Imported Upstream version 1.49.0upstream/1.49.0

1 files changed, 619 insertions, 0 deletions

diff --git a/boost/thread/win32/shared_mutex.hpp b/boost/thread/win32/shared_mutex.hpp
new file mode 100644
index 0000000000..aee40399e4
--- /dev/null
+++ b/boost/thread/win32/shared_mutex.hpp
@@ -0,0 +1,619 @@
+#ifndef BOOST_THREAD_WIN32_SHARED_MUTEX_HPP
+#define BOOST_THREAD_WIN32_SHARED_MUTEX_HPP
+
+//  (C) Copyright 2006-8 Anthony Williams
+//
+//  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)
+
+#include <boost/assert.hpp>
+#include <boost/detail/interlocked.hpp>
+#include <boost/thread/win32/thread_primitives.hpp>
+#include <boost/static_assert.hpp>
+#include <limits.h>
+#include <boost/utility.hpp>
+#include <boost/thread/thread_time.hpp>
+
+#include <boost/config/abi_prefix.hpp>
+
+namespace boost
+{
+    class shared_mutex
+    {
+    private:
+        shared_mutex(shared_mutex const&);
+        shared_mutex& operator=(shared_mutex const&);
+    private:
+        struct state_data
+        {
+            unsigned shared_count:11,
+                shared_waiting:11,
+                exclusive:1,
+                upgrade:1,
+                exclusive_waiting:7,
+                exclusive_waiting_blocked:1;
+
+            friend bool operator==(state_data const& lhs,state_data const& rhs)
+            {
+                return *reinterpret_cast<unsigned const*>(&lhs)==*reinterpret_cast<unsigned const*>(&rhs);
+            }
+        };
+
+
+        template<typename T>
+        T interlocked_compare_exchange(T* target,T new_value,T comparand)
+        {
+            BOOST_STATIC_ASSERT(sizeof(T)==sizeof(long));
+            long const res=BOOST_INTERLOCKED_COMPARE_EXCHANGE(reinterpret_cast<long*>(target),
+                                                              *reinterpret_cast<long*>(&new_value),
+                                                              *reinterpret_cast<long*>(&comparand));
+            return *reinterpret_cast<T const*>(&res);
+        }
+
+        enum
+        {
+            unlock_sem = 0,
+            exclusive_sem = 1
+        };
+
+        state_data state;
+        detail::win32::handle semaphores[2];
+        detail::win32::handle upgrade_sem;
+
+        void release_waiters(state_data old_state)
+        {
+            if(old_state.exclusive_waiting)
+            {
+                BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[exclusive_sem],1,0)!=0);
+            }
+
+            if(old_state.shared_waiting || old_state.exclusive_waiting)
+            {
+                BOOST_VERIFY(detail::win32::ReleaseSemaphore(semaphores[unlock_sem],old_state.shared_waiting + (old_state.exclusive_waiting?1:0),0)!=0);
+            }
+        }
+
+
+    public:
+        shared_mutex()
+        {
+            semaphores[unlock_sem]=detail::win32::create_anonymous_semaphore(0,LONG_MAX);
+            semaphores[exclusive_sem]=detail::win32::create_anonymous_semaphore_nothrow(0,LONG_MAX);
+            if (!semaphores[exclusive_sem])
+            {
+              detail::win32::release_semaphore(semaphores[unlock_sem],LONG_MAX);
+              boost::throw_exception(thread_resource_error());
+            }
+            upgrade_sem=detail::win32::create_anonymous_semaphore_nothrow(0,LONG_MAX);
+            if (!upgrade_sem)
+            {
+              detail::win32::release_semaphore(semaphores[unlock_sem],LONG_MAX);
+              detail::win32::release_semaphore(semaphores[exclusive_sem],LONG_MAX);
+              boost::throw_exception(thread_resource_error());
+            }
+            state_data state_={0};
+            state=state_;
+        }
+
+        ~shared_mutex()
+        {
+            detail::win32::CloseHandle(upgrade_sem);
+            detail::win32::CloseHandle(semaphores[unlock_sem]);
+            detail::win32::CloseHandle(semaphores[exclusive_sem]);
+        }
+
+        bool try_lock_shared()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                if(!new_state.exclusive && !new_state.exclusive_waiting_blocked)
+                {
+                    ++new_state.shared_count;
+                    if(!new_state.shared_count)
+                    {
+                        return false;
+                    }
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            return !(old_state.exclusive| old_state.exclusive_waiting_blocked);
+        }
+
+        void lock_shared()
+        {
+            BOOST_VERIFY(timed_lock_shared(::boost::detail::get_system_time_sentinel()));
+        }
+
+        template<typename TimeDuration>
+        bool timed_lock_shared(TimeDuration const & relative_time)
+        {
+            return timed_lock_shared(get_system_time()+relative_time);
+        }
+
+        bool timed_lock_shared(boost::system_time const& wait_until)
+        {
+            for(;;)
+            {
+                state_data old_state=state;
+                for(;;)
+                {
+                    state_data new_state=old_state;
+                    if(new_state.exclusive || new_state.exclusive_waiting_blocked)
+                    {
+                        ++new_state.shared_waiting;
+                        if(!new_state.shared_waiting)
+                        {
+                            boost::throw_exception(boost::lock_error());
+                        }
+                    }
+                    else
+                    {
+                        ++new_state.shared_count;
+                        if(!new_state.shared_count)
+                        {
+                            boost::throw_exception(boost::lock_error());
+                        }
+                    }
+
+                    state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                    if(current_state==old_state)
+                    {
+                        break;
+                    }
+                    old_state=current_state;
+                }
+
+                if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
+                {
+                    return true;
+                }
+
+                unsigned long const res=detail::win32::WaitForSingleObject(semaphores[unlock_sem],::boost::detail::get_milliseconds_until(wait_until));
