boost_1_45_0/libs/thread/doc/time.qbk

[/
  (C) Copyright 2007-8 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).
]

[section:time Date and Time Requirements]

As of Boost 1.35.0, the __boost_thread__ library uses the [link date_time Boost.Date_Time] library for all operations that require a
time out. These include (but are not limited to):

* __sleep__
* __timed_join__
* __cond_timed_wait__
* __timed_lock_ref__

For the overloads that accept an absolute time parameter, an object of type [link thread.time.system_time `boost::system_time`] is
required. Typically, this will be obtained by adding a duration to the current time, obtained with a call to [link
thread.time.get_system_time `boost::get_system_time()`]. e.g.

    boost::system_time const timeout=boost::get_system_time() + boost::posix_time::milliseconds(500);

    extern bool done;
    extern boost::mutex m;
    extern boost::condition_variable cond;

    boost::unique_lock<boost::mutex> lk(m);
    while(!done)
    {
        if(!cond.timed_wait(lk,timeout))
        {
            throw "timed out";
        }
    }

For the overloads that accept a ['TimeDuration] parameter, an object of any type that meets the [link
date_time.posix_time.time_duration Boost.Date_Time Time Duration requirements] can be used, e.g.

    boost::this_thread::sleep(boost::posix_time::milliseconds(25));
    
    boost::mutex m;
    if(m.timed_lock(boost::posix_time::nanoseconds(100)))
    {
        //  ...
    }

[section:system_time Typedef `system_time`]

    #include <boost/thread/thread_time.hpp>

    typedef boost::posix_time::ptime system_time;

See the documentation for [link date_time.posix_time.ptime_class `boost::posix_time::ptime`] in the Boost.Date_Time library.

[endsect]

[section:get_system_time Non-member function `get_system_time()`]

    #include <boost/thread/thread_time.hpp>

    system_time get_system_time();

[variablelist

[[Returns:] [The current time.]]

[[Throws:] [Nothing.]]

]

[endsect]


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