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

[Dirk Eddelbuettel]

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.

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 ...
|     |
|     |
|     |
|     | ----------------------------------------------------------------------
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|     | Rcpp-devel at lists.r-forge.r-project.org
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|     --
|     Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com
| 
| 

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