Restore check of the absolute number of children against maxSpare and

document rationale.

1 files changed, 6 insertions, 2 deletions

diff --git a/flup/server/preforkserver.py b/flup/server/preforkserver.py
index b7b2ff1..4c50e8c 100644
--- a/flup/server/preforkserver.py
+++ b/flup/server/preforkserver.py
@@ -126,8 +126,12 @@ class PreforkServer(object):
         
         # Main loop.
         while self._keepGoing:
-            # Maintain minimum number of children.
-            while len(self._children) < self._minSpare:
+            # Maintain minimum number of children. Note that we are checking
+            # the absolute number of children, not the number of "available"
+            # children. We explicitly test against _maxSpare to maintain
+            # an *optimistic* absolute minimum. The number of children will
+            # always be in the range [_maxSpare, _maxChildren].
+            while len(self._children) < self._maxSpare:
                 if not self._spawnChild(sock): break
 
             # Wait on any socket activity from live children.