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src/share/vm/gc/g1/g1PageBasedVirtualSpace.cpp

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  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(ReservedSpace rs, size_t used_size, size_t page_size) :
  48   _low_boundary(NULL), _high_boundary(NULL), _committed(), _page_size(0), _special(false),
  49   _dirty(), _executable(false) {
  50   initialize_with_page_size(rs, used_size, page_size);
  51 }
  52 
  53 void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size) {
  54   guarantee(rs.is_reserved(), "Given reserved space must have been reserved already.");
  55 
  56   vmassert(_low_boundary == NULL, "VirtualSpace already initialized");
  57   vmassert(page_size > 0, "Page size must be non-zero.");
  58 
  59   guarantee(is_ptr_aligned(rs.base(), page_size),
  60             err_msg("Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size));
  61   guarantee(is_size_aligned(used_size, os::vm_page_size()),
  62             err_msg("Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size));
  63   guarantee(used_size <= rs.size(),
  64             err_msg("Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size()));
  65   guarantee(is_size_aligned(rs.size(), page_size),
  66             err_msg("Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size));
  67 
  68   _low_boundary  = rs.base();
  69   _high_boundary = _low_boundary + used_size;
  70 
  71   _special = rs.special();
  72   _executable = rs.executable();
  73 
  74   _page_size = page_size;
  75 
  76   vmassert(_committed.size() == 0, "virtual space initialized more than once");
  77   BitMap::idx_t size_in_pages = rs.size() / page_size;
  78   _committed.resize(size_in_pages, /* in_resource_area */ false);
  79   if (_special) {
  80     _dirty.resize(size_in_pages, /* in_resource_area */ false);
  81   }
  82 
  83   _tail_size = used_size % _page_size;
  84 }
  85 
  86 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {


 120 size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
 121   return (addr - _low_boundary) / _page_size;
 122 }
 123 
 124 bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const {
 125   size_t end_page = start_page + size_in_pages;
 126   return _committed.get_next_zero_offset(start_page, end_page) >= end_page;
 127 }
 128 
 129 bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const {
 130   size_t end_page = start_page + size_in_pages;
 131   return _committed.get_next_one_offset(start_page, end_page) >= end_page;
 132 }
 133 
 134 char* G1PageBasedVirtualSpace::page_start(size_t index) const {
 135   return _low_boundary + index * _page_size;
 136 }
 137 
 138 bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const {
 139   guarantee(index <= _committed.size(),
 140             err_msg("Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size()));
 141   return index == _committed.size();
 142 }
 143 
 144 void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) {
 145   vmassert(num_pages > 0, "No full pages to commit");
 146   vmassert(start + num_pages <= _committed.size(),
 147            err_msg("Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " "
 148                    "that is outside of managed space of " SIZE_FORMAT " pages",
 149                    start, start + num_pages, _committed.size()));
 150 
 151   char* start_addr = page_start(start);
 152   size_t size = num_pages * _page_size;
 153 
 154   os::commit_memory_or_exit(start_addr, size, _page_size, _executable,
 155                             err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
 156                                     p2i(start_addr), p2i(start_addr + size), size));
 157 }
 158 
 159 void G1PageBasedVirtualSpace::commit_tail() {
 160   vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here");
 161 
 162   char* const aligned_end_address = (char*)align_ptr_down(_high_boundary, _page_size);
 163   os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable,
 164                             err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
 165                                     p2i(aligned_end_address), p2i(_high_boundary), _tail_size));
 166 }
 167 
 168 void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) {
 169   guarantee(start_page < end_page,
 170             err_msg("Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page));
 171   guarantee(end_page <= _committed.size(),
 172             err_msg("Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size()));
 173 
 174   size_t pages = end_page - start_page;
 175   bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial();
 176 
 177   // If we have to commit some (partial) tail area, decrease the amount of pages to avoid
 178   // committing that in the full-page commit code.
 179   if (need_to_commit_tail) {
 180     pages--;
 181   }
 182 
 183   if (pages > 0) {
 184     commit_preferred_pages(start_page, pages);
 185   }
 186 
 187   if (need_to_commit_tail) {
 188     commit_tail();
 189   }
 190 }
 191 
 192 char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const {
 193   return MIN2(_high_boundary, page_start(end_page));
 194 }
 195 
 196 void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) {
 197   guarantee(start_page < end_page,
 198             err_msg("Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page));
 199 
 200   os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page));
 201 }
 202 
 203 bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) {
 204   // We need to make sure to commit all pages covered by the given area.
 205   guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted");
 206 
 207   bool zero_filled = true;
 208   size_t end_page = start_page + size_in_pages;
 209 
 210   if (_special) {
 211     // Check for dirty pages and update zero_filled if any found.
