[CentOS] CentOS 7 as a guest VM

Tue Dec 3 16:18:43 UTC 2019
David G. Miller <dave at davenjudy.org>

On 12/3/19 8:46 AM, Jerry Geis wrote:
> I am experiencing an issue that my process does not wake out of a select()
> call when a single character is received in an input file descriptor when
> running as a VMware guest.
>
> Anyone ever experienced this ?
>
> I can run tshark and see the character arrive, but my process does not wake
> up and see that character. Most times it works - but once in a while it
> does not.
>
> So I made a change on my code - and did not just wait on select() - but
> just try to read the buffer all the time and print the results.  once in a
> while that character is "delayed" getting to my input buffer.  Top reports
> the machine is 99% idle.
>
> Any thoughts?
>
> Jerry
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You don't say what the app is written in but I ran into this with perl.  
perl apps can either be line buffered or character buffered ($| if I 
remember right is the switch).  Line buffered means the buffer is not 
delivered until a newline character is received.  If nothing else, try 
"<char>\n" and see if that gets consistently delivered.

Cheers,
Dave

-- 
"They that can give up essential liberty to obtain a little temporary safety deserve neither safety nor liberty."

-- Benjamin Franklin