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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 //[doc_anonymous_upgradable_mutexA
12 #include <boost/interprocess/shared_memory_object.hpp>
13 #include <boost/interprocess/mapped_region.hpp>
14 #include <boost/interprocess/sync/scoped_lock.hpp>
15 #include "doc_upgradable_mutex_shared_data.hpp"
16 #include <iostream>
17 #include <cstdio>
18 
19 using namespace boost::interprocess;
20 
main()21 int main ()
22 {
23    //Remove shared memory on destruction
24    struct shm_remove
25    {
26       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
27    } remover;
28    //<-
29    (void)remover;
30    //->
31 
32    //Create a shared memory object.
33    shared_memory_object shm
34       (create_only               //only create
35       ,"MySharedMemory"           //name
36       ,read_write   //read-write mode
37       );
38 
39    //Set size
40    shm.truncate(sizeof(shared_data));
41 
42    //Map the whole shared memory in this process
43    mapped_region region
44       (shm                       //What to map
45       ,read_write //Map it as read-write
46       );
47 
48    //Get the address of the mapped region
49    void * addr       = region.get_address();
50 
51    //Construct the shared structure in memory
52    shared_data * data = new (addr) shared_data;
53 
54    //Write some logs
55    for(int i = 0; i < shared_data::NumItems; ++i){
56       //Lock the upgradable_mutex
57       scoped_lock<interprocess_upgradable_mutex> lock(data->upgradable_mutex);
58       std::sprintf(data->items[(data->current_line++) % shared_data::NumItems]
59                ,"%s_%d", "process_a", i);
60       if(i == (shared_data::NumItems-1))
61          data->end_a = true;
62       //Mutex is released here
63    }
64 
65    //Wait until the other process ends
66    while(1){
67       scoped_lock<interprocess_upgradable_mutex> lock(data->upgradable_mutex);
68       if(data->end_b)
69          break;
70    }
71 
72    return 0;
73 }
74 //]
75 #include <boost/interprocess/detail/config_end.hpp>
76