Ticket #4635: save_binary_bug.cpp

#include <stdio.h>      // for printf()

#include <unistd.h>     // for getpagesize()
#include <sys/mman.h>   // for mmap()

#include <sstream>

#include <boost/archive/text_oarchive.hpp>

int
main(int argc, char**argv)
{
        // Get the page size.
        int pageSize = ::getpagesize();
        ::printf("pageSize = %d\n", pageSize);

        // Allocate a page of zeroes in a lonely part of the address space.
        char* addr = (char*) ::mmap(0, pageSize, PROT_READ|PROT_WRITE,
                MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
        ::printf("addr = %p\n", addr);

        // Serialize the last few bytes of the page.
        std::stringstream str;
        boost::archive::text_oarchive oar(str);
        oar.save_binary(addr + (pageSize-8), 8);

        return 0;

        //These cause an address fault:
        //oar.save_binary(addr + (pageSize-4), 4);
        //oar.save_binary(addr + (pageSize-8), 8);
        //oar.save_binary(addr + (pageSize-16), 16);
        //oar.save_binary(addr, pageSize);

        //These don't:
        //oar.save_binary(addr + (pageSize-9), 8);
        //oar.save_binary(addr + (pageSize-8), 7);
        //oar.save_binary(addr + (pageSize-17), 16);
        //oar.save_binary(addr + (pageSize-16), 15);
        //oar.save_binary(addr, pageSize-1);
}