Issue #13373: multiprocessing.Queue.get() could sometimes block indefinitely

pitrou · pitrou · commit 021572431ba0 · 2011-11-10T00:38:25.000+01:00
when called with a timeout.  Patch by Arnaud Ysmal.
diff --git a/Lib/multiprocessing/queues.py b/Lib/multiprocessing/queues.py
@@ -129,7 +129,11 @@ def get(self, block=True, timeout=None):
             if not self._rlock.acquire(block, timeout):
                 raise Empty
             try:
-                if not self._poll(block and (deadline-time.time()) or 0.0):
+                if block:
+                    timeout = deadline - time.time()
+                    if timeout < 0 or not self._poll(timeout):
+                        raise Empty
+                elif not self._poll():
                     raise Empty
                 res = self._recv()
                 self._sem.release()
diff --git a/Misc/ACKS b/Misc/ACKS
@@ -1068,6 +1068,7 @@ Bob Yodlowski
 Danny Yoo
 George Yoshida
 Masazumi Yoshikawa
+Arnaud Ysmal
 Bernard Yue
 Moshe Zadka
 Milan Zamazal
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -365,6 +365,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #13373: multiprocessing.Queue.get() could sometimes block indefinitely
+  when called with a timeout.  Patch by Arnaud Ysmal.
+
 - Issue #13254: Fix Maildir initialization so that maildir contents
   are read correctly.
 
