From 2c22c418199d6b5e8d005250c28f26f70b21ce5d Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Tue, 20 Mar 2018 13:01:26 +0545
Subject: [PATCH] issue #156: don't decrement `waking` if we timed out rather
 than being woken.

---
 docs/howitworks.rst | 6 +++---
 mitogen/core.py     | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/docs/howitworks.rst b/docs/howitworks.rst
index 4710b2f4..ec736758 100644
--- a/docs/howitworks.rst
+++ b/docs/howitworks.rst
@@ -925,9 +925,9 @@ item.
     :py:meth:`mitogen.core.Latch.put`.
 
 **4. Wake, Non-empty**
-    On wake it re-acquires `lock`, removes itself from `sleeping`, decrementing
-    `waking`, throws :py:class:`mitogen.core.TimeoutError` if no byte was
-    written, otherwise pops and returns the first item in `queue` that is
+    On wake it re-acquires `lock`, removes itself from `sleeping`, throws
+    :py:class:`mitogen.core.TimeoutError` if no byte was written, decrements
+    `waking`,  then pops and returns the first item in `queue` that is
     guaranteed to exist.
 
 
diff --git a/mitogen/core.py b/mitogen/core.py
index b9dd1488..7617be26 100644
--- a/mitogen/core.py
+++ b/mitogen/core.py
@@ -957,11 +957,11 @@ class Latch(object):
         self._lock.acquire()
         try:
             self._sleeping.remove(_tls.wsock)
-            self._waking -= 1
             if self.closed:
                 raise LatchError()
             if not rfds:
                 raise TimeoutError()
+            self._waking -= 1
             if _tls.rsock.recv(2) != '\x7f':
                 raise LatchError('internal error: received >1 wakeups')
             try: