# Re: udp\_recvmsg: possible bug causing infinite hang?

- From: Henrik Nordstrom \<hidden\>
- Date: 2004-10-12 08:56:26 
- List: netdev
- Page: https://ratatoskr.run/netdev/2004/10/10745065
- Thread: https://ratatoskr.run/netdev/2003/03/537766/t.md

```text
On Tue, 12 Oct 2004, Nagendra Singh Tomar wrote:

> checksumming. If the standard does not explicitly write anything about the
> guarantee of read/write passing after successful return from select, then
> its fine; but somehow that does not sound very rational.
> If anyone can point to the specific section in the POSIX standard that
> dictates this, it will be of great help.

>From SUSv3 on select():

      A descriptor shall be considered ready for reading when a
      call to an input function with O_NONBLOCK clear would not block,
      whether or not the function would transfer data successfully.
      (The function might return data, an end-of-file indication, or
      an error other than one indicating that it is blocked, and in
      each of these cases the descriptor shall be considered ready
      for reading.)

      A descriptor shall be considered ready for writing when a call
      to an output function with O_NONBLOCK clear would not block,
      whether or not the function would transfer data successfully.


so it seems to me the current Linux implementation is wrong in this regard.


Regards
Henrik
```