Using a wait-group seems to properly sync the threads for buffer depletion

1 files changed, 31 insertions, 1 deletions

diff --git a/git/util.py b/git/util.py
index 34b09d32..e211ca41 100644
--- a/git/util.py
+++ b/git/util.py
@@ -12,6 +12,7 @@ import stat
 import shutil
 import platform
 import getpass
+import threading
 
 # NOTE:  Some of the unused imports might be used/imported by others.
 # Handle once test-cases are back up and running.
@@ -32,7 +33,7 @@ from gitdb.util import (  # NOQA
 __all__ = ("stream_copy", "join_path", "to_native_path_windows", "to_native_path_linux",
            "join_path_native", "Stats", "IndexFileSHA1Writer", "Iterable", "IterableList",
            "BlockingLockFile", "LockFile", 'Actor', 'get_user_id', 'assure_directory_exists',
-           'RemoteProgress', 'rmtree')
+           'RemoteProgress', 'rmtree', 'WaitGroup')
 
 #{ Utility Methods
 
@@ -699,3 +700,32 @@ class Iterable(object):
         raise NotImplementedError("To be implemented by Subclass")
 
 #} END classes
+
+
+class WaitGroup(object):
+    """WaitGroup is like Go sync.WaitGroup.
+    
+    Without all the useful corner cases.
+    By Peter Teichman, taken from https://gist.github.com/pteichman/84b92ae7cef0ab98f5a8
+    """
+    def __init__(self):
+        self.count = 0
+        self.cv = threading.Condition()
+ 
+    def add(self, n):
+        self.cv.acquire()
+        self.count += n
+        self.cv.release()
+ 
+    def done(self):
+        self.cv.acquire()
+        self.count -= 1
+        if self.count == 0:
+            self.cv.notify_all()
+        self.cv.release()
+ 
+    def wait(self):
+        self.cv.acquire()
+        while self.count > 0:
+            self.cv.wait()
+        self.cv.release()