1 /* 2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 #ifndef OS_BSD_GC_Z_ZBACKINGFILE_BSD_HPP 25 #define OS_BSD_GC_Z_ZBACKINGFILE_BSD_HPP 26 27 #include "memory/allocation.hpp" 28 29 class ZPhysicalMemory; 30 31 // On macOS, we use a virtual backing file. It is represented by a reserved virtual 32 // address space, in which we commit physical memory using the mach_vm_map() API. 33 // The multi-mapping API simply remaps these addresses using mach_vm_remap() into 34 // the different heap views. This works as-if there was a backing file, it's just 35 // that the file is represented with memory mappings instead. 36 37 class ZBackingFile { 38 private: 39 uintptr_t _base; 40 size_t _size; 41 bool _initialized; 42 43 bool commit_inner(size_t offset, size_t length); 44 45 public: 46 ZBackingFile(); 47 48 bool is_initialized() const; 49 50 size_t size() const; 51 52 size_t commit(size_t offset, size_t length); 53 size_t uncommit(size_t offset, size_t length); 54 55 void map(uintptr_t addr, size_t size, uintptr_t offset) const; 56 void unmap(uintptr_t addr, size_t size) const; 57 }; 58 59 #endif // OS_BSD_GC_Z_ZBACKINGFILE_BSD_HPP