PYTHON-933 - "maxPoolSize=0" allowed, causes hang.

Author: aherlihy

pymongo/common.py

@@ -140,15 +140,25 @@ def validate_integer(option, value):
 
 
 def validate_positive_integer(option, value):
- """Validate that 'value' is a positive integer.
+ """Validate that 'value' is a positive integer, which does not include 0.
  """
  val = validate_integer(option, value)
- if val < 0:
+ if val <= 0:
  raise ValueError("The value of %s must be "
  "a positive integer" % (option,))
  return val
 
 
+def validate_non_negative_integer(option, value):
+ """Validate that 'value' is a positive integer or 0.
+ """
+ val = validate_integer(option, value)
+ if val < 0:
+ raise ValueError("The value of %s must be "
+ "a non negative integer" % (option,))
+ return val
+
+
 def validate_readable(option, value):
  """Validates that 'value' is file-like and readable.
  """
@@ -169,6 +179,14 @@ def validate_positive_integer_or_none(option, value):
  return validate_positive_integer(option, value)
 
 
+def validate_non_negative_integer_or_none(option, value):
+ """Validate that 'value' is a positive integer or 0 or None.
+ """
+ if value is None:
+ return value
+ return validate_non_negative_integer(option, value)
+
+
 def validate_string(option, value):
  """Validates that 'value' is an instance of `basestring` for Python 2
  or `str` for Python 3.
@@ -392,7 +410,7 @@ def validate_ok_for_update(update):
  'socketkeepalive': validate_boolean_or_string,
  'sockettimeoutms': validate_timeout_or_none,
  'waitqueuetimeoutms': validate_timeout_or_none,
- 'waitqueuemultiple': validate_positive_integer_or_none,
+ 'waitqueuemultiple': validate_non_negative_integer_or_none,
  'ssl': validate_boolean_or_string,
  'ssl_keyfile': validate_readable,
  'ssl_certfile': validate_readable,

pymongo/mongo_client.py

@@ -117,7 +117,7 @@ def __init__(
  - `maxPoolSize` (optional): The maximum number of connections
  that the pool will open simultaneously. If this is set, operations
  will block if there are `maxPoolSize` outstanding connections
- from the pool. Defaults to 100.
+ from the pool. Defaults to 100. Cannot be 0.
  - `socketTimeoutMS`: (integer or None) Controls how long (in
  milliseconds) the driver will wait for a response after sending an
  ordinary (non-monitoring) database operation before concluding that

test/test_client.py

@@ -121,6 +121,10 @@ def test_types(self):
 
  self.assertRaises(ConfigurationError, MongoClient, [])
 
+ def test_max_pool_size_zero(self):
+ with self.assertRaises(ValueError):
+ MongoClient(maxPoolSize=0)
+
  def test_get_db(self):
  def make_db(base, name):
  return base[name]

test/test_pooling.py

@@ -428,6 +428,10 @@ def f():
  self.assertEqual(nthreads, self.n_passed)
  self.assertTrue(len(cx_pool.sockets) > 1)
 
+ def test_max_pool_size_zero(self):
+ with self.assertRaises(ValueError):
+ rs_or_single_client(maxPoolSize=0)
+
  def test_max_pool_size_with_connection_failure(self):
  # The pool acquires its semaphore before attempting to connect; ensure
  # it releases the semaphore on connection failure.