 212     if (_dirty.get_next_one_offset(start_page, end_page) < end_page) {
 213       zero_filled = false;
 214       _dirty.clear_range(start_page, end_page);
 215     }
 216   } else {
 217     commit_internal(start_page, end_page);
 218   }
 219   _committed.set_range(start_page, end_page);
 220 
 221   if (AlwaysPreTouch) {
 222     pretouch_internal(start_page, end_page);
 223   }
 224   return zero_filled;
 225 }
 226 
 227 void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) {
 228   guarantee(start_page < end_page,
 229             err_msg("Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page));
 230 
 231   char* start_addr = page_start(start_page);
 232   os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char)));
 233 }
 234 
 235 void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) {
 236   guarantee(is_area_committed(start_page, size_in_pages), "checking");
 237 
 238   size_t end_page = start_page + size_in_pages;
 239   if (_special) {
 240     // Mark that memory is dirty. If committed again the memory might
 241     // need to be cleared explicitly.
 242     _dirty.set_range(start_page, end_page);
 243   } else {
 244     uncommit_internal(start_page, end_page);
 245   }
 246 
 247   _committed.clear_range(start_page, end_page);
 248 }
 249 


  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(ReservedSpace rs, size_t used_size, size_t page_size) :
  48   _low_boundary(NULL), _high_boundary(NULL), _committed(), _page_size(0), _special(false),
  49   _dirty(), _executable(false) {
  50   initialize_with_page_size(rs, used_size, page_size);
  51 }
  52 
  53 void G1PageBasedVirtualSpace::initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size) {
  54   guarantee(rs.is_reserved(), "Given reserved space must have been reserved already.");
  55 
  56   vmassert(_low_boundary == NULL, "VirtualSpace already initialized");
  57   vmassert(page_size > 0, "Page size must be non-zero.");
  58 
  59   guarantee(is_ptr_aligned(rs.base(), page_size),
  60             "Reserved space base " PTR_FORMAT " is not aligned to requested page size " SIZE_FORMAT, p2i(rs.base()), page_size);
  61   guarantee(is_size_aligned(used_size, os::vm_page_size()),
  62             "Given used reserved space size needs to be OS page size aligned (%d bytes) but is " SIZE_FORMAT, os::vm_page_size(), used_size);
  63   guarantee(used_size <= rs.size(),
  64             "Used size of reserved space " SIZE_FORMAT " bytes is smaller than reservation at " SIZE_FORMAT " bytes", used_size, rs.size());
  65   guarantee(is_size_aligned(rs.size(), page_size),
  66             "Expected that the virtual space is size aligned, but " SIZE_FORMAT " is not aligned to page size " SIZE_FORMAT, rs.size(), page_size);
  67 
  68   _low_boundary  = rs.base();
  69   _high_boundary = _low_boundary + used_size;
  70 
  71   _special = rs.special();
  72   _executable = rs.executable();
  73 
  74   _page_size = page_size;
  75 
  76   vmassert(_committed.size() == 0, "virtual space initialized more than once");
  77   BitMap::idx_t size_in_pages = rs.size() / page_size;
  78   _committed.resize(size_in_pages, /* in_resource_area */ false);
  79   if (_special) {
  80     _dirty.resize(size_in_pages, /* in_resource_area */ false);
  81   }
  82 
  83   _tail_size = used_size % _page_size;
  84 }
  85 
  86 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {


 120 size_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
 121   return (addr - _low_boundary) / _page_size;
 122 }
 123 
 124 bool G1PageBasedVirtualSpace::is_area_committed(size_t start_page, size_t size_in_pages) const {
 125   size_t end_page = start_page + size_in_pages;
 126   return _committed.get_next_zero_offset(start_page, end_page) >= end_page;
 127 }
 128 
 129 bool G1PageBasedVirtualSpace::is_area_uncommitted(size_t start_page, size_t size_in_pages) const {
 130   size_t end_page = start_page + size_in_pages;
 131   return _committed.get_next_one_offset(start_page, end_page) >= end_page;
 132 }
 133 
 134 char* G1PageBasedVirtualSpace::page_start(size_t index) const {
 135   return _low_boundary + index * _page_size;
 136 }
 137 
 138 bool G1PageBasedVirtualSpace::is_after_last_page(size_t index) const {
 139   guarantee(index <= _committed.size(),
 140             "Given boundary page " SIZE_FORMAT " is beyond managed page count " SIZE_FORMAT, index, _committed.size());
 141   return index == _committed.size();
 142 }
 143 
 144 void G1PageBasedVirtualSpace::commit_preferred_pages(size_t start, size_t num_pages) {
 145   vmassert(num_pages > 0, "No full pages to commit");
 146   vmassert(start + num_pages <= _committed.size(),
 147            "Tried to commit area from page " SIZE_FORMAT " to page " SIZE_FORMAT " "
 148            "that is outside of managed space of " SIZE_FORMAT " pages",
 149            start, start + num_pages, _committed.size());
 150 
 151   char* start_addr = page_start(start);
 152   size_t size = num_pages * _page_size;
 153 
 154   os::commit_memory_or_exit(start_addr, size, _page_size, _executable,
 155                             err_msg("Failed to commit area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
 156                             p2i(start_addr), p2i(start_addr + size), size));
 157 }
 158 
 159 void G1PageBasedVirtualSpace::commit_tail() {
 160   vmassert(_tail_size > 0, "The size of the tail area must be > 0 when reaching here");
 161 
 162   char* const aligned_end_address = (char*)align_ptr_down(_high_boundary, _page_size);
 163   os::commit_memory_or_exit(aligned_end_address, _tail_size, os::vm_page_size(), _executable,
 164                             err_msg("Failed to commit tail area from " PTR_FORMAT " to " PTR_FORMAT " of length " SIZE_FORMAT ".",
 165                             p2i(aligned_end_address), p2i(_high_boundary), _tail_size));
 166 }
 167 
 168 void G1PageBasedVirtualSpace::commit_internal(size_t start_page, size_t end_page) {
 169   guarantee(start_page < end_page,
 170             "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
 171   guarantee(end_page <= _committed.size(),
 172             "Given end page " SIZE_FORMAT " is beyond end of managed page amount of " SIZE_FORMAT, end_page, _committed.size());
 173 
 174   size_t pages = end_page - start_page;
 175   bool need_to_commit_tail = is_after_last_page(end_page) && is_last_page_partial();
 176 
 177   // If we have to commit some (partial) tail area, decrease the amount of pages to avoid
 178   // committing that in the full-page commit code.
 179   if (need_to_commit_tail) {
 180     pages--;
 181   }
 182 
 183   if (pages > 0) {
 184     commit_preferred_pages(start_page, pages);
 185   }
 186 
 187   if (need_to_commit_tail) {
 188     commit_tail();
 189   }
 190 }
 191 
 192 char* G1PageBasedVirtualSpace::bounded_end_addr(size_t end_page) const {
 193   return MIN2(_high_boundary, page_start(end_page));
 194 }
 195 
 196 void G1PageBasedVirtualSpace::pretouch_internal(size_t start_page, size_t end_page) {
 197   guarantee(start_page < end_page,
 198             "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
 199 
 200   os::pretouch_memory(page_start(start_page), bounded_end_addr(end_page));
 201 }
 202 
 203 bool G1PageBasedVirtualSpace::commit(size_t start_page, size_t size_in_pages) {
 204   // We need to make sure to commit all pages covered by the given area.
 205   guarantee(is_area_uncommitted(start_page, size_in_pages), "Specified area is not uncommitted");
 206 
 207   bool zero_filled = true;
 208   size_t end_page = start_page + size_in_pages;
 209 
 210   if (_special) {
 211     // Check for dirty pages and update zero_filled if any found.
 212     if (_dirty.get_next_one_offset(start_page, end_page) < end_page) {
 213       zero_filled = false;
 214       _dirty.clear_range(start_page, end_page);
 215     }
 216   } else {
 217     commit_internal(start_page, end_page);
 218   }
 219   _committed.set_range(start_page, end_page);
 220 
 221   if (AlwaysPreTouch) {
 222     pretouch_internal(start_page, end_page);
 223   }
 224   return zero_filled;
 225 }
 226 
 227 void G1PageBasedVirtualSpace::uncommit_internal(size_t start_page, size_t end_page) {
 228   guarantee(start_page < end_page,
 229             "Given start page " SIZE_FORMAT " is larger or equal to end page " SIZE_FORMAT, start_page, end_page);
 230 
 231   char* start_addr = page_start(start_page);
 232   os::uncommit_memory(start_addr, pointer_delta(bounded_end_addr(end_page), start_addr, sizeof(char)));
 233 }
 234 
 235 void G1PageBasedVirtualSpace::uncommit(size_t start_page, size_t size_in_pages) {
 236   guarantee(is_area_committed(start_page, size_in_pages), "checking");
 237 
 238   size_t end_page = start_page + size_in_pages;
 239   if (_special) {
 240     // Mark that memory is dirty. If committed again the memory might
 241     // need to be cleared explicitly.
 242     _dirty.set_range(start_page, end_page);
 243   } else {
 244     uncommit_internal(start_page, end_page);
 245   }
 246 
 247   _committed.clear_range(start_page, end_page);
 248 }
 249 
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