1654 lines
88 KiB
Plaintext
1654 lines
88 KiB
Plaintext
This is a rough history of garbage collector bugs and versions.
|
|
|
|
This has been maintained with varying diligence over the years.
|
|
|
|
I made an attempt to include recent contributors here. I apologize for any
|
|
omissions.
|
|
|
|
-------------------------
|
|
|
|
Version 1.3 and immediately preceding versions contained spurious
|
|
assembly language assignments to TMP_SP. Only the assignment in the PC/RT
|
|
code is necessary. On other machines, with certain compiler options,
|
|
the assignments can lead to an unsaved register being overwritten.
|
|
Known to cause problems under SunOS 3.5 WITHOUT the -O option. (With
|
|
-O the compiler recognizes it as dead code. It probably shouldn't,
|
|
but that's another story.)
|
|
|
|
Version 1.4 and earlier versions used compile time determined values
|
|
for the stack base. This no longer works on Sun 3s, since Sun 3/80s use
|
|
a different stack base. We now use a straightforward heuristic on all
|
|
machines on which it is known to work (incl. Sun 3s) and compile-time
|
|
determined values for the rest. There should really be library calls
|
|
to determine such values.
|
|
|
|
Version 1.5 and earlier did not ensure 8 byte alignment for objects
|
|
allocated on a sparc based machine.
|
|
|
|
Version 1.8 added ULTRIX support in gc_private.h.
|
|
|
|
Version 1.9 fixed a major bug in gc_realloc.
|
|
|
|
Version 2.0 introduced a consistent naming convention for collector
|
|
routines and added support for registering dynamic library data segments
|
|
in the standard mark_roots.c. Most of the data structures were revamped.
|
|
The treatment of interior pointers was completely changed. Finalization
|
|
was added. Support for locking was added. Object kinds were added.
|
|
We added a black listing facility to avoid allocating at addresses known
|
|
to occur as integers somewhere in the address space. Much of this
|
|
was accomplished by adapting ideas and code from the PCR collector.
|
|
The test program was changed and expanded.
|
|
|
|
Version 2.1 was the first stable version since 1.9, and added support
|
|
for PPCR.
|
|
|
|
Version 2.2 added debugging allocation, and fixed various bugs. Among them:
|
|
- GC_realloc could fail to extend the size of the object for certain large object sizes.
|
|
- A blatant subscript range error in GC_printf, which unfortunately
|
|
wasn't exercised on machines with sufficient stack alignment constraints.
|
|
- GC_register_displacement did the wrong thing if it was called after
|
|
any allocation had taken place.
|
|
- The leak finding code would eventually break after 2048 byte
|
|
byte objects leaked.
|
|
- interface.c didn't compile.
|
|
- The heap size remained much too small for large stacks.
|
|
- The stack clearing code behaved badly for large stacks, and perhaps
|
|
on HP/PA machines.
|
|
|
|
Version 2.3 added ALL_INTERIOR_POINTERS and fixed the following bugs:
|
|
- Missing declaration of etext in the A/UX version.
|
|
- Some PCR root-finding problems.
|
|
- Blacklisting was not 100% effective, because the plausible future
|
|
heap bounds were being miscalculated.
|
|
- GC_realloc didn't handle out-of-memory correctly.
|
|
- GC_base could return a nonzero value for addresses inside free blocks.
|
|
- test.c wasn't really thread safe, and could erroneously report failure
|
|
in a multithreaded environment. (The locking primitives need to be
|
|
replaced for other threads packages.)
|
|
- GC_CONS was thoroughly broken.
|
|
- On a SPARC with dynamic linking, signals stayed diabled while the
|
|
client code was running.
|
|
(Thanks to Manuel Serrano at INRIA for reporting the last two.)
|
|
|
|
Version 2.4 added GC_free_space_divisor as a tuning knob, added
|
|
support for OS/2 and linux, and fixed the following bugs:
|
|
- On machines with unaligned pointers (e.g. Sun 3), every 128th word could
|
|
fail to be considered for marking.
