interprocess/example/doc_file_mapping.cpp
Ion Gaztañaga b68e12a681 Updated copyright end year
[SVN r80138]
2012-08-22 11:26:55 +00:00

136 lines
3.9 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>
//[doc_file_mapping
#include <boost/interprocess/file_mapping.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <cstring>
#include <cstddef>
#include <cstdlib>
//<-
#include "../test/get_process_id_name.hpp"
//->
int main(int argc, char *argv[])
{
using namespace boost::interprocess;
//Define file names
//<-
#if 1
std::string file_name(boost::interprocess::ipcdetail::get_temporary_path());
file_name += "/"; file_name += test::get_process_id_name();
const char *FileName = file_name.c_str();
#else
//->
const char *FileName = "file.bin";
//<-
#endif
//->
const std::size_t FileSize = 10000;
if(argc == 1){ //Parent process executes this
{ //Create a file
file_mapping::remove(FileName);
std::filebuf fbuf;
fbuf.open(FileName, std::ios_base::in | std::ios_base::out
| std::ios_base::trunc | std::ios_base::binary);
//Set the size
fbuf.pubseekoff(FileSize-1, std::ios_base::beg);
fbuf.sputc(0);
}
//Remove on exit
struct file_remove
{
file_remove(const char *FileName)
: FileName_(FileName) {}
~file_remove(){ file_mapping::remove(FileName_); }
const char *FileName_;
} remover(FileName);
//Create a file mapping
file_mapping m_file(FileName, read_write);
//Map the whole file with read-write permissions in this process
mapped_region region(m_file, read_write);
//Get the address of the mapped region
void * addr = region.get_address();
std::size_t size = region.get_size();
//Write all the memory to 1
std::memset(addr, 1, size);
//Launch child process
std::string s(argv[0]); s += " child ";
//<-
s += "\""; s+= FileName; s += "\"";
//->
if(0 != std::system(s.c_str()))
return 1;
}
else{ //Child process executes this
{ //Open the file mapping and map it as read-only
//<-
#if 1
file_mapping m_file(argv[2], read_only);
#else
//->
file_mapping m_file(FileName, read_only);
//<-
#endif
//->
mapped_region region(m_file, read_only);
//Get the address of the mapped region
void * addr = region.get_address();
std::size_t size = region.get_size();
//Check that memory was initialized to 1
const char *mem = static_cast<char*>(addr);
for(std::size_t i = 0; i < size; ++i)
if(*mem++ != 1)
return 1; //Error checking memory
}
{ //Now test it reading the file
std::filebuf fbuf;
//<-
#if 1
fbuf.open(argv[2], std::ios_base::in | std::ios_base::binary);
#else
//->
fbuf.open(FileName, std::ios_base::in | std::ios_base::binary);
//<-
#endif
//->
//Read it to memory
std::vector<char> vect(FileSize, 0);
fbuf.sgetn(&vect[0], std::streamsize(vect.size()));
//Check that memory was initialized to 1
const char *mem = static_cast<char*>(&vect[0]);
for(std::size_t i = 0; i < FileSize; ++i)
if(*mem++ != 1)
return 1; //Error checking memory
}
}
return 0;
}
//]
#include <boost/interprocess/detail/config_end.hpp>