ceph/src/boost/libs/interprocess/example/doc_spawn_vector.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_spawn_vector
  13 #include <boost/interprocess/managed_shared_memory.hpp>
  14 #include <boost/interprocess/containers/vector.hpp>
  15 #include <boost/interprocess/allocators/allocator.hpp>
  16 #include <string>
  17 #include <cstdlib> //std::system
  18 //<-
  19 #include "../test/get_process_id_name.hpp"
  20 //->
  21
  22 using namespace boost::interprocess;
  23
  24 //Define an STL compatible allocator of ints that allocates from the managed_shared_memory.
  25 //This allocator will allow placing containers in the segment
  26 typedef allocator<int, managed_shared_memory::segment_manager>  ShmemAllocator;
  27
  28 //Alias a vector that uses the previous STL-like allocator so that allocates
  29 //its values from the segment
  30 typedef vector<int, ShmemAllocator> MyVector;
  31
  32 //Main function. For parent process argc == 1, for child process argc == 2
  33 int main(int argc, char *argv[])
  34 {
  35    if(argc == 1){ //Parent process
  36       //Remove shared memory on construction and destruction
  37       struct shm_remove
  38       {
  39       //<-
  40       #if 1
  41          shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
  42          ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
  43       #else
  44       //->
  45          shm_remove() { shared_memory_object::remove("MySharedMemory"); }
  46          ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  47       //<-
  48       #endif
  49       //->
  50       } remover;
  51       //<-
  52       (void)remover;
  53       //->
  54
  55       //Create a new segment with given name and size
  56       //<-
  57       #if 1
  58       managed_shared_memory segment(create_only, test::get_process_id_name(), 65536);
  59       #else
  60       //->
  61       managed_shared_memory segment(create_only, "MySharedMemory", 65536);
  62       //<-
  63       #endif
  64       //->
  65
  66       //Initialize shared memory STL-compatible allocator
  67       const ShmemAllocator alloc_inst (segment.get_segment_manager());
  68
  69       //Construct a vector named "MyVector" in shared memory with argument alloc_inst
  70       MyVector *myvector = segment.construct<MyVector>("MyVector")(alloc_inst);
  71
  72       for(int i = 0; i < 100; ++i)  //Insert data in the vector
  73          myvector->push_back(i);
  74
  75       //Launch child process
  76       std::string s(argv[0]); s += " child ";
  77       //<-
  78       s += test::get_process_id_name();
  79       //->
  80       if(0 != std::system(s.c_str()))
  81          return 1;
  82
  83       //Check child has destroyed the vector
  84       if(segment.find<MyVector>("MyVector").first)
  85          return 1;
  86    }
  87    else{ //Child process
  88       //Open the managed segment
  89       //<-
  90       #if 1
  91       managed_shared_memory segment(open_only, argv[2]);
  92       #else
  93       //->
  94       managed_shared_memory segment(open_only, "MySharedMemory");
  95       //<-
  96       #endif
  97       //->
  98
  99       //Find the vector using the c-string name
 100       MyVector *myvector = segment.find<MyVector>("MyVector").first;
 101
 102       //Use vector in reverse order
 103       std::sort(myvector->rbegin(), myvector->rend());
 104
 105       //When done, destroy the vector from the segment
 106       segment.destroy<MyVector>("MyVector");
 107    }
 108
 109    return 0;
 110 }
 111
 112 //]
 113