mono/libgc

This is a modified version of Boehm GC 6.1 for Mono.

* There are two main changes to the upstream version:

- Makefile changes:

libgc has a lot of configurable options which are AC_DEFINE()d in its
configure.in. To make it easier to build and bundle it with Mono, I
replaced most of the orignal configure.in and the makefiles with custom
versions which just define what we actually need for Mono.

This means that you can just run configure in this directory and it'll
do the right thing. Later on, we'll just include this package in Mono
and use AC_CONFIG_SUBDIRS().

- Threading changes

The original libgc has several *_threads.c files for each possible threading
implementation.

For Mono, we're using a vtable

typedef struct
{
void (* initialize) (void);
void (* lock) (void);
void (* unlock) (void);
void (* stop_world) (void);
void (* push_thread_structures) (void);
void (* push_all_stacks) (void);
void (* start_world) (void);
} GCThreadFunctions;

extern GCThreadFunctions *gc_thread_vtable;

and a mono_threads.c file.

- Deleted files

Some files from the original distribution have been deleted in this version.
These are files which weren't actually linked into the library so they were not
needed. When importing a new upstream version, you can either keep them removed
or just replace them with their new upstream versions.

- include/private/gc_locks.h

This file has been replaced with a custom version.

When importing a new upstream version, keep this custom version, ie. don't import the
new upstream gc_locks.h.

* Importing a new upstream version

This is really simple. Just import the new version to the vendor branch (LIBGC) in CVS
and then merge it into the main trunk.

To get a diff to the original version:

cvs diff -u -r LIBGC

When importing new upstream versions, don't import the new configure.in or any of the
Makefile.am's; they've been replaced by custom versions. Just import all the new source
files and it should be fine.


April 4th, 2003
Martin Baulig