ceph/src/boost/libs/interprocess/example/doc_offset_ptr.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006-2012. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10
  11 #include <boost/interprocess/detail/workaround.hpp>
  12 //[doc_offset_ptr
  13 #include <boost/interprocess/managed_shared_memory.hpp>
  14 #include <boost/interprocess/offset_ptr.hpp>
  15 //<-
  16 #include "../test/get_process_id_name.hpp"
  17 //->
  18
  19 using namespace boost::interprocess;
  20
  21 //Shared memory linked list node
  22 struct list_node
  23 {
  24    offset_ptr<list_node> next;
  25    int                   value;
  26 };
  27
  28 int main ()
  29 {
  30    //Remove shared memory on construction and destruction
  31    struct shm_remove
  32    {
  33    //<-
  34    #if 1
  35       shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
  36       ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
  37    #else
  38    //->
  39       shm_remove() { shared_memory_object::remove("MySharedMemory"); }
  40       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  41    //<-
  42    #endif
  43    //->
  44    } remover;
  45    //<-
  46    (void)remover;
  47    //->
  48
  49    //Create shared memory
  50    //<-
  51    #if 1
  52    managed_shared_memory segment(create_only,
  53                                  test::get_process_id_name(),  //segment name
  54                                  65536);
  55    #else
  56    //->
  57    managed_shared_memory segment(create_only,
  58                                  "MySharedMemory",  //segment name
  59                                  65536);
  60    //<-
  61    #endif
  62    //->
  63
  64    //Create linked list with 10 nodes in shared memory
  65    offset_ptr<list_node> prev = 0, current, first;
  66
  67    int i;
  68    for(i = 0; i < 10; ++i, prev = current){
  69       current = static_cast<list_node*>(segment.allocate(sizeof(list_node)));
  70       current->value = i;
  71       current->next  = 0;
  72
  73       if(!prev)
  74          first = current;
  75       else
  76          prev->next = current;
  77    }
  78
  79    //Communicate list to other processes
  80    //. . .
  81    //When done, destroy list
  82    for(current = first; current; /**/){
  83       prev = current;
  84       current = current->next;
  85       segment.deallocate(prev.get());
  86    }
  87    return 0;
  88 }
  89 //]
  90