diff --git a/eventlet/coros.py b/eventlet/coros.py
index b0db19e..f4242bc 100644
--- a/eventlet/coros.py
+++ b/eventlet/coros.py
@@ -6,6 +6,7 @@ import warnings
 from eventlet import api
 from eventlet import hubs
 from eventlet import greenthread
+from eventlet import semaphore as semaphoremod
 
 class NOT_USED:
     def __repr__(self):
@@ -27,137 +28,22 @@ def event(*a, **kw):
     return greenthread.Event(*a, **kw)
 
 
-class Semaphore(object):
-    """An unbounded semaphore.
-    Optionally initialize with a resource *count*, then :meth:`acquire` and
-    :meth:`release` resources as needed. Attempting to :meth:`acquire` when
-    *count* is zero suspends the calling coroutine until *count* becomes
-    nonzero again.
-    """
-
-    def __init__(self, count=0):
-        self.counter  = count
-        self._waiters = set()
-
-    def __repr__(self):
-        params = (self.__class__.__name__, hex(id(self)), self.counter, len(self._waiters))
-        return '<%s at %s c=%s _w[%s]>' % params
-
-    def __str__(self):
-        params = (self.__class__.__name__, self.counter, len(self._waiters))
-        return '<%s c=%s _w[%s]>' % params
-
-    def locked(self):
-        return self.counter <= 0
-
-    def bounded(self):
-        # for consistency with BoundedSemaphore
-        return False
-
-    def acquire(self, blocking=True):
-        if not blocking and self.locked():
-            return False
-        if self.counter <= 0:
-            self._waiters.add(api.getcurrent())
-            try:
-                while self.counter <= 0:
-                    hubs.get_hub().switch()
-            finally:
-                self._waiters.discard(api.getcurrent())
-        self.counter -= 1
-        return True
-
-    def __enter__(self):
-        self.acquire()
-
-    def release(self, blocking=True):
-        # `blocking' parameter is for consistency with BoundedSemaphore and is ignored
-        self.counter += 1
-        if self._waiters:
-            hubs.get_hub().schedule_call_global(0, self._do_acquire)
-        return True
-
-    def _do_acquire(self):
-        if self._waiters and self.counter>0:
-            waiter = self._waiters.pop()
-            waiter.switch()
-
-    def __exit__(self, typ, val, tb):
-        self.release()
-
-    @property
-    def balance(self):
-        # positive means there are free items
-        # zero means there are no free items but nobody has requested one
-        # negative means there are requests for items, but no items
-        return self.counter - len(self._waiters)
-
-
-class BoundedSemaphore(object):
-    """A bounded semaphore.
-    Optionally initialize with a resource *count*, then :meth:`acquire` and
-    :meth:`release` resources as needed. Attempting to :meth:`acquire` when
-    *count* is zero suspends the calling coroutine until count becomes nonzero
-    again.  Attempting to :meth:`release` after *count* has reached *limit*
-    suspends the calling coroutine until *count* becomes less than *limit*
-    again.
-    """
-    def __init__(self, count, limit):
-        if count > limit:
-            # accidentally, this also catches the case when limit is None
-            raise ValueError("'count' cannot be more than 'limit'")
-        self.lower_bound = Semaphore(count)
-        self.upper_bound = Semaphore(limit-count)
-
-    def __repr__(self):
-        params = (self.__class__.__name__, hex(id(self)), self.balance, self.lower_bound, self.upper_bound)
-        return '<%s at %s b=%s l=%s u=%s>' % params
-
-    def __str__(self):
-        params = (self.__class__.__name__, self.balance, self.lower_bound, self.upper_bound)
-        return '<%s b=%s l=%s u=%s>' % params
-
-    def locked(self):
-        return self.lower_bound.locked()
-
-    def bounded(self):
-        return self.upper_bound.locked()
-
-    def acquire(self, blocking=True):
-        if not blocking and self.locked():
-            return False
-        self.upper_bound.release()
-        try:
-            return self.lower_bound.acquire()
-        except:
-            self.upper_bound.counter -= 1
-            # using counter directly means that it can be less than zero.
-            # however I certainly don't need to wait here and I don't seem to have
-            # a need to care about such inconsistency
-            raise
-
-    def __enter__(self):
-        self.acquire()
-
-    def release(self, blocking=True):
-        if not blocking and self.bounded():
-            return False
-        self.lower_bound.release()
-        try:
-            return self.upper_bound.acquire()
-        except:
-            self.lower_bound.counter -= 1
-            raise
-
-    def __exit__(self, typ, val, tb):
-        self.release()
-
-    @property
-    def balance(self):
-        return self.lower_bound.balance - self.upper_bound.balance
+def Semaphore(count):
+    warnings.warn("The Semaphore class has moved!  Please "
+        "use semaphore.Semaphore instead.", 
+        DeprecationWarning, stacklevel=2)
+    return semaphoremod.Semaphore(count)
 
