[Rcpp-devel] RInside destructor not working properly?

[Dirk Eddelbuettel]

Christian,

On 27 August 2012 at 13:28, Christian Sigg wrote:
| The following program
| 
| #include <RInside.h>
| 
| void foo() {
|    RInside R;
| }
| 
| void bar() {
|    RInside R;
| }
| 
| int main(int argc, const char * argv[]) {
|    foo();
|    bar();
|    return 0;
| }
| 
| produces a great number of the following two lines
| 
| Error: bad target context--should NEVER happen;
| please bug.report() [R_run_onexits]
| 
| as output.
| 
| Question: Is the RInside destructor not working properly? I would have expected that both in foo() and bar(), an instance of R is created and then destroyed| immediately, without producing any kind of output.

No, wrong setup. R is single-threaded, and you can have only
precisely __ONE__ instance of R in your program. You have two.

Create one in main() and pass references around.

| Context: I'm developing code that calls the OpenCV library from R, with the help of Rcpp. For rapid development and unit testing, I use RInside to set up the environment before calling my C++ function that calls into the OpenCV library. The above mentioned error appears when the second unit test again calls the RInside constructor to set up its test environment.
| 
| This is on OS X 10.7 with Xcode 4.4.1 (Apple LLVM Compiler 4.0) and the latest version of the command line tools. I use R 2.15.1 and RInside 0.2.7.
| 
| If I avoid calling RInside() twice in the same program, my code is running smoothly.

That's the point. Use one, as R can only be called once per process.

There is a bit of a singleton-alike pattern in RInside::initialize() which
should have caught this. I am a bit surprised you got this far. If anybody
has ideas of how to prevent your design error from even passing the compile
stage I'd be all ears.

Dirk

| 
| Thanks for any assistance,
| Christian
| 
| 
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-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com