Mercurial > hg > graal-jvmci-8
view src/share/vm/runtime/handles.cpp @ 3979:4dfb2df418f2
6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
author | johnc |
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date | Thu, 22 Sep 2011 10:57:37 -0700 |
parents | f95d63e2154a |
children | f08d439fab8c |
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/* * Copyright (c) 1997, 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 "memory/allocation.inline.hpp" #include "oops/oop.inline.hpp" #include "runtime/handles.inline.hpp" #ifdef TARGET_OS_FAMILY_linux # include "os_linux.inline.hpp" # include "thread_linux.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_solaris # include "os_solaris.inline.hpp" # include "thread_solaris.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_windows # include "os_windows.inline.hpp" # include "thread_windows.inline.hpp" #endif #ifdef ASSERT oop* HandleArea::allocate_handle(oop obj) { assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); assert(SharedSkipVerify || obj->is_oop(), "sanity check"); return real_allocate_handle(obj); } Handle::Handle(Thread* thread, oop obj) { assert(thread == Thread::current(), "sanity check"); if (obj == NULL) { _handle = NULL; } else { _handle = thread->handle_area()->allocate_handle(obj); } } #endif static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) { oop* bottom = (oop*) chunk->bottom(); oop* top = (oop*) chunk_top; uintx handles_visited = top - bottom; assert(top >= bottom && top <= (oop*) chunk->top(), "just checking"); // during GC phase 3, a handle may be a forward pointer that // is not yet valid, so loosen the assertion while (bottom < top) { // assert((*bottom)->is_oop(), "handle should point to oop"); assert(Universe::heap()->is_in(*bottom), "handle should be valid heap address"); f->do_oop(bottom++); } return handles_visited; } // Used for debugging handle allocation. NOT_PRODUCT(jint _nof_handlemarks = 0;) void HandleArea::oops_do(OopClosure* f) { uintx handles_visited = 0; // First handle the current chunk. It is filled to the high water mark. handles_visited += chunk_oops_do(f, _chunk, _hwm); // Then handle all previous chunks. They are completely filled. Chunk* k = _first; while(k != _chunk) { handles_visited += chunk_oops_do(f, k, k->top()); k = k->next(); } // The thread local handle areas should not get very large if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) { #ifdef ASSERT warning("%d: Visited in HandleMark : %d", _nof_handlemarks, handles_visited); #else warning("Visited in HandleMark : %d", handles_visited); #endif } if (_prev != NULL) _prev->oops_do(f); } void HandleMark::initialize(Thread* thread) { _thread = thread; // Save area _area = thread->handle_area(); // Save current top _chunk = _area->_chunk; _hwm = _area->_hwm; _max = _area->_max; NOT_PRODUCT(_size_in_bytes = _area->_size_in_bytes;) debug_only(_area->_handle_mark_nesting++); assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks"); debug_only(Atomic::inc(&_nof_handlemarks);) // Link this in the thread set_previous_handle_mark(thread->last_handle_mark()); thread->set_last_handle_mark(this); } HandleMark::~HandleMark() { HandleArea* area = _area; // help compilers with poor alias analysis assert(area == _thread->handle_area(), "sanity check"); assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" ); debug_only(area->_handle_mark_nesting--); // Debug code to trace the number of handles allocated per mark/ #ifdef ASSERT if (TraceHandleAllocation) { size_t handles = 0; Chunk *c = _chunk->next(); if (c == NULL) { handles = area->_hwm - _hwm; // no new chunk allocated } else { handles = _max - _hwm; // add rest in first chunk while(c != NULL) { handles += c->length(); c = c->next(); } handles -= area->_max - area->_hwm; // adjust for last trunk not full } handles /= sizeof(void *); // Adjust for size of a handle if (handles > HandleAllocationLimit) { // Note: _nof_handlemarks is only set in debug mode warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles); } } #endif // Delete later chunks if( _chunk->next() ) { _chunk->next_chop(); } // Roll back arena to saved top markers area->_chunk = _chunk; area->_hwm = _hwm; area->_max = _max; NOT_PRODUCT(area->set_size_in_bytes(_size_in_bytes);) #ifdef ASSERT // clear out first chunk (to detect allocation bugs) if (ZapVMHandleArea) { memset(_hwm, badHandleValue, _max - _hwm); } Atomic::dec(&_nof_handlemarks); #endif // Unlink this from the thread _thread->set_last_handle_mark(previous_handle_mark()); } #ifdef ASSERT NoHandleMark::NoHandleMark() { HandleArea* area = Thread::current()->handle_area(); area->_no_handle_mark_nesting++; assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); } NoHandleMark::~NoHandleMark() { HandleArea* area = Thread::current()->handle_area(); assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" ); area->_no_handle_mark_nesting--; } ResetNoHandleMark::ResetNoHandleMark() { HandleArea* area = Thread::current()->handle_area(); _no_handle_mark_nesting = area->_no_handle_mark_nesting; area->_no_handle_mark_nesting = 0; } ResetNoHandleMark::~ResetNoHandleMark() { HandleArea* area = Thread::current()->handle_area(); area->_no_handle_mark_nesting = _no_handle_mark_nesting; } #endif