+def BoundedSemaphore(count):
+    warnings.warn("The BoundedSemaphore class has moved!  Please "
+        "use semaphore.BoundedSemaphore instead.", 
+        DeprecationWarning, stacklevel=2)
+    return semaphoremod.BoundedSemaphore(count)
 
 def semaphore(count=0, limit=None):
+    warnings.warn("coros.semaphore is deprecated.  Please use either "
+        "semaphore.Semaphore or semaphore.BoundedSemaphore instead.", 
+        DeprecationWarning, stacklevel=2)
     if limit is None:
         return Semaphore(count)
     else:
diff --git a/eventlet/green/thread.py b/eventlet/green/thread.py
index 449aaf3..b5fe8fb 100644
--- a/eventlet/green/thread.py
+++ b/eventlet/green/thread.py
@@ -2,7 +2,7 @@
 __thread = __import__('thread')
 from eventlet.support import greenlets as greenlet
 from eventlet.api import spawn
-from eventlet.coros import Semaphore as LockType
+from eventlet.semaphore import Semaphore as LockType
 
 error = __thread.error
 
diff --git a/eventlet/greenpool.py b/eventlet/greenpool.py
index c424cba..223dcbc 100644
--- a/eventlet/greenpool.py
+++ b/eventlet/greenpool.py
@@ -1,7 +1,8 @@
 import itertools
 
-from eventlet import greenthread
 from eventlet import coros
+from eventlet import greenthread
+from eventlet import semaphore
 
 __all__ = ['GreenPool', 'GreenPile']
                 
@@ -20,7 +21,7 @@ class GreenPool(object):
     def __init__(self, size):
         self.size = size
         self.coroutines_running = set()
-        self.sem = coros.Semaphore(size)
+        self.sem = semaphore.Semaphore(size)
         self.no_coros_running = greenthread.Event()
             
     def resize(self, new_size):
diff --git a/eventlet/greenthread.py b/eventlet/greenthread.py
index 146115c..04d6930 100644
--- a/eventlet/greenthread.py
+++ b/eventlet/greenthread.py
@@ -13,8 +13,9 @@ def kill(g, *throw_args):
     By default, this exception is GreenletExit, but a specific exception
     may be specified in the *throw_args*.
     """
-    get_hub_().schedule_call_global(0, g.throw, *throw_args)
-    if getcurrent() is not get_hub_().greenlet:
+    hub = hubs.get_hub()
+    hub.schedule_call_global(0, g.throw, *throw_args)
+    if getcurrent() is not hub.greenlet:
         sleep(0)
 