+                if(res==detail::win32::timeout)
+                {
+                    for(;;)
+                    {
+                        state_data new_state=old_state;
+                        if(new_state.exclusive || new_state.exclusive_waiting_blocked)
+                        {
+                            if(new_state.shared_waiting)
+                            {
+                                --new_state.shared_waiting;
+                            }
+                        }
+                        else
+                        {
+                            ++new_state.shared_count;
+                            if(!new_state.shared_count)
+                            {
+                                return false;
+                            }
+                        }
+
+                        state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                        if(current_state==old_state)
+                        {
+                            break;
+                        }
+                        old_state=current_state;
+                    }
+
+                    if(!(old_state.exclusive| old_state.exclusive_waiting_blocked))
+                    {
+                        return true;
+                    }
+                    return false;
+                }
+
+                BOOST_ASSERT(res==0);
+            }
+        }
+
+        void unlock_shared()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                bool const last_reader=!--new_state.shared_count;
+
+                if(last_reader)
+                {
+                    if(new_state.upgrade)
+                    {
+                        new_state.upgrade=false;
+                        new_state.exclusive=true;
+                    }
+                    else
+                    {
+                        if(new_state.exclusive_waiting)
+                        {
+                            --new_state.exclusive_waiting;
+                            new_state.exclusive_waiting_blocked=false;
+                        }
+                        new_state.shared_waiting=0;
+                    }
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    if(last_reader)
+                    {
+                        if(old_state.upgrade)
+                        {
+                            BOOST_VERIFY(detail::win32::ReleaseSemaphore(upgrade_sem,1,0)!=0);
+                        }
+                        else
+                        {
+                            release_waiters(old_state);
+                        }
+                    }
+                    break;
+                }
+                old_state=current_state;
+            }
+        }
+
+        void lock()
+        {
+            BOOST_VERIFY(timed_lock(::boost::detail::get_system_time_sentinel()));
+        }
+
+        template<typename TimeDuration>
+        bool timed_lock(TimeDuration const & relative_time)
+        {
+            return timed_lock(get_system_time()+relative_time);
+        }
+
+        bool try_lock()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                if(new_state.shared_count || new_state.exclusive)
+                {
+                    return false;
+                }
+                else
+                {
+                    new_state.exclusive=true;
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            return true;
+        }
+
+
+        bool timed_lock(boost::system_time const& wait_until)
+        {
+            for(;;)
+            {
+                state_data old_state=state;
+
+                for(;;)
+                {
+                    state_data new_state=old_state;
+                    if(new_state.shared_count || new_state.exclusive)
+                    {
+                        ++new_state.exclusive_waiting;
+                        if(!new_state.exclusive_waiting)
+                        {
+                            boost::throw_exception(boost::lock_error());
+                        }
+
+                        new_state.exclusive_waiting_blocked=true;
+                    }
+                    else
+                    {
+                        new_state.exclusive=true;
+                    }
+
+                    state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                    if(current_state==old_state)
+                    {
+                        break;
+                    }
+                    old_state=current_state;
+                }
+
+                if(!old_state.shared_count && !old_state.exclusive)
+                {
+                    return true;
+                }
+                #ifndef UNDER_CE
+                const bool wait_all = true;
+                #else
+                const bool wait_all = false;
+                #endif
+                unsigned long const wait_res=detail::win32::WaitForMultipleObjects(2,semaphores,wait_all,::boost::detail::get_milliseconds_until(wait_until));
+                if(wait_res==detail::win32::timeout)
+                {
+                    for(;;)
+                    {
+                        state_data new_state=old_state;
+                        if(new_state.shared_count || new_state.exclusive)
+                        {
+                            if(new_state.exclusive_waiting)
+                            {
+                                if(!--new_state.exclusive_waiting)
+                                {
+                                    new_state.exclusive_waiting_blocked=false;
+                                }
+                            }
+                        }
+                        else
+                        {
+                            new_state.exclusive=true;
+                        }
+
+                        state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                        if(current_state==old_state)
+                        {
+                            break;
+                        }
+                        old_state=current_state;
+                    }
+                    if(!old_state.shared_count && !old_state.exclusive)
+                    {
