Re: [Boost-users] multi-threaded safe circular_buffer

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-06-09 12:14:16

AMDG

Selçuk Giray Özdamar wrote:
> Hi everyone,
> I specialized the boost::circular_buffer template class for concurrent 
> access. But I have no idea about how the locking strategy must be for 
> copy ctor, and also assignment operator. I inserted question marks at 
> the end of the related lines.
>        
>         // copy ctor
>         CircularBuffer(const CircularBuffer& other)
>         {
>             //WriteLock w_lock(rw_mutex); ???????????
>             m_capacity = other.m_capacity;
>             m_buffer = other.m_buffer;   
>         }

You need a ReadLock on other.  There is no need to lock the object
being constructed.

>         // assignment operator

Use the swap trick.

// assignment operator
CircularBuffer& operator= (const CircularBuffer& other)
{
    CircularBuffer temp(other);
    WriteLock w_lock(rw_mutex);

    using std::swap;
    swap(m_capacity, other.m_capacity);
    swap(m_buffer, other.m_buffer);

    return *this;
}

In Christ,
Steven Watanabe