Message-ID: <CC3F55D9-684D-4347-80A5-188C8F900173@bak.io>
Date: 2014-07-02T19:10:18Z
From: Miëtek Bak
Subject: Embedded R, event loops, GUI events, and OS X
In-Reply-To: <57606014-442B-4B72-8A40-EA2A2D4D9638@r-project.org>
Hi Simon,
Thanks for the reply. I?m looking into giving you access to the H repository. Meanwhile, this is how we initialise embedded R, disabling stack limit checks:
// NOTE: It is crucial to set the two R stack globals after calling
// Rf_initialize_R() and before calling setup_Rmainloop().
// H_initUnlimitedEmbeddedR() is based on Rf_initEmbeddedR(), found in
// R 3.1.0 source code at src/gnuwin32/embeddedR.c:127.
int H_initUnlimitedEmbeddedR(int argc, char **argv)
{
Rf_initialize_R(argc, argv);
R_CStackLimit = -1;
R_CStackStart = -1;
setup_Rmainloop();
return(1);
}
We do use our own event loop. In order to mesh the H loop and the R loop, we do two things every 0.03 seconds, depending on the platform, neither of which fixes the issue on OS X:
1. On Linux, we call the following:
void processGUIEventsUnix(InputHandler** inputHandlers) {
if (*inputHandlers == NULL)
initStdinHandler();
R_runHandlers(*inputHandlers, R_checkActivityEx(1000, 0, NULL));
}
2. On Windows, we call `R_ProcessEvents`.
Can you say what exactly you have in mind when you say ?run the R event loop??
Best,
--
Mi?tek
On 2014-07-02, at 15:06, Simon Urbanek <simon.urbanek at r-project.org> wrote:
> Mi?tek,
>
> On Jul 2, 2014, at 1:43 PM, Mi?tek Bak <mietek at bak.io> wrote:
>
>> Hello,
>>
>> I?m helping with the development of an R-to-Haskell interoperability solution, called H. The project allows Haskell functions to seamlessly call R functions and vice versa, making use of an embedded R interpreter. H is developed in-house by Tweag I/O, and is soon to be open-sourced.
>>
>> The project is stable on Linux and Windows, and I?m focussing on an OS X port. Basic functionality is ready, but I?m having trouble with the GUI parts. Specifically, any graph window, e.g. the one expected for `plot(cars)`, appears blank and unresponsive when triggered from H.
>>
>> I think the issue lies between the H loop, the R event loop, and the Cocoa event loop. So far, I?ve pored over ?Writing R Extensions? (chapter 8, ?Linking GUIs and other front-ends to R?), the R 3.1.0 sources, (`./src/library/grDevices/src/qdCocoa.m`), and the R.app 1.6.4 sources (`./RController.m`, `./REngine/RCallbacks.m`, `./REngine/RInit.m`, and `./REngine/REngine.m`). I?ve also found interesting notes in the R.app `./ReadMe.txt`, but unfortunately, they no longer seem to be in sync with the code.
>>
>> As I?ve seemingly hit a wall, I?m looking for advice. Are any of the developers of the OS X port of R subscribed to this list?
>>
>
> Yes.
>
> In general, the trick is to make sure that you setup the R event loop. That is an extra step after initializing the embedded R. There is nothing special about the OS X port in that regard - as long as you run the R event loop all is well. It becomes more tricky if the app you use wants to use its own event loop - that can cause issues as you have to make sure the two loops mesh properly.
>
> For more specific help you'll need to ask more specific questions - possibly with link to reproducible code.
>
> Cheers,
> Simon
>
>
>
>> Thanks, and kind regards,
>>
>> --
>> Mi?tek Bak
>>
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