Re: [Boost-users] [thread] locking and time

Subject: Re: [Boost-users] [thread] locking and time
From: mur (mur_at_[hidden])
Date: 2009-01-05 08:30:38

Hello Vicente,

>> 2) (recursive timed) shared mutex: Is it not possible to lock with a period of
>> time instead of ptime?
>>     
> shared mutex are not recursive.
>   
So I had to check if I there is no place where another function which
also aquires a lock is called within the locked scope. But maybe I
should keep the old code. Now I use

a code based on boost::threads from
http://paulbridger.net/read_write_lock

which I modified in order to work with timed locks.

> You are right. The folowing should be added
>     template<typename TimeDuration>
>     bool shared_mutex::timed_lock_shared(TimeDuration const & relative_time);
>     template<typename TimeDuration>
>     bool shared_mutex::timed_lock(TimeDuration const & relative_time);
>
>   
>> 3) change of system time: What happens in a timed_lock if the system time is
>> advanced by e.g. one hour? Is there a difference of using ptime or time_period?
>>     
> I supose that the lock will expire. I don't think there is any difference because the relative time interface uses the absolute time one.
>   
If I modify the time in order it is one hour earlier, I guess the lock
could take one hour. This is even a bigger a problem with the sleep
function of the threads library.
So it is not possible to change the system time to earlier values for
certain applications.

> You should do a ticket on the Trac system for each issue.
>
>   

Yes, I submitted them.

Greetings
Ernst