Recursive Function Calls Throw StackOverFlowException
I've to call a function recursively. But after a moment it throws StackOverFlowException. When I used Invoke(new Action(Start)) method, it throws same exception but not in a long moment, this is shorter than the previous one.
How can I overcome this problem?
Example Code:
private void Start()
{
// run select query
mysql(selectQueryString.ToString());
msdr = mysql();
// is finished
if (!msdr.HasRows)
{
this.Finish();
return;
}
// get mysql fields
string[] mysqlFields = Common.GetFields(ref msdr);
while (msdr.Read())
{
// set lastSelectID
lastSelectID = Convert.ToInt32(msdr[idFieldName].ToString());
// fill mssql stored procedure parameters
for (int i = 0; i < matchTable.Count; i++)
{
string valueToAdd = Common.ConvertToEqualivantString(matchTable[i].Type, matchTable[i].Value, ref msdr, ref id, matchTable[i].Parameters);
sql.Ekle(matchTable[i].Key, valueToAdd);
}
// execute adding operation
lastInsertID = (int)sql(false);
// update status bar
this.UpdateStatusBar();
// update menues
this.UpdateMenues();
// increment id for "{id}" statement
id++;
}
// close data reader
msdr.Close();
msdr.Dispose();
mysql.DisposeCommand();
// increment select limit
selectQueryString.LimitFirst += selectQueryString.LimitLast;
// call itself until finish
this.Start();
}
When the last statement in a function is the call to the function itself, you have tail-recursion. While there are languages that optimize tail-recursion to avoid a stack overflow exception, C# is not one of them.
Recursion is not a good pattern for data that can be of an arbitrary length. Simply replace recursion by a while loop:
private void Start()
{
while(true) {
// run select query
mysql(selectQueryString.ToString());
msdr = mysql();
// is finished
if (!msdr.HasRows)
{
this.Finish();
break;
}
// rest of your code..
}
}