Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers

Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.

Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.

Copyright (c) 1999-2001 by Hewlett-Packard. All rights reserved.

THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED

OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.

Permission is hereby granted to use or copy this program

for any purpose,  provided the above notices are retained on all copies.

Permission to modify the code and to distribute modified code is granted,

provided the above notices are retained, and a notice that the code was

modified is included with the above copyright notice.

A few files have other copyright holders. A few of the files needed

to use the GNU-style build procedure come with a modified GPL license

that appears not to significantly restrict use of the collector, though

use of those files for a purpose other than building the collector may

require the resulting code to be covered by the GPL.

For more details and the names of other contributors, see the README.md,

doc/README.*, AUTHORS and include/gc.h files.  These files describe typical

use of the collector on a machine that is already supported.

For the version number, see README.md or include/gc_version.h files.

INSTALLATION:

Under UN*X, Linux:

Alternative 1 (the old way): type "make -f Makefile.direct check".

        Link against gc.a.

Alternative 2 (the new way): type

        "./configure --prefix=<dir>; make; make check; make install".

        Link against <dir>/lib/libgc.a or <dir>/lib/libgc.so.

        See doc/README.autoconf for details

Under Windows 95, 98, Me, NT, or 2000:

copy the appropriate makefile to MAKEFILE, read it, and type "nmake test".

(Under Windows, this assumes you have Microsoft command-line tools

installed, and suitably configured.)

Read the machine specific README.XXX in the doc directory if one exists.

If you need thread support, you will need to follow the special

platform-dependent instructions (win32), or define GC_THREADS

as described in doc/README.macros, or possibly use

--enable-threads=posix when running the configure script.

If you wish to use the cord (structured string) library with the stand-alone

Makefile.direct, type "make -f Makefile.direct cords".

(This requires an ANSI C compiler.  You may

need to redefine CC in the Makefile. The CORD_printf implementation in

cordprnt.c is known to be less than perfectly portable.  The rest of the

package should still work.)  See include/cord.h for the API.

If you wish to use the collector from C++, type "make c++", or use

--enable-cplusplus with the configure script.   With Makefile.direct,

these ones add further files to gc.a and to the include subdirectory.

With the alternate build process, this generates libgccpp.

See include/gc_cpp.h.

TYPICAL USE:

Include "gc.h" from the include subdirectory.  Link against the

appropriate library ("gc.a" under UN*X).  Replace calls to malloc

by calls to GC_MALLOC, and calls to realloc by calls to GC_REALLOC.

If the object is known to never contain pointers, use GC_MALLOC_ATOMIC

instead of GC_MALLOC.

Define GC_DEBUG before including gc.h for additional checking.

More documentation on the collector interface can be found in README.md,

doc/gcinterface.html, include/gc.h, and other files in the doc directory.

WARNINGS:

Do not store the only pointer to an object in memory allocated

with system malloc, since the collector usually does not scan

memory allocated in this way.

Use with threads may be supported on your system, but requires the

collector to be built with thread support.  See Makefile.  The collector

does not guarantee to scan thread-local storage (e.g. of the kind

accessed with pthread_getspecific()).  The collector does scan

thread stacks though, so generally the best solution is to ensure that

any pointers stored in thread-local storage are also stored on the

thread's stack for the duration of their lifetime.