Re: [boost] Re: Boost.Threads: Do we need all those mutexes?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-07-07 05:48:50

Howard Hinnant wrote:
> I like the latent_write_lock / upgradeable lock idea proposed by Bruno
> / Alexander.  I have been playing with the following interface:
>
> namespace detail
> {
>
> template <class RW_Mutex>
> class read_lock
> {
> public:
>      typedef RW_Mutex mutex_type;
>
>      explicit read_lock(mutex_type& m, bool lock_it = true);
>      explicit read_lock(upgradable_read_lock<mutex_type>& r);
>      explicit read_lock(write_lock<mutex_type>& w);
>
>      ~read_lock();
>
>      void lock();
>      bool try_lock();
>      void unlock();
>      bool locked() const;
>      operator int bool_type::* () const;
>
> private:
>      read_lock(const read_lock&);
>      read_lock& operator=(const read_lock&);
> };

[...]

Seems very good to me. Also demonstrates a better lock taxonomy (which
allows me to include some on-topic content ;-) ):

Lock

    Lock( Mutex&, bool = true );
    void lock();
    void unlock();
    bool locked() const;
    operator int bool_type::* () const;

TryLock: Lock

    +bool try_lock();

TimedLock: TryLock

    +bool timed_lock( xtime const & );