This adds a global my.cnf parameter, rocksdb_use_range_locking.

When it is ON, MyRocks will:
- initialize RocksDB to use range-locking lock manager
- for all DML operations (including SELECT .. FOR UPDATE) will lock
the scanned range before reading/modifying rows.
- In range locking mode, there is no snapshot checking (cannot do that
  for ranges). Instead, MyRocks will read and modify latest committed
  data, just like InnoDB does (in the code, grep for (start|end)
  _ignore_snapshot)
- Queries that do not have a finite range to scan, like
  UPDATE t1 .... ORDER BY t1.key LIMIT n
  will use a  "Locking iterator" which will read rows, lock the range,
  and re-read the rows. See class LockingIterator.

mysql-test/suite/rocksdb/combinations

@@ -7,3 +7,6 @@ rocksdb_write_policy=write_prepared
 [write_unprepared]
 rocksdb_write_policy=write_unprepared
 rocksdb_write_batch_flush_threshold=1
+
+[range_locking]
+rocksdb_use_range_locking=1

mysql-test/suite/rocksdb/include/have_range_locking.inc

@@ -0,0 +1,3 @@
+if (`select count(*) = 0 from performance_schema.session_variables where variable_name = 'rocksdb_use_range_locking' and variable_value = 'ON';`) {
+  --skip Test requires range locking
+}

mysql-test/suite/rocksdb/include/not_range_locking.inc

@@ -0,0 +1,5 @@
+--let $_use_range_locking= `select @@rocksdb_use_range_locking`
+if ($_use_range_locking == 1)
+{
+  --skip Test doesn't support range locking
+}

mysql-test/suite/rocksdb/include/select_from_is_rowlocks.inc

@@ -0,0 +1,77 @@
+--echo # select * from information_schema.rocksdb_locks; # With replacements by select_from_is_rowlocks.inc
+#
+#  An include to print contents of I_S.ROCKSB_LOCKS
+#
+#   Implicit "parameters"
+#     - Currently it prints locks on t1.PRIMARY
+#
+#   Explicit "parameter" variables:
+#     - $TRX1_ID  - print this transaction as "TRX1"
+#     - $TRX2_ID  - print this transaction as "TRX2"
+# 
+#     - $select_from_is_rowlocks_current_trx_only
+#     - $order_by_rowkey
+
+--disable_query_log
+set @cf_id=(select column_family from information_schema.rocksdb_ddl
+            where table_name='t1' and index_name='PRIMARY');
+set @rtrx_id=(select transaction_id from information_schema.rocksdb_trx
+              where thread_id=connection_id());
+set @indexnr= (select lower(
+                         concat(
+                            lpad(hex(db_number),8,'0'),
+                            lpad(hex(index_number),8,'0')
+                         )
+                      )
+               from information_schema.rocksdb_ddl
+               where table_name='t1' and index_name='PRIMARY');
+
+set @indexnr_next= (select lower(
+                             concat(
+                                lpad(hex(db_number),8,'0'),
+                                lpad(hex(index_number+1),8,'0')
+                              )
+                           )
+                    from information_schema.rocksdb_ddl
+                    where table_name='t1' and index_name='PRIMARY');
+
+let $extra_where = where 1;
+
+if ($select_from_is_rowlocks_current_trx_only) 
+{
+  let $extra_where = where transaction_id=(select transaction_id from information_schema.rocksdb_trx where connection_id()=thread_id);
+}
+
+# If TRX1_ID is not specified, get the current transaction:
+let $transaction_col= replace(transaction_id, @rtrx_id, "\$trx_id");
+if ($TRX1_ID)
+{
+  let $transaction_col = replace(transaction_id, '$TRX1_ID', "\$TRX1_ID");
+}
+
+if ($TRX2_ID)
+{
+  let $transaction_col = replace($transaction_col, '$TRX2_ID', "\$TRX2_ID");
+}
+
+if ($order_by_rowkey)
+{
+  let $extra_order_by = ORDER BY 3,2;
+}
+
+if (!$order_by_rowkey)
+{
+  --sorted_result
+}
+
+eval select 
+  replace(column_family_id, @cf_id, "\$cf_id") as COLUMN_FAMILY_ID,
+  $transaction_col as TRANSACTION_ID,
+  replace(
+     replace(`key`, @indexnr, '\${indexnr}'),
+     @indexnr_next, '\${indexnr+1}'
+  ) as `KEY`,
+  mode
+from information_schema.rocksdb_locks $extra_where $extra_order_by;
+
+--enable_query_log