Fix HTTPServer.serve_forever blocking whole process

Original report: https://github.com/eventlet/eventlet/issues/249

Explanation is in the comments in the code.

Originally reverted[1] because a commit preceding it[2] broke the build
but it wasn't clear what commit was responsible.

[1] 02b693a45db96bd2baf27c1d5128a8bcedb8fbfc
[2] 4656eadfa5ae1237036a63ad4004dbee4572debf

2 files changed, 32 insertions, 0 deletions

diff --git a/tests/isolated/patcher_socketserver_selectors.py b/tests/isolated/patcher_socketserver_selectors.py
new file mode 100644
index 0000000..97df6e2
--- /dev/null
+++ b/tests/isolated/patcher_socketserver_selectors.py
@@ -0,0 +1,28 @@
+if __name__ == '__main__':
+    import eventlet
+    eventlet.monkey_patch()
+
+    from eventlet.support.six.moves.BaseHTTPServer import (
+        HTTPServer,
+        BaseHTTPRequestHandler,
+    )
+    import threading
+
+    server = HTTPServer(('localhost', 0), BaseHTTPRequestHandler)
+    thread = threading.Thread(target=server.serve_forever)
+
+    # Before fixing it the code would never go pass this line because:
+    # * socketserver.BaseServer that's used behind the scenes here uses
+    #   selectors.PollSelector if it's available and we don't have green poll
+    #   implementation so this just couldn't work
+    # * making socketserver use selectors.SelectSelector wasn't enough as
+    #   until now we just failed to monkey patch selectors module
+    #
+    # Due to the issues above this thread.start() call effectively behaved
+    # like calling server.serve_forever() directly in the current thread
+    #
+    # Original report: https://github.com/eventlet/eventlet/issues/249
+    thread.start()
+
+    server.shutdown()
+    print('pass')
diff --git a/tests/patcher_test.py b/tests/patcher_test.py
index 2e458c5..deae8ef 100644
--- a/tests/patcher_test.py
+++ b/tests/patcher_test.py
@@ -506,3 +506,7 @@ def test_threading_condition():
 
 def test_threading_join():
     tests.run_isolated('patcher_threading_join.py')
+
+
+def test_socketserver_selectors():
+    tests.run_isolated('patcher_socketserver_selectors.py')