interprocess/example/doc_managed_heap_memory.cpp
2015-10-14 22:19:13 +02:00

82 lines
2.3 KiB
C++

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2012. 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>
#include <boost/interprocess/detail/workaround.hpp>
//[doc_managed_heap_memory
#include <boost/interprocess/containers/list.hpp>
#include <boost/interprocess/managed_heap_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <cstddef>
using namespace boost::interprocess;
typedef list<int, allocator<int, managed_heap_memory::segment_manager> >
MyList;
int main ()
{
//We will create a buffer of 1000 bytes to store a list
managed_heap_memory heap_memory(1000);
MyList * mylist = heap_memory.construct<MyList>("MyList")
(heap_memory.get_segment_manager());
//Obtain handle, that identifies the list in the buffer
managed_heap_memory::handle_t list_handle = heap_memory.get_handle_from_address(mylist);
//Fill list until there is no more memory in the buffer
try{
while(1) {
mylist->insert(mylist->begin(), 0);
}
}
catch(const bad_alloc &){
//memory is full
}
//Let's obtain the size of the list
MyList::size_type old_size = mylist->size();
//<-
(void)old_size;
//->
//To make the list bigger, let's increase the heap buffer
//in 1000 bytes more.
heap_memory.grow(1000);
//If memory has been reallocated, the old pointer is invalid, so
//use previously obtained handle to find the new pointer.
mylist = static_cast<MyList *>
(heap_memory.get_address_from_handle(list_handle));
//Fill list until there is no more memory in the buffer
try{
while(1) {
mylist->insert(mylist->begin(), 0);
}
}
catch(const bad_alloc &){
//memory is full
}
//Let's obtain the new size of the list
MyList::size_type new_size = mylist->size();
//<-
(void)new_size;
//->
assert(new_size > old_size);
//Destroy list
heap_memory.destroy_ptr(mylist);
return 0;
}
//]
#include <boost/interprocess/detail/config_end.hpp>