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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2007. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#include <boost/interprocess/detail/config_begin.hpp>
//[doc_managed_grow
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/managed_mapped_file.hpp>
#include <cassert>
class MyClass
{
//...
};
int main()
{
using namespace boost::interprocess;
try{
{ //Remove old shared memory if present
shared_memory_object::remove("MyManagedShm");
//Create a managed shared memory
managed_shared_memory shm(create_only, "MyManagedShm", 1000);
//Check size
assert(shm.get_size() == 1000);
//Construct a named object
MyClass *myclass = shm.construct<MyClass>("MyClass")();
//The managed segment is unmapped here
}
{
//Now that the segment is not mapped grow it adding extra 500 bytes
managed_shared_memory::grow("MyManagedShm", 500);
//Map it again
managed_shared_memory shm(open_only, "MyManagedShm");
//Check size
assert(shm.get_size() == 1500);
//Check "MyClass" is still there
MyClass *myclass = shm.find<MyClass>("MyClass").first;
assert(myclass != 0);
//The managed segment is unmapped here
}
{
//Now minimize the size of the segment
managed_shared_memory::shrink_to_fit("MyManagedShm");
//Map it again
managed_shared_memory shm(open_only, "MyManagedShm");
//Check size
assert(shm.get_size() < 1000);
//Check "MyClass" is still there
MyClass *myclass = shm.find<MyClass>("MyClass").first;
assert(myclass != 0);
//The managed segment is unmapped here
}
}
catch(...){
shared_memory_object::remove("MyManagedShm");
throw;
}
//Remove the managed segment
shared_memory_object::remove("MyManagedShm");
return 0;
}
//]
#include <boost/interprocess/detail/config_end.hpp>
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