Re: [PATCH] close.2: Mention a need of shutdown before closing socket

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Lukas,

On Mon, Aug 29, 2011 at 2:26 PM, Lukas Czerner <lczerner@xxxxxxxxxx> wrote:
> When dealing with sockets, we have to be sure that there is no recv
> still blocking on it on another thread, otherwise it might block forever,
> since no more messages will be send via the socket. We should advice to
> use shutdown before closing socket.

As far as I know, in the usual case, a simple close() is sufficient.
Can you say some more about how you determined the above statement and
in what circumstances it applies?

Thanks,

Michael


> Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx>
> ---
>  man2/close.2 |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/man2/close.2 b/man2/close.2
> index a2a2961..02472f3 100644
> --- a/man2/close.2
> +++ b/man2/close.2
> @@ -114,6 +114,13 @@ other threads in the same process.
>  Since a file descriptor may be reused,
>  there are some obscure race conditions
>  that may cause unintended side effects.
> +.PP
> +When dealing with sockets, you have to be sure that there is no
> +.BR recv (2)
> +still blocking on it on another thread, otherwise it might block forever,
> +since no more messages will be send via the socket. Be sure to use
> +.BR shutdown (2)
> +to shut down all parts the connection before closing the socket.
>  .\" Date: Tue, 4 Sep 2007 13:57:35 +0200
>  .\" From: Fredrik Noring <noring@xxxxxxxxxx>
>  .\" One such race involves signals and ERESTARTSYS. If a file descriptor
> --
> 1.7.4.4
>
>



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface"; http://man7.org/tlpi/
--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Kernel Documentation]     [Netdev]     [Linux Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux