[ros-dev] Re: [ros-diffs] [ion] 12774: Add more Critical Section Debug Data and fix two bugs.

[Robert Shearman]

Alex Ionescu wrote:

> By the way, I've made some serious performance improvements to the 
> code, by adding a static buffer which is used to hold up to 64 debug 
> sections. The rest are then allocated by using the heap. This has a 
> two fold advantage:
>
> 1) The first CS (used by the Heap Manager on ROS, probably on WINE 
> too), one for RtlInitializeHeapManager and the other for 
> RtlAllocateHeap now also have a valid Debug Section, because they use 
> the static one.
> 2) Because the kernel-call is removed, it offers significant 
> improvments on ROS,  on WINE too, since there is less code that must 
> run (a tiny loop versus a whole heap allocation).


A call to RtlAllocateHeap doesn't normally result in a kernel-call.

> I'm thinking about sending a patch to WineDevel... since it's only two 
> functions to be added and the brute heap calls to be replaced by the 
> function names, I think it would be easy to integrate.


For most process-wide critical sections we don't allocate a DebugInfo 
anyway; we just store the critical section and the DebugInfo structure 
in the .data section of the DLL and don't call 
RtlInitializeCriticalSectionAndSpinCount. So, I don't think it would be 
that much of a performance improvement for Wine. Anyway, if you wanted 
the performance, you should just disable the code that allocates the 
DebugInfo, like release versions of Windows do.
However, patches to manipulate the EntryCount and ContentionCount 
members would be welcome as they could be useful in identifying 
performance bottlenecks.

Rob