--- /dev/null
+/* Copyright 2003-2006 Joaquín M López Muñoz.
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt)
+ *
+ * See http://www.boost.org/libs/multi_index for library home page.
+ */
+
+#ifndef BOOST_MULTI_INDEX_DETAIL_SAFE_MODE_HPP
+#define BOOST_MULTI_INDEX_DETAIL_SAFE_MODE_HPP
+
+#if defined(_MSC_VER)&&(_MSC_VER>=1200)
+#pragma once
+#endif
+
+/* Safe mode machinery, in the spirit of Cay Hortmann's "Safe STL"
+ * (http://www.horstmann.com/safestl.html).
+ * In this mode, containers of type Container are derived from
+ * safe_container<Container>, and their corresponding iterators
+ * are wrapped with safe_iterator. These classes provide
+ * an internal record of which iterators are at a given moment associated
+ * to a given container, and properly mark the iterators as invalid
+ * when the container gets destroyed.
+ * Iterators are chained in a single attached list, whose header is
+ * kept by the container. More elaborate data structures would yield better
+ * performance, but I decided to keep complexity to a minimum since
+ * speed is not an issue here.
+ * Safe mode iterators automatically check that only proper operations
+ * are performed on them: for instance, an invalid iterator cannot be
+ * dereferenced. Additionally, a set of utilty macros and functions are
+ * provided that serve to implement preconditions and cooperate with
+ * the framework within the container.
+ * Iterators can also be unchecked, i.e. they do not have info about
+ * which container they belong in. This situation arises when the iterator
+ * is restored from a serialization archive: only information on the node
+ * is available, and it is not possible to determine to which container
+ * the iterator is associated to. The only sensible policy is to assume
+ * unchecked iterators are valid, though this can certainly generate false
+ * positive safe mode checks.
+ * This is not a full-fledged safe mode framework, and is only intended
+ * for use within the limits of Boost.MultiIndex.
+ */
+
+/* Assertion macros. These resolve to no-ops if
+ * !defined(BOOST_MULTI_INDEX_ENABLE_SAFE_MODE).
+ */
+
+#if !defined(BOOST_MULTI_INDEX_ENABLE_SAFE_MODE)
+#undef BOOST_MULTI_INDEX_SAFE_MODE_ASSERT
+#define BOOST_MULTI_INDEX_SAFE_MODE_ASSERT(expr,error_code) ((void)0)
+#else
+#if !defined(BOOST_MULTI_INDEX_SAFE_MODE_ASSERT)
+#include <boost/assert.hpp>
+#define BOOST_MULTI_INDEX_SAFE_MODE_ASSERT(expr,error_code) BOOST_ASSERT(expr)
+#endif
+#endif
+
+#define BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(it) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_valid_iterator(it), \
+ safe_mode::invalid_iterator);
+
+#define BOOST_MULTI_INDEX_CHECK_DEREFERENCEABLE_ITERATOR(it) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_dereferenceable_iterator(it), \
+ safe_mode::not_dereferenceable_iterator);
+
+#define BOOST_MULTI_INDEX_CHECK_INCREMENTABLE_ITERATOR(it) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_incrementable_iterator(it), \
+ safe_mode::not_incrementable_iterator);
+
+#define BOOST_MULTI_INDEX_CHECK_DECREMENTABLE_ITERATOR(it) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_decrementable_iterator(it), \
+ safe_mode::not_decrementable_iterator);
+
+#define BOOST_MULTI_INDEX_CHECK_IS_OWNER(it,cont) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_is_owner(it,cont), \
+ safe_mode::not_owner);
+
+#define BOOST_MULTI_INDEX_CHECK_SAME_OWNER(it0,it1) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_same_owner(it0,it1), \
+ safe_mode::not_same_owner);
+
+#define BOOST_MULTI_INDEX_CHECK_VALID_RANGE(it0,it1) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_valid_range(it0,it1), \
+ safe_mode::invalid_range);
+
+#define BOOST_MULTI_INDEX_CHECK_OUTSIDE_RANGE(it,it0,it1) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_outside_range(it,it0,it1), \
+ safe_mode::inside_range);
+
+#define BOOST_MULTI_INDEX_CHECK_IN_BOUNDS(it,n) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_in_bounds(it,n), \
+ safe_mode::out_of_bounds);
+
+#define BOOST_MULTI_INDEX_CHECK_DIFFERENT_CONTAINER(cont0,cont1) \
+ BOOST_MULTI_INDEX_SAFE_MODE_ASSERT( \
+ safe_mode::check_different_container(cont0,cont1), \
+ safe_mode::same_container);
+
+#if defined(BOOST_MULTI_INDEX_ENABLE_SAFE_MODE)
+#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
+#include <algorithm>
+#include <boost/detail/iterator.hpp>
+#include <boost/multi_index/detail/access_specifier.hpp>
+#include <boost/multi_index/detail/iter_adaptor.hpp>
+#include <boost/multi_index/safe_mode_errors.hpp>
+#include <boost/noncopyable.hpp>
+
+#if !defined(BOOST_MULTI_INDEX_DISABLE_SERIALIZATION)
+#include <boost/serialization/split_member.hpp>
+#endif
+
+#if defined(BOOST_HAS_THREADS)
+#include <boost/detail/lightweight_mutex.hpp>
+#endif
+
+namespace boost{
+
+namespace multi_index{
+
+namespace safe_mode{
+
+/* Checking routines. Assume the best for unchecked iterators
+ * (i.e. they pass the checking when there is not enough info
+ * to know.)
