// 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) // (C) Copyright 2007 Anthony Williams #ifndef BOOST_THREAD_LOCKS_HPP #define BOOST_THREAD_LOCKS_HPP #include #include #include #include #include #include #include #include namespace boost { struct xtime; #if defined(BOOST_NO_SFINAE) || \ BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600)) || \ BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) #define BOOST_THREAD_NO_AUTO_DETECT_MUTEX_TYPES #endif #ifndef BOOST_THREAD_NO_AUTO_DETECT_MUTEX_TYPES namespace detail { template struct has_member_lock { typedef char true_type; struct false_type { true_type dummy[2]; }; template static true_type has_member(U*,void (U::*dummy)()=&U::lock); static false_type has_member(void*); BOOST_STATIC_CONSTANT(bool, value=sizeof(has_member_lock::has_member((T*)NULL))==sizeof(true_type)); }; template struct has_member_unlock { typedef char true_type; struct false_type { true_type dummy[2]; }; template static true_type has_member(U*,void (U::*dummy)()=&U::unlock); static false_type has_member(void*); BOOST_STATIC_CONSTANT(bool, value=sizeof(has_member_unlock::has_member((T*)NULL))==sizeof(true_type)); }; template struct has_member_try_lock { typedef char true_type; struct false_type { true_type dummy[2]; }; template static true_type has_member(U*,bool (U::*dummy)()=&U::try_lock); static false_type has_member(void*); BOOST_STATIC_CONSTANT(bool, value=sizeof(has_member_try_lock::has_member((T*)NULL))==sizeof(true_type)); }; } template struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = detail::has_member_lock::value && detail::has_member_unlock::value && detail::has_member_try_lock::value); }; #else template struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = false); }; #endif struct defer_lock_t {}; struct try_to_lock_t {}; struct adopt_lock_t {}; const defer_lock_t defer_lock={}; const try_to_lock_t try_to_lock={}; const adopt_lock_t adopt_lock={}; template class shared_lock; template class upgrade_lock; template class unique_lock; namespace detail { template class try_lock_wrapper; } #ifdef BOOST_THREAD_NO_AUTO_DETECT_MUTEX_TYPES template struct is_mutex_type > { BOOST_STATIC_CONSTANT(bool, value = true); }; template struct is_mutex_type > { BOOST_STATIC_CONSTANT(bool, value = true); }; template struct is_mutex_type > { BOOST_STATIC_CONSTANT(bool, value = true); }; template struct is_mutex_type > { BOOST_STATIC_CONSTANT(bool, value = true); }; class mutex; class timed_mutex; class recursive_mutex; class recursive_timed_mutex; class shared_mutex; template<> struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = true); }; template<> struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = true); }; template<> struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = true); }; template<> struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = true); }; template<> struct is_mutex_type { BOOST_STATIC_CONSTANT(bool, value = true); }; #endif template class lock_guard { private: Mutex& m; explicit lock_guard(lock_guard&); lock_guard& operator=(lock_guard&); public: explicit lock_guard(Mutex& m_): m(m_) { m.lock(); } lock_guard(Mutex& m_,adopt_lock_t): m(m_) {} ~lock_guard() { m.unlock(); } }; template class unique_lock { private: Mutex* m; bool is_locked; unique_lock(unique_lock&); explicit unique_lock(upgrade_lock&); unique_lock& operator=(unique_lock&); unique_lock& operator=(upgrade_lock& other); public: unique_lock(): m(0),is_locked(false) {} explicit unique_lock(Mutex& m_): m(&m_),is_locked(false) { lock(); } unique_lock(Mutex& m_,adopt_lock_t): m(&m_),is_locked(true) {} unique_lock(Mutex& m_,defer_lock_t): m(&m_),is_locked(false) {} unique_lock(Mutex& m_,try_to_lock_t): m(&m_),is_locked(false) { try_lock(); } template