Issue #230: Fix patcher.original()230-patcher-original

Don't load a module twice when eventlet monkey-patched is not used.

3 files changed, 41 insertions, 0 deletions

diff --git a/eventlet/patcher.py b/eventlet/patcher.py
index a578637..517dd8c 100644
--- a/eventlet/patcher.py
+++ b/eventlet/patcher.py
@@ -182,6 +182,11 @@ def original(modname):
     if original_name in sys.modules:
         return sys.modules.get(original_name)
 
+    if not already_patched and modname in sys.modules:
+        # https://github.com/eventlet/eventlet/issues/230 Don't load a module twice
+        # when eventlet monkey-patched is not used
+        return sys.modules[modname]
+
     # re-import the "pure" module and store it in the global _originals
     # dict; be sure to restore whatever module had that name already
     saver = SysModulesSaver((modname,))
diff --git a/tests/isolated/patcher_threading_original.py b/tests/isolated/patcher_threading_original.py
new file mode 100644
index 0000000..42bb107
--- /dev/null
+++ b/tests/isolated/patcher_threading_original.py
@@ -0,0 +1,31 @@
+import sys
+import threading
+
+
+# no standard tests in this file, ignore
+__test__ = False
+
+
+class ImportEventlet(threading.Thread):
+    def __init__(self):
+        threading.Thread.__init__(self)
+        self.same_module = None
+
+    def run(self):
+        # https://github.com/eventlet/eventlet/issues/230
+        # Test importing eventlet for the first time in a thread:
+        # eventlet.patcher.original() must not reload threading.py twice.
+        mod1 = sys.modules['threading']
+        import eventlet.patcher
+        mod2 = eventlet.patcher.original('threading')
+        self.same_module = mod2 is mod1
+
+
+if __name__ == '__main__':
+    thread = ImportEventlet()
+    thread.start()
+    thread.join()
+    if thread.same_module:
+        print("pass")
+    else:
+        print("failed")
diff --git a/tests/patcher_test.py b/tests/patcher_test.py
index f1ef1f9..2053f7b 100644
--- a/tests/patcher_test.py
+++ b/tests/patcher_test.py
@@ -493,6 +493,11 @@ def test_threading_condition():
     tests.run_isolated('patcher_threading_condition.py')
 
 
+def test_threading_original():
+    # https://github.com/eventlet/eventlet/issues/230 test for non-regression of threading+original()
+    tests.run_isolated('patcher_threading_original.py')
+
+
 def test_threading_join():
     tests.run_isolated('patcher_threading_join.py')