dtrace discuss - Oct 2006 - data object sharing between DTRACE script and c program

Is there any method by which a DTRACE script and a user-defined C program can
share a data object?

I am looking for some method by which a C-program can access some buffer
allocated by DTRACE script.

Any help on it ? 

Vijay
 
 
This message posted from opensolaris.org

I suspect you''re looking for a more elegant way than this, but what 
about having your C program "popen" the DTrace program and capture the
recorded data as it''s being consumed.

And I suppose that data could flow the other way, if the D program had 
PID provider probes for the C program that invoked it.

Seems a bit sticky doesn''t it.  :-)

Chip

vijay meena wrote:
> Is there any method by which a DTRACE script and a user-defined C program
can share a data object?
>
> I am looking for some method by which a C-program can access some buffer
allocated by DTRACE script.
>
> Any help on it ? 
>
> Vijay
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>

I''d suggest you take a look at libdtrace but the library is still
private so you risk your application failing upon the next patch.
However, at least you get great examples like plockstat(1M) and
intrstat(1M).

On 10/11/06, Chip Bennett <cbennett at laurustech.com>
wrote:
> I suspect you''re looking for a more elegant way than this, but
what
> about having your C program "popen" the DTrace program and
capture the
> recorded data as it''s being consumed.
>
> And I suppose that data could flow the other way, if the D program had
> PID provider probes for the C program that invoked it.
>
> Seems a bit sticky doesn''t it.  :-)
>
> Chip
>
> vijay meena wrote:
> > Is there any method by which a DTRACE script and a user-defined C
program can share a data object?
> >
> > I am looking for some method by which a C-program can access some
buffer allocated by DTRACE script.
> >
> > Any help on it ?
> >
> > Vijay
> >
> >
> > This message posted from opensolaris.org
> > _______________________________________________
> > dtrace-discuss mailing list
> > dtrace-discuss at opensolaris.org
> >
>
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>

-- 
Just me,
Wire ...

Hi Vijay,

One of the powerful things about DTrace is that it allows you to write
scripts that emit whatever output you want. I''d argue that the best way
to have a C program interact with DTrace is to invoke the dtrace(1M)
command with a script that feeds your program the data it wants in a
convenient form (e.g. XML).

It''s possible to use libdtrace directly, but it''s not a stable
interface
and could (easily) break not just between releases of Solaris, but from
one nightly build to the next.

Adam

On Wed, Oct 11, 2006 at 02:57:12AM -0700, vijay meena
wrote:
> Is there any method by which a DTRACE script and a user-defined C program
can share a data object?
> 
> I am looking for some method by which a C-program can access some buffer
allocated by DTRACE script.
> 
> Any help on it ? 
> 
> Vijay
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Solaris Kernel Development       http://blogs.sun.com/ahl

Hi Adam.

Thanks for your suggestion. I like the idea of feeding the data from Dtrace
script to C  program but since the amount of data is more, I do not want to
create any intermediate disk file to pass this data to C program, because my
design cant afford  disk i/o.
If you could suggest me any other means of communication , like - socket
communication, shared memory between Dtrace script and C program. That would be
very helpful for me.

Thanks
Vijay
 
 
This message posted from opensolaris.org

Vijay,

If a Java program rather than a C program works with your design, you
could use the Java DTrace API in Solaris Express:

    /usr/share/lib/java/dtrace.jar
    /usr/share/lib/java/javadoc/dtrace/api/index.html

You would then listen for probe data in the dataReceived() method of
your ConsumerListener.

Tom

On Wed, Oct 11, 2006 at 08:51:52AM -0700, vijay meena
wrote:
> Hi Adam.
> 
> Thanks for your suggestion. I like the idea of feeding the data from Dtrace
script to C  program but since the amount of data is more, I do not want to
create any intermediate disk file to pass this data to C program, because my
design cant afford  disk i/o.
> If you could suggest me any other means of communication , like - socket
communication, shared memory between Dtrace script and C program. That would be
very helpful for me.
> 
> Thanks
> Vijay
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org

Is there a way that a structure defined in "C" library could be
accessed through the d script? I know that we could use -c option and #include
the header file, but what I am looking for it accessing the data structure by
referencing the library file through may be "-L" option. However it
really does not seem to work. Any help will be great.
 
 
This message posted from opensolaris.org