+                        return true;
+                    }
+                    return false;
+                }
+                BOOST_ASSERT(wait_res<2);
+            }
+        }
+
+        void unlock()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                new_state.exclusive=false;
+                if(new_state.exclusive_waiting)
+                {
+                    --new_state.exclusive_waiting;
+                    new_state.exclusive_waiting_blocked=false;
+                }
+                new_state.shared_waiting=0;
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            release_waiters(old_state);
+        }
+
+        void lock_upgrade()
+        {
+            for(;;)
+            {
+                state_data old_state=state;
+                for(;;)
+                {
+                    state_data new_state=old_state;
+                    if(new_state.exclusive || new_state.exclusive_waiting_blocked || new_state.upgrade)
+                    {
+                        ++new_state.shared_waiting;
+                        if(!new_state.shared_waiting)
+                        {
+                            boost::throw_exception(boost::lock_error());
+                        }
+                    }
+                    else
+                    {
+                        ++new_state.shared_count;
+                        if(!new_state.shared_count)
+                        {
+                            boost::throw_exception(boost::lock_error());
+                        }
+                        new_state.upgrade=true;
+                    }
+
+                    state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                    if(current_state==old_state)
+                    {
+                        break;
+                    }
+                    old_state=current_state;
+                }
+
+                if(!(old_state.exclusive|| old_state.exclusive_waiting_blocked|| old_state.upgrade))
+                {
+                    return;
+                }
+
+                BOOST_VERIFY(!detail::win32::WaitForSingleObject(semaphores[unlock_sem],detail::win32::infinite));
+            }
+        }
+
+        bool try_lock_upgrade()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                if(new_state.exclusive || new_state.exclusive_waiting_blocked || new_state.upgrade)
+                {
+                    return false;
+                }
+                else
+                {
+                    ++new_state.shared_count;
+                    if(!new_state.shared_count)
+                    {
+                        return false;
+                    }
+                    new_state.upgrade=true;
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            return true;
+        }
+
+        void unlock_upgrade()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                new_state.upgrade=false;
+                bool const last_reader=!--new_state.shared_count;
+
+                if(last_reader)
+                {
+                    if(new_state.exclusive_waiting)
+                    {
+                        --new_state.exclusive_waiting;
+                        new_state.exclusive_waiting_blocked=false;
+                    }
+                    new_state.shared_waiting=0;
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    if(last_reader)
+                    {
+                        release_waiters(old_state);
+                    }
+                    break;
+                }
+                old_state=current_state;
+            }
+        }
+
+        void unlock_upgrade_and_lock()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                bool const last_reader=!--new_state.shared_count;
+
+                if(last_reader)
+                {
+                    new_state.upgrade=false;
+                    new_state.exclusive=true;
+                }
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    if(!last_reader)
+                    {
+                        BOOST_VERIFY(!detail::win32::WaitForSingleObject(upgrade_sem,detail::win32::infinite));
+                    }
+                    break;
+                }
+                old_state=current_state;
+            }
+        }
+
+        void unlock_and_lock_upgrade()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                new_state.exclusive=false;
+                new_state.upgrade=true;
+                ++new_state.shared_count;
+                if(new_state.exclusive_waiting)
+                {
+                    --new_state.exclusive_waiting;
+                    new_state.exclusive_waiting_blocked=false;
+                }
+                new_state.shared_waiting=0;
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            release_waiters(old_state);
+        }
+
+        void unlock_and_lock_shared()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                new_state.exclusive=false;
+                ++new_state.shared_count;
+                if(new_state.exclusive_waiting)
+                {
+                    --new_state.exclusive_waiting;
+                    new_state.exclusive_waiting_blocked=false;
+                }
+                new_state.shared_waiting=0;
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            release_waiters(old_state);
+        }
+
+        void unlock_upgrade_and_lock_shared()
+        {
+            state_data old_state=state;
+            for(;;)
+            {
+                state_data new_state=old_state;
+                new_state.upgrade=false;
+                if(new_state.exclusive_waiting)
+                {
+                    --new_state.exclusive_waiting;
+                    new_state.exclusive_waiting_blocked=false;
+                }
+                new_state.shared_waiting=0;
+
+                state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);
+                if(current_state==old_state)
+                {
+                    break;
+                }
+                old_state=current_state;
+            }
+            release_waiters(old_state);
+        }
+
+    };
+}
+
+#include <boost/config/abi_suffix.hpp>
+
+#endif