/*
* Copyright (c) 2009, 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
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*/
#ifndef SHARE_VM_UTILITIES_STACK_INLINE_HPP
#define SHARE_VM_UTILITIES_STACK_INLINE_HPP
#include "utilities/stack.hpp"
template <MEMFLAGS F> StackBase<F>::StackBase(size_t segment_size, size_t max_cache_size,
size_t max_size):
_seg_size(segment_size),
_max_cache_size(max_cache_size),
_max_size(adjust_max_size(max_size, segment_size))
{
assert(_max_size % _seg_size == 0, "not a multiple");
}
template <MEMFLAGS F> size_t StackBase<F>::adjust_max_size(size_t max_size, size_t seg_size)
{
assert(seg_size > 0, "cannot be 0");
assert(max_size >= seg_size || max_size == 0, "max_size too small");
const size_t limit = max_uintx - (seg_size - 1);
if (max_size == 0 || max_size > limit) {
max_size = limit;
}
return (max_size + seg_size - 1) / seg_size * seg_size;
}
template <class E, MEMFLAGS F>
Stack<E, F>::Stack(size_t segment_size, size_t max_cache_size, size_t max_size):
StackBase<F>(adjust_segment_size(segment_size), max_cache_size, max_size)
{
reset(true);
}
template <class E, MEMFLAGS F>
void Stack<E, F>::push(E item)
{
assert(!is_full(), "pushing onto a full stack");
if (this->_cur_seg_size == this->_seg_size) {
push_segment();
}
this->_cur_seg[this->_cur_seg_size] = item;
++this->_cur_seg_size;
}
template <class E, MEMFLAGS F>
E Stack<E, F>::pop()
{
assert(!is_empty(), "popping from an empty stack");
if (this->_cur_seg_size == 1) {
E tmp = _cur_seg[--this->_cur_seg_size];
pop_segment();
return tmp;
}
return this->_cur_seg[--this->_cur_seg_size];
}
template <class E, MEMFLAGS F>
void Stack<E, F>::clear(bool clear_cache)
{
free_segments(_cur_seg);
if (clear_cache) free_segments(_cache);
reset(clear_cache);
}
template <class E, MEMFLAGS F>
size_t Stack<E, F>::default_segment_size()
{
// Number of elements that fit in 4K bytes minus the size of two pointers
// (link field and malloc header).
return (4096 - 2 * sizeof(E*)) / sizeof(E);
}
template <class E, MEMFLAGS F>
size_t Stack<E, F>::adjust_segment_size(size_t seg_size)
{
const size_t elem_sz = sizeof(E);
const size_t ptr_sz = sizeof(E*);
assert(elem_sz % ptr_sz == 0 || ptr_sz % elem_sz == 0, "bad element size");
if (elem_sz < ptr_sz) {
return align_size_up(seg_size * elem_sz, ptr_sz) / elem_sz;
}
return seg_size;
}
template <class E, MEMFLAGS F>
size_t Stack<E, F>::link_offset() const
{
return align_size_up(this->_seg_size * sizeof(E), sizeof(E*));
}
template <class E, MEMFLAGS F>
size_t Stack<E, F>::segment_bytes() const
{
return link_offset() + sizeof(E*);
}
template <class E, MEMFLAGS F>
E** Stack<E, F>::link_addr(E* seg) const
{
return (E**) ((char*)seg + link_offset());
}
template <class E, MEMFLAGS F>
E* Stack<E, F>::get_link(E* seg) const
{
return *link_addr(seg);
}
template <class E, MEMFLAGS F>
E* Stack<E, F>::set_link(E* new_seg, E* old_seg)
{
*link_addr(new_seg) = old_seg;
return new_seg;
}
template <class E, MEMFLAGS F>
E* Stack<E, F>::alloc(size_t bytes)
{
return (E*) NEW_C_HEAP_ARRAY(char, bytes, F);
}
template <class E, MEMFLAGS F>
void Stack<E, F>::free(E* addr, size_t bytes)
{
FREE_C_HEAP_ARRAY(char, (char*) addr, F);
}
template <class E, MEMFLAGS F>
void Stack<E, F>::push_segment()
{
assert(this->_cur_seg_size == this->_seg_size, "current segment is not full");
E* next;
if (this->_cache_size > 0) {
// Use a cached segment.
