fix comments

src/pool/mempool.rs

@@ -150,25 +150,31 @@ impl<SP: starknet::providers::Provider + Send + Sync + Clone + 'static> AccountM
         // Collect the accounts into a vector for shuffling
         let mut accounts: Vec<_> = self.accounts.iter().collect();
 
+        // Shuffle the accounts randomly before iterating
+        accounts.shuffle(&mut rng);
+
         loop {
             if accounts.is_empty() {
                 return Err(eyre::eyre!("failed to fetch funded account"));
             }
 
-            // Shuffle the accounts randomly before iterating
-            accounts.shuffle(&mut rng);
-
+            // Create the future locks with indices for more efficient removal
             // use [`select_all`] to poll an iterator over impl Future<Output = (Felt, MutexGuard<Felt>)>
             // We use Box::pin because this Future doesn't implement `Unpin`.
-            let fut_locks = accounts.iter().map(|(address, nonce)| Box::pin(async { (*address, nonce.lock().await) }));
-            let ((account_address, guard), _, _) = select_all(fut_locks).await;
+            let fut_locks = accounts
+                .iter()
+                .enumerate()
+                .map(|(index, (address, nonce))| Box::pin(async move { (index, *address, nonce.lock().await) }));
+
+            // Select the first account that gets unlocked
+            let ((index, account_address, guard), _, _) = select_all(fut_locks).await;
 
             // Fetch the balance of the selected account
             let balance = self.get_balance(*account_address).await?;
 
-            // If the balance is lower than the threshold, continue
+            // If the balance is lower than the threshold, remove the account using swap_remove
             if balance < U256::from(ONE_TENTH_ETH) {
-                accounts.retain(|(addr, _)| *addr != account_address);
+                accounts.swap_remove(index);
                 continue;
             }