Subj : Re: experimental smr-based 100% lock-free eventcount schema for windows...
To   : comp.programming.threads
From : SenderX
Date : Wed Feb 02 2005 01:01 am

Another bug that will cause a waitset memory leak:


> DWORD ac_event_count_wait
> ( ac_event_count_t *_this,
>   DWORD ec_cmp,
>   DWORD timeout )
> {
>     int dtor = 0;
^^^^^^^^^^^^^^^^^^^^^^

change to:

ac_waitset_t *dtor = 0;


>     DWORD wait_ret = WAIT_OBJECT_0;
>     register ac_event_count_t cmp, xchg;
>     regitser ac_waitset_t *local_waitset = 0;
>     void **hazard = ac_lfgc_get_hazard( 1 );

[...]


>     if ( xchg.cmp == ec_cmp )
>     {
>         InterlockedIncrement
>             ( &xchg.active_waitset->refs );
>
>         wait_ret = WaitForSingleObject
>                     ( &xchg.active_waitset->queue );
>
>         if ( ! InterlockedDecrement
>                 ( &xchg->active_waitset->refs ) )
>         {
>             if ( ! InterlockedExchange
>                     ( &xchg->active_waitset->dtor,
>                       1 ) )
>             {
>                 xchg.active_waitset = 0;
^^^^^^^^^^^^^^^^^^^^^^

change to:

dtor =  xchg.active_waitset;
xchg.active_waitset = 0;


>
>                 np_ac_atomic_dwcas_rel
>                     ( _this,
>                       &cmp,
>                       &xchg );
>
>                 dtor = 1;
^^^^^^^^^^^^^^^^^^^

remove.



>             }
>         }
>
>         *hazard = 0;
>
>         if ( dtor )
>         {
>             ac_lfgc_collect
>                 ( xchg->active_waitset,
^^^^^^^^^^^^^^^^^^^^^^^^


change to:

( dtor,


>                   ac_waitset_dtor );
>         }
>     }
>
>     return wait_ret;
> }

.