Use NullContext when invoking certain greenlet switch operations

- Prevents StackContextInconsistentError from popping up

CHANGELOG.rst

@@ -1,3 +1,8 @@
+0.2.1 - 2016-04-19
+------------------
+* Fix :exc:`.StackContextInconsistentError` when using gyield inside of a
+  :class:`tornado.stack_context.StackContext` context block
+
 0.2.0 - 2016-04-06
 ------------------
 * Breaking change: Changed behavior of gyield timeout to throw, instead of

greenado/concurrent.py

@@ -21,6 +21,7 @@
 import greenlet
 
 from tornado import concurrent, gen
+from tornado.stack_context import NullContext
 from tornado.ioloop import IOLoop
 
 import logging
@@ -63,8 +64,9 @@ def greenlet_base():
         else:
             future.set_result(result)
 
-    gr = greenlet.greenlet(greenlet_base)        
-    gr.switch()
+    gr = greenlet.greenlet(greenlet_base)
+    with NullContext():
+        gr.switch()
 
     return future
 
@@ -171,8 +173,9 @@ def greenlet_base():
             else:
                 future.set_result(result)
 
-        gr = greenlet.greenlet(greenlet_base)        
-        gr.switch()
+        gr = greenlet.greenlet(greenlet_base)
+        with NullContext():
+            gr.switch()
 
         return future
 
@@ -204,8 +207,9 @@ def on_timeout():
 
     io_loop.add_timeout(io_loop.time() + timeout, on_timeout)
 
-    while not done[0]:
-        gr.parent.switch()
+    with NullContext():
+        while not done[0]:
+            gr.parent.switch()
 
 
 def gyield(future, timeout=None):
@@ -283,11 +287,13 @@ def on_complete(result):
             )
 
         io_loop.add_future(future, on_complete)
-        gr.parent.switch()
 
-        while not wait_future.done():
+        with NullContext():
             gr.parent.switch()
 
+            while not wait_future.done():
+                gr.parent.switch()
+
         wait_future.result()
 
     return future.result()

tests/test_greenado.py

@@ -1,9 +1,10 @@
 
+from contextlib import contextmanager
 import greenado
 
 import pytest
 
-from tornado import gen, concurrent
+from tornado import gen, concurrent, stack_context
 from tornado.ioloop import IOLoop
 import time
 
@@ -452,10 +453,73 @@ def test_gsleep_2():
     @greenado.groutine
     def _main():
         now = time.time()
-        greenado.gsleep(1)
-        assert time.time() > now + 1
+        greenado.gsleep(.5)
+        assert time.time() > now + .5
 
         return True
 
     main_retval = IOLoop.current().run_sync(_main)
     assert main_retval == True
+
+@contextmanager
+def _mgr():
+    yield
+
+def test_stack_context_gcall():
+
+    def _fn():
+        greenado.gsleep(0.1)
+        return True
+
+    @greenado.groutine
+    def _main():
+        with stack_context.StackContext(_mgr):
+            greenado.gyield(greenado.gcall(_fn))
+        return True
+
+    main_retval = IOLoop.current().run_sync(_main)
+    assert main_retval == True
+
+def test_stack_context_groutine():
+
+    @greenado.groutine
+    def _fn():
+        greenado.gsleep(0.1)
+        return True
+
+    @greenado.groutine
+    def _main():
+        with stack_context.StackContext(_mgr):
+            greenado.gyield(_fn())
+        return True
+
+    main_retval = IOLoop.current().run_sync(_main)
+    assert main_retval == True
+
+
+def test_stack_context_gsleep():
+
+    @greenado.groutine
+    def _main():
+        with stack_context.StackContext(_mgr):
+            greenado.gsleep(0.1)
+        return True
+
+    main_retval = IOLoop.current().run_sync(_main)
+    assert main_retval == True
+
+def test_stack_context_gyield_1():
+    @greenado.groutine
+    def _main():
+        f = gen.Future()
+
+        def _doit():
+            f.set_result(True)
+
+        IOLoop.current().spawn_callback(_doit)
+
+        with stack_context.StackContext(_mgr):
+            return greenado.gyield(f)
+
+    main_retval = IOLoop.current().run_sync(_main)
+    assert main_retval == True