Question

Boost by default is using System V shared memory and creating file for communication. I want it to use POSIX shared memory.

Is their a way to force boost to use POSIX shared memory instead of trying to create a file?

Do I have to change something in source code (Boost.Interprocess)?

I am using 1.46.1 version of boost in my project on OS X (10.6, 10.7 and 10.8). But I can use 1.52.0 too. Before to migrate I want to know if it’s even possible to do.

Answer 1

From the documentation, Boost Interprocess will use POSIX when available. Digging further into it, it appears that on Max OSX it does not because the implementation has some non-conforming behavior (according to the header) . Below is the code from boost/interprocess/detail/workaround.hpp.

//Check for XSI shared memory objects. They are available in nearly all UNIX platforms
   #if !defined(__QNXNTO__)
      #define BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS
   #endif

   #if defined(_POSIX_SHARED_MEMORY_OBJECTS) && ((_POSIX_SHARED_MEMORY_OBJECTS - 0) > 0)
      #define BOOST_INTERPROCESS_POSIX_SHARED_MEMORY_OBJECTS
   #else
      //VMS and MACOS don't define it but they have shm_open/close interface
      #if defined(__vms)
         #if __CRTL_VER >= 70200000
            #define BOOST_INTERPROCESS_POSIX_SHARED_MEMORY_OBJECTS
         #endif
         //Mac OS has some non-conformant features like names limited to SHM_NAME_MAX
      #elif defined (__APPLE__)
         //#define BOOST_INTERPROCESS_POSIX_SHARED_MEMORY_OBJECTS
         //#define BOOST_INTERPROCESS_POSIX_SHARED_MEMORY_OBJECTS_NO_GROW
      #endif
   #endif