[fireball] 50000: [HEAP] - Time has come to get rid of a slightly modified implementation of WINE's heap, which is a hack based on Windows 95's heap implementation, itself a hack of DOS memory mana...

Author: fireball
Date: Fri Dec 10 09:33:20 2010
New Revision: 50000

URL: http://svn.reactos.org/svn/reactos?rev=50000&view=rev
Log:
[HEAP]
- Time has come to get rid of a slightly modified implementation of WINE's heap, which
is a hack based on Windows 95's heap implementation, itself a hack of DOS memory
management. It supported 3 out of the 18 possible NT Heap Flags, did not support custom
allocation/deallocation routines, and was about 50-80x slower with fragmentation rates up
to 500x higher when compared to NT's LFH (WINE is lucky because the advanced NT Heap
features are used in kernel-mode usually, not in user-mode, and they are crossing their
fingers for this being the same). Several high-end SQL/Database applications would
significantly benefit from custom heap features provided by NT. Not to say about removing
crappy support for a custom Commit routine and crappy support for User-defined flags and
the User-defined value.

- So, the glorious moment for a new heap manager, which is (to remind you) a totally new
heap manager, resembling real NT heap manager, based on data structures similar to Windows
2003 and Vista+'s heap structures, supporting advanced heap flags (e.g. useful for
debugging), having substantially lower fragmentation rates (and thus speed and
reliability), having native support for user-defined flags and user-defined values, also
native support for a custom commit routine, which is very important for trunk's win32
subsystem. It also reserves, commits, decommits and frees memory on the fly, unlike
existing heap manager which prefers to reserve and commit as much as possible, and
doesn't decommit when it's no longer necessary. Not to say about support for per
process heaps, with a proper lock, and a further support for a special so-called debug
heap allocator (to be implemented in heapdbg.c) which will be useful for finding heap
corruptions.

Yeah, I'm not a fun person :D

Added:
    trunk/reactos/lib/rtl/heap.c
      - copied unchanged from r49999, trunk/reactos/lib/rtl/heap_rewrite.c
Removed:
    trunk/reactos/lib/rtl/heap_rewrite.c

[This mail would be too long, it was shortened to contain the URLs only.]

Removed: trunk/reactos/lib/rtl/heap_rewrite.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/rtl/heap_rewrite.c?rev…