[Rcpp-devel] using Rcpp function Module twice triggers segfault

[Dirk Eddelbuettel]

On 7 September 2012 at 06:40, Dirk Eddelbuettel wrote:
| 
| On 6 September 2012 at 23:51, Jiqiang Guo wrote:
| | 
| | 
| | On Thu, Sep 6, 2012 at 11:43 PM, Dirk Eddelbuettel <edd at debian.org> wrote:
| | 
| | 
| |     On 6 September 2012 at 21:24, Jiqiang Guo wrote:
| |     | Dear List,
| |     |
| |     | In the middle of figure out another problem, I used function Module
| |     twice, but
| |     | then I got segfault.  Is there any solution for this?  For the time
| |     being, I
| |     | really need to call function Module more than once.  
| | 
| |     a) I simply never combine Rcpp modules with inline. With a package, things
| |     work. 
| | 
| | 
| |     b) In
| | 
| |           m <- Module("foo1", getDynLib(fx))
| |           m2 <- Module("foo1", getDynLib(fx))
| | 
| |        are you by chance mistaking Module() [ ie the declaration ] with new()
| |     [
| |        ie the instantiation of an object ] ?
| | 
| | No. I am just trying to narrow down what causes the real problem I have. And I
| | think now it is because I called Module a second time. Following Module call, I
| | do have new .... 
| | 
| | Anyway, the above a) and b) do not explain and solve the problem I have. 
| 
| Use new() twice to create not two objects.

Sorry, typed too fast: remove the 'not'.  If I understand what you want
(which is not clear as you haven't really stated WHY you want to call Module
twice, which you simply should not):  use new() twice.

Dirk

| 
| Dirk
| 
| | Thanks,
| | 
| | Jiqiang
| | 
| | 
| |  
| | 
| | 
| |     Dirk
| | 
| | 
| |     | Best,
| |     | Jiqiang
| |     |
| |     | P.S. an example code and the dump of output.
| |     | In addition, my sessionInfo()
| |     |
| |     | > sessionInfo()
| |     | R version 2.15.1 (2012-06-22)
| |     | Platform: x86_64-pc-linux-gnu (64-bit)
| |     |
| |     | locale:
| |     |  [1] LC_CTYPE=en_US.utf8       LC_NUMERIC=C             
| |     |  [3] LC_TIME=en_US.utf8        LC_COLLATE=en_US.utf8    
| |     |  [5] LC_MONETARY=en_US.utf8    LC_MESSAGES=en_US.utf8   
| |     |  [7] LC_PAPER=C                LC_NAME=C                
| |     |  [9] LC_ADDRESS=C              LC_TELEPHONE=C           
| |     | [11] LC_MEASUREMENT=en_US.utf8 LC_IDENTIFICATION=C      
| |     |
| |     | attached base packages:
| |     | [1] stats     graphics  grDevices utils     datasets  methods  
| |     base  
| |     |   
| |     |
| |     | other attached packages:
| |     | [1] inline_0.3.8 Rcpp_0.9.13 
| |     |
| |     | loaded via a namespace (and not attached):
| |     | [1] tools_2.15.1
| |     |
| |     |
| |     | require("Rcpp")
| |     | require("inline")
| |     |
| |     | inc <- '
| |     | class Foo {
| |     | private:
| |     |   int x_;
| |     | public:
| |     |   Foo(int x) : x_(x) { } 
| |     |   void setx(int x) { x_ = x;}
| |     |   int getx() const { return x_;}
| |     | }; 
| |     |
| |     | RCPP_MODULE(foo1) {
| |     |   class_<Foo>("Foo")
| |     |   .constructor<int>() 
| |     |   .method("setx", &Foo::setx) 
| |     |   .method("getx", &Foo::getx) 
| |     |   ;
| |     | }
| |     | '
| |     | fx <- cxxfunction(signature(), "", include = inc, plugin = "Rcpp",
| |     verbose = !
| |     | TRUE)
| |     | m <- Module("foo1", getDynLib(fx))
| |     | m2 <- Module("foo1", getDynLib(fx))
| |     |
| |     | ====== 
| |     |
| |     | > m <- Module("foo1", getDynLib(fx))
| |     | > m2 <- Module("foo1", getDynLib(fx))
| |     | >
| |     | > f <- new(m$Foo, 1)
| |     | > f2 <- new(m2$Foo, 1)
| |     |
| |     |  *** caught segfault ***
| |     | address 0x90, cause 'memory not mapped'
| |     |
| |     | Traceback:
| |     |  1: .Call(symbol)
| |     |  2: Module(module, mustStart = TRUE)
| |     |  3: .getModulePointer(x)
| |     |  4: m2$Foo
| |     |  5: .getClassFromCache(Class, where)
| |     |  6: getClass(Class, where = topenv(parent.frame()))
| |     |  7: new(m2$Foo, 1)
| |     | aborting ...
| |     |
| |     |
| |     |
| |     | ----------------------------------------------------------------------
| |     | _______________________________________________
| |     | Rcpp-devel mailing list
| |     | Rcpp-devel at lists.r-forge.r-project.org
| |     | https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
| |     --
| |     Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com
| | 
| | 
| 
| -- 
| Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com  

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com