--- a/hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.hpp Wed Jul 05 20:31:05 2017 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,197 +0,0 @@
-/*
- * Copyright (c) 2001, 2015, 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_PARNEW_PARGCALLOCBUFFER_HPP
-#define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
-
-#include "gc_implementation/shared/gcUtil.hpp"
-#include "memory/allocation.hpp"
-#include "runtime/atomic.hpp"
-#include "utilities/globalDefinitions.hpp"
-
-// Forward declarations.
-class PLABStats;
-
-// A per-thread allocation buffer used during GC.
-class ParGCAllocBuffer: public CHeapObj<mtGC> {
-protected:
- char head[32];
- size_t _word_sz; // In HeapWord units
- HeapWord* _bottom;
- HeapWord* _top;
- HeapWord* _end; // Last allocatable address + 1
- HeapWord* _hard_end; // _end + AlignmentReserve
- // In support of ergonomic sizing of PLAB's
- size_t _allocated; // in HeapWord units
- size_t _wasted; // in HeapWord units
- char tail[32];
- static size_t AlignmentReserve;
-
- // Force future allocations to fail and queries for contains()
- // to return false. Returns the amount of unused space in this PLAB.
- size_t invalidate() {
- _end = _hard_end;
- size_t remaining = pointer_delta(_end, _top); // Calculate remaining space.
- _top = _end; // Force future allocations to fail.
- _bottom = _end; // Force future contains() queries to return false.
- return remaining;
- }
-
- // Fill in remaining space with a dummy object and invalidate the PLAB. Returns
- // the amount of remaining space.
- size_t retire_internal();
-
-public:
- // Initializes the buffer to be empty, but with the given "word_sz".
- // Must get initialized with "set_buf" for an allocation to succeed.
- ParGCAllocBuffer(size_t word_sz);
- virtual ~ParGCAllocBuffer() {}
-
- // Minimum PLAB size.
- static size_t min_size();
- // Maximum PLAB size.
- static size_t max_size();
-
- // If an allocation of the given "word_sz" can be satisfied within the
- // buffer, do the allocation, returning a pointer to the start of the
- // allocated block. If the allocation request cannot be satisfied,
- // return NULL.
- HeapWord* allocate(size_t word_sz) {
- HeapWord* res = _top;
- if (pointer_delta(_end, _top) >= word_sz) {
- _top = _top + word_sz;
- return res;
- } else {
- return NULL;
- }
- }
-
- // Allocate the object aligned to "alignment_in_bytes".
- HeapWord* allocate_aligned(size_t word_sz, unsigned short alignment_in_bytes);
-
- // Undo the last allocation in the buffer, which is required to be of the
- // "obj" of the given "word_sz".
- void undo_allocation(HeapWord* obj, size_t word_sz) {
- assert(pointer_delta(_top, _bottom) >= word_sz, "Bad undo");
- assert(pointer_delta(_top, obj) == word_sz, "Bad undo");
- _top = obj;
- }
-
- // The total (word) size of the buffer, including both allocated and
- // unallocated space.
- size_t word_sz() { return _word_sz; }
-
- // Should only be done if we are about to reset with a new buffer of the
- // given size.
- void set_word_size(size_t new_word_sz) {
- assert(new_word_sz > AlignmentReserve, "Too small");
- _word_sz = new_word_sz;
- }
-
- // The number of words of unallocated space remaining in the buffer.
- size_t words_remaining() {
- assert(_end >= _top, "Negative buffer");
- return pointer_delta(_end, _top, HeapWordSize);
- }
-
- bool contains(void* addr) {
- return (void*)_bottom <= addr && addr < (void*)_hard_end;
- }
-
- // Sets the space of the buffer to be [buf, space+word_sz()).
- virtual void set_buf(HeapWord* buf) {
- _bottom = buf;
- _top = _bottom;
- _hard_end = _bottom + word_sz();
- _end = _hard_end - AlignmentReserve;
- assert(_end >= _top, "Negative buffer");
- // In support of ergonomic sizing
- _allocated += word_sz();
- }
-
- // Flush allocation statistics into the given PLABStats supporting ergonomic
- // sizing of PLAB's and retire the current buffer. To be called at the end of
- // GC.
- void flush_and_retire_stats(PLABStats* stats);
-
- // Fills in the unallocated portion of the buffer with a garbage object and updates
- // statistics. To be called during GC.
- virtual void retire();
-
- void print() PRODUCT_RETURN;
-};
-
-// PLAB book-keeping.
-class PLABStats VALUE_OBJ_CLASS_SPEC {
- size_t _allocated; // Total allocated
- size_t _wasted; // of which wasted (internal fragmentation)
- size_t _unused; // Unused in last buffer
- size_t _desired_plab_sz;// Output of filter (below), suitably trimmed and quantized
- AdaptiveWeightedAverage
- _filter; // Integrator with decay
-
- void reset() {
- _allocated = 0;
- _wasted = 0;
- _unused = 0;
- }
- public:
- PLABStats(size_t desired_plab_sz_, unsigned wt) :
- _allocated(0),
- _wasted(0),
- _unused(0),
- _desired_plab_sz(desired_plab_sz_),
- _filter(wt)
- { }
-
- static const size_t min_size() {
- return ParGCAllocBuffer::min_size();
- }
-
- static const size_t max_size() {
- return ParGCAllocBuffer::max_size();
- }
-
- size_t desired_plab_sz() {
- return _desired_plab_sz;
- }
-
- // Updates the current desired PLAB size. Computes the new desired PLAB size,
- // updates _desired_plab_sz and clears sensor accumulators.
- void adjust_desired_plab_sz(uint no_of_gc_workers);
-
- void add_allocated(size_t v) {
- Atomic::add_ptr(v, &_allocated);
- }
-
- void add_unused(size_t v) {
- Atomic::add_ptr(v, &_unused);
- }
-
- void add_wasted(size_t v) {
- Atomic::add_ptr(v, &_wasted);
- }
-};
-
-#endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP