Re: [Boost-users] Named mutex..

Jason Robertson writes:

I'm trying to create simple locks based on a string name.  I looked at the interprocess module which has a named mutex, but it seems not well suited/efficient for use in a single process, though I know it's supposed to work. Instead, I'm just creating a map in a NamedMutexManager class.  It's used as a singleton and uses brute force locking to implement a named lock pattern.  Main method is

shared_ptr<mutex> GetMutex(string name) { BigLock (only one thread at a time can get a lock so we synchronize access to map) check map     if we have entry, make sure weak_ptr hasn't been reclaimed         If so, make a new shared_ptr, save weak_ptr by name, return shared_ptr         If not, return shared_ptr copy from weak_ptr.lock()     If we habe no entry,         make a new shared_ptr, save weak_ptr by name, return shared_ptr }

I'm just getting back to C++ after years, so I'm 99% sure there's probably a much better way.  Is there a better way to do an intra-process, reliable mutex by std::string name so I can lock things by name?  How are other people doing this, do you find interprocess:named_mutex suitable for use in-process?  I had problems with it. Thanks! Jason

A common way to do named mutexes is with a hash table. In the absence of a true concurrent hash table, you can use a fixed number of buckets, with a mutex on each. You then hash the name to choose a bucket, lock the appropriate mutex and search the bucket for the entry, adding a new one if not there. Anthony -- Anthony Williams | Just Software Solutions Ltd Custom Software Development | http://www.justsoftwaresolutions.co.uk Registered in England, Company Number 5478976. Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL