// 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
// (C) Copyright 2007 David Deakins

#define _WIN32_WINNT 0x400
#define WINVER 0x400

#include <boost/thread/thread.hpp>
#include <algorithm>
#include <windows.h>
#ifndef UNDER_CE
#include <process.h>
#endif
#include <stdio.h>
#include <boost/thread/once.hpp>
#include <boost/thread/tss.hpp>
#include <boost/assert.hpp>
#include <boost/thread/detail/tss_hooks.hpp>
#include <boost/date_time/posix_time/conversion.hpp>

namespace boost
{
    namespace
    {
        boost::once_flag current_thread_tls_init_flag=BOOST_ONCE_INIT;
        DWORD current_thread_tls_key=0;

        void create_current_thread_tls_key()
        {
            current_thread_tls_key=TlsAlloc();
            BOOST_ASSERT(current_thread_tls_key!=TLS_OUT_OF_INDEXES);
        }

        detail::thread_data_base* get_current_thread_data()
        {
            boost::call_once(current_thread_tls_init_flag,create_current_thread_tls_key);
            return (detail::thread_data_base*)TlsGetValue(current_thread_tls_key);
        }

        void set_current_thread_data(detail::thread_data_base* new_data)
        {
            boost::call_once(current_thread_tls_init_flag,create_current_thread_tls_key);
            BOOST_VERIFY(TlsSetValue(current_thread_tls_key,new_data));
        }

#ifdef BOOST_NO_THREADEX
// Windows CE doesn't define _beginthreadex

        struct ThreadProxyData
        {
            typedef unsigned (__stdcall* func)(void*);
            func start_address_;
            void* arglist_;
            ThreadProxyData(func start_address,void* arglist) : start_address_(start_address), arglist_(arglist) {}
        };

        DWORD WINAPI ThreadProxy(LPVOID args)
        {
            ThreadProxyData* data=reinterpret_cast<ThreadProxyData*>(args);
            DWORD ret=data->start_address_(data->arglist_);
            delete data;
            return ret;
        }
        
        typedef void* uintptr_t;

        inline uintptr_t const _beginthreadex(void* security, unsigned stack_size, unsigned (__stdcall* start_address)(void*),
                                              void* arglist, unsigned initflag, unsigned* thrdaddr)
        {
            DWORD threadID;
            HANDLE hthread=CreateThread(static_cast<LPSECURITY_ATTRIBUTES>(security),stack_size,ThreadProxy,
                                        new ThreadProxyData(start_address,arglist),initflag,&threadID);
            if (hthread!=0)
                *thrdaddr=threadID;
            return reinterpret_cast<uintptr_t const>(hthread);
        }

#endif

    }

    void thread::yield()
    {
        this_thread::yield();
    }
    
    void thread::sleep(const system_time& target)
    {
        system_time const now(get_system_time());
        
        if(target<=now)
        {
            this_thread::yield();
        }
        else
        {
            this_thread::sleep(target-now);
        }
    }

    namespace detail
    {
        struct thread_exit_callback_node
        {
            boost::detail::thread_exit_function_base* func;
            thread_exit_callback_node* next;

            thread_exit_callback_node(boost::detail::thread_exit_function_base* func_,
                                      thread_exit_callback_node* next_):
                func(func_),next(next_)
            {}
        };

        struct tss_data_node
        {
            void const* key;
            boost::shared_ptr<boost::detail::tss_cleanup_function> func;
            void* value;
            tss_data_node* next;

            tss_data_node(void const* key_,boost::shared_ptr<boost::detail::tss_cleanup_function> func_,void* value_,
                          tss_data_node* next_):
                key(key_),func(func_),value(value_),next(next_)
            {}
        };

    }

    namespace
    {
        void run_thread_exit_callbacks()
        {
            detail::thread_data_ptr current_thread_data(get_current_thread_data(),false);
            if(current_thread_data)
            {
                while(current_thread_data->tss_data || current_thread_data->thread_exit_callbacks)
                {
                    while(current_thread_data->thread_exit_callbacks)
                    {
                        detail::thread_exit_callback_node* const current_node=current_thread_data->thread_exit_callbacks;
                        current_thread_data->thread_exit_callbacks=current_node->next;
                        if(current_node->func)
                        {
                            (*current_node->func)();
                            boost::detail::heap_delete(current_node->func);
                        }
                        boost::detail::heap_delete(current_node);
                    }
                    while(current_thread_data->tss_data)
                    {
                        detail::tss_data_node* const current_node=current_thread_data->tss_data;
                        current_thread_data->tss_data=current_node->next;
                        if(current_node->func)
                        {
                            (*current_node->func)(current_node->value);
                        }
                        boost::detail::heap_delete(current_node);
                    }
                }
                
