[multi-db] Added tests for thread isolation of db-related settings.

git-svn-id: http://code.djangoproject.com/svn/django/branches/multiple-db-support@3417 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/othertests/thread_isolation.py

@@ -0,0 +1,287 @@
+# tests that db settings can be different in different threads
+#
+#
+#    What's going on here:
+#
+#    Simulating multiple web requests in a threaded environment, one in
+#    which settings are different for each request. So we replace
+#    django.conf.settings with a thread local, with different
+#    configurations in each thread, and then fire off three
+#    simultaneous requests (using a condition to sync them up), and
+#    test that each thread sees its own settings and the models in each
+#    thread attempt to connect to the correct database as per their
+#    settings.
+#
+
+
+import copy
+import os
+import sys
+import threading
+from thread import get_ident
+
+from django import conf
+from django.core.handlers.wsgi import WSGIHandler
+from django.db import models, model_connection_name, _default, connection, \
+     connections
+from django.http import HttpResponse
+
+try:
+    # Only exists in Python 2.4+
+    from threading import local
+except ImportError:
+    # Import copy of _thread_local.py from Python 2.4
+    from django.utils._threading_local import local
+
+# state holder
+S = {}
+
+# models
+class MQ(models.Model):
+    val = models.CharField(maxlength=10)
+    class Meta:
+        app_label = 'ti'
+
+
+class MX(models.Model):
+    val = models.CharField(maxlength=10)
+    class Meta:
+        app_label = 'ti'
+
+        
+class MY(models.Model):
+    val = models.CharField(maxlength=10)
+    class Meta:
+        app_label = 'ti'
+
+# eventused to synchronize threads so we can be sure they are running
+# together
+ev = threading.Event()
+
+
+def test_one(path, request):
+    """Start out with settings as originally configured"""
+    from django.conf import settings
+    debug("test_one: %s", settings.OTHER_DATABASES)
+
+    assert model_connection_name(MQ) == _default
+    assert model_connection_name(MX) == 'django_test_db_a', \
+           "%s != 'django_test_db_a'" % model_connection_name(MX)
+    assert MX._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME']
+    assert model_connection_name(MY) == 'django_test_db_b'
+    assert MY._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'], \
+           "%s != %s" % \
+           (MY._default_manager.db.connection.settings.DATABASE_NAME,
+            settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'])
+    assert MQ._default_manager.db.connection is \
+           connections[_default].connection        
+    assert MQ._default_manager.db.connection.settings.DATABASE_NAME == \
+           settings.DATABASE_NAME
+    assert connection.settings.DATABASE_NAME ==  settings.DATABASE_NAME
+
+
+def test_two(path, request):
+    """Between the first and second requests, settings change to assign
+    model MY to a different connection
+    """
+    from django.conf import settings
+    debug("test_two: %s", settings.OTHER_DATABASES)
+
+    try:
+        assert model_connection_name(MQ) == _default
+        assert model_connection_name(MX) == 'django_test_db_a'
+        assert MX._default_manager.db.connection.settings.DATABASE_NAME == \
+               settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME']
+        assert model_connection_name(MY) == _default
+        assert MY._default_manager.db.connection.settings.DATABASE_NAME == \
+               settings.DATABASE_NAME, "%s != %s" % \
+               (MY._default_manager.db.connection.settings.DATABASE_NAME,
+                settings.DATABASE_NAME)
+        assert MQ._default_manager.db.connection is \
+           connections[_default].connection        
+        assert MQ._default_manager.db.connection.settings.DATABASE_NAME == \
+               settings.DATABASE_NAME
+        assert connection.settings.DATABASE_NAME == settings.DATABASE_NAME
+    except:
+        S.setdefault('errors',[]).append(sys.exc_info())
+
+
+def test_three(path, request):
+    """Between the 2nd and 3rd requests, the settings at the names in
+    OTHER_DATABASES have changed.
