Files
interprocess/doc/code/doc_managed_mapped_file.cpp
Ion Gaztañaga 18646362ed no message
[SVN r34286]
2006-06-12 17:39:55 +00:00

69 lines
2.1 KiB
C++

#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/interprocess/containers/list.hpp>
#include <boost/interprocess/managed_mapped_file.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <cstddef>
#include <cstdio>
using namespace boost::interprocess;
typedef list<int, allocator<int, managed_mapped_file::segment_manager> >
MyList;
int main ()
{
const char *FileName = "file_mapping";
const std::size_t FileSize = 1000;
std::remove(FileName);
managed_mapped_file mfile_memory(create_only, FileName, FileSize);
MyList * mylist = mfile_memory.construct<MyList>("MyList")
(mfile_memory.get_segment_manager());
//Obtain handle, that identifies the list in the buffer
managed_mapped_file::handle_t list_handle = mfile_memory.get_handle_from_address(mylist);
//Fill list until there is no more room in the file
try{
while(1) {
mylist->insert(mylist->begin(), 0);
}
}
catch(const bad_alloc &){
//mapped file is full
}
//Let's obtain the size of the list
std::size_t old_size = mylist->size();
//To make the list bigger, let's increase the mapped file
//in FileSize bytes more.
// mfile_memory.grow(FileSize);
//If mapping address has changed, the old pointer is invalid,
//so use previously obtained handle to find the new pointer.
mylist = static_cast<MyList *>
(mfile_memory.get_address_from_handle(list_handle));
//Fill list until there is no more room in the file
try{
while(1) {
mylist->insert(mylist->begin(), 0);
}
}
catch(const bad_alloc &){
//mapped file is full
}
//Let's obtain the new size of the list
std::size_t new_size = mylist->size();
assert(new_size > old_size);
//Destroy list
mfile_memory.destroy_ptr(mylist);
return 0;
}
#include <boost/interprocess/detail/config_end.hpp>