src/share/vm/gc_implementation/parallelScavenge/parMarkBitMap.cpp

Sat, 08 Oct 2016 09:31:28 -0400

author
fujie
date
Sat, 08 Oct 2016 09:31:28 -0400
changeset 124
9d7e35a93fad
parent 0
f90c822e73f8
child 6876
710a3c8b516e
permissions
-rw-r--r--

The parallel GC mark-phase should be MT-safe for 3A2000.

     1 /*
     2  * Copyright (c) 2005, 2013, 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  */
    25 #include "precompiled.hpp"
    26 #include "gc_implementation/parallelScavenge/parMarkBitMap.hpp"
    27 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
    28 #include "oops/oop.inline.hpp"
    29 #include "runtime/os.hpp"
    30 #include "utilities/bitMap.inline.hpp"
    31 #include "services/memTracker.hpp"
    32 #ifdef TARGET_OS_FAMILY_linux
    33 # include "os_linux.inline.hpp"
    34 #endif
    35 #ifdef TARGET_OS_FAMILY_solaris
    36 # include "os_solaris.inline.hpp"
    37 #endif
    38 #ifdef TARGET_OS_FAMILY_windows
    39 # include "os_windows.inline.hpp"
    40 #endif
    41 #ifdef TARGET_OS_FAMILY_aix
    42 # include "os_aix.inline.hpp"
    43 #endif
    44 #ifdef TARGET_OS_FAMILY_bsd
    45 # include "os_bsd.inline.hpp"
    46 #endif
    48 bool
    49 ParMarkBitMap::initialize(MemRegion covered_region)
    50 {
    51   const idx_t bits = bits_required(covered_region);
    52   // The bits will be divided evenly between two bitmaps; each of them should be
    53   // an integral number of words.
    54   assert(bits % (BitsPerWord * 2) == 0, "region size unaligned");
    56   const size_t words = bits / BitsPerWord;
    57   const size_t raw_bytes = words * sizeof(idx_t);
    58   const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10);
    59   const size_t granularity = os::vm_allocation_granularity();
    60   _reserved_byte_size = align_size_up(raw_bytes, MAX2(page_sz, granularity));
    62   const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 :
    63     MAX2(page_sz, granularity);
    64   ReservedSpace rs(_reserved_byte_size, rs_align, rs_align > 0);
    65   os::trace_page_sizes("par bitmap", raw_bytes, raw_bytes, page_sz,
    66                        rs.base(), rs.size());
    68   MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
    70   _virtual_space = new PSVirtualSpace(rs, page_sz);
    71   if (_virtual_space != NULL && _virtual_space->expand_by(_reserved_byte_size)) {
    72     _region_start = covered_region.start();
    73     _region_size = covered_region.word_size();
    74     idx_t* map = (idx_t*)_virtual_space->reserved_low_addr();
    75     _beg_bits.set_map(map);
    76     _beg_bits.set_size(bits / 2);
    77     _end_bits.set_map(map + words / 2);
    78     _end_bits.set_size(bits / 2);
    79     return true;
    80   }
    82   _region_start = 0;
    83   _region_size = 0;
    84   if (_virtual_space != NULL) {
    85     delete _virtual_space;
    86     _virtual_space = NULL;
    87     // Release memory reserved in the space.
    88     rs.release();
    89   }
    90   return false;
    91 }
    93 #ifdef ASSERT
    94 extern size_t mark_bitmap_count;
    95 extern size_t mark_bitmap_size;
    96 #endif  // #ifdef ASSERT
    98 bool
    99 ParMarkBitMap::mark_obj(HeapWord* addr, size_t size)
   100 {
   101   const idx_t beg_bit = addr_to_bit(addr);
   102   if (_beg_bits.par_set_bit(beg_bit)) {
   103     const idx_t end_bit = addr_to_bit(addr + size - 1);
   104     bool end_bit_ok = _end_bits.par_set_bit(end_bit);
   105     assert(end_bit_ok, "concurrency problem");
   106     DEBUG_ONLY(Atomic::inc_ptr(&mark_bitmap_count));
   107     DEBUG_ONLY(Atomic::add_ptr(size, &mark_bitmap_size));
   108 #ifdef MIPS64
   109     if (Use3A2000) OrderAccess::fence();
   110 #endif 
   111     return true;
   112   }
   113   return false;
   114 }
   116 size_t ParMarkBitMap::live_words_in_range(HeapWord* beg_addr, oop end_obj) const
   117 {
   118   assert(beg_addr <= (HeapWord*)end_obj, "bad range");
   119   assert(is_marked(end_obj), "end_obj must be live");
   121   idx_t live_bits = 0;
   123   // The bitmap routines require the right boundary to be word-aligned.
   124   const idx_t end_bit = addr_to_bit((HeapWord*)end_obj);
   125   const idx_t range_end = BitMap::word_align_up(end_bit);
   127   idx_t beg_bit = find_obj_beg(addr_to_bit(beg_addr), range_end);
   128   while (beg_bit < end_bit) {
   129     idx_t tmp_end = find_obj_end(beg_bit, range_end);
   130     assert(tmp_end < end_bit, "missing end bit");
