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Boost-Commit : |
Subject: [Boost-commit] svn:boost r49927 - in trunk: boost/unordered/detail libs/unordered/doc
From: daniel_james_at_[hidden]
Date: 2008-11-24 18:15:56
Author: danieljames
Date: 2008-11-24 18:15:55 EST (Mon, 24 Nov 2008)
New Revision: 49927
URL: http://svn.boost.org/trac/boost/changeset/49927
Log:
Use aligned storage for the value.
Text files modified:
trunk/boost/unordered/detail/hash_table.hpp | 2
trunk/boost/unordered/detail/hash_table_impl.hpp | 180 +++++++++------------------------------
trunk/libs/unordered/doc/changes.qbk | 7 +
3 files changed, 50 insertions(+), 139 deletions(-)
Modified: trunk/boost/unordered/detail/hash_table.hpp
==============================================================================
--- trunk/boost/unordered/detail/hash_table.hpp (original)
+++ trunk/boost/unordered/detail/hash_table.hpp 2008-11-24 18:15:55 EST (Mon, 24 Nov 2008)
@@ -26,6 +26,8 @@
#include <boost/static_assert.hpp>
#include <boost/unordered/detail/allocator_helpers.hpp>
#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/aligned_storage.hpp>
+#include <boost/type_traits/alignment_of.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/and.hpp>
#include <boost/detail/workaround.hpp>
Modified: trunk/boost/unordered/detail/hash_table_impl.hpp
==============================================================================
--- trunk/boost/unordered/detail/hash_table_impl.hpp (original)
+++ trunk/boost/unordered/detail/hash_table_impl.hpp 2008-11-24 18:15:55 EST (Mon, 24 Nov 2008)
@@ -34,7 +34,6 @@
public:
typedef BOOST_UNORDERED_TABLE_DATA data;
- struct node_base;
struct node;
struct bucket;
typedef std::size_t size_type;
@@ -46,9 +45,6 @@
boost::unordered_detail::rebind_wrap<Alloc, node>::type
node_allocator;
typedef BOOST_DEDUCED_TYPENAME
- boost::unordered_detail::rebind_wrap<Alloc, node_base>::type
- node_base_allocator;
- typedef BOOST_DEDUCED_TYPENAME
boost::unordered_detail::rebind_wrap<Alloc, bucket>::type
bucket_allocator;
@@ -88,39 +84,36 @@
}
};
+ // Value Base
+
+ struct value_base {
+ typename boost::aligned_storage<
+ sizeof(value_type),
+ boost::alignment_of<value_type>::value>::type data_;
+
+ void* address() { return this; }
+ };
+
// Hash Node
//
// all no throw
- struct node_base : bucket
- {
+ struct node : value_base, bucket {
#if BOOST_UNORDERED_EQUIVALENT_KEYS
public:
- node_base() : group_prev_()
+ node() : group_prev_()
{
BOOST_UNORDERED_MSVC_RESET_PTR(group_prev_);
}
link_ptr group_prev_;
#endif
- };
-
- struct node : node_base
- {
- public:
-#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
- template <typename... Args>
- node(Args&&... args)
- : node_base(), value_(std::forward<Args>(args)...) {}
-#else
- node(value_type const& v) : node_base(), value_(v) {}
-#endif
- value_type value_;
+ value_type& value() {
+ return *static_cast<value_type*>(this->address());
+ }
};
-#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
-
// allocators
//
// Stores all the allocators that we're going to need.
