id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
5797	readRawBufferPtr cannot be interrupted by exception on Windows with -threaded	joeyadams		"On Windows, in a program compiled with -threaded, if a thread receives from a Handle created by the network package (e.g. with hGetLine), it cannot be interrupted by an asynchronous exception.

I've traced it down to readRawBufferPtr, which is used by Network.Socket.recv.  Although I haven't tested readRawBufferPtr directly, my test case (attached) tests Network.Socket.recv.

For Windows, base 4.4.1.0 implements it as:

{{{
readRawBufferPtr :: String -> FD -> Ptr Word8 -> Int -> CSize -> IO CInt
readRawBufferPtr loc !fd buf off len
  | threaded  = blockingReadRawBufferPtr loc fd buf off len
  | otherwise = asyncReadRawBufferPtr    loc fd buf off len

...

blockingReadRawBufferPtr :: String -> FD -> Ptr Word8 -> Int -> CSize -> IO CInt
blockingReadRawBufferPtr loc fd buf off len
  = fmap fromIntegral $ throwErrnoIfMinus1Retry loc $
        if fdIsSocket fd
           then c_safe_recv (fdFD fd) (buf `plusPtr` off) len 0
           else c_safe_read (fdFD fd) (buf `plusPtr` off) len

...

-- NOTE: ""safe"" versions of the read/write calls for use by the threaded RTS.
-- These calls may block, but that's ok.

foreign import stdcall safe ""recv""
   c_safe_recv :: CInt -> Ptr Word8 -> CSize -> CInt{-flags-} -> IO CSsize

foreign import stdcall safe ""send""
   c_safe_send :: CInt -> Ptr Word8 -> CSize -> CInt{-flags-} -> IO CSsize
}}}

If I understand correctly, safe foreign calls cannot be interrupted by asynchronous exceptions.

Is this a bug in readRawBufferPtr, or a bug in the network package?  Can a caller expect readRawBufferPtr to be interruptible by an exception?"	bug	new	normal	_|_	libraries/base	7.2.2				Windows	x86	Incorrect result at runtime	Unknown