 def sleep(seconds=0):
diff --git a/eventlet/semaphore.py b/eventlet/semaphore.py
new file mode 100644
index 0000000..3072a97
--- /dev/null
+++ b/eventlet/semaphore.py
@@ -0,0 +1,131 @@
+from eventlet import greenthread
+from eventlet import hubs
+
+class Semaphore(object):
+    """An unbounded semaphore.
+    Optionally initialize with a resource *count*, then :meth:`acquire` and
+    :meth:`release` resources as needed. Attempting to :meth:`acquire` when
+    *count* is zero suspends the calling coroutine until *count* becomes
+    nonzero again.
+    """
+
+    def __init__(self, count=0):
+        self.counter  = count
+        self._waiters = set()
+
+    def __repr__(self):
+        params = (self.__class__.__name__, hex(id(self)), self.counter, len(self._waiters))
+        return '<%s at %s c=%s _w[%s]>' % params
+
+    def __str__(self):
+        params = (self.__class__.__name__, self.counter, len(self._waiters))
+        return '<%s c=%s _w[%s]>' % params
+
+    def locked(self):
+        return self.counter <= 0
+
+    def bounded(self):
+        # for consistency with BoundedSemaphore
+        return False
+
+    def acquire(self, blocking=True):
+        if not blocking and self.locked():
+            return False
+        if self.counter <= 0:
+            self._waiters.add(greenthread.getcurrent())
+            try:
+                while self.counter <= 0:
+                    hubs.get_hub().switch()
+            finally:
+                self._waiters.discard(greenthread.getcurrent())
+        self.counter -= 1
+        return True
+
+    def __enter__(self):
+        self.acquire()
+
+    def release(self, blocking=True):
+        # `blocking' parameter is for consistency with BoundedSemaphore and is ignored
+        self.counter += 1
+        if self._waiters:
+            hubs.get_hub().schedule_call_global(0, self._do_acquire)
+        return True
+
+    def _do_acquire(self):
+        if self._waiters and self.counter>0:
+            waiter = self._waiters.pop()
+            waiter.switch()
+
+    def __exit__(self, typ, val, tb):
+        self.release()
+
+    @property
+    def balance(self):
+        # positive means there are free items
+        # zero means there are no free items but nobody has requested one
+        # negative means there are requests for items, but no items
+        return self.counter - len(self._waiters)
+
+
+class BoundedSemaphore(object):
+    """A bounded semaphore.
+    Optionally initialize with a resource *count*, then :meth:`acquire` and
+    :meth:`release` resources as needed. Attempting to :meth:`acquire` when
+    *count* is zero suspends the calling coroutine until count becomes nonzero
+    again.  Attempting to :meth:`release` after *count* has reached *limit*
+    suspends the calling coroutine until *count* becomes less than *limit*
+    again.
+    """
+    def __init__(self, count, limit):
+        if count > limit:
+            # accidentally, this also catches the case when limit is None
+            raise ValueError("'count' cannot be more than 'limit'")
+        self.lower_bound = Semaphore(count)
+        self.upper_bound = Semaphore(limit-count)
+
+    def __repr__(self):
+        params = (self.__class__.__name__, hex(id(self)), self.balance, self.lower_bound, self.upper_bound)
+        return '<%s at %s b=%s l=%s u=%s>' % params
+
+    def __str__(self):
+        params = (self.__class__.__name__, self.balance, self.lower_bound, self.upper_bound)
+        return '<%s b=%s l=%s u=%s>' % params
+
+    def locked(self):
+        return self.lower_bound.locked()
+
+    def bounded(self):
+        return self.upper_bound.locked()
+
+    def acquire(self, blocking=True):
+        if not blocking and self.locked():
+            return False
+        self.upper_bound.release()
+        try:
+            return self.lower_bound.acquire()
+        except:
+            self.upper_bound.counter -= 1
+            # using counter directly means that it can be less than zero.
+            # however I certainly don't need to wait here and I don't seem to have
+            # a need to care about such inconsistency
+            raise
+
+    def __enter__(self):
+        self.acquire()
+
+    def release(self, blocking=True):
+        if not blocking and self.bounded():
+            return False
+        self.lower_bound.release()
+        try:
+            return self.upper_bound.acquire()
+        except:
+            self.lower_bound.counter -= 1
+            raise
+
+    def __exit__(self, typ, val, tb):
+        self.release()
+
+    @property
+    def balance(self):
+        return self.lower_bound.balance - self.upper_bound.balance
\ No newline at end of file
diff --git a/tests/test__coros_semaphore.py b/tests/semaphore_test.py
similarity index 62%
rename from tests/test__coros_semaphore.py
rename to tests/semaphore_test.py
index 81eb869..131c0be 100644
--- a/tests/test__coros_semaphore.py
+++ b/tests/semaphore_test.py
@@ -1,28 +1,30 @@
 import unittest
-from eventlet import api, coros
+import eventlet
+from eventlet import semaphore
 from tests import LimitedTestCase
 
 class TestSemaphore(LimitedTestCase):
-
     def test_bounded(self):
-        # this was originally semaphore's doctest
-        sem = coros.BoundedSemaphore(2, limit=3)
+        sem = semaphore.BoundedSemaphore(2, limit=3)
         self.assertEqual(sem.acquire(), True)
         self.assertEqual(sem.acquire(), True)
-        api.spawn(sem.release)
+        gt1 = eventlet.spawn(sem.release)
         self.assertEqual(sem.acquire(), True)
         self.assertEqual(-3, sem.balance)
         sem.release()
         sem.release()
         sem.release()
-        api.spawn(sem.acquire)
+        gt2 = eventlet.spawn(sem.acquire)
         sem.release()
         self.assertEqual(3, sem.balance)
+        gt1.wait()
+        gt2.wait()
    
     def test_bounded_with_zero_limit(self):
-        sem = coros.semaphore(0, 0)
-        api.spawn(sem.acquire)
+        sem = semaphore.BoundedSemaphore(0, 0)
+        gt = eventlet.spawn(sem.acquire)
         sem.release()
+        gt.wait()
 
 
 if __name__=='__main__':