If you are using an external pointer you can register a finalizer that
does the cleanup at gc time in case of an abnormal exit. Otherwise
you should for now be able to use R_ToplevelExec tigether with
R_CheckUserInterrupt as I suggested previously.
Best,
luke
On Wed, 21 May 2008, Kjell Konis wrote:
I have a structure from a library that I am using an external pointer to keep
track of. The methods in this library (lp_solve) have the facility to call a
function periodically and I would like to use R_ProcessEvents. The problem is
that if an interrupt is requested then R returns to the command prompt
without completing the library method. This leaves the structure in a
messed-up state so that I can't even successfully delete it, potentially
leaking a lot of memory. So what I am trying to do is find a way to see if an
event has occurred (in this case an interrupt) so I can respond to it before
onintr() gets called.
Kjell
On 20 mai 08, at 19:22, Simon Urbanek wrote:
On May 20, 2008, at 10:58 AM, Kjell Konis wrote:
I would actually prefer a mechanism that simply returns a flag indicating
that an interrupt has been requested. Then I would be able to clean up and
return on my own - no longjmp required. Also, it would be useful if there
was a function similar to R_ProcessEvents that only dealt with keeping the
GUI responsive.
I don't understand what you mean by the last sentence - that is exactly
what R_ProcessEvents is for - or am I missing something?
Cheers,
Simon
Cheers,
Kjell
On 16 mai 08, at 13:54, Luke Tierney wrote:
I'm not sure you can make this work as some of the things needed
either are or should be private to the core implementation and not
available to package code. In any case I would not recommend this
approach for two reasons. First, details of what happens in interrupt
checking are subject to change and your code would miss those changes
unless you track them carefully. More importantly, several things
here could generate an error that results in a longjmp and leaves your
code in an unstable state.
What is needed for this is a mechanism for detecting an interrupt but
not doing the longjmp, just returning a flag that a longjmp is needed
and enough information to allow it to be made after cleanup code has
been run. This has been on my to do list for a while but getting the
semantics right is tricky and so it hasn't happened yet. Hopefully it
will be in 2.8.0. In the interim you can cobble something together
using R_ToplevelExec, interpreting all FALSE return values as user
interrupts.
Another option, also under consideration but not available yet, is a C
mechanism for registering cleanup operations if a longjmp occurs. A
quick and dirty version of that could be provided fairly easily but a
better version, which would be preferable in the long run, requires a
rewrite of the code that implements jumps and cleanup/on.exit actions.
This may take a bit longer to implement.
Best,
luke
On Fri, 16 May 2008, Kjell Konis wrote:
You mean something like this (I return 1 instead of calling onintr())?
Will HAVE_AQUA and Win32 be appropriately defined when building my
package (I can't see how to check with R CMD config)?
int My_CheckUserInterrupt(void)
{
R_CheckStack();
#if ( defined(HAVE_AQUA) )
/* R_ProcessEvents() from unix/aqua.c*/
if (ptr_R_ProcessEvents)
ptr_R_ProcessEvents();
if (R_interrupts_pending)
return(1);
#elseif ( defined(Win32) )
/* R_ProcessEvents() from gnuwin32/system.c */
while (peekevent()) doevent();
if (UserBreak) {
UserBreak = FALSE;
return(1);
}
R_CallBackHook();
if(R_tcldo) R_tcldo();
#else
R_PolledEvents();
if (R_interrupts_pending)
return(1);
#endif
return(0);
}
On 16 mai 08, at 12:43, Prof Brian Ripley wrote:
On Fri, 16 May 2008, Kjell Konis wrote:
The problem is that my package uses an external pointer to keep track
of a structure created by the lp_solve library. If I use
R_CheckUserInterrupt in the lp_solve abort function it leaves the
structure in a messed-up state after an interrupt occurs. I am not
even able to free the memory allocated in the structure. I need to be
able to tell the lp_solve functions to interrupt themselves if I am
going to support interrupts at all.
I took a longer look at errors.c and it seems my solution should work
as long as neither HAVE_AQUA nor Win32 are defined. Under the
circumstances, I think that's the best I can do.
Any suggestions for a UI independent way to check for interrupts would
be appreciated.
Why not use the same code as R_CheckUserInterrupt but instead of
calling onintr, call your own interrupt routine?
Thanks,
Kjell
On 15 mai 08, at 16:41, Prof Brian Ripley wrote:
How is R_interrupts_pending going to be set?
It is set in the interrupt handler for SIGINT, but that is not the
only way to indicate an interrupt, and it is not necessarily
available to users of GUIs and embedded R.
Without servicing the GUIs all interaction will be dead, including
sending an interrrupt from menus/buttons/keyboard. See the comment
in the code for R_CheckUserInterrupt.
On Thu, 15 May 2008, Kjell Konis wrote:
Hello,
I have some native code that I would like to allow users to
interrupt. However, I would like to do it more gracefully than with
R_CheckUserInterrupt(). The solution I came up with is to call the
following abort function periodically - if it returns 1 then I clean
up and return.
int __WINAPI RlpSolveAbortFunction(lprec *lp, void *userhandle)
{
if(R_interrupts_pending)
return(1);
return(0);
}
This seems to work fine on Mac (sans Aqua) and Linux. Is this going
to be portable? Also, is there anything else I need to do? For
instance set R_interrupts_pending to 0 after I respond to it?
Thanks.
Kjell
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: [EMAIL PROTECTED]
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: [EMAIL PROTECTED]
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
