Neverwinter Nights Forum News (Jan. 02, 05)

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Here are today's Neverwinter Nights forum highlights, collected by NWVault. Please take into account that these are only single parts of various threads and should not be taken out of context. Bear in mind also that the posts presented here are copied as-is, and that any bad spelling and grammar does not get corrected on our end.

Tim Smith, Tools Programmer

found memory leak, please verify
I would love to know how MemTurbo gets rid of memory leaks. Does it look into the future and discover that my program won't use that block of 512 bytes that I allocated 5 minutes ago?

I think not.

It seems to be little more than a working set and modified list purging utility. By purging working sets and moving pages from the modified list to the free list, applications will start faster since pages can be removed from the free list much faster than the modified list. The modified list is a list of pages which contain modified data. If that page needs to be used by another application, the contents of that page will have to be written to the page's assigned backing store. For most pages, the backing store is page file. For exe and dlls that don't need their pages modified can use the exe and dll file on the disk as their backing store. If there are no pages available in the free list or modified list, the operating system will automatically purge working sets to make pages available.

The best I can tell is that MemTurbo does nothing the operating system normally does, it just changes when it does it.

More:

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This is not true if the app is allocating the memory from Global System Memory. If it was allocated from the application heap the OS treats it differently and grabs it back at the end as you have suggested since it resides in the App's program space. But GSM is not handled that way since the OS allows you to allocate GSM for shared use between multiple running apps and you don't want the OS to deallocate it if one of the sharing programs shuts down. GSM memory does not reside in the program space of any app. When GSM is used it is the responsibility of the APP to keep track of it. The OS will never reclaim it though it does know which app was originally responsible for requesting it... As far as the OS is concerned in that case the memory is still in use by some app. One more note about GSM, there is far more GSM available to a programmer than app heap memory. So it is not uncommon practice at all to always use the vast GSM pool rather than worry about the heap running out of space. Many apps don't allocate heap memory at all but instead always use GSM blocks. Any app that has its own memory mangagement routines is virtually assured to be doing it using GSM unless it was written by morons. The Heap size is fixed for the app also whereas GSM is not -- another reason programmers like GSM over heap.

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GSM?

If you are talking about the difference between using LocalAlloc and GlobalAlloc, the problems with LocalAlloc went away with Win32. GlobalAlloc and LocalAlloc now use the same heap. This heap is "non-system" memory (below 0x8000000) which is managed by the operating system and will be released when the process terminates.

Most high level languages such as C/C++ build their own allocation systems on top of API such as HeapAlloc. For performance reasons, it would be silly to use GlobalAlloc for memory allocations unless you are building your own sub-allocation system on top of it. GlobalAlloc has performance problems.

BTW, with Win32, GlobalAlloc does not allocated shared memory. To support old window messages such as a DDE and the clipboard, they had to add special processing to move that memory from one address space to another. (I am not totally clear on exactly what they did.)

found memory leak, please verify
Click Here

GlobalAlloc uses the same heap as LocalAlloc in all Win32 operating systems. However, there are other things that the 9x series of operating system (95, 98, ME) fails to release as well as your NT series of operating systems (NT, W2K, XP). However, GlobalAlloc isn't one of them and as I said before, GlobalAlloc does not allocate shared memory. On Win32 operating systems, shared memory is done using memory mapped files.

James Henley, Technical Designer

Protection from uber-gamers?
Honestly, my first suggestion would be to find a better place to play with more mature players, rather than have to stoop to their level of creating "uber" gear. Neverwinterconnections.com is the matching service I used to play on, and it's definitely one of the best if you're looking for a mature game. Might be worth checking out.