[ECOS] Re: remote syslog support in Redboot?

[Grant Edwards <grante@visi.com>]

On 2007-05-10, Gary Thomas <gary@mlbassoc.com> wrote:

>>>> Has anyone implemented the ability to have diag_printf()
>>>> messages be sent to a remote syslog server in Redboot/ecos?
>>>
>>> You will have to be careful when doing this. diag_printf()
>>> uses a very simple polled IO, blocking serial device driver.
>>> The idea is that it should always work, in any context. So you
>>> can do a diag_printf() in an ISR or a DSR, not just a thread.
>>> It is also guaranteed the output will be out the serial port
>>> before diag_printf() returns.
>> 
>> How is this guaranteed if I connect to Redboot on tcp port
>> 9000?
>
> RedBoot uses a polled TCP connection, thus when you make a
> call to diag_printf() that channels through RedBoot, it _will_
> complete at the receiver before continuing.

I've wondered about that.  

The comment for __tcp_write_block() says that it blocks until
sent.  What it appears to do by calling __tcp_drain() (and what
is implied by your statement above) is that it blocks until the
data is _ACKed_ not until the data is _sent_.

-- 
Grant Edwards                   grante             Yow! My BIOLOGICAL ALARM
                                  at               CLOCK just went off ... It
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