            }
            set_current_thread_data(0);
        }
        
    }
    

    unsigned __stdcall thread::thread_start_function(void* param)
    {
        detail::thread_data_base* const thread_info(reinterpret_cast<detail::thread_data_base*>(param));
        set_current_thread_data(thread_info);
        try
        {
            thread_info->run();
        }
        catch(thread_interrupted const&)
        {
        }
        catch(...)
        {
            std::terminate();
        }
        run_thread_exit_callbacks();
        return 0;
    }

    thread::thread()
    {}

    void thread::start_thread()
    {
        uintptr_t const new_thread=_beginthreadex(0,0,&thread_start_function,thread_info.get(),CREATE_SUSPENDED,&thread_info->id);
        if(!new_thread)
        {
            throw thread_resource_error();
        }
        intrusive_ptr_add_ref(thread_info.get());
        thread_info->thread_handle=(detail::win32::handle)(new_thread);
        ResumeThread(thread_info->thread_handle);
    }

    thread::thread(detail::thread_data_ptr data):
        thread_info(data)
    {}

    namespace
    {
        struct externally_launched_thread:
            detail::thread_data_base
        {
            externally_launched_thread()
            {
                ++count;
                interruption_enabled=false;
            }
            
            void run()
            {}
        };

        void make_external_thread_data()
        {
            externally_launched_thread* me=detail::heap_new<externally_launched_thread>();
            set_current_thread_data(me);
        }

        detail::thread_data_base* get_or_make_current_thread_data()
        {
            detail::thread_data_base* current_thread_data(get_current_thread_data());
            if(!current_thread_data)
            {
                make_external_thread_data();
                current_thread_data=get_current_thread_data();
            }
            return current_thread_data;
        }
        
    }

    thread::~thread()
    {
        detach();
    }
    
    thread::thread(detail::thread_move_t<thread> x)
    {
        lock_guard<mutex> lock(x->thread_info_mutex);
        thread_info=x->thread_info;
        x->thread_info=0;
    }
    
    thread& thread::operator=(detail::thread_move_t<thread> x)
    {
        thread new_thread(x);
        swap(new_thread);
        return *this;
    }
        
    thread::operator detail::thread_move_t<thread>()
    {
        return move();
    }

    detail::thread_move_t<thread> thread::move()
    {
        detail::thread_move_t<thread> x(*this);
        return x;
    }

    void thread::swap(thread& x)
    {
        thread_info.swap(x.thread_info);
    }

    thread::id thread::get_id() const
    {
        return thread::id(get_thread_info());
    }

    bool thread::joinable() const
    {
        return get_thread_info();
    }

    void thread::join()
    {
        detail::thread_data_ptr local_thread_info=get_thread_info();
        if(local_thread_info)
        {
            this_thread::interruptible_wait(local_thread_info->thread_handle,detail::timeout::sentinel());
            release_handle();
        }
    }

    bool thread::timed_join(boost::system_time const& wait_until)
    {
        detail::thread_data_ptr local_thread_info=get_thread_info();
        if(local_thread_info)
        {
            if(!this_thread::interruptible_wait(local_thread_info->thread_handle,get_milliseconds_until(wait_until)))
            {
                return false;
            }
            release_handle();
        }
        return true;
    }
    
    void thread::detach()
    {
        release_handle();
    }

    void thread::release_handle()
    {
        lock_guard<mutex> l1(thread_info_mutex);
        thread_info=0;
    }
    
    void thread::interrupt()
    {
        detail::thread_data_ptr local_thread_info=get_thread_info();
        if(local_thread_info)
        {
            local_thread_info->interrupt();
        }
    }
    
    bool thread::interruption_requested() const
    {
        detail::thread_data_ptr local_thread_info=get_thread_info();
        return local_thread_info.get() && (detail::win32::WaitForSingleObject(local_thread_info->interruption_handle,0)==0);
    }
    