+ */
+
+template<typename Iterator>
+inline bool check_valid_iterator(const Iterator& it)
+{
+ return it.valid()||it.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_dereferenceable_iterator(const Iterator& it)
+{
+ return it.valid()&&it!=it.owner()->end()||it.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_incrementable_iterator(const Iterator& it)
+{
+ return it.valid()&&it!=it.owner()->end()||it.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_decrementable_iterator(const Iterator& it)
+{
+ return it.valid()&&it!=it.owner()->begin()||it.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_is_owner(
+ const Iterator& it,const typename Iterator::container_type& cont)
+{
+ return it.valid()&&it.owner()==&cont||it.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_same_owner(const Iterator& it0,const Iterator& it1)
+{
+ return it0.valid()&&it1.valid()&&it0.owner()==it1.owner()||
+ it0.unchecked()||it1.unchecked();
+}
+
+template<typename Iterator>
+inline bool check_valid_range(const Iterator& it0,const Iterator& it1)
+{
+ if(!check_same_owner(it0,it1))return false;
+
+ if(it0.valid()){
+ Iterator last=it0.owner()->end();
+ if(it1==last)return true;
+
+ for(Iterator first=it0;first!=last;++first){
+ if(first==it1)return true;
+ }
+ return false;
+ }
+ return true;
+}
+
+template<typename Iterator>
+inline bool check_outside_range(
+ const Iterator& it,const Iterator& it0,const Iterator& it1)
+{
+ if(!check_same_owner(it0,it1))return false;
+
+ if(it0.valid()){
+ Iterator last=it0.owner()->end();
+ bool found=false;
+
+ Iterator first=it0;
+ for(;first!=last;++first){
+ if(first==it1)break;
+
+ /* crucial that this check goes after previous break */
+
+ if(first==it)found=true;
+ }
+ if(first!=it1)return false;
+ return !found;
+ }
+ return true;
+}
+
+template<typename Iterator,typename Difference>
+inline bool check_in_bounds(const Iterator& it,Difference n)
+{
+ if(it.unchecked())return true;
+ if(!it.valid()) return false;
+ if(n>0) return it.owner()->end()-it>=n;
+ else return it.owner()->begin()-it<=n;
+}
+
+template<typename Container>
+inline bool check_different_container(
+ const Container& cont0,const Container& cont1)
+{
+ return &cont0!=&cont1;
+}
+
+/* Invalidates all iterators equivalent to that given. Safe containers
+ * must call this when deleting elements: the safe mode framework cannot
+ * perform this operation automatically without outside help.
