condition_variables.qbk

来自「Boost provides free peer-reviewed portab」· QBK 代码 · 共 514 行 · 第 1/2 页

function exits with an exception.]]

[[Returns:] [`false` if the call is returning because the time period specified
by `rel_time` has elapsed, `true` otherwise.]]

[[Postcondition:] [`lock` is locked by the current thread.]]

[[Throws:] [__thread_resource_error__ if an error
occurs. __thread_interrupted__ if the wait was interrupted by a call to
__interrupt__ on the __thread__ object associated with the current thread of execution.]]

]

[note The duration overload of timed_wait is difficult to use correctly. The overload taking a predicate should be preferred in most cases.]

[endsect]

[section:timed_wait_predicate `template<typename predicate_type> bool timed_wait(boost::unique_lock<boost::mutex>& lock, boost::system_time const& abs_time, predicate_type pred)`]

[variablelist

[[Effects:] [As-if ``
while(!pred())
{
    if(!timed_wait(lock,abs_time))
    {
        return pred();
    }
}
return true;
``]]

]

[endsect]


[endsect]

[section:condition_variable_any Class `condition_variable_any`]

    #include <boost/thread/condition_variable.hpp>

    namespace boost
    {
        class condition_variable_any
        {
        public:
            condition_variable_any();
            ~condition_variable_any();

            void notify_one();
            void notify_all();

            template<typename lock_type>
            void wait(lock_type& lock);

            template<typename lock_type,typename predicate_type>
            void wait(lock_type& lock,predicate_type predicate);

            template<typename lock_type>
            bool timed_wait(lock_type& lock,boost::system_time const& abs_time);

            template<typename lock_type,typename duration_type>
            bool timed_wait(lock_type& lock,duration_type const& rel_time);

            template<typename lock_type,typename predicate_type>
            bool timed_wait(lock_type& lock,boost::system_time const& abs_time,predicate_type predicate);

            template<typename lock_type,typename duration_type,typename predicate_type>
            bool timed_wait(lock_type& lock,duration_type const& rel_time,predicate_type predicate);

        // backwards compatibility

            template<typename lock_type>
            bool timed_wait(lock_type>& lock,boost::xtime const& abs_time);

            template<typename lock_type,typename predicate_type>
            bool timed_wait(lock_type& lock,boost::xtime const& abs_time,predicate_type predicate);
        };
    }

[section:constructor `condition_variable_any()`]

[variablelist

[[Effects:] [Constructs an object of class `condition_variable_any`.]]

[[Throws:] [__thread_resource_error__ if an error occurs.]]

]

[endsect]

[section:destructor `~condition_variable_any()`]

[variablelist

[[Precondition:] [All threads waiting on `*this` have been notified by a call to
`notify_one` or `notify_all` (though the respective calls to `wait` or
`timed_wait` need not have returned).]]

[[Effects:] [Destroys the object.]]

[[Throws:] [Nothing.]]

]

[endsect]

[section:notify_one `void notify_one()`]

[variablelist

[[Effects:] [If any threads are currently __blocked__ waiting on `*this` in a call
to `wait` or `timed_wait`, unblocks one of those threads.]]

[[Throws:] [Nothing.]]

]

[endsect]

[section:notify_all `void notify_all()`]

[variablelist

[[Effects:] [If any threads are currently __blocked__ waiting on `*this` in a call
to `wait` or `timed_wait`, unblocks all of those threads.]]

[[Throws:] [Nothing.]]

]

[endsect]

[section:wait `template<typename lock_type> void wait(lock_type& lock)`]

[variablelist

[[Effects:] [Atomically call `lock.unlock()` and blocks the current thread. The
thread will unblock when notified by a call to `this->notify_one()` or
`this->notify_all()`, or spuriously. When the thread is unblocked (for whatever
reason), the lock is reacquired by invoking `lock.lock()` before the call to
`wait` returns. The lock is also reacquired by invoking `lock.lock()` if the
function exits with an exception.]]

[[Postcondition:] [`lock` is locked by the current thread.]]

[[Throws:] [__thread_resource_error__ if an error
occurs. __thread_interrupted__ if the wait was interrupted by a call to
__interrupt__ on the __thread__ object associated with the current thread of execution.]]

]

[endsect]

[section:wait_predicate `template<typename lock_type,typename predicate_type> void wait(lock_type& lock, predicate_type pred)`]

[variablelist

[[Effects:] [As-if ``
while(!pred())
{
    wait(lock);
}
``]]

]

[endsect]

[section:timed_wait `template<typename lock_type> bool timed_wait(lock_type& lock,boost::system_time const& abs_time)`]

[variablelist

[[Effects:] [Atomically call `lock.unlock()` and blocks the current thread. The
thread will unblock when notified by a call to `this->notify_one()` or
`this->notify_all()`, when the time as reported by `boost::get_system_time()`
would be equal to or later than the specified `abs_time`, or spuriously. When
the thread is unblocked (for whatever reason), the lock is reacquired by
invoking `lock.lock()` before the call to `wait` returns. The lock is also
reacquired by invoking `lock.lock()` if the function exits with an exception.]]

[[Returns:] [`false` if the call is returning because the time specified by
`abs_time` was reached, `true` otherwise.]]

[[Postcondition:] [`lock` is locked by the current thread.]]

[[Throws:] [__thread_resource_error__ if an error
occurs. __thread_interrupted__ if the wait was interrupted by a call to
__interrupt__ on the __thread__ object associated with the current thread of execution.]]

]

[endsect]

[section:timed_wait_rel `template<typename lock_type,typename duration_type> bool timed_wait(lock_type& lock,duration_type const& rel_time)`]

[variablelist

[[Effects:] [Atomically call `lock.unlock()` and blocks the current thread. The
thread will unblock when notified by a call to `this->notify_one()` or
`this->notify_all()`, after the period of time indicated by the `rel_time`
argument has elapsed, or spuriously. When the thread is unblocked (for whatever
reason), the lock is reacquired by invoking `lock.lock()` before the call to
`wait` returns. The lock is also reacquired by invoking `lock.lock()` if the
function exits with an exception.]]

[[Returns:] [`false` if the call is returning because the time period specified
by `rel_time` has elapsed, `true` otherwise.]]

[[Postcondition:] [`lock` is locked by the current thread.]]

[[Throws:] [__thread_resource_error__ if an error
occurs. __thread_interrupted__ if the wait was interrupted by a call to
__interrupt__ on the __thread__ object associated with the current thread of execution.]]

]

[note The duration overload of timed_wait is difficult to use correctly. The overload taking a predicate should be preferred in most cases.]

[endsect]

[section:timed_wait_predicate `template<typename lock_type,typename predicate_type> bool timed_wait(lock_type& lock, boost::system_time const& abs_time, predicate_type pred)`]

[variablelist

[[Effects:] [As-if ``
while(!pred())
{
    if(!timed_wait(lock,abs_time))
    {
        return pred();
    }
}
return true;
``]]

]

[endsect]

[endsect]

[section:condition Typedef `condition`]

    #include <boost/thread/condition.hpp>

    typedef condition_variable_any condition;

The typedef `condition` is provided for backwards compatibility with previous boost releases.

[endsect]

[endsect]