Re: Why does "target remote" to a non-stop target stop one thread

[Jeremy Bennett <jeremy dot bennett at embecosm dot com>]

On 28/06/13 10:14, Yao Qi wrote:
> On 06/28/2013 04:38 AM, Jeremy Bennett wrote:
>> hen I connect to the target, even in non-stop mode, it insists on
>> stopping one thread. The comment in notice_new_inferior () is:
>>
>>> >       /* We're going to install breakpoints, and poke at memory,
>>> >     ensure that the inferior is stopped for a moment while we do
>>> >     that.  */
>> My question is, why we need to stop any thread. Surely the whole point
>> of non-stop mode is that we don't generally want to stop any threads if
>> it can be avoided.
> 
> Hi Jeremy,
> AFAIK, "non-stop" means when GDB is examining one stopped thread while
> other threads are _not stopped_.
> 
> See
> http://sourceware.org/gdb/onlinedocs/gdb/Non_002dStop-Mode.html#Non_002dStop-Mode
> 
> 
> GDB needs the thread stopped because ptrace can't be performed on the
> running thread.
> 
Hi Yao,

Thanks for the explanation. Since I am working on a RTOS that does not
use ptrace, and can perform actions on running threads, I don't need to
stop. So it looks like something like the patch suggested by Raphael
Zulliger that makes this configurable depending on the target would be a
useful.

I'll work on this.


Jeremy

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