jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/shared/spaceDecorator.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/spaceDecorator.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/spaceDecorator.cpp

Thu, 20 Sep 2012 09:52:56 -0700

author: johnc
date: Thu, 20 Sep 2012 09:52:56 -0700
changeset 4067: b2ef234911c9
parent 2314: f95d63e2154a
child 6680: 78bbf4d43a14
permissions: -rw-r--r--

7190666: G1: assert(_unused == 0) failed: Inconsistency in PLAB stats
Summary: Reset the fields in ParGCAllocBuffer, that are used for accumulating values for the ResizePLAB sensors in PLABStats, to zero after flushing the values to the PLABStats fields. Flush PLABStats values only when retiring the final allocation buffers prior to disposing of a G1ParScanThreadState object, rather than when retiring every allocation buffer.
Reviewed-by: jwilhelm, jmasa, ysr

 /*
  * Copyright (c) 2002, 2010, 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.
  *
  */
 #include "precompiled.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "memory/space.inline.hpp"
 #include "utilities/copy.hpp"
 // Catch-all file for utility classes
 #ifndef PRODUCT
 // Returns true is the location q matches the mangling
 // pattern.
 bool SpaceMangler::is_mangled(HeapWord* q) {
   // This test loses precision but is good enough
   return badHeapWord == (max_juint & (uintptr_t) q->value());
 }
 void SpaceMangler::set_top_for_allocations(HeapWord* v)  {
   if (v < end()) {
     assert(!CheckZapUnusedHeapArea || is_mangled(v),
       "The high water mark is not mangled");
   }
   _top_for_allocations = v;
 }
 // Mangle only the unused space that has not previously
 // been mangled and that has not been allocated since being
 // mangled.
 void SpaceMangler::mangle_unused_area() {
   assert(ZapUnusedHeapArea, "Mangling should not be in use");
   // Mangle between top and the high water mark.  Safeguard
   // against the space changing since top_for_allocations was
   // set.
   HeapWord* mangled_end = MIN2(top_for_allocations(), end());
   if (top() < mangled_end) {
     MemRegion mangle_mr(top(), mangled_end);
     SpaceMangler::mangle_region(mangle_mr);
     // Light weight check of mangling.
     check_mangled_unused_area(end());
   }
   // Complete check of unused area which is functional when
   // DEBUG_MANGLING is defined.
   check_mangled_unused_area_complete();
 }
 // A complete mangle is expected in the
 // exceptional case where top_for_allocations is not
 // properly tracking the high water mark for mangling.
 // This can be the case when to-space is being used for
 // scratch space during a mark-sweep-compact.  See
 // contribute_scratch() and PSMarkSweep::allocate_stacks().
 void SpaceMangler::mangle_unused_area_complete() {
   assert(ZapUnusedHeapArea, "Mangling should not be in use");
   MemRegion mangle_mr(top(), end());
   SpaceMangler::mangle_region(mangle_mr);
 }
 // Simply mangle the MemRegion mr.
 void SpaceMangler::mangle_region(MemRegion mr) {
   assert(ZapUnusedHeapArea, "Mangling should not be in use");
 #ifdef ASSERT
   if(TraceZapUnusedHeapArea) {
     gclog_or_tty->print("Mangling [0x%x to 0x%x)", mr.start(), mr.end());
   }
   Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord);
   if(TraceZapUnusedHeapArea) {
     gclog_or_tty->print_cr(" done");
   }
 #endif
 }
 // Check that top, top_for_allocations and the last
 // word of the space are mangled.  In a tight memory
 // situation even this light weight mangling could
 // cause paging by touching the end of the space.
 void  SpaceMangler::check_mangled_unused_area(HeapWord* limit) {
   if (CheckZapUnusedHeapArea) {
     // This method can be called while the spaces are
     // being reshaped so skip the test if the end of the
     // space is beyond the specified limit;
     if (end() > limit) return;
     assert(top() == end() ||
            (is_mangled(top())), "Top not mangled");
     assert((top_for_allocations() < top()) ||
            (top_for_allocations() >= end()) ||
            (is_mangled(top_for_allocations())),
            "Older unused not mangled");
     assert(top() == end() ||
            (is_mangled(end() - 1)), "End not properly mangled");
     // Only does checking when DEBUG_MANGLING is defined.
     check_mangled_unused_area_complete();
   }
 }
 #undef DEBUG_MANGLING
 // This should only be used while debugging the mangling
 // because of the high cost of checking the completeness.
 void  SpaceMangler::check_mangled_unused_area_complete() {
   if (CheckZapUnusedHeapArea) {
     assert(ZapUnusedHeapArea, "Not mangling unused area");
 #ifdef DEBUG_MANGLING
     HeapWord* q = top();
     HeapWord* limit = end();
     bool passed = true;
     while (q < limit) {
       if (!is_mangled(q)) {
         passed = false;
         break;
       }
       q++;
     }
     assert(passed, "Mangling is not complete");
 #endif
   }
 }
 #undef DEBUG_MANGLING
 #endif // not PRODUCT

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/shared/spaceDecorator.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/spaceDecorator.cpp