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/***************************************************************************
* lib/io/mmap_file.cpp
*
* Part of the STXXL. See http://stxxl.sourceforge.net
*
* Copyright (C) 2002 Roman Dementiev <dementiev@mpi-sb.mpg.de>
* Copyright (C) 2008 Andreas Beckmann <beckmann@cs.uni-frankfurt.de>
*
* 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)
**************************************************************************/
#include <stxxl/bits/io/mmap_file.h>
#if STXXL_HAVE_MMAP_FILE
#include <stxxl/bits/io/iostats.h>
#include <stxxl/bits/common/error_handling.h>
#include "ufs_platform.h"
#include <sys/mman.h>
STXXL_BEGIN_NAMESPACE
void mmap_file::serve(void* buffer, offset_type offset, size_type bytes,
request::request_type type)
{
scoped_mutex_lock fd_lock(fd_mutex);
//assert(offset + bytes <= _size());
stats::scoped_read_write_timer read_write_timer(bytes, type == request::WRITE);
int prot = (type == request::READ) ? PROT_READ : PROT_WRITE;
void* mem = mmap(NULL, bytes, prot, MAP_SHARED, file_des, offset);
// void *mem = mmap (buffer, bytes, prot , MAP_SHARED|MAP_FIXED , file_des, offset);
// STXXL_MSG("Mmaped to "<<mem<<" , buffer suggested at "<<buffer);
if (mem == MAP_FAILED)
{
STXXL_THROW_ERRNO(io_error,
" mmap() failed." <<
" path=" << filename <<
" bytes=" << bytes <<
" Page size: " << sysconf(_SC_PAGESIZE) <<
" offset modulo page size " << (offset % sysconf(_SC_PAGESIZE)));
}
else if (mem == 0)
{
STXXL_THROW_ERRNO(io_error, "mmap() returned NULL");
}
else
{
if (type == request::READ)
{
memcpy(buffer, mem, bytes);
}
else
{
memcpy(mem, buffer, bytes);
}
STXXL_THROW_ERRNO_NE_0(munmap(mem, bytes), io_error,
"munmap() failed");
}
}
const char* mmap_file::io_type() const
{
return "mmap";
}
STXXL_END_NAMESPACE
#endif // #if STXXL_HAVE_MMAP_FILE
// vim: et:ts=4:sw=4
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