Re: [boost] [thread] boost::shared_mutex vs. pthread_rwlock_unlock

Subject: Re: [boost] [thread] boost::shared_mutex vs. pthread_rwlock_unlock
From: Anthony Williams (anthony.ajw_at_[hidden])
Date: 2009-05-05 06:36:55

Rush Manbert <rush_at_[hidden]> writes:

> I am replacing a pthread threading implementation with a boost threads
> implementation so I can use the code on Windows.
>
> class ReadWriteMutex {
> public:
>   ReadWriteMutex();
>   virtual ~ReadWriteMutex() {}
>
>   // these get the lock and block until it is done successfully
>   virtual void acquireRead() const;
>   virtual void acquireWrite() const;
>
>   // these attempt to get the lock, returning false immediately if
> they fail
>   virtual bool attemptRead() const;
>   virtual bool attemptWrite() const;
>
>   // this releases both read and write locks
>   virtual void release() const;
>
> Note the release() method that works for a thread that holds either
> the read or write lock.

> AFAICT there is no equivalent to the pthread_rwlock_unlock() call that
> the original version of release() called.
>
> Am I missing something?

No, this is correct --- you must explicitly call unlock() or
unlock_shared() depending on what sort of lock you have.

Anthony
-- 
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