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94 lines
3.0 KiB
C++
94 lines
3.0 KiB
C++
//////////////////////////////////////////////////////////////////////////////
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//
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// (C) Copyright Ion Gaztanaga 2006-2007. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/interprocess for documentation.
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//
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//////////////////////////////////////////////////////////////////////////////
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#include <boost/interprocess/detail/config_begin.hpp>
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//[doc_file_mapping
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#include <boost/interprocess/file_mapping.hpp>
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#include <boost/interprocess/mapped_region.hpp>
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#include <iostream>
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#include <fstream>
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#include <string>
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#include <vector>
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#include <cstring>
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#include <cstddef>
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#include <cstdlib>
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int main(int argc, char *argv[])
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{
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using namespace boost::interprocess;
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const std::size_t FileSize = 10000;
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if(argc == 1){ //Parent process executes this
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{ //Create a file
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std::filebuf fbuf;
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fbuf.open("file.bin", std::ios_base::in | std::ios_base::out
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| std::ios_base::trunc | std::ios_base::binary);
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//Set the size
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fbuf.pubseekoff(FileSize-1, std::ios_base::beg);
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fbuf.sputc(0);
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}
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//Remove file on exit
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struct file_remove
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{
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~file_remove (){ file_mapping::remove("file.bin"); }
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} destroy_on_exit;
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//Create a file mapping
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file_mapping m_file("file.bin", read_write);
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//Map the whole file with read-write permissions in this process
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mapped_region region(m_file, read_write);
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//Get the address of the mapped region
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void * addr = region.get_address();
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std::size_t size = region.get_size();
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//Write all the memory to 1
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std::memset(addr, 1, size);
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//Launch child process
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std::string s(argv[0]); s += " child";
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if(0 != std::system(s.c_str()))
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return 1;
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}
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else{ //Child process executes this
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{ //Open the file mapping and map it as read-only
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file_mapping m_file ("file.bin", read_only);
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mapped_region region(m_file, read_only);
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//Get the address of the mapped region
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void * addr = region.get_address();
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std::size_t size = region.get_size();
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//Check that memory was initialized to 1
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const char *mem = static_cast<char*>(addr);
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for(std::size_t i = 0; i < size; ++i)
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if(*mem++ != 1)
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return 1; //Error checking memory
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}
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{ //Now test it reading the file
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std::filebuf fbuf;
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fbuf.open("file.bin", std::ios_base::in | std::ios_base::binary);
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//Read it to memory
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std::vector<char> vect(FileSize, 0);
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fbuf.sgetn(&vect[0], std::streamsize(vect.size()));
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//Check that memory was initialized to 1
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const char *mem = static_cast<char*>(&vect[0]);
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for(std::size_t i = 0; i < FileSize; ++i)
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if(*mem++ != 1)
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return 1; //Error checking memory
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}
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}
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return 0;
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}
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//]
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#include <boost/interprocess/detail/config_end.hpp>
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