Otherwise it is required to stay there to keep the relative order.
     if (is_ooo && !trans->IsMulti())
-      DCHECK_EQ(keep, trans->DEBUG_GetTxqPosInShard(sid) != TxQueue::kEnd);
+      LOG_IF(DFATAL, concludes != (trans->DEBUG_GetTxqPosInShard(sid) == TxQueue::kEnd));
   }
   if (update_stats) {
     CacheStats();

src/server/transaction.cc

@@ -591,7 +591,6 @@ bool Transaction::RunInShard(EngineShard* shard, bool txq_ooo) {
 
   bool was_suspended = sd.local_mask & SUSPENDED_Q;
   bool awaked_prerun = sd.local_mask & AWAKED_Q;
-
   IntentLock::Mode mode = LockMode();
 
   DCHECK(IsGlobal() || (sd.local_mask & KEYLOCK_ACQUIRED) || (multi_ && multi_->mode == GLOBAL));

src/server/transaction.h

@@ -207,8 +207,7 @@ class Transaction {
 
   // Called by engine shard to execute a transaction hop.
   // txq_ooo is set to true if the transaction is running out of order
-  // not as the tx queue head.
-  // Returns true if the transaction continues running in the thread
+  // not as the tx queue head. Returns true if the transaction concludes.
   bool RunInShard(EngineShard* shard, bool txq_ooo);
 
   // Registers transaction into watched queue and blocks until a) either notification is received.