unique_lock(Mutex& m_,TimeDuration const& target_time): m(&m_),is_locked(false) { timed_lock(target_time); } unique_lock(Mutex& m_,system_time const& target_time): m(&m_),is_locked(false) { timed_lock(target_time); } #ifdef BOOST_HAS_RVALUE_REFS unique_lock(unique_lock&& other): m(other.m),is_locked(other.is_locked) { other.is_locked=false; other.m=0; } explicit unique_lock(upgrade_lock&& other); unique_lock&& move() { return static_cast&&>(*this); } unique_lock& operator=(unique_lock&& other) { unique_lock temp(other); swap(temp); return *this; } unique_lock& operator=(upgrade_lock&& other) { unique_lock temp(other); swap(temp); return *this; } void swap(unique_lock&& other) { std::swap(m,other.m); std::swap(is_locked,other.is_locked); } #else unique_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { other->is_locked=false; other->m=0; } unique_lock(detail::thread_move_t > other); operator detail::thread_move_t >() { return move(); } detail::thread_move_t > move() { return detail::thread_move_t >(*this); } unique_lock& operator=(detail::thread_move_t > other) { unique_lock temp(other); swap(temp); return *this; } unique_lock& operator=(detail::thread_move_t > other) { unique_lock temp(other); swap(temp); return *this; } void swap(unique_lock& other) { std::swap(m,other.m); std::swap(is_locked,other.is_locked); } void swap(detail::thread_move_t > other) { std::swap(m,other->m); std::swap(is_locked,other->is_locked); } #endif ~unique_lock() { if(owns_lock()) { m->unlock(); } } void lock() { if(owns_lock()) { throw boost::lock_error(); } m->lock(); is_locked=true; } bool try_lock() { if(owns_lock()) { throw boost::lock_error(); } is_locked=m->try_lock(); return is_locked; } template bool timed_lock(TimeDuration const& relative_time) { is_locked=m->timed_lock(relative_time); return is_locked; } bool timed_lock(::boost::system_time const& absolute_time) { is_locked=m->timed_lock(absolute_time); return is_locked; } bool timed_lock(::boost::xtime const& absolute_time) { is_locked=m->timed_lock(absolute_time); return is_locked; } void unlock() { if(!owns_lock()) { throw boost::lock_error(); } m->unlock(); is_locked=false; } typedef void (unique_lock::*bool_type)(); operator bool_type() const { return is_locked?&unique_lock::lock:0; } bool operator!() const { return !owns_lock(); } bool owns_lock() const { return is_locked; } Mutex* mutex() const { return m; } Mutex* release() { Mutex* const res=m; m=0; is_locked=false; return res; } friend class shared_lock; friend class upgrade_lock; }; #ifdef BOOST_HAS_RVALUE_REFS template void swap(unique_lock&& lhs,unique_lock&& rhs) { lhs.swap(rhs); } #else template void swap(unique_lock& lhs,unique_lock& rhs) { lhs.swap(rhs); } #endif #ifdef BOOST_HAS_RVALUE_REFS template inline unique_lock&& move(unique_lock&& ul) { return ul; } #endif template class shared_lock { protected: Mutex* m; bool is_locked; private: explicit shared_lock(shared_lock&); shared_lock& operator=(shared_lock&); public: shared_lock(): m(0),is_locked(false) {} explicit shared_lock(Mutex& m_): m(&m_),is_locked(false) { lock(); } shared_lock(Mutex& m_,adopt_lock_t): m(&m_),is_locked(true) {} shared_lock(Mutex& m_,defer_lock_t): m(&m_),is_locked(false) {} shared_lock(Mutex& m_,try_to_lock_t): m(&m_),is_locked(false) { try_lock(); } shared_lock(Mutex& m_,system_time const& target_time): m(&m_),is_locked(false) { timed_lock(target_time); } shared_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { other->is_locked=false; other->m=0; } shared_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { if(is_locked) { m->unlock_and_lock_shared(); } other->is_locked=false; other->m=0; } shared_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { if(is_locked) { m->unlock_upgrade_and_lock_shared(); } other->is_locked=false; other->m=0; } operator detail::thread_move_t >() { return move(); } detail::thread_move_t > move() { return detail::thread_move_t >(*this); } shared_lock& operator=(detail::thread_move_t > other) { shared_lock temp(other); swap(temp); return *this; } shared_lock& operator=(detail::thread_move_t > other) { shared_lock temp(other); swap(temp); return *this; } shared_lock& operator=(detail::thread_move_t > other) { shared_lock temp(other); swap(temp); return *this; } #ifdef BOOST_HAS_RVALUE_REFS void swap(shared_lock&& other) { std::swap(m,other.m); std::swap(is_locked,other.is_locked); } #else void swap(shared_lock& other) { std::swap(m,other.m); std::swap(is_locked,other.is_locked); } void swap(boost::detail::thread_move_t > other) { std::swap(m,other->m); std::swap(is_locked,other->is_locked); } #endif Mutex* mutex() const { return m; } ~shared_lock() { if(owns_lock()) { m->unlock_shared(); } } void lock() { if(owns_lock()) { throw boost::lock_error(); } m->lock_shared(); is_locked=true; } bool try_lock() { if(owns_lock()) { throw boost::lock_error(); } is_locked=m->try_lock_shared(); return is_locked; } bool timed_lock(boost::system_time const& target_time) { if(owns_lock()) { throw boost::lock_error(); } is_locked=m->timed_lock_shared(target_time); return is_locked; } template bool timed_lock(Duration const& target_time) { if(owns_lock()) { throw boost::lock_error(); } is_locked=m->timed_lock_shared(target_time); return is_locked; } void unlock() { if(!owns_lock()) { throw boost::lock_error(); } m->unlock_shared(); is_locked=false; } typedef void (shared_lock::*bool_type)(); operator bool_type() const { return is_locked?&shared_lock::lock:0; } bool operator!() const { return !owns_lock(); } bool owns_lock() const { return is_locked; } }; #ifdef BOOST_HAS_RVALUE_REFS template void swap(shared_lock&& lhs,shared_lock&& rhs) { lhs.swap(rhs); } #else template void swap(shared_lock& lhs,shared_lock& rhs) { lhs.swap(rhs); } #endif template class upgrade_lock { protected: Mutex* m; bool is_locked; private: explicit upgrade_lock(upgrade_lock&); upgrade_lock& operator=(upgrade_lock&); public: upgrade_lock(): m(0),is_locked(false) {} explicit upgrade_lock(Mutex& m_): m(&m_),is_locked(false) { lock(); } upgrade_lock(Mutex& m_,adopt_lock_t): m(&m_),is_locked(true) {} upgrade_lock(Mutex& m_,defer_lock_t): m(&m_),is_locked(false) {} upgrade_lock(Mutex& m_,try_to_lock_t): m(&m_),is_locked(false) { try_lock(); } upgrade_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { other->is_locked=false; other->m=0; } upgrade_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { if(is_locked) { m->unlock_and_lock_upgrade(); } other->is_locked=false; other->m=0; } operator detail::thread_move_t >() { return move(); } detail::thread_move_t > move() { return detail::thread_move_t >(*this); } upgrade_lock& operator=(detail::thread_move_t > other) { upgrade_lock temp(other); swap(temp); return *this; } upgrade_lock& operator=(detail::thread_move_t > other) { upgrade_lock temp(other); swap(temp); return *this; } void swap(upgrade_lock& other) { std::swap(m,other.m); std::swap(is_locked,other.is_locked); } ~upgrade_lock() { if(owns_lock()) { m->unlock_upgrade(); } } void lock() { if(owns_lock()) { throw boost::lock_error(); } m->lock_upgrade(); is_locked=true; } bool try_lock() { if(owns_lock()) { throw boost::lock_error(); } is_locked=m->try_lock_upgrade(); return is_locked; } void unlock() { if(!owns_lock()) { throw boost::lock_error(); } m->unlock_upgrade(); is_locked=false; } typedef void (upgrade_lock::*bool_type)(); operator bool_type() const { return is_locked?