    unsigned thread::hardware_concurrency()
    {
        SYSTEM_INFO info={0};
        GetSystemInfo(&info);
        return info.dwNumberOfProcessors;
    }
    
    thread::native_handle_type thread::native_handle()
    {
        detail::thread_data_ptr local_thread_info=get_thread_info();
        return local_thread_info?(detail::win32::handle)local_thread_info->thread_handle:detail::win32::invalid_handle_value;
    }

    detail::thread_data_ptr thread::get_thread_info() const
    {
        boost::mutex::scoped_lock l(thread_info_mutex);
        return thread_info;
    }

    namespace this_thread
    {
        namespace
        {
            LARGE_INTEGER get_due_time(detail::timeout const&  target_time)
            {
                LARGE_INTEGER due_time={0};
                if(target_time.relative)
                {
                    unsigned long const elapsed_milliseconds=GetTickCount()-target_time.start;
                    LONGLONG const remaining_milliseconds=(target_time.milliseconds-elapsed_milliseconds);
                    LONGLONG const hundred_nanoseconds_in_one_millisecond=10000;

                    if(remaining_milliseconds>0)
                    {
                        due_time.QuadPart=-(remaining_milliseconds*hundred_nanoseconds_in_one_millisecond);
                    }
                }
                else
                {
                    SYSTEMTIME target_system_time={0};
                    target_system_time.wYear=target_time.abs_time.date().year();
                    target_system_time.wMonth=target_time.abs_time.date().month();
                    target_system_time.wDay=target_time.abs_time.date().day();
                    target_system_time.wHour=(WORD)target_time.abs_time.time_of_day().hours();
                    target_system_time.wMinute=(WORD)target_time.abs_time.time_of_day().minutes();
                    target_system_time.wSecond=(WORD)target_time.abs_time.time_of_day().seconds();

                    if(!SystemTimeToFileTime(&target_system_time,((FILETIME*)&due_time)))
                    {
                        due_time.QuadPart=0;
                    }
                    else
                    {
                        long const hundred_nanoseconds_in_one_second=10000000;
                        due_time.QuadPart+=target_time.abs_time.time_of_day().fractional_seconds()*(hundred_nanoseconds_in_one_second/target_time.abs_time.time_of_day().ticks_per_second());
                    }
                }
                return due_time;
            }
        }
        

        bool interruptible_wait(detail::win32::handle handle_to_wait_for,detail::timeout target_time)
        {
            detail::win32::handle handles[3]={0};
            unsigned handle_count=0;
            unsigned wait_handle_index=~0U;
            unsigned interruption_index=~0U;
            unsigned timeout_index=~0U;
            if(handle_to_wait_for!=detail::win32::invalid_handle_value)
            {
                wait_handle_index=handle_count;
                handles[handle_count++]=handle_to_wait_for;
            }
            if(get_current_thread_data() && get_current_thread_data()->interruption_enabled)
            {
                interruption_index=handle_count;
                handles[handle_count++]=get_current_thread_data()->interruption_handle;
            }

            detail::win32::handle_manager timer_handle;
            
#ifndef UNDER_CE
            unsigned const min_timer_wait_period=20;
            
            if(!target_time.is_sentinel())
            {
                detail::timeout::remaining_time const time_left=target_time.remaining_milliseconds();
                if(time_left.milliseconds > min_timer_wait_period)
                {
                    // for a long-enough timeout, use a waitable timer (which tracks clock changes)
                    timer_handle=CreateWaitableTimer(NULL,false,NULL);
                    if(timer_handle!=0)
                    {
                        LARGE_INTEGER due_time=get_due_time(target_time);
                        
                        bool const set_time_succeeded=SetWaitableTimer(timer_handle,&due_time,0,0,0,false)!=0;
                        if(set_time_succeeded)
                        {
                            timeout_index=handle_count;
                            handles[handle_count++]=timer_handle;
                        }
                    }
                }
                else if(!target_time.relative)
                {
                    // convert short absolute-time timeouts into relative ones, so we don't race against clock changes
                    target_time=detail::timeout(time_left.milliseconds);
                }
            }
#endif
        
            bool const using_timer=timeout_index!=~0u;
            detail::timeout::remaining_time time_left(0);
            
            do
            {
                if(!using_timer)
                {
                    time_left=target_time.remaining_milliseconds();
                }
                
