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/* scoped_mmap, automatically unmap files
Copyright (C) 2018-2020 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef COMMON_SCOPED_MMAP_H
#define COMMON_SCOPED_MMAP_H
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
/* A smart-pointer-like class to mmap() and automatically munmap() a memory
mapping. */
class scoped_mmap
{
public:
scoped_mmap () noexcept : m_mem (MAP_FAILED), m_length (0) {}
scoped_mmap (void *addr, size_t length, int prot, int flags, int fd,
off_t offset) noexcept : m_length (length)
{
m_mem = mmap (addr, m_length, prot, flags, fd, offset);
}
~scoped_mmap ()
{
destroy ();
}
scoped_mmap (scoped_mmap &&rhs)
{
destroy ();
m_mem = rhs.m_mem;
m_length = rhs.m_length;
rhs.m_mem = MAP_FAILED;
rhs.m_length = 0;
}
DISABLE_COPY_AND_ASSIGN (scoped_mmap);
ATTRIBUTE_UNUSED_RESULT void *release () noexcept
{
void *mem = m_mem;
m_mem = MAP_FAILED;
m_length = 0;
return mem;
}
void reset (void *addr, size_t length, int prot, int flags, int fd,
off_t offset) noexcept
{
destroy ();
m_length = length;
m_mem = mmap (addr, m_length, prot, flags, fd, offset);
}
size_t size () const noexcept { return m_length; }
void *get () const noexcept { return m_mem; }
private:
void destroy ()
{
if (m_mem != MAP_FAILED)
munmap (m_mem, m_length);
}
void *m_mem;
size_t m_length;
};
/* Map FILENAME in memory. Throw an error if anything goes wrong. */
scoped_mmap mmap_file (const char *filename);
#endif /* HAVE_SYS_MMAN_H */
#endif /* COMMON_SCOPED_MMAP_H */
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