1 /*
   2  * Copyright (c) 2015, 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_CPU_LINUX_X86_GC_Z_ZBACKINGFILE_LINUX_X86_HPP
  25 #define OS_CPU_LINUX_X86_GC_Z_ZBACKINGFILE_LINUX_X86_HPP
  26 
  27 #include "memory/allocation.hpp"
  28 
  29 class ZErrno;
  30 
  31 class ZBackingFile {
  32 private:
  33   int      _fd;
  34   size_t   _size;
  35   uint64_t _filesystem;
  36   size_t   _block_size;
  37   size_t   _available;
  38   bool     _initialized;
  39 
  40   int create_mem_fd(const char* name) const;
  41   int create_file_fd(const char* name) const;
  42   int create_fd(const char* name) const;
  43 
  44   bool is_tmpfs() const;
  45   bool is_hugetlbfs() const;
  46   bool tmpfs_supports_transparent_huge_pages() const;
  47 
  48   ZErrno fallocate_compat_ftruncate(size_t size) const;
  49   ZErrno fallocate_compat_mmap(size_t offset, size_t length, bool reserve_only) const;
  50   ZErrno fallocate_compat_pwrite(size_t offset, size_t length) const;
  51   ZErrno fallocate_fill_hole_compat(size_t offset, size_t length);
  52   ZErrno fallocate_fill_hole_syscall(size_t offset, size_t length);
  53   ZErrno fallocate_fill_hole(size_t offset, size_t length);
  54   ZErrno fallocate_punch_hole(size_t offset, size_t length);
  55   ZErrno split_and_fallocate(bool punch_hole, size_t offset, size_t length);
  56   ZErrno fallocate(bool punch_hole, size_t offset, size_t length);
  57 
  58   bool commit_inner(size_t offset, size_t length);
  59 
  60 public:
  61   ZBackingFile();
  62 
  63   bool is_initialized() const;
  64 
  65   int fd() const;
  66   size_t size() const;
  67   size_t available() const;
  68 
  69   size_t commit(size_t offset, size_t length);
  70   size_t uncommit(size_t offset, size_t length);
  71 };
  72 
  73 #endif // OS_CPU_LINUX_X86_GC_Z_ZBACKINGFILE_LINUX_X86_HPP