[rhmessaging-commits] rhmessaging commits: r1828 - store/trunk/cpp/lib.

[Gordon Sim]

rhmessaging-commits at lists.jboss.org wrote:
> Author: kpvdr
> Date: 2008-04-01 16:18:44 -0400 (Tue, 01 Apr 2008)
> New Revision: 1828
[...]
> ===================================================================
> --- store/trunk/cpp/lib/JournalImpl.cpp	2008-04-01 19:04:26 UTC (rev 1827)
> +++ store/trunk/cpp/lib/JournalImpl.cpp	2008-04-01 20:18:44 UTC (rev 1828)
> @@ -34,6 +34,7 @@
>  using namespace rhm::journal;
>  
>  qpid::broker::Timer* JournalImpl::journalTimerPtr = 0;
> +u_int32_t JournalImpl::cnt = 0;
>  
>  void InactivityFireEvent::fire() { if (parent) parent->flushFire(); }
>  void GetEventsFireEvent::fire() {
> @@ -64,6 +65,7 @@
>      if (journalTimerPtr == 0)
>          journalTimerPtr = new qpid::broker::Timer;
>      assert (journalTimerPtr != 0);
> +    cnt++;
>      journalTimerPtr->start();
>      journalTimerPtr->add(inactivityFireEventPtr);
>  
> @@ -98,7 +100,7 @@
>          ::free(_datap);
>          _datap = 0;
>      }
> -    if (journalTimerPtr)
> +    if (journalTimerPtr && --cnt == 0)
>      {
>          delete journalTimerPtr;
>          journalTimerPtr = 0;

I believe this change is not threadsafe (unless there is some hiigher 
level scheme to prevent Journal instance constructors/destructors being 
called concurrently).

Perhaps a lazily initialised shared pointer might be a nice way of doing 
that, with each journal instance taking a shared_ptr instance on
construction.  If we had a factory class it could hold the singleton 
instance via a weak_ptr and provide a method to get an instance. This 
method would need to be locked to prevent multiple instances being 
created; it would check whether the weak_ptr was valid, and if not 
create an instance an initialise it.