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condition_variable.hpp
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condition_variable.hpp
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#ifndef BOOST_THREAD_CONDITION_VARIABLE_WIN32_HPP
#define BOOST_THREAD_CONDITION_VARIABLE_WIN32_HPP
// 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 2007-8 Anthony Williams
// (C) Copyright 2011-2012 Vicente J. Botet Escriba
#include <boost/thread/win32/thread_primitives.hpp>
#include <boost/thread/win32/thread_data.hpp>
#include <boost/thread/win32/thread_data.hpp>
#include <boost/thread/win32/interlocked_read.hpp>
#include <boost/thread/cv_status.hpp>
#if defined BOOST_THREAD_USES_DATETIME
#include <boost/thread/xtime.hpp>
#endif
#include <boost/thread/mutex.hpp>
#include <boost/thread/thread_time.hpp>
#include <boost/thread/lock_guard.hpp>
#include <boost/thread/lock_types.hpp>
#include <boost/thread/detail/platform_time.hpp>
#include <boost/assert.hpp>
#include <boost/intrusive_ptr.hpp>
#ifdef BOOST_THREAD_USES_CHRONO
#include <boost/chrono/system_clocks.hpp>
#include <boost/chrono/ceil.hpp>
#endif
#include <limits.h>
#include <algorithm>
#include <vector>
#include <boost/config/abi_prefix.hpp>
namespace boost
{
namespace detail
{
class basic_cv_list_entry;
void intrusive_ptr_add_ref(basic_cv_list_entry * p);
void intrusive_ptr_release(basic_cv_list_entry * p);
class basic_cv_list_entry
{
private:
detail::win32::handle_manager semaphore;
detail::win32::handle_manager wake_sem;
long waiters;
bool notified;
long references;
public:
BOOST_THREAD_NO_COPYABLE(basic_cv_list_entry)
explicit basic_cv_list_entry(detail::win32::handle_manager const& wake_sem_):
semaphore(detail::win32::create_anonymous_semaphore(0,LONG_MAX)),
wake_sem(wake_sem_.duplicate()),
waiters(1),notified(false),references(0)
{}
static bool no_waiters(boost::intrusive_ptr<basic_cv_list_entry> const& entry)
{
return !detail::interlocked_read_acquire(&entry->waiters);
}
void add_waiter()
{
BOOST_INTERLOCKED_INCREMENT(&waiters);
}
void remove_waiter()
{
BOOST_INTERLOCKED_DECREMENT(&waiters);
}
void release(unsigned count_to_release)
{
notified=true;
winapi::ReleaseSemaphore(semaphore,count_to_release,0);
}
void release_waiters()
{
release(detail::interlocked_read_acquire(&waiters));
}
bool is_notified() const
{
return notified;
}
bool interruptible_wait(detail::internal_platform_timepoint const &timeout)
{
return this_thread::interruptible_wait(semaphore, timeout);
}
bool woken()
{
unsigned long const woken_result=winapi::WaitForSingleObjectEx(wake_sem,0,0);
BOOST_ASSERT((woken_result==detail::win32::timeout) || (woken_result==0));
return woken_result==0;
}
friend void intrusive_ptr_add_ref(basic_cv_list_entry * p);
friend void intrusive_ptr_release(basic_cv_list_entry * p);
};
inline void intrusive_ptr_add_ref(basic_cv_list_entry * p)
{
BOOST_INTERLOCKED_INCREMENT(&p->references);
}
inline void intrusive_ptr_release(basic_cv_list_entry * p)
{
if(!BOOST_INTERLOCKED_DECREMENT(&p->references))
{
delete p;
}
}
class basic_condition_variable
{
boost::mutex internal_mutex;
long total_count;
unsigned active_generation_count;
typedef basic_cv_list_entry list_entry;
typedef boost::intrusive_ptr<list_entry> entry_ptr;
typedef std::vector<entry_ptr> generation_list;
generation_list generations;
detail::win32::handle_manager wake_sem;
void wake_waiters(long count_to_wake)
{
detail::interlocked_write_release(&total_count,total_count-count_to_wake);
winapi::ReleaseSemaphore(wake_sem,count_to_wake,0);
}
template<typename lock_type>
struct relocker
{
BOOST_THREAD_NO_COPYABLE(relocker)
lock_type& _lock;
bool _unlocked;
relocker(lock_type& lock_):
_lock(lock_), _unlocked(false)
{}
void unlock()
{
if ( ! _unlocked )
{
_lock.unlock();
_unlocked=true;
}
}
void lock()
{
if ( _unlocked )
{
_lock.lock();
_unlocked=false;
}
}
~relocker() BOOST_NOEXCEPT_IF(false)
{
lock();
}
};
entry_ptr get_wait_entry()
{
boost::lock_guard<boost::mutex> lk(internal_mutex);
if(!wake_sem)
{
wake_sem=detail::win32::create_anonymous_semaphore(0,LONG_MAX);
BOOST_ASSERT(wake_sem);
}
detail::interlocked_write_release(&total_count,total_count+1);
if(generations.empty() || generations.back()->is_notified())
{
entry_ptr new_entry(new list_entry(wake_sem));
generations.push_back(new_entry);
return new_entry;
}
else
{
generations.back()->add_waiter();
return generations.back();
}
}
struct entry_manager
{
entry_ptr entry;
boost::mutex& internal_mutex;
BOOST_THREAD_NO_COPYABLE(entry_manager)
#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
entry_manager(entry_ptr&& entry_, boost::mutex& mutex_):
entry(static_cast< entry_ptr&& >(entry_)), internal_mutex(mutex_)
{}
#else
entry_manager(entry_ptr const& entry_, boost::mutex& mutex_):
entry(entry_), internal_mutex(mutex_)
{}
#endif
void remove_waiter_and_reset()
{
if (entry) {
boost::lock_guard<boost::mutex> internal_lock(internal_mutex);
entry->remove_waiter();
entry.reset();
}
}
~entry_manager() BOOST_NOEXCEPT_IF(false)
{
remove_waiter_and_reset();
}
list_entry* operator->()
{
return entry.get();
}
};
protected:
basic_condition_variable(const basic_condition_variable& other);
basic_condition_variable& operator=(const basic_condition_variable& other);
public:
basic_condition_variable():
total_count(0),active_generation_count(0),wake_sem(0)
{}
~basic_condition_variable()
{}
// When this function returns true:
// * A notification (or sometimes a spurious OS signal) has been received
// * Do not assume that the timeout has not been reached
// * Do not assume that the predicate has been changed
//
// When this function returns false:
// * The timeout has been reached
// * Do not assume that a notification has not been received
// * Do not assume that the predicate has not been changed
template<typename lock_type>
bool do_wait_until(lock_type& lock, detail::internal_platform_timepoint const &timeout)
{
relocker<lock_type> locker(lock);
entry_manager entry(get_wait_entry(), internal_mutex);
locker.unlock();
bool woken=false;
while(!woken)
{
if(!entry->interruptible_wait(timeout))
{
return false;
}
woken=entry->woken();
}
// do it here to avoid throwing on the destructor
entry.remove_waiter_and_reset();
locker.lock();
return true;
}
void notify_one() BOOST_NOEXCEPT
{
if(detail::interlocked_read_acquire(&total_count))
{
boost::lock_guard<boost::mutex> internal_lock(internal_mutex);
if(!total_count)
{
return;
}
wake_waiters(1);
for(generation_list::iterator it=generations.begin(),
end=generations.end();
it!=end;++it)
{
(*it)->release(1);
}
generations.erase(std::remove_if(generations.begin(),generations.end(),&basic_cv_list_entry::no_waiters),generations.end());
}
}
void notify_all() BOOST_NOEXCEPT
{
if(detail::interlocked_read_acquire(&total_count))
{
boost::lock_guard<boost::mutex> internal_lock(internal_mutex);
if(!total_count)
{
return;
}
wake_waiters(total_count);
for(generation_list::iterator it=generations.begin(),
end=generations.end();
it!=end;++it)
{
(*it)->release_waiters();
}
generations.clear();
wake_sem=detail::win32::handle(0);
}
}
};
}
class condition_variable:
private detail::basic_condition_variable
{
public:
BOOST_THREAD_NO_COPYABLE(condition_variable)
condition_variable()
{}
using detail::basic_condition_variable::do_wait_until;
using detail::basic_condition_variable::notify_one;
using detail::basic_condition_variable::notify_all;
void wait(unique_lock<mutex>& m)
{
do_wait_until(m, detail::internal_platform_timepoint::getMax());
}
template<typename predicate_type>
void wait(unique_lock<mutex>& m,predicate_type pred)
{
while (!pred())
{
wait(m);
}
}
#if defined BOOST_THREAD_USES_DATETIME
bool timed_wait(unique_lock<mutex>& m,boost::system_time const& abs_time)
{
// The system time may jump while this function is waiting. To compensate for this and time
// out near the correct time, we could call do_wait_until() in a loop with a short timeout
// and recheck the time remaining each time through the loop. However, because we can't
// check the predicate each time do_wait_until() completes, this introduces the possibility
// of not exiting the function when a notification occurs, since do_wait_until() may report
// that it timed out even though a notification was received. The best this function can do
// is report correctly whether or not it reached the timeout time.
