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.
This commit is contained in:
Markus Metzger
parent
ea4a088812
commit
84696f37ae
4 changed files with 176 additions and 0 deletions
|
|
@ -1,3 +1,10 @@
|
|||
2018-02-09 Markus Metzger <markus.t.metzger@intel.com>
|
||||
|
||||
* 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 Markus Metzger <markus.t.metzger@intel.com>
|
||||
|
||||
* common/scoped_fd.h: New.
|
||||
|
|
|
|||
|
|
@ -425,6 +425,7 @@ SUBDIR_UNITTESTS_SRCS = \
|
|||
unittests/ptid-selftests.c \
|
||||
unittests/rsp-low-selftests.c \
|
||||
unittests/scoped_fd-selftests.c \
|
||||
unittests/scoped_mmap-selftests.c \
|
||||
unittests/scoped_restore-selftests.c \
|
||||
unittests/xml-utils-selftests.c
|
||||
|
||||
|
|
|
|||
76
gdb/common/scoped_mmap.h
Normal file
76
gdb/common/scoped_mmap.h
Normal file
|
|
@ -0,0 +1,76 @@
|
|||
/* 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 */
|
||||
92
gdb/unittests/scoped_mmap-selftests.c
Normal file
92
gdb/unittests/scoped_mmap-selftests.c
Normal file
|
|
@ -0,0 +1,92 @@
|
|||
/* Self tests for scoped_mmap for GDB, the GNU debugger.
|
||||
|
||||
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/>. */
|
||||
|
||||
#include "defs.h"
|
||||
|
||||
#include "common/scoped_mmap.h"
|
||||
#include "config.h"
|
||||
|
||||
#if defined(HAVE_SYS_MMAN_H) && defined(HAVE_UNISTD_H)
|
||||
|
||||
#include "selftest.h"
|
||||
|
||||
#include <unistd.h>
|
||||
|
||||
namespace selftests {
|
||||
namespace scoped_mmap {
|
||||
|
||||
/* Test that the file is unmapped. */
|
||||
static void
|
||||
test_destroy ()
|
||||
{
|
||||
void *mem;
|
||||
|
||||
errno = 0;
|
||||
{
|
||||
::scoped_mmap smmap (nullptr, sysconf (_SC_PAGESIZE), PROT_WRITE,
|
||||
MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
|
||||
|
||||
mem = smmap.get ();
|
||||
SELF_CHECK (mem != nullptr);
|
||||
}
|
||||
|
||||
SELF_CHECK (msync (mem, sysconf (_SC_PAGESIZE), 0) == -1 && errno == ENOMEM);
|
||||
}
|
||||
|
||||
/* Test that the memory can be released. */
|
||||
static void
|
||||
test_release ()
|
||||
{
|
||||
void *mem;
|
||||
|
||||
errno = 0;
|
||||
{
|
||||
::scoped_mmap smmap (nullptr, sysconf (_SC_PAGESIZE), PROT_WRITE,
|
||||
MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
|
||||
|
||||
mem = smmap.release ();
|
||||
SELF_CHECK (mem != nullptr);
|
||||
}
|
||||
|
||||
SELF_CHECK (msync (mem, sysconf (_SC_PAGESIZE), 0) == 0 || errno != ENOMEM);
|
||||
|
||||
munmap (mem, sysconf (_SC_PAGESIZE));
|
||||
}
|
||||
|
||||
/* Run selftests. */
|
||||
static void
|
||||
run_tests ()
|
||||
{
|
||||
test_destroy ();
|
||||
test_release ();
|
||||
}
|
||||
|
||||
} /* namespace scoped_mmap */
|
||||
} /* namespace selftests */
|
||||
|
||||
#endif /* !defined(HAVE_SYS_MMAN_H) || !defined(HAVE_UNISTD_H) */
|
||||
|
||||
void
|
||||
_initialize_scoped_mmap_selftests ()
|
||||
{
|
||||
#if defined(HAVE_SYS_MMAN_H) && defined(HAVE_UNISTD_H)
|
||||
selftests::register_test ("scoped_mmap",
|
||||
selftests::scoped_mmap::run_tests);
|
||||
#endif
|
||||
}
|
||||
Loading…
Add table
Reference in a new issue