from socket import error as SocketError
try:
from select import poll, POLLIN
except ImportError: # `poll` doesn't exist on OSX and other platforms
poll = False
try:
from select import select
except ImportError: # `select` doesn't exist on AppEngine.
select = False
def is_connection_dropped(conn): # Platform-specific
"""
Returns True if the connection is dropped and should be closed.
:param conn:
:class:`httplib.HTTPConnection` object.
Note: For platforms like AppEngine, this will always return ``False`` to
let the platform handle connection recycling transparently for us.
"""
sock = getattr(conn, 'sock', False)
if sock is False: # Platform-specific: AppEngine
return False
if sock is None: # Connection already closed (such as by httplib).
return False
if not poll:
if not select: # Platform-specific: AppEngine
return False
try:
return select([sock], [], [], 0.0)[0]
except SocketError:
return True
# This version is better on platforms that support it.
p = poll()
p.register(sock, POLLIN)
for (fno, ev) in p.poll(0.0):
if fno == sock.fileno():
# Either data is buffered (bad), or the connection is dropped.
return True