const detail::real_platform_timepoint ts(abs_time);
const detail::platform_duration d(ts - detail::real_platform_clock::now());
do_wait_until(m, detail::internal_platform_clock::now() + d);
return ts > detail::real_platform_clock::now();
}
bool timed_wait(unique_lock<mutex>& m,boost::xtime const& abs_time)
{
return timed_wait(m, system_time(abs_time));
}
template<typename duration_type>
bool timed_wait(unique_lock<mutex>& m,duration_type const& wait_duration)
{
if (wait_duration.is_pos_infinity())
{
wait(m);
return true;
}
if (wait_duration.is_special())
{
return true;
}
const detail::platform_duration d(wait_duration);
return do_wait_until(m, detail::internal_platform_clock::now() + d);
}
template<typename predicate_type>
bool timed_wait(unique_lock<mutex>& m,boost::system_time const& abs_time,predicate_type pred)
{
// The system time may jump while this function is waiting. To compensate for this
// and time out near the correct time, we call do_wait_until() in a loop with a
// short timeout and recheck the time remaining each time through the loop.
const detail::real_platform_timepoint ts(abs_time);
while (!pred())
{
detail::platform_duration d(ts - detail::real_platform_clock::now());
if (d <= detail::platform_duration::zero()) break; // timeout occurred
d = (std::min)(d, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
do_wait_until(m, detail::internal_platform_clock::now() + d);
}
return pred();
}
template<typename predicate_type>
bool timed_wait(unique_lock<mutex>& m,boost::xtime const& abs_time,predicate_type pred)
{
return timed_wait(m, system_time(abs_time), pred);
}
template<typename duration_type,typename predicate_type>
bool timed_wait(unique_lock<mutex>& m,duration_type const& wait_duration,predicate_type pred)
{
if (wait_duration.is_pos_infinity())
{
while (!pred())
{
wait(m);
}
return true;
}
if (wait_duration.is_special())
{
return pred();
}
const detail::platform_duration d(wait_duration);
const detail::internal_platform_timepoint ts(detail::internal_platform_clock::now() + d);
while (!pred())
{
if (!do_wait_until(m, ts)) break; // timeout occurred
}
return pred();
}
#endif
#ifdef BOOST_THREAD_USES_CHRONO
template <class Duration>
cv_status
wait_until(
unique_lock<mutex>& lock,
const chrono::time_point<detail::internal_chrono_clock, Duration>& t)
{
const detail::internal_platform_timepoint ts(t);
if (do_wait_until(lock, ts)) return cv_status::no_timeout;
else return cv_status::timeout;
}
template <class Clock, class Duration>
cv_status
wait_until(
unique_lock<mutex>& lock,
const chrono::time_point<Clock, Duration>& t)
{
// The system time may jump while this function is waiting. To compensate for this and time
// out near the correct time, we could call do_wait_until() in a loop with a short timeout
// and recheck the time remaining each time through the loop. However, because we can't
// check the predicate each time do_wait_until() completes, this introduces the possibility
// of not exiting the function when a notification occurs, since do_wait_until() may report
// that it timed out even though a notification was received. The best this function can do
// is report correctly whether or not it reached the timeout time.
typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
common_duration d(t - Clock::now());
do_wait_until(lock, detail::internal_chrono_clock::now() + d);
if (t > Clock::now()) return cv_status::no_timeout;
else return cv_status::timeout;
}
template <class Rep, class Period>
cv_status
wait_for(
unique_lock<mutex>& lock,
const chrono::duration<Rep, Period>& d)
{
return wait_until(lock, chrono::steady_clock::now() + d);
}
template <class Duration, class Predicate>
bool
wait_until(
unique_lock<mutex>& lock,
const chrono::time_point<detail::internal_chrono_clock, Duration>& t,
Predicate pred)
{
const detail::internal_platform_timepoint ts(t);
while (!pred())
{
if (!do_wait_until(lock, ts)) break; // timeout occurred
}
return pred();
}
template <class Clock, class Duration, class Predicate>
bool
wait_until(
unique_lock<mutex>& lock,
const chrono::time_point<Clock, Duration>& t,
Predicate pred)
{
// The system time may jump while this function is waiting. To compensate for this
// and time out near the correct time, we call do_wait_until() in a loop with a
// short timeout and recheck the time remaining each time through the loop.
typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
while (!pred())
{
common_duration d(t - Clock::now());
if (d <= common_duration::zero()) break; // timeout occurred
d = (std::min)(d, common_duration(chrono::milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS)));
do_wait_until(lock, detail::internal_platform_clock::now() + detail::platform_duration(d));
}
return pred();
}
template <class Rep, class Period, class Predicate>
bool
wait_for(
unique_lock<mutex>& lock,
const chrono::duration<Rep, Period>& d,
Predicate pred)
{
return wait_until(lock, chrono::steady_clock::now() + d, boost::move(pred));
}
#endif
};
class condition_variable_any:
private detail::basic_condition_variable
{
public:
BOOST_THREAD_NO_COPYABLE(condition_variable_any)
condition_variable_any()
{}
using detail::basic_condition_variable::do_wait_until;
using detail::basic_condition_variable::notify_one;
using detail::basic_condition_variable::notify_all;
template<typename lock_type>
void wait(lock_type& m)
{
do_wait_until(m, detail::internal_platform_timepoint::getMax());
}
template<typename lock_type,typename predicate_type>
void wait(lock_type& m,predicate_type pred)
{
while (!pred())
{
wait(m);
}
}
#if defined BOOST_THREAD_USES_DATETIME
template<typename lock_type>
bool timed_wait(lock_type& m,boost::system_time const& abs_time)
{
// The system time may jump while this function is waiting. To compensate for this and time
// out near the correct time, we could call do_wait_until() in a loop with a short timeout
// and recheck the time remaining each time through the loop. However, because we can't
// check the predicate each time do_wait_until() completes, this introduces the possibility
// of not exiting the function when a notification occurs, since do_wait_until() may report
// that it timed out even though a notification was received. The best this function can do
// is report correctly whether or not it reached the timeout time.
const detail::real_platform_timepoint ts(abs_time);
const detail::platform_duration d(ts - detail::real_platform_clock::now());
do_wait_until(m, detail::internal_platform_clock::now() + d);
return ts > detail::real_platform_clock::now();
}
template<typename lock_type>
bool timed_wait(lock_type& m,boost::xtime const& abs_time)
{
return timed_wait(m, system_time(abs_time));
}
template<typename lock_type,typename duration_type>
bool timed_wait(lock_type& m,duration_type const& wait_duration)
{
if (wait_duration.is_pos_infinity())
{
wait(m);
return true;
}
if (wait_duration.is_special())
{
return true;
}
const detail::platform_duration d(wait_duration);
return do_wait_until(m, detail::internal_platform_clock::now() + d);
}
template<typename lock_type,typename predicate_type>
bool timed_wait(lock_type& m,boost::system_time const& abs_time,predicate_type pred)
{
// The system time may jump while this function is waiting. To compensate for this
// and time out near the correct time, we call do_wait_until() in a loop with a
// short timeout and recheck the time remaining each time through the loop.
