Stop accessing private _links variable.

src/gevent/greenlet.pxd

@@ -36,15 +36,14 @@ cdef class Greenlet(greenlet):
     cdef public dict spawn_tree_locals
 
     cdef readonly _Frame spawning_stack
-    # A test case reads this, otherwise they would
-    # be private
-    cdef readonly list _links
 
-    cdef object tuple _exc_info
+    cdef list _links
+    cdef tuple _exc_info
     cdef object _notifier
     cdef object _start_event
     cdef dict _kwargs
 
+    cpdef bint has_links(self)
 
     cdef bint __started_but_aborted(self)
     cdef bint __start_cancelled_by_kill(self)

src/gevent/greenlet.py

@@ -674,6 +674,9 @@ class Greenlet(greenlet):
         # pylint: disable=method-hidden
         return
 
+    def has_links(self):
+        return len(self._links)
+
     def rawlink(self, callback):
         """Register a callable to be executed when the greenlet finishes execution.
 
@@ -708,6 +711,14 @@ class Greenlet(greenlet):
         except ValueError:
             pass
 
+    def unlink_all(self):
+        """
+        Remove all the callbacks.
+
+        .. versionadded:: 1.3a2
+        """
+        del self._links[:]
+
     def link_value(self, callback, SpawnedLink=SuccessSpawnedLink):
         """
         Like :meth:`link` but *callback* is only notified when the greenlet

src/greentest/test__greenlet.py

@@ -96,14 +96,17 @@ class TestUnlink(greentest.TestCase):
 
     def _test_func(self, p, link):
         link(dummy_test_func)
-        assert len(p._links) == 1, p._links
+        self.assertEqual(1, p.has_links())
+
         p.unlink(dummy_test_func)
-        assert not p._links, p._links
+        self.assertEqual(0, p.has_links())
 
         link(self.setUp)
-        assert len(p._links) == 1, p._links
+        self.assertEqual(1, p.has_links())
+
         p.unlink(self.setUp)
-        assert not p._links, p._links
+        self.assertEqual(0, p.has_links())
+
         p.kill()
 
     def test_func_link(self):
@@ -170,8 +173,7 @@ class TestReturn_link(LinksTestCase):
     p = None
 
     def cleanup(self):
-        while self.p._links:
-            self.p._links.pop()
+        self.p.unlink_all()
         self.p = None
 
     def test_return(self):

src/greentest/test__local.py

@@ -273,7 +273,7 @@ class GeventLocalTestCase(greentest.TestCase):
             self.assertEqual(count, len(deleted_sentinels))
 
             # The links were removed as well.
-            self.assertEqual(list(running_greenlet._links), [])
+            self.assertFalse(running_greenlet.has_links())
 
 
         running_greenlet = gevent.spawn(demonstrate_my_local)