   131     live_bits += tmp_end - beg_bit + 1;
   132     beg_bit = find_obj_beg(tmp_end + 1, range_end);
   133   }
   134   return bits_to_words(live_bits);
   135 }
   137 ParMarkBitMap::IterationStatus
   138 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
   139                        idx_t range_beg, idx_t range_end) const
   140 {
   141   DEBUG_ONLY(verify_bit(range_beg);)
   142   DEBUG_ONLY(verify_bit(range_end);)
   143   assert(range_beg <= range_end, "live range invalid");
   145   // The bitmap routines require the right boundary to be word-aligned.
   146   const idx_t search_end = BitMap::word_align_up(range_end);
   148   idx_t cur_beg = find_obj_beg(range_beg, search_end);
   149   while (cur_beg < range_end) {
   150     const idx_t cur_end = find_obj_end(cur_beg, search_end);
   151     if (cur_end >= range_end) {
   152       // The obj ends outside the range.
   153       live_closure->set_source(bit_to_addr(cur_beg));
   154       return incomplete;
   155     }
   157     const size_t size = obj_size(cur_beg, cur_end);
   158     IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
   159     if (status != incomplete) {
   160       assert(status == would_overflow || status == full, "sanity");
   161       return status;
   162     }
   164     // Successfully processed the object; look for the next object.
   165     cur_beg = find_obj_beg(cur_end + 1, search_end);
   166   }
   168   live_closure->set_source(bit_to_addr(range_end));
   169   return complete;
   170 }
   172 ParMarkBitMap::IterationStatus
   173 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
   174                        ParMarkBitMapClosure* dead_closure,
   175                        idx_t range_beg, idx_t range_end,
   176                        idx_t dead_range_end) const
   177 {
   178   DEBUG_ONLY(verify_bit(range_beg);)
   179   DEBUG_ONLY(verify_bit(range_end);)
   180   DEBUG_ONLY(verify_bit(dead_range_end);)
   181   assert(range_beg <= range_end, "live range invalid");
   182   assert(range_end <= dead_range_end, "dead range invalid");
   184   // The bitmap routines require the right boundary to be word-aligned.
   185   const idx_t live_search_end = BitMap::word_align_up(range_end);
   186   const idx_t dead_search_end = BitMap::word_align_up(dead_range_end);
   188   idx_t cur_beg = range_beg;
   189   if (range_beg < range_end && is_unmarked(range_beg)) {
   190     // The range starts with dead space.  Look for the next object, then fill.
   191     cur_beg = find_obj_beg(range_beg + 1, dead_search_end);
   192     const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
   193     const size_t size = obj_size(range_beg, dead_space_end);
   194     dead_closure->do_addr(bit_to_addr(range_beg), size);
   195   }
   197   while (cur_beg < range_end) {
   198     const idx_t cur_end = find_obj_end(cur_beg, live_search_end);
   199     if (cur_end >= range_end) {
   200       // The obj ends outside the range.
   201       live_closure->set_source(bit_to_addr(cur_beg));
   202       return incomplete;
   203     }
   205     const size_t size = obj_size(cur_beg, cur_end);
   206     IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
   207     if (status != incomplete) {
   208       assert(status == would_overflow || status == full, "sanity");
   209       return status;
   210     }
   212     // Look for the start of the next object.
   213     const idx_t dead_space_beg = cur_end + 1;
   214     cur_beg = find_obj_beg(dead_space_beg, dead_search_end);
   215     if (cur_beg > dead_space_beg) {
   216       // Found dead space; compute the size and invoke the dead closure.
   217       const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
   218       const size_t size = obj_size(dead_space_beg, dead_space_end);
   219       dead_closure->do_addr(bit_to_addr(dead_space_beg), size);
   220     }
   221   }
   223   live_closure->set_source(bit_to_addr(range_end));
   224   return complete;
   225 }
   227 #ifdef ASSERT
   228 void ParMarkBitMap::verify_clear() const
   229 {
   230   const idx_t* const beg = (const idx_t*)_virtual_space->committed_low_addr();
   231   const idx_t* const end = (const idx_t*)_virtual_space->committed_high_addr();
   232   for (const idx_t* p = beg; p < end; ++p) {
   233     assert(*p == 0, "bitmap not clear");
   234   }
   235 }
   236 #endif  // #ifdef ASSERT

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