|
|
- Dynamic_load.c erroneously added 4 bytes to the length of the data and
|
|
bss sections of the dynamic library. This could result in a bad memory
|
|
reference if the actual length was a multiple of a page. (Observed on
|
|
Sun 3. Can probably also happen on a Sun 4.)
|
|
(Thanks to Robert Brazile for pointing out that the Sun 3 version
|
|
was broken. Dynamic library handling is still broken on Sun 3s
|
|
under 4.1.1U1, but apparently not 4.1.1. If you have such a machine,
|
|
use -Bstatic.)
|
|
|
|
Version 2.5 fixed the following bugs:
|
|
- Removed an explicit call to exit(1)
|
|
- Fixed calls to GC_printf and GC_err_printf, so the correct number of
|
|
arguments are always supplied. The OS/2 C compiler gets confused if
|
|
the number of actuals and the number of formals differ. (ANSI C
|
|
doesn't require this to work. The ANSI sanctioned way of doing things
|
|
causes too many compatibility problems.)
|
|
|
|
Version 3.0 added generational/incremental collection and stubborn
|
|
objects.
|
|
|
|
Version 3.1 added the following features:
|
|
- A workaround for a SunOS 4.X SPARC C compiler
|
|
misfeature that caused problems when the collector was turned into
|
|
a dynamic library.
|
|
- A fix for a bug in GC_base that could result in a memory fault.
|
|
- A fix for a performance bug (and several other misfeatures) pointed
|
|
out by Dave Detlefs and Al Dosser.
|
|
- Use of dirty bit information for static data under Solaris 2.X.
|
|
- DEC Alpha/OSF1 support (thanks to Al Dosser).
|
|
- Incremental collection on more platforms.
|
|
- A more refined heap expansion policy. Less space usage by default.
|
|
- Various minor enhancements to reduce space usage, and to reduce
|
|
the amount of memory scanned by the collector.
|
|
- Uncollectable allocation without per object overhead.
|
|
- More conscientious handling of out-of-memory conditions.
|
|
- Fixed a bug in debugging stubborn allocation.
|
|
- Fixed a bug that resulted in occasional erroneous reporting of smashed
|
|
objects with debugging allocation.
|
|
- Fixed bogus leak reports of size 4096 blocks with FIND_LEAK.
|
|
|
|
Version 3.2 fixed a serious and not entirely repeatable bug in
|
|
the incremental collector. It appeared only when dirty bit info
|
|
on the roots was available, which is normally only under Solaris.
|
|
It also added GC_general_register_disappearing_link, and some
|
|
testing code. Interface.c disappeared.
|
|
|
|
Version 3.3 fixes several bugs and adds new ports:
|
|
- PCR-specific bugs.
|
|
- Missing locking in GC_free, redundant FASTUNLOCK
|
|
in GC_malloc_stubborn, and 2 bugs in
|
|
GC_unregister_disappearing_link.
|
|
All of the above were pointed out by Neil Sharman
|
|
(neil@cs.mu.oz.au).
|
|
- Common symbols allocated by the SunOS4.X dynamic loader
|
|
were not included in the root set.
|
|
- Bug in GC_finalize (reported by Brian Beuning and Al Dosser)
|
|
- Merged Amiga port from Jesper Peterson (untested)
|
|
- Merged NeXT port from Thomas Funke (significantly
|
|
modified and untested)
|
|
|
|
Version 3.4:
|
|
- Fixed a performance bug in GC_realloc.
|
|
- Updated the amiga port.
|
|
- Added NetBSD and 386BSD ports.
|
|
- Added cord library.
|
|
- Added trivial performance enhancement for
|
|
ALL_INTERIOR_POINTERS. (Don't scan last word.)
|
|
|
|
Version 3.5
|
|
- Minor collections now mark from roots only once, if that
|
|
doesn't cause an excessive pause.
|
|
- The stack clearing heuristic was refined to prevent anomalies
|
|
with very heavily recursive programs and sparse stacks.
