def send_impl(self, obj, channels=None):
data = util.pickle.dumps(obj)
# If no channels, just send the data.
if not channels:
self.sock.sendall(struct.pack('ii', len(data), 0))
self.sock.sendall(data)
return
# Construct the actual message.
buf = bytearray(data)
while len(buf) < 8:
# Work around a Python bug where we need at least 8 bytes.
buf.append(0)
# Send the data length and # of channels.
self.sock.sendall(struct.pack('ii', len(buf), len(channels)))
cmsg = cmsghdr_t(len(channels))
for index, channel in enumerate(channels):
cmsg.cmsg_data[index] = channel.fd
buffer_t = ctypes.c_byte * len(buf)
iov_base = buffer_t.from_buffer(buf)
iovec = iovec_t()
iovec.iov_base = ctypes.addressof(iov_base)
iovec.iov_len = len(buf)
msg = msghdr_t()
msg.msg_name = None
msg.msg_namelen = 0
msg.msg_iov = ctypes.pointer(iovec)
msg.msg_iovlen = 1
msg.msg_control = ctypes.addressof(cmsg)
msg.msg_controllen = cmsg.cmsg_len
msg.msg_flags = 0
res = sendmsg(self.sock.fileno(), ctypes.pointer(msg), MSG_NOSIGNAL)
check_errno(res)
# On Linux, it's now safe to close all the channels we just sent.
if util.IsLinux():
for channel in channels:
channel.close()
MSG_CTRUNC = 0x20
def CMSG_NXTHDR(msg, cmsg):
cmsg_len = cmsg.contents.cmsg_len
if cmsg_len < ctypes.sizeof(cmsghdr_base_t):
return None
cmsg_len = Align(cmsg_len, ctypes.sizeof(ctypes.c_uint))
addr = ctypes.addressof(cmsg.contents) + cmsg_len
check = addr + Align(ctypes.sizeof(cmsghdr_base_t), ctypes.sizeof(ctypes.c_uint))
if check > msg.msg_control + msg.msg_controllen:
return None
return ctypes.cast(addr, cmsghdr_base_t_p)
elif util.IsLinux():
sLibC = ctypes.CDLL('libc.so.6', use_errno=True)
pid_t = ctypes.c_int
msg_socklen_t = ctypes.c_size_t
SOL_SOCKET = 1
SCM_RIGHTS = 1
MSG_NOSIGNAL = 0x4000
MSG_CTRUNC = 0x8
class posix_spawn_file_actions_t(ctypes.Structure):
_fields_ = [
('allocated', ctypes.c_int),
('used', ctypes.c_int),
('spawn_action', ctypes.c_void_p),
('pad', ctypes.c_int * 16)