Merge pull request #10 from gmjosack/racing

Add support for multiprocessing.

bin/hermes-server

@@ -14,7 +14,6 @@ import hermes
 from hermes import version
 from hermes.app import Application
 from hermes.settings import settings
-from hermes.models import get_db_engine, Session
 
 
 from sqlalchemy.exc import OperationalError
@@ -64,12 +63,10 @@ def main():
         "cookie_secret": settings.secret_key,
     }
 
-    db_engine = get_db_engine(settings.database)
-    Session.configure(bind=db_engine)
-
     my_settings = {
-        "db_engine": db_engine,
-        "db_session": Session,
+        "db_uri": settings.database,
+        "db_engine": None,
+        "db_session": None,
         "domain": settings.domain
     }
 

hermes/handlers/util.py

@@ -32,9 +32,17 @@ def request_get(cls, path="", params={}):
 
 class BaseHandler(RequestHandler):
     def initialize(self):
-        self.session = self.application.my_settings.get("db_session")()
-        self.engine = self.application.my_settings.get("db_engine")
-        self.domain = self.application.my_settings.get("domain")
+
+        my_settings = self.application.my_settings
+
+        # Lazily build the engine and session for support of multi-processing
+        if my_settings.get("db_engine") is None and my_settings.get("db_session") is None:
+            my_settings["db_engine"] = models.get_db_engine(my_settings.get("db_uri"))
+            my_settings["db_session"] = models.Session.configure(bind=my_settings["db_engine"])
+
+        self.session = my_settings.get("db_session")()
+        self.engine = my_settings.get("db_engine")
+        self.domain = my_settings.get("domain")
 
     def on_finish(self):
         self.session.close()