&upgrade_lock::lock:0; } bool operator!() const { return !owns_lock(); } bool owns_lock() const { return is_locked; } friend class shared_lock; friend class unique_lock; }; #ifdef BOOST_HAS_RVALUE_REFS template unique_lock::unique_lock(upgrade_lock&& other): m(other.m),is_locked(other.is_locked) { other.is_locked=false; if(is_locked) { m.unlock_upgrade_and_lock(); } } #else template unique_lock::unique_lock(detail::thread_move_t > other): m(other->m),is_locked(other->is_locked) { other->is_locked=false; if(is_locked) { m->unlock_upgrade_and_lock(); } } #endif template class upgrade_to_unique_lock { private: upgrade_lock* source; unique_lock exclusive; explicit upgrade_to_unique_lock(upgrade_to_unique_lock&); upgrade_to_unique_lock& operator=(upgrade_to_unique_lock&); public: explicit upgrade_to_unique_lock(upgrade_lock& m_): source(&m_),exclusive(move(*source)) {} ~upgrade_to_unique_lock() { if(source) { *source=move(exclusive); } } upgrade_to_unique_lock(detail::thread_move_t > other): source(other->source),exclusive(move(other->exclusive)) { other->source=0; } upgrade_to_unique_lock& operator=(detail::thread_move_t > other) { upgrade_to_unique_lock temp(other); swap(temp); return *this; } void swap(upgrade_to_unique_lock& other) { std::swap(source,other.source); exclusive.swap(other.exclusive); } typedef void (upgrade_to_unique_lock::*bool_type)(upgrade_to_unique_lock&); operator bool_type() const { return exclusive.owns_lock()?&upgrade_to_unique_lock::swap:0; } bool operator!() const { return !owns_lock(); } bool owns_lock() const { return exclusive.owns_lock(); } }; namespace detail { template class try_lock_wrapper: private unique_lock { typedef unique_lock base; public: try_lock_wrapper() {} explicit try_lock_wrapper(Mutex& m): base(m,try_to_lock) {} try_lock_wrapper(Mutex& m_,adopt_lock_t): base(m_,adopt_lock) {} try_lock_wrapper(Mutex& m_,defer_lock_t): base(m_,defer_lock) {} try_lock_wrapper(Mutex& m_,try_to_lock_t): base(m_,try_to_lock) {} try_lock_wrapper(detail::thread_move_t > other): base(detail::thread_move_t(*other)) {} operator detail::thread_move_t >() { return move(); } detail::thread_move_t > move() { return detail::thread_move_t >(*this); } try_lock_wrapper& operator=(detail::thread_move_t > other) { try_lock_wrapper temp(other); swap(temp); return *this; } #ifdef BOOST_HAS_RVALUE_REFS void swap(try_lock_wrapper&& other) { base::swap(other); } #else void swap(try_lock_wrapper& other) { base::swap(other); } void swap(detail::thread_move_t > other) { base::swap(*other); } #endif void lock() { base::lock(); } bool try_lock() { return base::try_lock(); } void unlock() { base::unlock(); } bool owns_lock() const { return base::owns_lock(); } Mutex* mutex() const { return base::mutex(); } Mutex* release() { return base::release(); } bool operator!() const { return !this->owns_lock(); } typedef typename base::bool_type bool_type; operator bool_type() const { return base::operator bool_type(); } }; #ifdef BOOST_HAS_RVALUE_REFS template void swap(try_lock_wrapper&& lhs,try_lock_wrapper&& rhs) { lhs.swap(rhs); } #else template void swap(try_lock_wrapper& lhs,try_lock_wrapper& rhs) { lhs.swap(rhs); } #endif template unsigned try_lock_internal(MutexType1& m1,MutexType2& m2) { boost::unique_lock l1(m1,boost::try_to_lock); if(!l1) { return 1; } if(!m2.try_lock()) { return 2; } l1.release(); return 0; } template unsigned try_lock_internal(MutexType1& m1,MutexType2& m2,MutexType3& m3) { boost::unique_lock l1(m1,boost::try_to_lock); if(!l1) { return 