1/* scoped_mmap, automatically unmap files 2 3 Copyright (C) 2018-2023 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 COMMON_SCOPED_MMAP_H 21#define COMMON_SCOPED_MMAP_H 22 23#ifdef HAVE_SYS_MMAN_H 24 25#include <sys/mman.h> 26 27/* A smart-pointer-like class to mmap() and automatically munmap() a memory 28 mapping. */ 29 30class scoped_mmap 31{ 32public: 33 scoped_mmap () noexcept : m_mem (MAP_FAILED), m_length (0) {} 34 scoped_mmap (void *addr, size_t length, int prot, int flags, int fd, 35 off_t offset) noexcept : m_length (length) 36 { 37 m_mem = mmap (addr, m_length, prot, flags, fd, offset); 38 } 39 40 ~scoped_mmap () 41 { 42 destroy (); 43 } 44 45 scoped_mmap (scoped_mmap &&rhs) noexcept 46 : m_mem (rhs.m_mem), 47 m_length (rhs.m_length) 48 { 49 rhs.m_mem = MAP_FAILED; 50 rhs.m_length = 0; 51 } 52 53 DISABLE_COPY_AND_ASSIGN (scoped_mmap); 54 55 ATTRIBUTE_UNUSED_RESULT void *release () noexcept 56 { 57 void *mem = m_mem; 58 m_mem = MAP_FAILED; 59 m_length = 0; 60 return mem; 61 } 62 63 void reset (void *addr, size_t length, int prot, int flags, int fd, 64 off_t offset) noexcept 65 { 66 destroy (); 67 68 m_length = length; 69 m_mem = mmap (addr, m_length, prot, flags, fd, offset); 70 } 71 72 size_t size () const noexcept { return m_length; } 73 void *get () const noexcept { return m_mem; } 74 75private: 76 void destroy () 77 { 78 if (m_mem != MAP_FAILED) 79 munmap (m_mem, m_length); 80 } 81 82 void *m_mem; 83 size_t m_length; 84}; 85 86/* Map FILENAME in memory. Throw an error if anything goes wrong. */ 87scoped_mmap mmap_file (const char *filename); 88 89#endif /* HAVE_SYS_MMAN_H */ 90 91#endif /* COMMON_SCOPED_MMAP_H */ 92