I have written a program using C++/C, the MySQL C++ connector and ncurses/CDK. It compiles just fine, and runs fine as well on an x86/64 architecture. It crashes, however, when run on a Raspberry Pi B+ (ArchLinux).
I realize this is a pretty hard question to answer, but maybe someone more experienced can help.
Here's the (hopefully) relevant Code:
//Open Connection to the Database
nrpeout::MYSQL_CON localhost("127.0.0.1", 3306, "root", "toor");
//localhost.write_attributes_to_console();
con = localhost.open_database_connection();
//Create a new object of type nrpeoutputquery
nrpeout::Nrpeoutputquery current_query("SELECT * FROM nrpeout", con);
//Execute query
res = current_query.execute_query();
//Close Database Connection
localhost.close_database_connection(con);
} catch (sql::SQLException &e) {
//Handle SQL-Exceptions
std::cout << "# ERR: SQLException in " << __FILE__;
std::cout << "(" << __FUNCTION__ << ") on line "
<< __LINE__ << std::endl;
std::cout << "# ERR: " << e.what();
std::cout << " (MySQL error code: " << e.getErrorCode();
std::cout << ", SQLState: " << e.getSQLState() << " )" << std::endl;
} catch(...) {
//Handle Standard Exceptions
std::cout << "Unknown Exception raised. Please contact your Administrator" << std::endl;
}
nrpeout::NrpeResultSet* currentResults = new nrpeout::NrpeResultSet(res);
Using Valgrind and GDB, I have tried to narrow the error down to the line where I create the object "currentResults".
Here's the member function that saves the query results:
nrpeout::NrpeResultSet::NrpeResultSet(sql::ResultSet* res)
{
for (unsigned int i = 0; i < res->rowsCount(); ++i)
{
res->next();
std::string command = res->getString("command");
//Shorten the String
size_t posCommand = command.find("_");
std::string shortened_command = command.substr(posCommand+1);
int ret = res->getInt("ret");
std::string text = res->getString("text");
//Shorten the Text
size_t posText = text.find("|");
std::string shortened_text = text.substr(0, posText-1);
std::string last_updated = res->getString("last_updated");
this->results.push_back(Row(shortened_command, ret, shortened_text, last_updated));
}
Well, you are not catching an exception, which you may want to handle. InvalidInstanceException is thrown when using closed databse connections, statements or resultsets .
My suggestion is to run your code with a gdb and catch exceptions:
gdb ./some-program
$ catch throw
$ r
This will break after each exception being thrown. (But also includes handled exceptions, so there may be quite a few breaks, depending on how long it takes you to get to the important part.)
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