Re: [Boost-users] Boost multi-thread issue ---- use macro

From: Nat Goodspeed (nat_at_[hidden])
Date: 2008-05-14 12:26:16

Peisheng Wang wrote:

> Why
> 
> #if ISTHREADSAFE
>         boost::mutex::scoped_lock lock(CacheInfo_mutex);
> # endif   
> 
> functions well , but not
> 
> if(isThreadSafe)
> {
>     boost::mutex::scoped_lock lock(CacheInfo_mutex);
> }

Because the scoped_lock declaration goes out of scope at the }. If you 
had written:

#if ISTHREADSAFE
{
     boost::mutex::scoped_lock lock(CacheInfo_mutex);
}
# endif

it would have the same problem.