+    """
+    from django.conf import settings
+    debug("3 %s: %s", get_ident(), settings.OTHER_DATABASES)
+    debug("3 %s: default: %s", get_ident(), settings.DATABASE_NAME)
+    debug("3 %s: conn: %s", get_ident(), connection.settings.DATABASE_NAME)
+    
+    try:
+        assert model_connection_name(MQ) == _default
+        assert model_connection_name(MX) == 'django_test_db_b'
+        assert MX._default_manager.db.connection.settings.DATABASE_NAME == \
+               settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'],\
+               "%s != %s" % \
+               (MX._default_manager.db.connection.settings.DATABASE_NAME,
+                settings.OTHER_DATABASES['django_test_db_b']['DATABASE_NAME'])
+        assert model_connection_name(MY) == 'django_test_db_a'
+        assert MY._default_manager.db.connection.settings.DATABASE_NAME == \
+               settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME'],\
+               "%s != %s" % \
+               (MY._default_manager.db.connection.settings.DATABASE_NAME,
+                settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME'])
+        assert MQ._default_manager.db.connection is \
+           connections[_default].connection
+        assert connection.settings.DATABASE_NAME == \
+               settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME'],\
+               "%s != %s" % \
+               (connection.settings.DATABASE_NAME,
+                settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME'])
+    except:
+        S.setdefault('errors',[]).append(sys.exc_info())
+        
+    
+
+# helpers
+def thread_two(func, *arg):
+    def start():
+        from django.conf import settings
+        for attr in [ a for a in dir(S['base_settings']) if a == a.upper() ]:
+            setattr(settings, attr,
+                    copy.deepcopy(getattr(S['base_settings'], attr)))
+        
+        settings.OTHER_DATABASES['django_test_db_b']['MODELS'] = []
+        debug("t2 waiting")
+        ev.wait(2.0)
+        func(*arg)
+        debug("t2 complete")
+    t2 = threading.Thread(target=start)
+    t2.start()
+    return t2
+
+
+def thread_three(func, *arg):
+    def start():
+        from django.conf import settings
+        for attr in [ a for a in dir(S['base_settings']) if a == a.upper() ]:
+            setattr(settings, attr,
+                    copy.deepcopy(getattr(S['base_settings'], attr)))
+            
+        settings.OTHER_DATABASES['django_test_db_b']['MODELS'] = ['ti.MY']
+        settings.OTHER_DATABASES['django_test_db_b'], \
+            settings.OTHER_DATABASES['django_test_db_a'] = \
+            settings.OTHER_DATABASES['django_test_db_a'], \
+            settings.OTHER_DATABASES['django_test_db_b']
+
+        settings.DATABASE_NAME = \
+            settings.OTHER_DATABASES['django_test_db_a']['DATABASE_NAME']
+
+        # we just manually changed settings, so reset the default
+        # connection (normally this isn't needed
+
+        debug("3 %s: start: default: %s", get_ident(), settings.DATABASE_NAME)
+        debug("3 %s: start: conn: %s", get_ident(),
+              connection.settings.DATABASE_NAME)
+        
+        debug("t3 waiting")
+        ev.wait(2.0)
+        func(*arg)
+        debug("t3 complete")
+    t3 = threading.Thread(target=start)
+    t3.start()
+    return t3
+    
+
+class MockHandler(WSGIHandler):
+
+    def __init__(self, test):
+        self.test = test
+        super(MockHandler, self).__init__()
+        
+    def get_response(self, path, request):
+        # debug("mock handler answering %s, %s", path, request)
+        return HttpResponse(self.test(path, request))
+        
+
+def pr(*arg):
+    if S['verbosity'] >= 1:
+        msg, arg = arg[0], arg[1:]
+        print msg % arg
+
+
+def debug(*arg):
+    if S['verbosity'] >= 2:
+        msg, arg = arg[0], arg[1:]
+        print msg % arg
+
+
+def setup():
+    debug("setup")
+    S['settings'] = copy.deepcopy(conf.settings)
+    S['base_settings'] = copy.deepcopy(conf.settings)
+    S['base_settings'].OTHER_DATABASES['django_test_db_a']['MODELS'] = \
+        ['ti.MX']
+    S['base_settings'].OTHER_DATABASES['django_test_db_b']['MODELS'] = \
+        ['ti.MY']
+    
+    conf.settings = local()
+    for attr in [ a for a in dir(S['base_settings']) if a == a.upper() ]:
+        setattr(conf.settings, attr,
+                copy.deepcopy(getattr(S['base_settings'], attr)))
+
+    conf.settings.__module__ = S['settings'].__module__
+    debug("Setup: %s", conf.settings.OTHER_DATABASES)
+
+    
+def teardown():
+    debug("teardown")
+    conf.settings = S['settings']
+
+
+def start_response(code, headers):
+    debug("start response: %s %s", code, headers)
+    pass
+
+
+def main():
+    debug("running tests")
+
+    env = os.environ.copy()
+    env['PATH_INFO'] = '/'
+    env['REQUEST_METHOD'] = 'GET'
+    
+    t2 = thread_two(MockHandler(test_two), env, start_response)
+    t3 = thread_three(MockHandler(test_three), env, start_response)
+    
+    try:
+        ev.set()
+        MockHandler(test_one)(env, start_response)
+    finally:
+        t2.join()
+        t3.join()
+        err = S.get('errors', [])
+        if err:
+            import traceback        
+            for e in err:
+                traceback.print_exception(*e)
+                raise AssertionError("%s thread%s failed" %
+                                     (len(err), len(err) > 1 and 's' or ''))
+    
+def run_tests(verbosity=0):
+    S['verbosity'] = verbosity
+    
+    setup()
+    try:
+        main()
+    finally:
+        teardown()
+
+        
+if __name__ == '__main__':
+    from django.conf import settings
+    
+    settings.DATABASE_NAME = ':memory:'
+    print "MAIN start! ", connection.settings.DATABASE_NAME
+    connection.cursor()
+    run_tests(2)