|
|
- Fixed a bug that prevented mark stack growth in some cases.
|
|
GC_objects_are_marked should be set to TRUE after a call
|
|
to GC_push_roots and as part of GC_push_marked, since
|
|
both can now set mark bits. I think this is only a performance
|
|
bug, but I wouldn't bet on it. It's certainly very hard to argue
|
|
that the old version was correct.
|
|
- Fixed an incremental collection bug that prevented it from
|
|
working at all when HBLKSIZE != getpagesize()
|
|
- Changed dynamic_loading.c to include gc_priv.h before testing
|
|
DYNAMIC_LOADING. SunOS dynamic library scanning
|
|
must have been broken in 3.4.
|
|
- Object size rounding now adapts to program behavior.
|
|
- Added a workaround (provided by Manuel Serrano and
|
|
colleagues) to a long-standing SunOS 4.X (and 3.X?) ld bug
|
|
that I had incorrectly assumed to have been squished.
|
|
The collector was broken if the text segment size was within
|
|
32 bytes of a multiple of 8K bytes, and if the beginning of
|
|
the data segment contained interesting roots. The workaround
|
|
assumes a demand-loadable executable. The original may have
|
|
have "worked" in some other cases.
|
|
- Added dynamic library support under IRIX5.
|
|
- Added support for EMX under OS/2 (thanks to Ari Huttunen).
|
|
|
|
Version 3.6:
|
|
- fixed a bug in the mark stack growth code that was introduced
|
|
in 3.4.
|
|
- fixed Makefile to work around DEC AXP compiler tail recursion
|
|
bug.
|
|
|
|
Version 3.7:
|
|
- Added a workaround for an HP/UX compiler bug.
|
|
- Fixed another stack clearing performance bug. Reworked
|
|
that code once more.
|
|
|
|
Version 4.0:
|
|
- Added support for Solaris threads (which was possible
|
|
only by reimplementing some fraction of Solaris threads,
|
|
since Sun doesn't currently make the thread debugging
|
|
interface available).
|
|
- Added non-threads win32 and win32S support.
|
|
- (Grudgingly, with suitable muttering of obscenities) renamed
|
|
files so that the collector distribution could live on a FAT
|
|
file system. Files that are guaranteed to be useless on
|
|
a PC still have long names. Gc_inline.h and gc_private.h
|
|
still exist, but now just include gc_inl.h and gc_priv.h.
|
|
- Fixed a really obscure bug in finalization that could cause
|
|
undetected mark stack overflows. (I would be surprised if
|
|
any real code ever tickled this one.)
|
|
- Changed finalization code to dynamically resize the hash
|
|
tables it maintains. (This probably does not matter for well-
|
|
-written code. It no doubt does for C++ code that overuses
|
|
destructors.)
|
|
- Added typed allocation primitives. Rewrote the marker to
|
|
accommodate them with more reasonable efficiency. This
|
|
change should also speed up marking for GC_malloc allocated
|
|
objects a little. See gc_typed.h for new primitives.
|
|
- Improved debugging facilities slightly. Allocation time
|
|
stack traces are now kept by default on SPARC/SUNOS4.
|
|
(Thanks to Scott Schwartz.)
|
|
- Added better support for small heap applications.
|
|
- Significantly extended cord package. Fixed a bug in the
|
|
implementation of lazily read files. Printf and friends now
|
|
have cord variants. Cord traversals are a bit faster.
|
|
- Made ALL_INTERIOR_POINTERS recognition the default.
|
|
- Fixed de so that it can run in constant space, independent
|
|
of file size. Added simple string searching to cords and de.
|
|
- Added the Hull-Ellis C++ interface.
|
|
- Added dynamic library support for OSF/1.
|
|
(Thanks to Al Dosser and Tim Bingham at DEC.)
|
|
- Changed argument to GC_expand_hp to be expressed
|
|
in units of bytes instead of heap blocks. (Necessary
|
|
since the heap block size now varies depending on
|
|
configuration. The old version was never very clean.)
