Questions on vCont

Questions on vCont

[Vardhana, Ananda]

'vCont[;action[:thread-id]]...'

      Resume the inferior, specifying different actions for each thread. If an action is specified with no thread-id, then it is applied to any thread s that don't have a specific action specified;
 if no default action is specified then other threads should remain stopped in all-stop mode and in their current state in non-stop mode. Specifying multiple default actions is an error; specifying no actions is also an error. Thread IDs are specified using the syntax described in thread-id
syntax<https://sourceware.org/gdb/onlinedocs/gdb/Packets.html>.

Could some kind folk clear up some of my doubts:

1.      "Resume the inferior, specifying different actions for each thread" --> what does this first sentence mean? What does word inferior mean in this context?
2.      "Specifying multiple default actions is an error" -->   Please give me couple of examples.
3.      "specifying no actions is also an error". An example for this too please.
4.      Lastly please tell me what all commands I have specified here is wrong
a.      vCont;c:ab;c:cd --> ab, cd are thread id's
b.      vCont;c:12;s:23;t:45
c.      vCont;c:3;s:3 --> This is wrong for sure
d.      vCont;c-1 --> Putting anything after this wrong as we have continue on all processors


'C sig'

      Continue with signal sig. The signal sig should be two hex digits.
5.      What is the meaning of a signal in this context?
6.      Why is the name 'sig' not appearing in the usage shown above. Or why is it they talk only about thread-id only?
7.      Please give me an example of the usage syntax with signals?
8.      I hope the C sig & S sig are still a supported

'r start,end'

9.      Please give me a usage format for it. Would it be like r 0x12345678, 1234570C

If there is a web site where these kind of questions have been answered please point me to it.

Thanks in advance

Regards
Ananda

Re: Questions on vCont

[Sergio Durigan Junior]

Hi Ananda,

On Monday, June 09 2014, Ananda Vardhana wrote:

> Could some kind folk clear up some of my doubts:
>
> 1.      "Resume the inferior, specifying different actions for each thread" --> what does this first sentence mean? What does word inferior mean in this context?

Inferior is the GDB parlance for the program being debugged.

> 2.      "Specifying multiple default actions is an error" -->   Please give me couple of examples.

I have answered this one in private.

> 3.      "specifying no actions is also an error". An example for this too please.

Likewise.

> 4.      Lastly please tell me what all commands I have specified here is wrong
> a.      vCont;c:ab;c:cd --> ab, cd are thread id's
> b.      vCont;c:12;s:23;t:45
> c.      vCont;c:3;s:3 --> This is wrong for sure
> d.      vCont;c-1 --> Putting anything after this wrong as we have continue on all processors

On (d) you're missing a colon between "c" and "-1" (I think I already
answered this one before, too).

>
> 'C sig'
>
>       Continue with signal sig. The signal sig should be two hex digits.
> 5.      What is the meaning of a signal in this context?

Means a POSIX signal, like SIGINT.

> 6.      Why is the name 'sig' not appearing in the usage shown above. Or why is it they talk only about thread-id only?

Because the usage lists "action", whose definition gets expanded below.

> 8.      I hope the C sig & S sig are still a supported

I'm not sure I understand this last question.

> If there is a web site where these kind of questions have been answered please point me to it.

[I am not answering all questions from this message.]

The GDB documentation should answer your questions; if it does not, then
you can submit a patch improving it (please, do so!).  Also, an obvious
good source of documentation is the source code itself.  I answered some
of those questions in private (in reply to your message), and pointed
you to some functions that you might be interested in reading.

Cheers,

-- 
Sergio
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Please send encrypted e-mail if possible
http://blog.sergiodj.net/