fix sqlite threading issue

freqtrade/persistence.py

@@ -5,9 +5,11 @@ from typing import Optional, Dict
 
 import arrow
 from sqlalchemy import Boolean, Column, DateTime, Float, Integer, String, create_engine
+from sqlalchemy.engine import Engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm.scoping import scoped_session
 from sqlalchemy.orm.session import sessionmaker
+from sqlalchemy.pool import StaticPool
 
 logging.basicConfig(level=logging.DEBUG,
                     format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
@@ -17,23 +19,25 @@ _CONF = {}
 _DECL_BASE = declarative_base()
 
 
-def init(config: dict, db_url: Optional[str] = None) -> None:
+def init(config: dict, engine: Optional[Engine] = None) -> None:
     """
     Initializes this module with the given config,
     registers all known command handlers
     and starts polling for message updates
     :param config: config to use
-    :param db_url: database connector string for sqlalchemy (Optional)
+    :param engine: database engine for sqlalchemy (Optional)
     :return: None
     """
     _CONF.update(config)
-    if not db_url:
+    if not engine:
         if _CONF.get('dry_run', False):
-            db_url = 'sqlite://'
+            engine = create_engine('sqlite://',
+                                   connect_args={'check_same_thread': False},
+                                   poolclass=StaticPool,
+                                   echo=False)
         else:
-            db_url = 'sqlite:///tradesv3.sqlite'
+            engine = create_engine('sqlite:///tradesv3.sqlite')
 
-    engine = create_engine(db_url, echo=False)
     session = scoped_session(sessionmaker(bind=engine, autoflush=True, autocommit=True))
     Trade.session = session()
     Trade.query = session.query_property()

freqtrade/tests/test_main.py

@@ -4,6 +4,7 @@ from unittest.mock import MagicMock
 
 import pytest
 import requests
+from sqlalchemy import create_engine
 
 from freqtrade.exchange import Exchanges
 from freqtrade.main import create_trade, handle_trade, close_trade_if_fulfilled, init, \
@@ -20,7 +21,7 @@ def test_process_trade_creation(default_conf, ticker, mocker):
                           validate_pairs=MagicMock(),
                           get_ticker=ticker,
                           buy=MagicMock(return_value='mocked_limit_buy'))
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
 
     trades = Trade.query.filter(Trade.is_open.is_(True)).all()
     assert len(trades) == 0
@@ -49,7 +50,7 @@ def test_process_exchange_failures(default_conf, ticker, mocker):
                           validate_pairs=MagicMock(),
                           get_ticker=ticker,
                           buy=MagicMock(side_effect=requests.exceptions.RequestException))
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
     result = _process()
     assert result is False
     assert sleep_mock.has_calls()
@@ -64,7 +65,7 @@ def test_process_runtime_error(default_conf, ticker, mocker):
                           validate_pairs=MagicMock(),
                           get_ticker=ticker,
                           buy=MagicMock(side_effect=RuntimeError))
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
     assert get_state() == State.RUNNING
 
     result = _process()
@@ -82,7 +83,7 @@ def test_process_trade_handling(default_conf, ticker, limit_buy_order, mocker):
                           get_ticker=ticker,
                           buy=MagicMock(return_value='mocked_limit_buy'),
                           get_order=MagicMock(return_value=limit_buy_order))
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
 
     trades = Trade.query.filter(Trade.is_open.is_(True)).all()
     assert len(trades) == 0
@@ -106,7 +107,7 @@ def test_create_trade(default_conf, ticker, limit_buy_order, mocker):
     # Save state of current whitelist
     whitelist = copy.deepcopy(default_conf['exchange']['pair_whitelist'])
 
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
     trade = create_trade(15.0)
     Trade.session.add(trade)
     Trade.session.flush()
@@ -167,7 +168,7 @@ def test_handle_trade(default_conf, limit_buy_order, limit_sell_order, mocker):
                           }),
                           buy=MagicMock(return_value='mocked_limit_buy'),
                           sell=MagicMock(return_value='mocked_limit_sell'))
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
     trade = create_trade(15.0)
     trade.update(limit_buy_order)
     Trade.session.add(trade)
@@ -197,7 +198,7 @@ def test_close_trade(default_conf, ticker, limit_buy_order, limit_sell_order, mo
                           buy=MagicMock(return_value='mocked_limit_buy'))
 
     # Create trade and sell it
-    init(default_conf, 'sqlite://')
+    init(default_conf, create_engine('sqlite://'))
     trade = create_trade(15.0)
     trade.update(limit_buy_order)
     trade.update(limit_sell_order)