next = _cache;
_cache = get_link(_cache);
--this->_cache_size;
} else {
next = alloc(segment_bytes());
DEBUG_ONLY(zap_segment(next, true);)
}
const bool at_empty_transition = is_empty();
this->_cur_seg = set_link(next, _cur_seg);
this->_cur_seg_size = 0;
this->_full_seg_size += at_empty_transition ? 0 : this->_seg_size;
DEBUG_ONLY(verify(at_empty_transition);)
}
template <class E, MEMFLAGS F>
void Stack<E, F>::pop_segment()
{
assert(this->_cur_seg_size == 0, "current segment is not empty");
E* const prev = get_link(_cur_seg);
if (this->_cache_size < this->_max_cache_size) {
// Add the current segment to the cache.
DEBUG_ONLY(zap_segment(_cur_seg, false);)
_cache = set_link(_cur_seg, _cache);
++this->_cache_size;
} else {
DEBUG_ONLY(zap_segment(_cur_seg, true);)
free(_cur_seg, segment_bytes());
}
const bool at_empty_transition = prev == NULL;
this->_cur_seg = prev;
this->_cur_seg_size = this->_seg_size;
this->_full_seg_size -= at_empty_transition ? 0 : this->_seg_size;
DEBUG_ONLY(verify(at_empty_transition);)
}
template <class E, MEMFLAGS F>
void Stack<E, F>::free_segments(E* seg)
{
const size_t bytes = segment_bytes();
while (seg != NULL) {
E* const prev = get_link(seg);
free(seg, bytes);
seg = prev;
}
}
template <class E, MEMFLAGS F>
void Stack<E, F>::reset(bool reset_cache)
{
this->_cur_seg_size = this->_seg_size; // So push() will alloc a new segment.
this->_full_seg_size = 0;
_cur_seg = NULL;
if (reset_cache) {
this->_cache_size = 0;
_cache = NULL;
}
}
#ifdef ASSERT
template <class E, MEMFLAGS F>
void Stack<E, F>::verify(bool at_empty_transition) const
{
assert(size() <= this->max_size(), "stack exceeded bounds");
assert(this->cache_size() <= this->max_cache_size(), "cache exceeded bounds");
assert(this->_cur_seg_size <= this->segment_size(), "segment index exceeded bounds");
assert(this->_full_seg_size % this->_seg_size == 0, "not a multiple");
assert(at_empty_transition || is_empty() == (size() == 0), "mismatch");
assert((_cache == NULL) == (this->cache_size() == 0), "mismatch");
if (is_empty()) {
assert(this->_cur_seg_size == this->segment_size(), "sanity");
}
}
template <class E, MEMFLAGS F>
void Stack<E, F>::zap_segment(E* seg, bool zap_link_field) const
{
if (!ZapStackSegments) return;
const size_t zap_bytes = segment_bytes() - (zap_link_field ? 0 : sizeof(E*));
uint32_t* cur = (uint32_t*)seg;
const uint32_t* end = cur + zap_bytes / sizeof(uint32_t);
while (cur < end) {
*cur++ = 0xfadfaded;
}
}
#endif
template <class E, MEMFLAGS F>
E* ResourceStack<E, F>::alloc(size_t bytes)
{
return (E*) resource_allocate_bytes(bytes);
}
template <class E, MEMFLAGS F>
void ResourceStack<E, F>::free(E* addr, size_t bytes)
{
resource_free_bytes((char*) addr, bytes);
}
template <class E, MEMFLAGS F>
void StackIterator<E, F>::sync()
{
_full_seg_size = _stack._full_seg_size;
_cur_seg_size = _stack._cur_seg_size;
_cur_seg = _stack._cur_seg;
}
template <class E, MEMFLAGS F>
E* StackIterator<E, F>::next_addr()
{
assert(!is_empty(), "no items left");
if (_cur_seg_size == 1) {
E* addr = _cur_seg;
_cur_seg = _stack.get_link(_cur_seg);
_cur_seg_size = _stack.segment_size();
_full_seg_size -= _stack.segment_size();
return addr;
}
return _cur_seg + --_cur_seg_size;
}
#endif // SHARE_VM_UTILITIES_STACK_INLINE_HPP