@@ -136,7 +129,9 @@
void destroy(link_ptr ptr)
{
- node_ptr n(node_alloc_.address(*static_cast<node*>(&*ptr)));
+ node* raw_ptr = static_cast<node*>(&*ptr);
+ raw_ptr->value().~value_type();
+ node_ptr n(node_alloc_.address(*raw_ptr));
node_alloc_.destroy(n);
node_alloc_.deallocate(n, 1);
}
@@ -163,146 +158,62 @@
node_ptr node_;
bool node_constructed_;
+ bool value_constructed_;
public:
node_constructor(allocators& a)
: allocators_(a),
- node_(), node_constructed_(false)
+ node_(), node_constructed_(false), value_constructed_(false)
{
}
~node_constructor()
{
if (node_) {
+ if (value_constructed_) {
+ node_->value().~value_type();
+ }
+
if (node_constructed_)
allocators_.node_alloc_.destroy(node_);
allocators_.node_alloc_.deallocate(node_, 1);
}
}
+#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
template <typename... Args>
void construct(Args&&... args)
{
BOOST_ASSERT(!node_);
node_constructed_ = false;
+ value_constructed_ = false;
node_ = allocators_.node_alloc_.allocate(1);
- allocators_.node_alloc_.construct(node_, std::forward<Args>(args)...);
- node_constructed_ = true;
- }
- node_ptr get() const
- {
- BOOST_ASSERT(node_);
- return node_;
- }
+ allocators_.node_alloc_.construct(node_, node());
+ node_constructed_ = true;
- // no throw
- link_ptr release()
- {
- node_ptr p = node_;
- unordered_detail::reset(node_);
- return link_ptr(allocators_.bucket_alloc_.address(*p));
+ new(node_->address()) value_type(std::forward<Args>(args)...);
+ value_constructed_ = true;
}
-
- private:
- node_constructor(node_constructor const&);
- node_constructor& operator=(node_constructor const&);
- };
#else
-
- // allocators
- //
- // Stores all the allocators that we're going to need.
-
- struct allocators
- {
- node_allocator node_alloc_;
- bucket_allocator bucket_alloc_;
- value_allocator value_alloc_;
- node_base_allocator node_base_alloc_;
-
- allocators(value_allocator const& a)
- : node_alloc_(a), bucket_alloc_(a),
- value_alloc_(a), node_base_alloc_(a)
- {}
-
- void destroy(link_ptr ptr)
- {
- node_ptr n(node_alloc_.address(*static_cast<node*>(&*ptr)));
- value_alloc_.destroy(value_alloc_.address(n->value_));
- node_base_alloc_.destroy(node_base_alloc_.address(*n));
- node_alloc_.deallocate(n, 1);
- }
-
- void swap(allocators& x)
- {
- boost::swap(node_alloc_, x.node_alloc_);
- boost::swap(bucket_alloc_, x.bucket_alloc_);
- boost::swap(value_alloc_, x.value_alloc_);
- boost::swap(node_base_alloc_, x.node_base_alloc_);
- }
-
- bool operator==(allocators const& x)
- {
- return value_alloc_ == x.value_alloc_;
- }
- };
-
- // node_constructor
- //
- // Used to construct nodes in an exception safe manner.
-
- class node_constructor
- {
- allocators& allocators_;
-
- node_ptr node_;
- bool value_constructed_;
- bool node_base_constructed_;
-
- public:
-
- node_constructor(allocators& a)
- : allocators_(a),
- node_(), value_constructed_(false), node_base_constructed_(false)
- {
- BOOST_UNORDERED_MSVC_RESET_PTR(node_);
- }
-
- ~node_constructor()
- {
- if (node_) {
- if (value_constructed_)
- allocators_.value_alloc_.destroy(
- allocators_.value_alloc_.address(node_->value_));
- if (node_base_constructed_)
- allocators_.node_base_alloc_.destroy(
- allocators_.node_base_alloc_.address(*node_));
-
- allocators_.node_alloc_.deallocate(node_, 1);
- }
- }
-
template <typename V>
void construct(V const& v)
{
BOOST_ASSERT(!node_);
+ node_constructed_ = false;
value_constructed_ = false;
- node_base_constructed_ = false;
node_ = allocators_.node_alloc_.allocate(1);
- allocators_.node_base_alloc_.construct(
- allocators_.node_base_alloc_.address(*node_),
- node_base());
- node_base_constructed_ = true;
+ allocators_.node_alloc_.construct(node_, node());
+ node_constructed_ = true;
- allocators_.value_alloc_.construct(
- allocators_.value_alloc_.address(node_->value_), v);
+ new(node_->address()) value_type(v);
value_constructed_ = true;
}
+#endif
node_ptr get() const
{
@@ -322,7 +233,6 @@
node_constructor(node_constructor const&);
node_constructor& operator=(node_constructor const&);
};
-#endif
// Methods for navigating groups of elements with equal keys.
@@ -351,8 +261,7 @@
// pre: Must be pointing to a node
static inline reference get_value(link_ptr p) {
- BOOST_ASSERT(p);
- return static_cast<node*>(&*p)->value_;
+ return get_node(p).value();
}
class iterator_base
@@ -1357,17 +1266,10 @@
// accessors
// no throw
-#if defined(BOOST_HAS_RVALUE_REFS) && defined(BOOST_HAS_VARIADIC_TMPL)
node_allocator get_allocator() const
{
return data_.allocators_.node_alloc_;
}
-#else
- value_allocator get_allocator() const
- {
- return data_.allocators_.value_alloc_;
- }
-#endif
// no throw
hasher const& hash_function() const
@@ -1728,7 +1630,7 @@
iterator_base insert_impl(node_constructor& a)
{
- key_type const& k = extract_key(a.get()->value_);
+ key_type const& k = extract_key(a.get()->value());
size_type hash_value = hash_function()(k);
bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
link_ptr position = find_iterator(bucket, k);
@@ -1750,7 +1652,7 @@
iterator_base insert_hint_impl(iterator_base const& it, node_constructor& a)
{
// equal can throw, but with no effects
- if (it == data_.end() || !equal(extract_key(a.get()->value_), *it)) {
+ if (it == data_.end() || !equal(extract_key(a.get()->value()), *it)) {
// Use the standard insert if the iterator doesn't point
// to a matching key.
return insert_impl(a);
@@ -1766,7 +1668,7 @@
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
bucket_ptr base = reserve_for_insert(size() + 1) ?
- get_bucket(extract_key(a.get()->value_)) : it.bucket_;
+ get_bucket(extract_key(a.get()->value())) : it.bucket_;
// Nothing after this point can throw
@@ -1796,7 +1698,7 @@
for (; i != j; ++i) {
a.construct(*i);
- key_type const& k = extract_key(a.get()->value_);
+ key_type const& k = extract_key(a.get()->value());
bucket_ptr bucket = get_bucket(k);
link_ptr position = find_iterator(bucket, k);
@@ -1981,7 +1883,7 @@
a.construct(std::forward<Args>(args)...);
// No side effects in this initial code
- key_type const& k = extract_key(a.get()->value_);
+ key_type const& k = extract_key(a.get()->value());
size_type hash_value = hash_function()(k);
bucket_ptr bucket = data_.bucket_ptr_from_hash(hash_value);
link_ptr pos = find_iterator(bucket, k);
Modified: trunk/libs/unordered/doc/changes.qbk
==============================================================================
--- trunk/libs/unordered/doc/changes.qbk (original)
+++ trunk/libs/unordered/doc/changes.qbk 2008-11-24 18:15:55 EST (Mon, 24 Nov 2008)
@@ -52,5 +52,12 @@
* [@https://svn.boost.org/trac/boost/ticket/1710 Ticket 1710]:
Use a larger prime number list. Thanks to Thorsten Ottosen and Hervé
Brönnimann.
+* Use
+ [@../../libs/type_traits/doc/html/boost_typetraits/category/alignment.html
+ aligned storage] to store the types. This changes the way the allocator is
+ used to construct nodes. It used to construct the node with two calls to
+ the allocator's `construct` method - once for the pointers and once for the
+ value. It now constructs the node with a single call to construct and
+ then constructs the value using in place construction.
[endsect]
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