jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegion.inline.hpp@2c6ef90f030a (annotated)

src/share/vm/gc_implementation/g1/heapRegion.inline.hpp@2c6ef90f030a (annotated)

src/share/vm/gc_implementation/g1/heapRegion.inline.hpp

Mon, 07 Jul 2014 10:12:40 +0200

author: stefank
date: Mon, 07 Jul 2014 10:12:40 +0200
changeset 6992: 2c6ef90f030a
parent 6990: 1526a938e670
child 6996: f3aeae1f9fc5
permissions: -rw-r--r--

8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

 /*
  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP
 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.hpp"
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "memory/space.hpp"
 #include "runtime/atomic.inline.hpp"
 // This version requires locking.
 inline HeapWord* G1OffsetTableContigSpace::allocate_impl(size_t size,
                                                 HeapWord* const end_value) {
   HeapWord* obj = top();
   if (pointer_delta(end_value, obj) >= size) {
     HeapWord* new_top = obj + size;
     set_top(new_top);
     assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
     return obj;
   } else {
     return NULL;
   }
 }
 // This version is lock-free.
 inline HeapWord* G1OffsetTableContigSpace::par_allocate_impl(size_t size,
                                                     HeapWord* const end_value) {
   do {
     HeapWord* obj = top();
     if (pointer_delta(end_value, obj) >= size) {
       HeapWord* new_top = obj + size;
       HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
       // result can be one of two:
       //  the old top value: the exchange succeeded
       //  otherwise: the new value of the top is returned.
       if (result == obj) {
         assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
         return obj;
       }
     } else {
       return NULL;
     }
   } while (true);
 }
 inline HeapWord* G1OffsetTableContigSpace::allocate(size_t size) {
   HeapWord* res = allocate_impl(size, end());
   if (res != NULL) {
     _offsets.alloc_block(res, size);
   }
   return res;
 }
 // Because of the requirement of keeping "_offsets" up to date with the
 // allocations, we sequentialize these with a lock.  Therefore, best if
 // this is used for larger LAB allocations only.
 inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t size) {
   MutexLocker x(&_par_alloc_lock);
   return allocate(size);
 }
 inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
   return _offsets.block_start(p);
 }
 inline HeapWord*
 G1OffsetTableContigSpace::block_start_const(const void* p) const {
   return _offsets.block_start_const(p);
 }
 inline bool
 HeapRegion::block_is_obj(const HeapWord* p) const {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   return !g1h->is_obj_dead(oop(p), this);
 }
 inline size_t
 HeapRegion::block_size(const HeapWord *addr) const {
   // Old regions' dead objects may have dead classes
   // We need to find the next live object in some other
   // manner than getting the oop size
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   if (g1h->is_obj_dead(oop(addr), this)) {
     HeapWord* next = g1h->concurrent_mark()->prevMarkBitMap()->
         getNextMarkedWordAddress(addr, prev_top_at_mark_start());
     assert(next > addr, "must get the next live object");
     return pointer_delta(next, addr);
   } else if (addr == top()) {
     return pointer_delta(end(), addr);
   }
   return oop(addr)->size();
 }
 inline HeapWord* HeapRegion::par_allocate_no_bot_updates(size_t word_size) {
   assert(is_young(), "we can only skip BOT updates on young regions");
   return par_allocate_impl(word_size, end());
 }
 inline HeapWord* HeapRegion::allocate_no_bot_updates(size_t word_size) {
   assert(is_young(), "we can only skip BOT updates on young regions");
   return allocate_impl(word_size, end());
 }
 inline void HeapRegion::note_start_of_marking() {
   _next_marked_bytes = 0;
   _next_top_at_mark_start = top();
 }
 inline void HeapRegion::note_end_of_marking() {
   _prev_top_at_mark_start = _next_top_at_mark_start;
   _prev_marked_bytes = _next_marked_bytes;
   _next_marked_bytes = 0;
   assert(_prev_marked_bytes <=
          (size_t) pointer_delta(prev_top_at_mark_start(), bottom()) *
          HeapWordSize, "invariant");
 }
 inline void HeapRegion::note_start_of_copying(bool during_initial_mark) {
   if (is_survivor()) {
     // This is how we always allocate survivors.
     assert(_next_top_at_mark_start == bottom(), "invariant");
   } else {
     if (during_initial_mark) {
       // During initial-mark we'll explicitly mark any objects on old
       // regions that are pointed to by roots. Given that explicit
       // marks only make sense under NTAMS it'd be nice if we could
       // check that condition if we wanted to. Given that we don't
       // know where the top of this region will end up, we simply set
       // NTAMS to the end of the region so all marks will be below
       // NTAMS. We'll set it to the actual top when we retire this region.
       _next_top_at_mark_start = end();
     } else {
       // We could have re-used this old region as to-space over a
       // couple of GCs since the start of the concurrent marking
       // cycle. This means that [bottom,NTAMS) will contain objects
       // copied up to and including initial-mark and [NTAMS, top)
       // will contain objects copied during the concurrent marking cycle.
       assert(top() >= _next_top_at_mark_start, "invariant");
     }
   }
 }
 inline void HeapRegion::note_end_of_copying(bool during_initial_mark) {
   if (is_survivor()) {
     // This is how we always allocate survivors.
     assert(_next_top_at_mark_start == bottom(), "invariant");
   } else {
     if (during_initial_mark) {
       // See the comment for note_start_of_copying() for the details
       // on this.
       assert(_next_top_at_mark_start == end(), "pre-condition");
       _next_top_at_mark_start = top();
     } else {
       // See the comment for note_start_of_copying() for the details
       // on this.
       assert(top() >= _next_top_at_mark_start, "invariant");
     }
   }
 }
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/heapRegion.inline.hpp@2c6ef90f030a (annotated)

src/share/vm/gc_implementation/g1/heapRegion.inline.hpp