binutils-gdb/gdb/common/scoped_mmap.h
Markus Metzger 84696f37ae common: add scoped_mmap
Add a simple helper to automatically unmap a memory mapping.

gdb/
	* common/scoped_mmap.h: New.
	* unittests/scoped_mmap-selftest.c: New.
	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	unittests/scoped_mmap-selftest.c.
2018-02-09 14:03:19 +01:00

77 lines
1.9 KiB
C++

/* scoped_mmap, automatically unmap files
Copyright (C) 2018 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 SCOPED_MMAP_H
#define SCOPED_MMAP_H
#include "config.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 ()
{
if (m_mem != MAP_FAILED)
munmap (m_mem, m_length);
}
DISABLE_COPY_AND_ASSIGN (scoped_mmap);
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
{
if (m_mem != MAP_FAILED)
munmap (m_mem, m_length);
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 *m_mem;
size_t m_length;
};
#endif /* HAVE_SYS_MMAN_H */
#endif /* SCOPED_MMAP_H */