+ */
+
+template<typename Iterator>
+inline void detach_equivalent_iterators(Iterator& it)
+{
+ if(it.valid()){
+ Iterator *prev_,*next_;
+ for(
+ prev_=static_cast<Iterator*>(&it.cont->header);
+ (next_=static_cast<Iterator*>(prev_->next))!=0;){
+ if(next_!=&it&&*next_==it){
+ prev_->next=next_->next;
+ next_->cont=0;
+ }
+ else prev_=next_;
+ }
+ it.detach();
+ }
+}
+
+template<typename Container> class safe_container; /* fwd decl. */
+
+} /* namespace multi_index::safe_mode */
+
+namespace detail{
+
+class safe_container_base; /* fwd decl. */
+
+class safe_iterator_base
+{
+public:
+ bool valid()const{return cont!=0;}
+ bool unchecked()const{return unchecked_;}
+
+ inline void detach();
+
+ void uncheck()
+ {
+ detach();
+ unchecked_=true;
+ }
+
+protected:
+ safe_iterator_base():cont(0),next(0),unchecked_(false){}
+
+ explicit safe_iterator_base(safe_container_base* cont_):
+ unchecked_(false)
+ {
+ attach(cont_);
+ }
+
+ safe_iterator_base(const safe_iterator_base& it):
+ unchecked_(it.unchecked_)
+ {
+ attach(it.cont);
+ }
+
+ safe_iterator_base& operator=(const safe_iterator_base& it)
+ {
+ unchecked_=it.unchecked_;
+ safe_container_base* new_cont=it.cont;
+ if(cont!=new_cont){
+ detach();
+ attach(new_cont);
+ }
+ return *this;
+ }
+
+ ~safe_iterator_base()
+ {
+ detach();
+ }
+
+ const safe_container_base* owner()const{return cont;}
+
+BOOST_MULTI_INDEX_PRIVATE_IF_MEMBER_TEMPLATE_FRIENDS:
+ friend class safe_container_base;
+
+#if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
+ template<typename> friend class safe_mode::safe_container;
+ template<typename Iterator> friend
+ void safe_mode::detach_equivalent_iterators(Iterator&);
+#endif
+
+ inline void attach(safe_container_base* cont_);
+
+ safe_container_base* cont;
+ safe_iterator_base* next;
+ bool unchecked_;
+};
+
+class safe_container_base:private noncopyable
+{
+public:
+ safe_container_base(){}
+
+BOOST_MULTI_INDEX_PROTECTED_IF_MEMBER_TEMPLATE_FRIENDS:
+ friend class safe_iterator_base;
+
+#if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
+ template<typename Iterator> friend
+ void safe_mode::detach_equivalent_iterators(Iterator&);
+#endif
+
+ ~safe_container_base()
+ {
+ /* Detaches all remaining iterators, which by now will
+ * be those pointing to the end of the container.
+ */
+
+ for(safe_iterator_base* it=header.next;it;it=it->next)it->cont=0;
+ header.next=0;
+ }
+
+ void swap(safe_container_base& x)
+ {
+ for(safe_iterator_base* it0=header.next;it0;it0=it0->next)it0->cont=&x;
+ for(safe_iterator_base* it1=x.header.next;it1;it1=it1->next)it1->cont=this;
+ std::swap(header.cont,x.header.cont);
+ std::swap(header.next,x.header.next);
+ }
+
+ safe_iterator_base header;
+
+#if defined(BOOST_HAS_THREADS)
+ boost::detail::lightweight_mutex mutex;
+#endif
+};
+
+void safe_iterator_base::attach(safe_container_base* cont_)
+{
+ cont=cont_;
+ if(cont){
+#if defined(BOOST_HAS_THREADS)
+ boost::detail::lightweight_mutex::scoped_lock lock(cont->mutex);
+#endif
+
+ next=cont->header.next;
+ cont->header.next=this;
+ }
+}
+
+void safe_iterator_base::detach()
+{
+ if(cont){
+#if defined(BOOST_HAS_THREADS)
+ boost::detail::lightweight_mutex::scoped_lock lock(cont->mutex);
+#endif
+
+ safe_iterator_base *prev_,*next_;
+ for(prev_=&cont->header;(next_=prev_->next)!=this;prev_=next_){}
+ prev_->next=next;
+ cont=0;
+ }
+}
+
+} /* namespace multi_index::detail */
+
+namespace safe_mode{
+
+/* In order to enable safe mode on a container:
+ * - The container must derive from safe_container<container_type>,
+ * - iterators must be generated via safe_iterator, which adapts a
+ * preexistent unsafe iterator class.