const detail::real_platform_timepoint ts(abs_time);
while (!pred())
{
detail::platform_duration d(ts - detail::real_platform_clock::now());
if (d <= detail::platform_duration::zero()) break; // timeout occurred
d = (std::min)(d, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
do_wait_until(m, detail::internal_platform_clock::now() + d);
}
return pred();
}
template<typename lock_type,typename predicate_type>
bool timed_wait(lock_type& m,boost::xtime const& abs_time,predicate_type pred)
{
return timed_wait(m, system_time(abs_time), pred);
}
template<typename lock_type,typename duration_type,typename predicate_type>
bool timed_wait(lock_type& m,duration_type const& wait_duration,predicate_type pred)
{
if (wait_duration.is_pos_infinity())
{
while (!pred())
{
wait(m);
}
return true;
}
if (wait_duration.is_special())
{
return pred();
}
const detail::platform_duration d(wait_duration);
const detail::internal_platform_timepoint ts(detail::internal_platform_clock::now() + d);
while (!pred())
{
if (!do_wait_until(m, ts)) break; // timeout occurred
}
return pred();
}
#endif
#ifdef BOOST_THREAD_USES_CHRONO
template <class lock_type,class Duration>
cv_status
wait_until(
lock_type& lock,
const chrono::time_point<detail::internal_chrono_clock, Duration>& t)
{
const detail::internal_platform_timepoint ts(t);
if (do_wait_until(lock, ts)) return cv_status::no_timeout;
else return cv_status::timeout;
}
template <class lock_type, class Clock, class Duration>
cv_status
wait_until(
lock_type& lock,
const chrono::time_point<Clock, Duration>& t)
{
// The system time may jump while this function is waiting. To compensate for this and time
// out near the correct time, we could call do_wait_until() in a loop with a short timeout
// and recheck the time remaining each time through the loop. However, because we can't
// check the predicate each time do_wait_until() completes, this introduces the possibility
// of not exiting the function when a notification occurs, since do_wait_until() may report
// that it timed out even though a notification was received. The best this function can do
// is report correctly whether or not it reached the timeout time.
typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
common_duration d(t - Clock::now());
do_wait_until(lock, detail::internal_chrono_clock::now() + d);
if (t > Clock::now()) return cv_status::no_timeout;
else return cv_status::timeout;
}
template <class lock_type, class Rep, class Period>
cv_status
wait_for(
lock_type& lock,
const chrono::duration<Rep, Period>& d)
{
return wait_until(lock, chrono::steady_clock::now() + d);
}
template <class lock_type, class Clock, class Duration, class Predicate>
bool
wait_until(
lock_type& lock,
const chrono::time_point<detail::internal_chrono_clock, Duration>& t,
Predicate pred)
{
const detail::internal_platform_timepoint ts(t);
while (!pred())
{
if (!do_wait_until(lock, ts)) break; // timeout occurred
}
return pred();
}
template <class lock_type, class Clock, class Duration, class Predicate>
bool
wait_until(
lock_type& lock,
const chrono::time_point<Clock, Duration>& t,
Predicate pred)
{
// The system time may jump while this function is waiting. To compensate for this
// and time out near the correct time, we call do_wait_until() in a loop with a
// short timeout and recheck the time remaining each time through the loop.
typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
while (!pred())
{
common_duration d(t - Clock::now());
if (d <= common_duration::zero()) break; // timeout occurred
d = (std::min)(d, common_duration(chrono::milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS)));
do_wait_until(lock, detail::internal_platform_clock::now() + detail::platform_duration(d));
}
return pred();
}
template <class lock_type, class Rep, class Period, class Predicate>
bool
wait_for(
lock_type& lock,
const chrono::duration<Rep, Period>& d,
Predicate pred)
{
return wait_until(lock, chrono::steady_clock::now() + d, boost::move(pred));
}
#endif
};
BOOST_THREAD_DECL void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
}
#include <boost/config/abi_suffix.hpp>
#endif