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From: rick68 (rick68_at_[hidden])
Date: 2007-07-02 09:20:19
On 7/2/07, Anthony Williams <anthony_w.geo_at_[hidden]> wrote:
>
> rick68 <rick68_at_[hidden]> writes:
>
> >
> >
> > If I use boost::timed_mutex::scoped_timed_lock to do lock (m_locked is
> true)
> >
> > ==<boost/thread/detail/lock.hpp>==
> > void boost::detail::thread::scoped_try_lock<boost::timed_mutex>::lock()
> > {
> > if (m_locked) throw lock_error();
> > lock_ops<TimedMutex>::lock(m_mutex);
> > m_locked = true;
> > }
> > ========================
> >
> > lock will throw lock_error, so I thought maybe to use while-loop will be
> > fine.
>
> This is a different m_locked. The m_locked in timed_mutex is the variable
> associated with the mutex --- is the mutex locked by any thread? The
> m_locked
> in the scoped_timed_lock member function you quoted above is associated
> with
> the scoped_timed_lock --- does this scoped_timed_lock object own the
> associated mutex?
Oops, this is the key pointer, I didn't detect timed_time has a m_locked.
I confuse they two.
> > I just read about thread code and test it.
> >
> > Can use condition and mutex to substitute for timed_mutex, but I want to
> > know how to use timed_mutex.
>
> timed_mutex is just a mutex, but with timeouts on the locks --- if the
> mutex
> is locked when you try and acquire it, you can pass in a timeout to
> specify
> how long to wait before giving up trying to acquire the lock. Look at
> test_timedlock in libs/thread/test/test_mutex.cpp for example usage.
Thank you very much!
I got it~ :D
Rick