| 1 | /* scoped_mmap, automatically unmap files |
| 2 | |
| 3 | Copyright (C) 2018 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #ifndef SCOPED_MMAP_H |
| 21 | #define SCOPED_MMAP_H |
| 22 | |
| 23 | #include "config.h" |
| 24 | |
| 25 | #ifdef HAVE_SYS_MMAN_H |
| 26 | |
| 27 | #include <sys/mman.h> |
| 28 | |
| 29 | /* A smart-pointer-like class to mmap() and automatically munmap() a memory |
| 30 | mapping. */ |
| 31 | |
| 32 | class scoped_mmap |
| 33 | { |
| 34 | public: |
| 35 | scoped_mmap () noexcept : m_mem (MAP_FAILED), m_length (0) {} |
| 36 | scoped_mmap (void *addr, size_t length, int prot, int flags, int fd, |
| 37 | off_t offset) noexcept : m_length (length) |
| 38 | { |
| 39 | m_mem = mmap (addr, m_length, prot, flags, fd, offset); |
| 40 | } |
| 41 | |
| 42 | ~scoped_mmap () |
| 43 | { |
| 44 | destroy (); |
| 45 | } |
| 46 | |
| 47 | scoped_mmap (scoped_mmap &&rhs) |
| 48 | { |
| 49 | destroy (); |
| 50 | |
| 51 | m_mem = rhs.m_mem; |
| 52 | m_length = rhs.m_length; |
| 53 | |
| 54 | rhs.m_mem = MAP_FAILED; |
| 55 | rhs.m_length = 0; |
| 56 | } |
| 57 | |
| 58 | DISABLE_COPY_AND_ASSIGN (scoped_mmap); |
| 59 | |
| 60 | void *release () noexcept |
| 61 | { |
| 62 | void *mem = m_mem; |
| 63 | m_mem = MAP_FAILED; |
| 64 | m_length = 0; |
| 65 | return mem; |
| 66 | } |
| 67 | |
| 68 | void reset (void *addr, size_t length, int prot, int flags, int fd, |
| 69 | off_t offset) noexcept |
| 70 | { |
| 71 | destroy (); |
| 72 | |
| 73 | m_length = length; |
| 74 | m_mem = mmap (addr, m_length, prot, flags, fd, offset); |
| 75 | } |
| 76 | |
| 77 | size_t size () const noexcept { return m_length; } |
| 78 | void *get () const noexcept { return m_mem; } |
| 79 | |
| 80 | private: |
| 81 | void destroy () |
| 82 | { |
| 83 | if (m_mem != MAP_FAILED) |
| 84 | munmap (m_mem, m_length); |
| 85 | } |
| 86 | |
| 87 | void *m_mem; |
| 88 | size_t m_length; |
| 89 | }; |
| 90 | |
| 91 | /* Map FILENAME in memory. Throw an error if anything goes wrong. */ |
| 92 | scoped_mmap mmap_file (const char *filename); |
| 93 | |
| 94 | #endif /* HAVE_SYS_MMAN_H */ |
| 95 | #endif /* SCOPED_MMAP_H */ |