Re: EPICS Base 3.15.8: Name resolution requests directed to non-existing hosts block CA Server

["Johnson, Andrew N. via Core-talk" <core-talk at aps.anl.gov>]

On Jun 4, 2021, at 8:24 AM, Michael Davidsaver via Core-talk <core-talk at aps.anl.gov> wrote:

On 6/4/21 1:50 AM, Goetz Pfeiffer via Core-talk wrote:

We provide the "MSG_DONTWAIT" flag to the "sendto" call. By this, sendto never blocks even if internal

UDP buffers are full.

I have added a patch file for this to this e-mail.

I don't see any issue with this change, though I would format it as:

#ifndef MSG_DONTWAIT
#  define MSG_DONTWAIT (0)
#endif

Both VxWorks 5.5 and MacOS define MSG_DONTWAIT in sys/socket.h but in the MacOSX SDK it's inside this conditional:

#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)

#define MSG_DONTWAIT    0x80            /* this message should be nonblocking */

I doubt that _POSIX_C_SOURCE is defined so I think the flag should be available there, but Michael’s conditional is a good idea anyway.

- Andrew

-- 

Complexity comes for free, simplicity you have to work for.