1 files changed, 16 insertions, 10 deletions
diff --git a/Lib/threading.py b/Lib/threading.py
index 6c34d49782..415a993b0a 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -10,6 +10,12 @@ except ImportError:
     from time import time as _time
 from traceback import format_exc as _format_exc
 from _weakrefset import WeakSet
+try:
+    from _itertools import islice as _slice
+    from _collections import deque as _deque
+except ImportError:
+    from itertools import islice as _islice
+    from collections import deque as _deque
 
 # Note regarding PEP 8 compliant names
 #  This threading model was originally inspired by Java, and inherited
@@ -79,7 +85,7 @@ class _RLock:
     def acquire(self, blocking=True, timeout=-1):
         me = get_ident()
         if self._owner == me:
-            self._count = self._count + 1
+            self._count += 1
             return 1
         rc = self._block.acquire(blocking, timeout)
         if rc:
@@ -146,7 +152,7 @@ class Condition:
             self._is_owned = lock._is_owned
         except AttributeError:
             pass
-        self._waiters = []
+        self._waiters = _deque()
 
     def __enter__(self):
         return self._lock.__enter__()
@@ -216,14 +222,14 @@ class Condition:
     def notify(self, n=1):
         if not self._is_owned():
             raise RuntimeError("cannot notify on un-acquired lock")
-        __waiters = self._waiters
-        waiters = __waiters[:n]
-        if not waiters:
+        all_waiters = self._waiters
+        waiters_to_notify = _deque(_islice(all_waiters, n))
+        if not waiters_to_notify:
             return
-        for waiter in waiters:
+        for waiter in waiters_to_notify:
             waiter.release()
             try:
-                __waiters.remove(waiter)
+                all_waiters.remove(waiter)
             except ValueError:
                 pass
 
@@ -261,7 +267,7 @@ class Semaphore:
                         break
             self._cond.wait(timeout)
         else:
-            self._value = self._value - 1
+            self._value -= 1
             rc = True
         self._cond.release()
         return rc
@@ -270,7 +276,7 @@ class Semaphore:
 
     def release(self):
         self._cond.acquire()
-        self._value = self._value + 1
+        self._value += 1
         self._cond.notify()
         self._cond.release()
 
@@ -506,7 +512,7 @@ class BrokenBarrierError(RuntimeError): pass
 _counter = 0
 def _newname(template="Thread-%d"):
     global _counter
-    _counter = _counter + 1
+    _counter += 1
     return template % _counter
 
 # Active thread administration