libs/interprocess/example/doc_multi_index.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 #include <boost/interprocess/detail/config_begin.hpp>
  11 #include <boost/interprocess/detail/workaround.hpp>
  12 //[doc_multi_index
  13 #include <boost/interprocess/managed_shared_memory.hpp>
  14 #include <boost/interprocess/allocators/allocator.hpp>
  15 #include <boost/interprocess/containers/string.hpp>
  16
  17 //<-
  18 //Shield against external warnings
  19 #include <boost/interprocess/detail/config_external_begin.hpp>
  20 //->
  21
  22 #include <boost/multi_index_container.hpp>
  23 #include <boost/multi_index/member.hpp>
  24 #include <boost/multi_index/ordered_index.hpp>
  25
  26 //<-
  27 #include <boost/interprocess/detail/config_external_end.hpp>
  28 #include "../test/get_process_id_name.hpp"
  29 //->
  30
  31 using namespace boost::interprocess;
  32 namespace bmi = boost::multi_index;
  33
  34 typedef managed_shared_memory::allocator<char>::type              char_allocator;
  35 typedef basic_string<char, std::char_traits<char>, char_allocator>shm_string;
  36
  37 //Data to insert in shared memory
  38 struct employee
  39 {
  40    int         id;
  41    int         age;
  42    shm_string  name;
  43    employee( int id_
  44            , int age_
  45            , const char *name_
  46            , const char_allocator &a)
  47       : id(id_), age(age_), name(name_, a)
  48    {}
  49 };
  50
  51 //Tags
  52 struct id{};
  53 struct age{};
  54 struct name{};
  55
  56 // Define a multi_index_container of employees with following indices:
  57 //   - a unique index sorted by employee::int,
  58 //   - a non-unique index sorted by employee::name,
  59 //   - a non-unique index sorted by employee::age.
  60 typedef bmi::multi_index_container<
  61   employee,
  62   bmi::indexed_by<
  63     bmi::ordered_unique
  64       <bmi::tag<id>,  bmi::member<employee,int,&employee::id> >,
  65     bmi::ordered_non_unique<
  66       bmi::tag<name>, bmi::member<employee,shm_string,&employee::name> >,
  67     bmi::ordered_non_unique
  68       <bmi::tag<age>, bmi::member<employee,int,&employee::age> > >,
  69   managed_shared_memory::allocator<employee>::type
  70 > employee_set;
  71
  72 int main ()
  73 {
  74    //Remove shared memory on construction and destruction
  75    struct shm_remove
  76    {
  77    //<-
  78    #if 1
  79       shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
  80       ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
  81    #else
  82    //->
  83       shm_remove() { shared_memory_object::remove("MySharedMemory"); }
  84       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  85    //<-
  86    #endif
  87    //->
  88    } remover;
  89    //<-
  90    (void)remover;
  91    //->
  92
  93    //Create shared memory
  94    //<-
  95    #if 1
  96    managed_shared_memory segment(create_only,test::get_process_id_name(), 65536);
  97    #else
  98    //->
  99    managed_shared_memory segment(create_only,"MySharedMemory", 65536);
 100    //<-
 101    #endif
 102    //->
 103
 104    //Construct the multi_index in shared memory
 105    employee_set *es = segment.construct<employee_set>
 106       ("My MultiIndex Container")            //Container's name in shared memory
 107       ( employee_set::ctor_args_list()
 108       , segment.get_allocator<employee>());  //Ctor parameters
 109
 110    //Now insert elements
 111    char_allocator ca(segment.get_allocator<char>());
 112    es->insert(employee(0,31, "Joe", ca));
 113    es->insert(employee(1,27, "Robert", ca));
 114    es->insert(employee(2,40, "John", ca));
 115    return 0;
 116 }
 117 //]
 118 #include <boost/interprocess/detail/config_end.hpp>