Re: Boost.Threads draft library submission

From: williamkempf_at_[hidden]
Date: 2001-03-15 14:53:12

--- In boost_at_y..., terekhov_at_y... wrote:
> --- In boost_at_y..., williamkempf_at_h... wrote:
> the checks are only needed (if at all) in debug mode.
> POSIX threads standard (and coming SUS) does have recursive mutex.

OK, POSIX defines three attributes that deal with this: 
PTHREAD_MUTEX_NORMAL, PTHREAD_MUTEX_ERRORCHECK and 
PTHREAD_MUTEX_RECURSIVE.  I'm still trying to determine if these 
types are universally acceptable or if there will be implementations 
that don't support some of the options here.  If they were 
universally available it might help to simplify some things.  
Unfortunately, it won't help with the boost::recursive_mutex.  It 
seems that the recursive mutex is not recommended for use with 
condtion variables "because the implicit unlock performed for a 
pthread_cond_wait() or pthread_cond_timedwait() will not actually 
release the mutex (if  it had been locked multiple times)."  The 
Boost.Threads implementation deals with this and allows for proper 
usage.

If there's a pthreads expert that wants to tackle the issue of the 
implementation here I'd be more than willing to work with them to 
resolve this.

Bill Kempf