def _delete_product_after_sleep(self):
with get_connection() as conn:
for i in range(3):
self._sleep(1)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Select Product and got "{product}"')
self._logger.info(f'Delete product')
pd.delete_product(conn, self.id)
self._logger.info(f'Product deleted')
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Select Product again and got "{product}"')
def _select_sleep_select(self):
with get_connection() as conn:
self._begin(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" at the first select')
self._sleep(5)
# get None when commited here
#self._commit(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" before commit')
# still have product due to REPEATABLE READ
self._commit(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after commit')
def _read_after_sleep(self):
self._sleep(3)
with get_connection() as conn:
#conn.begin()
for i in range(10):
self._sleep(1)
# Actually we can read the row even using FOR UPDATE !?
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Select Product and got "{product}"')
def _select_sleep_update(self):
with get_connection() as conn:
self._begin(conn)
product = pd.select_product_for_update_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" at select for update')
self._sleep(5)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" before update')
pd.update_product_total(conn, self.id, 50)
self._logger.info(f'Product updated')
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after update')
self._commit(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after commit')
def _select_sleep_update(self):
with get_connection() as conn:
self._begin(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" at the first select')
self._sleep(5)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" before update')
pd.update_product_total(conn, self.id, 50)
self._logger.info(f'Product updated')
# Cannot know the update because it was already deleted
# Can know the update if the record still exists
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after update')
self._commit(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after commit')
def _select_sleep_update(self):
with get_connection() as conn:
self._begin(conn)
# When using for share, another thread will get deadlock exception
# https://stackoverflow.com/questions/32827650/mysql-innodb-difference-between-for-update-and-lock-in-share-mode
product = pd.select_product_for_share_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" at select for share')
self._sleep(5)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" before update')
pd.update_product_total(conn, self.id, 50)
self._logger.info(f'Product updated')
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after update')
self._commit(conn)
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'Got product "{product}" after commit')
def _close(self, conn):
product = pd.select_product_by_id(conn, self.id)
self._logger.info(f'{self.__class__.__name__}: Got product {product}')
pd.delete_product(conn, self.id)