+ */
+
+template<typename Container>
+class safe_container;
+
+template<typename Iterator,typename Container>
+class safe_iterator:
+ public detail::iter_adaptor<safe_iterator<Iterator,Container>,Iterator>,
+ public detail::safe_iterator_base
+{
+ typedef detail::iter_adaptor<safe_iterator,Iterator> super;
+ typedef detail::safe_iterator_base safe_super;
+
+public:
+ typedef Container container_type;
+ typedef typename Iterator::reference reference;
+ typedef typename Iterator::difference_type difference_type;
+
+ safe_iterator(){}
+ explicit safe_iterator(safe_container<container_type>* cont_):
+ safe_super(cont_){}
+ template<typename T0>
+ safe_iterator(const T0& t0,safe_container<container_type>* cont_):
+ super(Iterator(t0)),safe_super(cont_){}
+ template<typename T0,typename T1>
+ safe_iterator(
+ const T0& t0,const T1& t1,safe_container<container_type>* cont_):
+ super(Iterator(t0,t1)),safe_super(cont_){}
+
+ safe_iterator& operator=(const safe_iterator& x)
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(x);
+ this->base_reference()=x.base_reference();
+ safe_super::operator=(x);
+ return *this;
+ }
+
+ const container_type* owner()const
+ {
+ return
+ static_cast<const container_type*>(
+ static_cast<const safe_container<container_type>*>(
+ this->safe_super::owner()));
+ }
+
+ /* get_node is not to be used by the user */
+
+ typedef typename Iterator::node_type node_type;
+
+ node_type* get_node()const{return this->base_reference().get_node();}
+
+private:
+ friend class boost::multi_index::detail::iter_adaptor_access;
+
+ reference dereference()const
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_DEREFERENCEABLE_ITERATOR(*this);
+ return *(this->base_reference());
+ }
+
+ bool equal(const safe_iterator& x)const
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(x);
+ BOOST_MULTI_INDEX_CHECK_SAME_OWNER(*this,x);
+ return this->base_reference()==x.base_reference();
+ }
+
+ void increment()
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_INCREMENTABLE_ITERATOR(*this);
+ ++(this->base_reference());
+ }
+
+ void decrement()
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_DECREMENTABLE_ITERATOR(*this);
+ --(this->base_reference());
+ }
+
+ void advance(difference_type n)
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_IN_BOUNDS(*this,n);
+ this->base_reference()+=n;
+ }
+
+ difference_type distance_to(const safe_iterator& x)const
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(x);
+ BOOST_MULTI_INDEX_CHECK_SAME_OWNER(*this,x);
+ return x.base_reference()-this->base_reference();
+ }
+
+#if !defined(BOOST_MULTI_INDEX_DISABLE_SERIALIZATION)
+ /* Serialization. Note that Iterator::save and Iterator:load
+ * are assumed to be defined and public: at first sight it seems
+ * like we could have resorted to the public serialization interface
+ * for doing the forwarding to the adapted iterator class:
+ * ar<<base_reference();
+ * ar>>base_reference();
+ * but this would cause incompatibilities if a saving
+ * program is in safe mode and the loading program is not, or
+ * viceversa --in safe mode, the archived iterator data is one layer
+ * deeper, this is especially relevant with XML archives.
+ * It'd be nice if Boost.Serialization provided some forwarding
+ * facility for use by adaptor classes.
+ */
+
+ friend class boost::serialization::access;
+
+ BOOST_SERIALIZATION_SPLIT_MEMBER()
+
+ template<class Archive>
+ void save(Archive& ar,const unsigned int version)const
+ {
+ BOOST_MULTI_INDEX_CHECK_VALID_ITERATOR(*this);
+ this->base_reference().save(ar,version);
+ }
+
+ template<class Archive>
+ void load(Archive& ar,const unsigned int version)
+ {
+ this->base_reference().load(ar,version);
+ safe_super::uncheck();
+ }
+#endif
+};
+
+template<typename Container>
+class safe_container:public detail::safe_container_base
+{
+ typedef detail::safe_container_base super;
+
+public:
+ void detach_dereferenceable_iterators()
+ {
+ typedef typename Container::iterator iterator;
+
+ iterator end_=static_cast<Container*>(this)->end();
+ iterator *prev_,*next_;
+ for(
+ prev_=static_cast<iterator*>(&this->header);
+ (next_=static_cast<iterator*>(prev_->next))!=0;){
+ if(*next_!=end_){
+ prev_->next=next_->next;
+ next_->cont=0;
+ }
+ else prev_=next_;
+ }
+ }
+
+ void swap(safe_container<Container>& x)
+ {
+ super::swap(x);
+ }
+};
+
+} /* namespace multi_index::safe_mode */
+
+} /* namespace multi_index */
+
+} /* namespace boost */
+
+#endif /* BOOST_MULTI_INDEX_ENABLE_SAFE_MODE */
+
+#endif
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