Barry Kelly <barry_j_kelly@hotmail.com>, 19 April 2004
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This archive contains a simple API unit for the Boehm Garbage Collector DLL,
along with another unit which makes it easier to use with classes, and a 
demonstration application. Also included is the Boehm GC DLL binary, along 
with source code in the gc_dll_src directory.

The files:

BoehmGc.pas
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This unit exports a dozen or so routines from the Boehm GC dll. Since the
GC integrates with and replaces the Delphi default memory manager, you 
probably don't need to use this unit unless you want to fine-tune the
behaviour of the DLL. The DLL exports more routines than are in this unit;
the C prototypes are in the gc_dll_src/gc.h header file, and can be imported
as needed.

If you allocate large chunks of memory (>100K) which don't contain references
to other chunks (and thus don't need to be scanned for pointers), there are
routines in this unit which you can use to increase performance. 
General advice: don't tweak until you need to tweak.

Gc.pas
------
This is the main unit. Put this unit first in the uses clause of you project
and the project will automatically use garbage collection. If you want to use
objects which require finalization and you don't want to have to call TObject.Free 
TObject.Destroy on them manually, you can use the MarkForFinalization(TObject)
function. The basic pattern is to register the object for finalization in its
constructor and unregister it with UnmarkForFinalization in its destructor. 
This handles the two most common use cases for finalization: GC-invoked 
finalization and manual finalization.

Note that it's always safe to behave as if GC doesn't exist, and use 
GetMem/FreeMem, New/Dispose, Create/Free etc. The use of these units simply
allows you to also program with garbage collection.

GcTest.dpr & GcTest.exe
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This program contains simple sample code demonstrating the garbage collector in 
action.

BoehmGC.dll
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This contains the implementation of the garbage collector itself. The DLL can
be recompiled from the source in gc_dll_src with various options, including
multithreaded support, different pointer alignment granularities, etc.


****

The original Boehm GC source comes from:

  http://www.hpl.hp.com/personal/Hans_Boehm/gc/

I'm Barry Kelly: barry_j_kelly@hotmail.com

You can do anything you like with my source code (*.pas, *.dpr). 
See the file gc_dll_src/LICENSEa for permissions for the GC itself.