(I'm resending this because it seems that my other message got garbled.)
I'm writting on random positions on a mapped file, but it seems that if I
seek past 2GB, write something, then seek to a lower position, I got a
segfault. Here is the code:
#include <cassert>
#include <iostream>
#include <fstream>
#include
#include
using namespace std;
using boost::iostreams::stream;
using boost::iostreams::mapped_file;
int main(int argc, char** argv)
{
const size_t GIGA = 1024l*1024l*1024l;
const size_t FILESIZE = 2l * GIGA + 10000;
ofstream block("file", ios::binary | ios::out);
assert(block.good());
block.seekp(FILESIZE);
block.write("", 1);
block.close();
mapped_file mappedFile("file");
stream file(mappedFile, ios::binary|ios::out);
assert(mappedFile.is_open());
char buffer[10] = {0};
cout << 0 << endl;
file.seekp(0);
file.write(buffer, 1);
cout << FILESIZE - 1 << endl;
file.seekp(FILESIZE - 1);
file.write(buffer, 1);
cout << 1 * GIGA << endl;
file.seekp(1 * GIGA);
file.write(buffer, 1);
return 0;
}
I'm compiling under Ubuntu 14.10 (amd64):
$ g++ boost-mmap.cpp -lboost_iostreams
$ ./a.out
0
2147493647
Segmentation fault (core dumped)
Everything is 64-bits:
$ file a.out
a.out: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically
linked (uses shared libs), for GNU/Linux 2.6.32,
BuildID[sha1]=d39e3dc0c99e666631747e496bf798b92e4d4c71, not stripped
I have the same issue compiling with Visual Studio and running under
Windows 8 (amd64).
What I'm doing wrong?
--
[]s, Narcélio.
