I think I have a question to ask associated to this thread: How can I implement a "global pool" of objects. Let me say it better, I want a global pool of database connection, first because I have a limited number of connections and second, because I want to be able to dominate the dbms accesses. All developed as an "ansi C" apache module, but I thing is the same. I'm running Apache 1.3. Is this the same thing? Leonardo Javier Belen. AFIP-AR
----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, September 25, 2002 3:29 PM Subject: Re: How Do I Create A Per-Worker Pool? > On Wed, 25 Sep 2002, Charles Reitzel wrote: > > > Hi All, > > > > This is a thorny (to me) module development question. I have asked on > the > > module list and searched the archives, but have found only a partial > > answer. Any pointers will be appreciated. > > > > Objective: to create a mutex-free pool per worker in non-MPM-specific > way. > > > > I found this exchange in a June posting: > > > > Another change we made, as I mentioned in a previous > > > > Email, was using non-mutexing per-thread memory > > > > pools (HeapCreate(HEAP_NO_SERIALIZE, ...)). > To get > > > > best performance with Apache 2 we would really need > > > > such a memory pool. > > > > > >And we already have it! Just do: > > > > > > apr_allocator_t *allocator; > > > apr_allocator_create(&allocator); > > > apr_pool_create_ex(&pool, parent_pool, abort_fn, allocator); > > > apr_allocator_owner_set(allocator, pool); > > > > > >Now you have a mutexless allocator associated with a pool. All child > pools > > >of this pool will use the same allocator and will therefor also have > no mutex. > > > > Looks good. But I have questions. What is the correct place to put > this > > code and where do keep the pool pointer afterwards. I.e. how do you > find > > the pool from within a module handler? > > > > <comment> > > To my mind, the Apache module API is missing an important data > structure: > > worker_rec. It is obviously redundant (but does no harm) in the > prefork > > MPM, but is a necessary ingredient in _any_ threaded MPM. Such a > structure > > would allow modules to be written as thread-safe - independent of the > MPM > > currently configured by the user. The request record could and should > > > contain a pointer to the current worker for easy access. In the > absence of > > a worker_rec, however, some guidance on the above would be helpful. > > </comment> > > The structures in Apache are designed around an HTTP request, not the > entity that is running the request. Every threaded MPM has a pool for > each thread, which does allow for thread-safe programming. > > Why exactly would you want a worker_rec? What problem are you having? > > Ryan > > ________________________________________________________________________ > _______ > Ryan Bloom [EMAIL PROTECTED] > 550 Jean St > Oakland CA 94610 > ------------------------------------------------------------------------ > -------
