Re: [Boost-users] [Interprocess] managed_shared_memory problem in 64-bit windows (v. 1.48.0)

Subject: Re: [Boost-users] [Interprocess] managed_shared_memory problem in 64-bit windows (v. 1.48.0)
From: Damien (damien_at_[hidden])
Date: 2011-12-20 15:18:47

Michael,

If you're trying to spin up a copy of the MUMPS solver as a separate 
process from within C++ using boost::interprocess, I've done that and it 
works on every platform.  Email me at this address and I'll help you out.

Damien

On 20/12/2011 1:00 PM, Michel Lestrade wrote:
> Hi,
>
> I am trying to make a shared memory block between 2 Intel Fortran 
> programs and thought to use a small C/C++ lib file to accomplish this: 
> Fortran can use the ISO_C_BINDING module to make its pointers point to 
> C objects but not vice versa and there is a vast Fortran code base 
> which we have no intention of porting.
>
> There is a native pipe mechanism but given the amount of data I will 
> be exchanging, disk access is something I want to avoid. The 
> application is FEM modeling and the sparse matrix can be several 
> hundred MBs; as the program evolves and the matrix changes, I expect 
> hundreds of GBs of data in total I/O. Seems like it would be better to 
> have a shared memory region and let the OS manage things as much as 
> possible.
>
> Starting small to test the idea, I am running into trouble with 
> something which seems easy enough to do in the examples but which only 
> seems to work in 32-bit. Here is an incomplete fragment (got stuck 
> early):
>
> #include <string>
> #include <boost/interprocess/managed_shared_memory.hpp>
> using namespace boost::interprocess;
>
> struct shm_remove
> {
>   shm_remove(const char *input)
>   {
>     name = std::string(input);
>     shared_memory_object::remove(name.c_str());
>   }
>   ~shm_remove() {shared_memory_object::remove(name.c_str());}
>   std::string name;
> } *remover;
>
> extern "C" void alloc_mumps(const int n, const int nnz, const char *name)
> {
>   int size_shm = sizeof(int)*(2+2*nnz) + sizeof(double)*(nnz+2*n);
>
>   remover = new shm_remove(name);
>   managed_shared_memory managed_shm(create_only,name,size_shm);
>
>   // Trying to do the equivalent of *i = new int
>   int *i  = managed_shm.construct<int>(anonymous_instance)[1](n);
> }
>
> Calling the function with n=3 and nnz=6 (a very small value compared 
> to my final application) works OK when the application is compiled 
> under 32-bit. Compiling under 64-bit produces an access violation 
> error in win32_api.hpp:
>
> inline long interlocked_compare_exchange(long volatile *addr, long 
> val1, long val2)
> {  return BOOST_INTERLOCKED_COMPARE_EXCHANGE(addr, val1, val2);  }
>
> values in debugger: addr=0, val1=1 val2=0.
>
> I do not know enough about Boost to know whether this is a design 
> limitation, a bug or just an issue with my initial build. Just for 
> reference, this is what I used:
>
> bjam --toolset=msvc-9.0 address-model=64 --build-type=complete stage
>
> Any suggestions ?
>
> Michel Lestrade
> Crosslight Software
>
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