On Fri, Sep 07, 2012 at 01:43:29PM +0900, UMEZAWA Takeshi wrote:
> I have added send(2) MSG_DONTWAIT support, which enables us to choose
> nonblocking or blocking for each send(2) call.
I think this diff is OK.
Does anyone know why SS_NBIO and MSG_DONTWAIT are not used identically
in sosend() and soreceive()? Especially locking the socket buffer
sblock() with SS_NBIO is different in sosend() and soreceive().
Should't SS_NBIO and MSG_DONTWAIT be evaluated consistently everywhere?
bluhm
> diff --git a/lib/libc/sys/send.2 b/lib/libc/sys/send.2
> index d58588f..b3b8d93 100644
> --- a/lib/libc/sys/send.2
> +++ b/lib/libc/sys/send.2
> @@ -103,6 +103,8 @@ bypass routing, use direct interface
> .It Dv MSG_NOSIGNAL
> don't send
> .Dv SIGPIPE
> +.It Dv MSG_DONTWAIT
> +don't block
> .El
> .Pp
> The flag
> diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
> index 653de7d..10ef153 100644
> --- a/sys/kern/uipc_socket.c
> +++ b/sys/kern/uipc_socket.c
> @@ -451,7 +451,7 @@ restart:
> snderr(EMSGSIZE);
> if (space < resid + clen &&
> (atomic || space < so->so_snd.sb_lowat || space < clen)) {
> - if (so->so_state & SS_NBIO)
> + if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT))
> snderr(EWOULDBLOCK);
> sbunlock(&so->so_snd);
> error = sbwait(&so->so_snd);