                if(handle_count)
                {
                    unsigned long const notified_index=detail::win32::WaitForMultipleObjects(handle_count,handles,false,using_timer?INFINITE:time_left.milliseconds);
                    if(notified_index<handle_count)
                    {
                        if(notified_index==wait_handle_index)
                        {
                            return true;
                        }
                        else if(notified_index==interruption_index)
                        {
                            detail::win32::ResetEvent(get_current_thread_data()->interruption_handle);
                            throw thread_interrupted();
                        }
                        else if(notified_index==timeout_index)
                        {
                            return false;
                        }
                    }
                }
                else
                {
                    detail::win32::Sleep(time_left.milliseconds);
                }
                if(target_time.relative)
                {
                    target_time.milliseconds-=detail::timeout::max_non_infinite_wait;
                }
            }
            while(time_left.more);
            return false;
        }

        thread::id get_id()
        {
            return thread::id(get_or_make_current_thread_data());
        }

        void interruption_point()
        {
            if(interruption_enabled() && interruption_requested())
            {
                detail::win32::ResetEvent(get_current_thread_data()->interruption_handle);
                throw thread_interrupted();
            }
        }
        
        bool interruption_enabled()
        {
            return get_current_thread_data() && get_current_thread_data()->interruption_enabled;
        }
        
        bool interruption_requested()
        {
            return get_current_thread_data() && (detail::win32::WaitForSingleObject(get_current_thread_data()->interruption_handle,0)==0);
        }

        void yield()
        {
            detail::win32::Sleep(0);
        }
        
        disable_interruption::disable_interruption():
            interruption_was_enabled(interruption_enabled())
        {
            if(interruption_was_enabled)
            {
                get_current_thread_data()->interruption_enabled=false;
            }
        }
        
        disable_interruption::~disable_interruption()
        {
            if(get_current_thread_data())
            {
                get_current_thread_data()->interruption_enabled=interruption_was_enabled;
            }
        }

        restore_interruption::restore_interruption(disable_interruption& d)
        {
            if(d.interruption_was_enabled)
            {
                get_current_thread_data()->interruption_enabled=true;
            }
        }
        
        restore_interruption::~restore_interruption()
        {
            if(get_current_thread_data())
            {
                get_current_thread_data()->interruption_enabled=false;
            }
        }
    }

    namespace detail
    {
        void add_thread_exit_function(thread_exit_function_base* func)
        {
            detail::thread_data_base* const current_thread_data(get_or_make_current_thread_data());
            thread_exit_callback_node* const new_node=
                heap_new<thread_exit_callback_node>(func,
                                                    current_thread_data->thread_exit_callbacks);
            current_thread_data->thread_exit_callbacks=new_node;
        }

        tss_data_node* find_tss_data(void const* key)
        {
            detail::thread_data_base* const current_thread_data(get_current_thread_data());
            if(current_thread_data)
            {
                detail::tss_data_node* current_node=current_thread_data->tss_data;
                while(current_node)
                {
                    if(current_node->key==key)
                    {
                        return current_node;
                    }
                    current_node=current_node->next;
                }
            }
            return NULL;
        }

        void* get_tss_data(void const* key)
        {
            if(tss_data_node* const current_node=find_tss_data(key))
            {
                return current_node->value;
            }
            return NULL;
        }
        
        void set_tss_data(void const* key,boost::shared_ptr<tss_cleanup_function> func,void* tss_data,bool cleanup_existing)
        {
            tss_cleanup_implemented(); // if anyone uses TSS, we need the cleanup linked in
            if(tss_data_node* const current_node=find_tss_data(key))
            {
                if(cleanup_existing && current_node->func.get())
                {
                    (*current_node->func)(current_node->value);
                }
                current_node->func=func;
                current_node->value=tss_data;
            }
            else
            {
                detail::thread_data_base* const current_thread_data(get_or_make_current_thread_data());
                tss_data_node* const new_node=heap_new<tss_data_node>(key,func,tss_data,current_thread_data->tss_data);
                current_thread_data->tss_data=new_node;
            }
        }
    }
}


extern "C" BOOST_THREAD_DECL void on_process_enter()
{}

extern "C" BOOST_THREAD_DECL void on_thread_enter()
{}

extern "C" BOOST_THREAD_DECL void on_process_exit()
{}

extern "C" BOOST_THREAD_DECL void on_thread_exit()
{
    boost::run_thread_exit_callbacks();
}