1; } if(unsigned const failed_lock=try_lock_internal(m2,m3)) { return failed_lock+1; } l1.release(); return 0; } template unsigned try_lock_internal(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4) { boost::unique_lock l1(m1,boost::try_to_lock); if(!l1) { return 1; } if(unsigned const failed_lock=try_lock_internal(m2,m3,m4)) { return failed_lock+1; } l1.release(); return 0; } template unsigned try_lock_internal(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4,MutexType5& m5) { boost::unique_lock l1(m1,boost::try_to_lock); if(!l1) { return 1; } if(unsigned const failed_lock=try_lock_internal(m2,m3,m4,m5)) { return failed_lock+1; } l1.release(); return 0; } template unsigned lock_helper(MutexType1& m1,MutexType2& m2) { boost::unique_lock l1(m1); if(!m2.try_lock()) { return 1; } l1.release(); return 0; } template unsigned lock_helper(MutexType1& m1,MutexType2& m2,MutexType3& m3) { boost::unique_lock l1(m1); if(unsigned const failed_lock=try_lock_internal(m2,m3)) { return failed_lock; } l1.release(); return 0; } template unsigned lock_helper(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4) { boost::unique_lock l1(m1); if(unsigned const failed_lock=try_lock_internal(m2,m3,m4)) { return failed_lock; } l1.release(); return 0; } template unsigned lock_helper(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4,MutexType5& m5) { boost::unique_lock l1(m1); if(unsigned const failed_lock=try_lock_internal(m2,m3,m4,m5)) { return failed_lock; } l1.release(); return 0; } } namespace detail { template struct is_mutex_type_wrapper {}; template void lock_impl(MutexType1& m1,MutexType2& m2,is_mutex_type_wrapper) { unsigned const lock_count=2; unsigned lock_first=0; while(true) { switch(lock_first) { case 0: lock_first=detail::lock_helper(m1,m2); if(!lock_first) return; break; case 1: lock_first=detail::lock_helper(m2,m1); if(!lock_first) return; lock_first=(lock_first+1)%lock_count; break; } } } template void lock_impl(Iterator begin,Iterator end,is_mutex_type_wrapper); } template void lock(MutexType1& m1,MutexType2& m2) { detail::lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template void lock(const MutexType1& m1,MutexType2& m2) { detail::lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template void lock(MutexType1& m1,const MutexType2& m2) { detail::lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template void lock(const MutexType1& m1,const MutexType2& m2) { detail::lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template void lock(MutexType1& m1,MutexType2& m2,MutexType3& m3) { unsigned const lock_count=3; unsigned lock_first=0; while(true) { switch(lock_first) { case 0: lock_first=detail::lock_helper(m1,m2,m3); if(!lock_first) return; break; case 1: lock_first=detail::lock_helper(m2,m3,m1); if(!lock_first) return; lock_first=(lock_first+1)%lock_count; break; case 2: lock_first=detail::lock_helper(m3,m1,m2); if(!lock_first) return; lock_first=(lock_first+2)%lock_count; break; } } } template void lock(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4) { unsigned const lock_count=4; unsigned lock_first=0; while(true) { switch(lock_first) { case 0: lock_first=detail::lock_helper(m1,m2,m3,m4); if(!lock_first) return; break; case 1: lock_first=detail::lock_helper(m2,m3,m4,m1); if(!lock_first) return; lock_first=(lock_first+1)%lock_count; break; case 2: lock_first=detail::lock_helper(m3,m4,m1,m2); if(!lock_first) return; lock_first=(lock_first+2)%lock_count; break; case 3: lock_first=detail::lock_helper(m4,m1,m2,m3); if(!lock_first) return; lock_first=(lock_first+3)%lock_count; break; } } } template void lock(MutexType1& m1,MutexType2& m2,MutexType3& m3, MutexType4& m4,MutexType5& m5) { unsigned