request 16M-1 stmt_prepare command packet connect hang

int sql_str_size(unsigned int sqlsize)

{

    char prefx[] = "select ''";

    return sqlsize -  strlen(prefx) - 1;

}

void gen_select_sqlstr(char *sqlstr, unsigned int strsize, int sqlsize)

{

    strcpy(sqlstr, "select '");

    memset(sqlstr+strlen("select '"), 'f', strsize);

    sqlstr[sqlsize-2] = '\'';

    sqlstr[sqlsize-1] = '\0';

}

void test()

{

    strsize = sql_str_size(sqlsize);

    sqlstr = (char *)malloc(sqlsize);

    gen_select_sqlstr(sqlstr, strsize, sqlsize);

   if (mysql_stmt_prepare(stmt, sqlstr, strlen(sqlstr)) != 0) // where strlen(sqlstr) == 16777215

}