1 /*
   2  * Copyright (c) 2014, 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 
  25 #include "precompiled.hpp"
  26 #include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp"
  27 #include "oops/markOop.hpp"
  28 #include "oops/oop.inline.hpp"
  29 #include "services/memTracker.hpp"
  30 #ifdef TARGET_OS_FAMILY_linux
  31 # include "os_linux.inline.hpp"
  32 #endif
  33 #ifdef TARGET_OS_FAMILY_solaris
  34 # include "os_solaris.inline.hpp"
  35 #endif
  36 #ifdef TARGET_OS_FAMILY_windows
  37 # include "os_windows.inline.hpp"
  38 #endif
  39 #ifdef TARGET_OS_FAMILY_aix
  40 # include "os_aix.inline.hpp"
  41 #endif
  42 #ifdef TARGET_OS_FAMILY_bsd
  43 # include "os_bsd.inline.hpp"
  44 #endif
  45 #include "utilities/bitMap.inline.hpp"
  46 
  47 G1PageBasedVirtualSpace::G1PageBasedVirtualSpace() : _low_boundary(NULL),
  48   _high_boundary(NULL), _committed(), _page_size(0), _special(false),
  49   _dirty(), _executable(false) {
  50 }
  51 
  52 bool G1PageBasedVirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t page_size) {
  53   if (!rs.is_reserved()) {
  54     return false;  // Allocation failed.
  55   }
  56   assert(_low_boundary == NULL, "VirtualSpace already initialized");
  57   assert(page_size > 0, "Granularity must be non-zero.");
  58 
  59   _low_boundary  = rs.base();
  60   _high_boundary = _low_boundary + rs.size();
  61 
  62   _special = rs.special();
  63   _executable = rs.executable();
  64 
  65   _page_size = page_size;
  66 
  67   assert(_committed.size() == 0, "virtual space initialized more than once");
  68   uintx size_in_bits = rs.size() / page_size;
  69   _committed.resize(size_in_bits, /* in_resource_area */ false);
  70   if (_special) {
  71     _dirty.resize(size_in_bits, /* in_resource_area */ false);
  72   }
  73 
  74   return true;
  75 }
  76 
  77 
  78 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {
  79   release();
  80 }
  81 
  82 void G1PageBasedVirtualSpace::release() {
  83   // This does not release memory it never reserved.
  84   // Caller must release via rs.release();
  85   _low_boundary           = NULL;
  86   _high_boundary          = NULL;
  87   _special                = false;
  88   _executable             = false;
  89   _page_size              = 0;
  90   _committed.resize(0, false);
  91   _dirty.resize(0, false);
  92 }
  93 
  94 size_t G1PageBasedVirtualSpace::committed_size() const {
  95   return _committed.count_one_bits() * _page_size;
  96 }
  97 
  98 size_t G1PageBasedVirtualSpace::reserved_size() const {
  99   return pointer_delta(_high_boundary, _low_boundary, sizeof(char));
 100 }
 101 
 102 size_t G1PageBasedVirtualSpace::uncommitted_size()  const {
 103   return reserved_size() - committed_size();
 104 }
 105 
 106 uintptr_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
 107   return (addr - _low_boundary) / _page_size;
 108 }
 109 
 110 bool G1PageBasedVirtualSpace::is_area_committed(uintptr_t start, size_t size_in_pages) const {
 111   uintptr_t end = start + size_in_pages;
 112   return _committed.get_next_zero_offset(start, end) >= end;
 113 }
 114 
 115 bool G1PageBasedVirtualSpace::is_area_uncommitted(uintptr_t start, size_t size_in_pages) const {
 116   uintptr_t end = start + size_in_pages;
 117   return _committed.get_next_one_offset(start, end) >= end;
 118 }
 119 
 120 char* G1PageBasedVirtualSpace::page_start(uintptr_t index) {
 121   return _low_boundary + index * _page_size;
 122 }
 123 
 124 size_t G1PageBasedVirtualSpace::byte_size_for_pages(size_t num) {
 125   return num * _page_size;
 126 }
 127 
 128 bool G1PageBasedVirtualSpace::commit(uintptr_t start, size_t size_in_pages) {
 129   // We need to make sure to commit all pages covered by the given area.
 130   guarantee(is_area_uncommitted(start, size_in_pages), "Specified area is not uncommitted");
 131 
 132   bool zero_filled = true;
 133   uintptr_t end = start + size_in_pages;
 134 
 135   if (_special) {
 136     // Check for dirty pages and update zero_filled if any found.
 137     if (_dirty.get_next_one_offset(start,end) < end) {
 138       zero_filled = false;
 139       _dirty.clear_range(start, end);
 140     }
 141   } else {
 142     os::commit_memory_or_exit(page_start(start), byte_size_for_pages(size_in_pages), _executable,
 143                               err_msg("Failed to commit pages from "SIZE_FORMAT" of length "SIZE_FORMAT, start, size_in_pages));
 144   }
 145   _committed.set_range(start, end);
 146 
 147   return zero_filled;
 148 }
 149 
 150 void G1PageBasedVirtualSpace::uncommit(uintptr_t start, size_t size_in_pages) {
 151   guarantee(is_area_committed(start, size_in_pages), "checking");
 152 
 153   if (_special) {
 154     // Mark that memory is dirty. If committed again the memory might
 155     // need to be cleared explicitly.
 156     _dirty.set_range(start, start + size_in_pages);
 157   } else {
 158     os::uncommit_memory(page_start(start), byte_size_for_pages(size_in_pages));
 159   }
 160 
 161   _committed.clear_range(start, start + size_in_pages);
 162 }
 163 
 164 bool G1PageBasedVirtualSpace::contains(const void* p) const {
 165   return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;
 166 }
 167 
 168 #ifndef PRODUCT
 169 void G1PageBasedVirtualSpace::print_on(outputStream* out) {
 170   out->print   ("Virtual space:");
 171   if (_special) out->print(" (pinned in memory)");
 172   out->cr();
 173   out->print_cr(" - committed: " SIZE_FORMAT, committed_size());
 174   out->print_cr(" - reserved:  " SIZE_FORMAT, reserved_size());
 175   out->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]",  p2i(_low_boundary), p2i(_high_boundary));
 176 }
 177 
 178 void G1PageBasedVirtualSpace::print() {
 179   print_on(tty);
 180 }
 181 #endif