Re: [PATCH] Add autoload-breakpoints [3/7] ReportAsync-doc

[Hui Zhu <hui_zhu@mentor.com>]

On 03/22/12 02:27, Eli Zaretskii wrote:
>> Date: Wed, 21 Mar 2012 15:23:02 +0800
>> From: Hui Zhu<hui_zhu@mentor.com>
>> CC:<gdb-patches@sourceware.org>,<stan_shebs@mentor.com>
>>
>>>>>> +The @value{GDBN} remote serial protocol includes @dfn{reportasync},
>>>>>> +packets that the stub can report status or do an operation in any time.
>>>>>
>>>>> I don't understand the "do an operation in any time" part.  What does
>>>>> it mean in practice?
>>>>
>>>> It is means that after gdb connected with the stub, the stub can report
>>>> when the inferior is running and GDB is waiting it, or inferior is
>>>> stoped and GDB just control it.
>>>> It make the stub can report the status for any time.
>>>
>>> You mean, as in "asynchronously"?
>>
>> Yes, that is my mean.
>
> Then please use
>
>   The @value{GDBN} remote serial protocol supports @dfn{reportasync}
>   that can be used asynchronously to report status or send commands.
>
>>> I still don't understand why you used the word "simple".  "Simple" as
>>> opposed to what other packet handling?
>>
>> Maybe "normal" is better. "Normal" as opposed to reportasync packets.
>
> "As usual" or "usual" would be better.  But see below.
>
>>>>>     After the handshake, the stub can send @samp{reportasync} packets to
>>>>>     @value{GDBN}, using the same packet format as in simple remote serial
>>>>>     protocol.
>>>>>
>>>>> Is this only for the failed handshake?  If so, perhaps we need to tell
>>>>> what happens when the handshake succeeds.
>>>>
>>>> No, this is for success.
>>>
>>> The problem here is that you again used "simple protocol", and before
>>> that you mentioned "simple packet" when the handshake failed.
>>>
>>> So this again boils down to the same question: why do you use the word
>>> "simple" in this context?
>>
>> Yes, it looks really odd even if change it to normal.  That is because
>> after shakes mode, the packet will use the normal format
>
> But you said
>
>    After the handshake, the stub can send @samp{reportasync} packets to
>    @value{GDBN}, using the same packet format as in simple remote serial
>    protocol.
>
> which actually tells me that the "normal" packets are _not_ in
> contrast with reportasync packets, since reportasync packets can be
> sent in the "normal format".  What am I missing?

Yes, after success shake hands, the stub will send packet in normal 
format to GDB.
If need, GDB will answer this packets in normal format.

For example:
static void
remote_reportasync_handler (struct remote_state *rs)
{
   int len;
   struct cleanup *old_chain
     = make_cleanup_restore_integer (&inside_reportasync_handler);

   /* Shake hands with remote part.  */
   serial_write (remote_desc, "^", 1);

   inside_reportasync_handler = 1;

   if (getpkt_sane (&rs->buf, &rs->buf_size, 0) < 0)
     return;

   if (remote_debug)
     fprintf_unfiltered (gdb_stdlog, "ReportAsync: %s\n", rs->buf);

   if (strncmp (rs->buf, "QBDP", strlen ("QBDP")) == 0)
     {
       if (parse_autoload_breakpoint_definition_to_breakpoints
	      (rs->buf + strlen ("QBDP")) == 0)
	putpkt ("OK");
       else
	putpkt ("E01");
     }
   else
     putpkt ("");

   do_cleanups (old_chain);
}

This function will be call when GDB got a ^ and is OK to shake hands.
It call serial_write (remote_desc, "^", 1); to shake hands.  Then call 
getpkt_sane to get the package from the stub.  And use putpkt reply.

Thanks,
Hui