const lock_count=5; unsigned lock_first=0; while(true) { switch(lock_first) { case 0: lock_first=detail::lock_helper(m1,m2,m3,m4,m5); if(!lock_first) return; break; case 1: lock_first=detail::lock_helper(m2,m3,m4,m5,m1); if(!lock_first) return; lock_first=(lock_first+1)%lock_count; break; case 2: lock_first=detail::lock_helper(m3,m4,m5,m1,m2); if(!lock_first) return; lock_first=(lock_first+2)%lock_count; break; case 3: lock_first=detail::lock_helper(m4,m5,m1,m2,m3); if(!lock_first) return; lock_first=(lock_first+3)%lock_count; break; case 4: lock_first=detail::lock_helper(m5,m1,m2,m3,m4); if(!lock_first) return; lock_first=(lock_first+4)%lock_count; break; } } } namespace detail { template::value> struct try_lock_impl_return { typedef int type; }; template struct try_lock_impl_return { typedef Iterator type; }; template int try_lock_impl(MutexType1& m1,MutexType2& m2,is_mutex_type_wrapper) { return ((int)detail::try_lock_internal(m1,m2))-1; } template Iterator try_lock_impl(Iterator begin,Iterator end,is_mutex_type_wrapper); } template typename detail::try_lock_impl_return::type try_lock(MutexType1& m1,MutexType2& m2) { return detail::try_lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template typename detail::try_lock_impl_return::type try_lock(const MutexType1& m1,MutexType2& m2) { return detail::try_lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template typename detail::try_lock_impl_return::type try_lock(MutexType1& m1,const MutexType2& m2) { return detail::try_lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template typename detail::try_lock_impl_return::type try_lock(const MutexType1& m1,const MutexType2& m2) { return detail::try_lock_impl(m1,m2,detail::is_mutex_type_wrapper::value>()); } template int try_lock(MutexType1& m1,MutexType2& m2,MutexType3& m3) { return ((int)detail::try_lock_internal(m1,m2,m3))-1; } template int try_lock(MutexType1& m1,MutexType2& m2,MutexType3& m3,MutexType4& m4) { return ((int)detail::try_lock_internal(m1,m2,m3,m4))-1; } template int try_lock(MutexType1& m1,MutexType2& m2,MutexType3& m3,MutexType4& m4,MutexType5& m5) { return ((int)detail::try_lock_internal(m1,m2,m3,m4,m5))-1; } namespace detail { template struct range_lock_guard { Iterator begin; Iterator end; range_lock_guard(Iterator begin_,Iterator end_): begin(begin_),end(end_) { lock(begin,end); } void release() { begin=end; } ~range_lock_guard() { for(;begin!=end;++begin) { begin->unlock(); } } }; template Iterator try_lock_impl(Iterator begin,Iterator end,is_mutex_type_wrapper) { if(begin==end) { return end; } typedef typename std::iterator_traits::value_type lock_type; unique_lock guard(*begin,try_to_lock); if(!guard.owns_lock()) { return begin; } Iterator const failed=try_lock(++begin,end); if(failed==end) { guard.release(); } return failed; } } namespace detail { template void lock_impl(Iterator begin,Iterator end,is_mutex_type_wrapper) { typedef typename std::iterator_traits::value_type lock_type; if(begin==end) { return; } bool start_with_begin=true; Iterator second=begin; ++second; Iterator next=second; for(;;) { unique_lock begin_lock(*begin,defer_lock); if(start_with_begin) { begin_lock.lock(); Iterator const failed_lock=try_lock(next,end); if(failed_lock==end) { begin_lock.release(); return; } start_with_begin=false; next=failed_lock; } else { detail::range_lock_guard guard(next,end); if(begin_lock.try_lock()) { Iterator const failed_lock=try_lock(second,next); if(failed_lock==next) { begin_lock.release(); guard.release(); return; } start_with_begin=false; next=failed_lock; } else { start_with_begin=true; next=second; } } } } } } #include #endif