|
|
- Added GC_get_heap_size(). The previous "equivalent"
|
|
was broken.
|
|
- Restructured the Makefile a bit.
|
|
|
|
Since version 4.0:
|
|
- Changed finalization implementation to guarantee that
|
|
finalization procedures are called outside of the allocation
|
|
lock, making direct use of the interface a little less dangerous.
|
|
MAY BREAK EXISTING CLIENTS that assume finalizers
|
|
are protected by a lock. Since there seem to be few multithreaded
|
|
clients that use finalization, this is hopefully not much of
|
|
a problem.
|
|
- Fixed a gross bug in CORD_prev.
|
|
- Fixed a bug in blacklst.c that could result in unbounded
|
|
heap growth during startup on machines that do not clear
|
|
memory obtained from the OS (e.g. win32S).
|
|
- Ported de editor to win32/win32S. (This is now the only
|
|
version with a mouse-sensitive UI.)
|
|
- Added GC_malloc_ignore_off_page to allocate large arrays
|
|
in the presence of ALL_INTERIOR_POINTERS.
|
|
- Changed GC_call_with_alloc_lock to not disable signals in
|
|
the single-threaded case.
|
|
- Reduced retry count in GC_collect_or_expand for garbage
|
|
collecting when out of memory.
|
|
- Made uncollectable allocations bypass black-listing, as they
|
|
should.
|
|
- Fixed a bug in typed_test in test.c that could cause (legitimate)
|
|
GC crashes.
|
|
- Fixed some potential synchronization problems in finalize.c
|
|
- Fixed a real locking problem in typd_mlc.c.
|
|
- Worked around an AIX 3.2 compiler feature that results in
|
|
out of bounds memory references.
|
|
- Partially worked around an IRIX5.2 beta problem (which may
|
|
or may not persist to the final release).
|
|
- Fixed a bug in the heap integrity checking code that could
|
|
result in explicitly deallocated objects being identified as
|
|
smashed. Fixed a bug in the dbg_mlc stack saving code
|
|
that caused old argument pointers to be considered live.
|
|
- Fixed a bug in CORD_ncmp (and hence CORD_str).
|
|
- Repaired the OS2 port, which had suffered from bit rot
|
|
in 4.0. Worked around what appears to be CSet/2 V1.0
|
|
optimizer bug.
|
|
- Fixed a Makefile bug for target "c++".
|
|
|
|
Since version 4.1:
|
|
- Multiple bug fixes/workarounds in the Solaris threads version.
|
|
(It occasionally failed to locate some register contents for
|
|
marking. It also turns out that thr_suspend and friends are
|
|
unreliable in Solaris 2.3. Dirty bit reads appear
|
|
to be unreliable under some weird
|
|
circumstances. My stack marking code
|
|
contained a serious performance bug. The new code is
|
|
extremely defensive, and has not failed in several cpu
|
|
hours of testing. But no guarantees ...)
|
|
- Added MacOS support (thanks to Patrick Beard.)
|
|
- Fixed several syntactic bugs in gc_c++.h and friends. (These
|
|
didn't bother g++, but did bother most other compilers.)
|
|
Fixed gc_c++.h finalization interface. (It didn't.)
|
|
- 64 bit alignment for allocated objects was not guaranteed in a
|
|
few cases in which it should have been.
|
|
- Added GC_malloc_atomic_ignore_off_page.
|
|
- Added GC_collect_a_little.
|
|
- Added some prototypes to gc.h.
|
|
- Some other minor bug fixes (notably in Makefile).
|
|
- Fixed OS/2 / EMX port (thanks to Ari Huttunen).
|
|
- Fixed AmigaDOS port. (thanks to Michel Schinz).
|
|
- Fixed the DATASTART definition under Solaris. There
|
|
was a 1 in 16K chance of the collector missing the first
|
|
64K of static data (and thus crashing).
|
|
- Fixed some blatant anachronisms in the README file.
|
|
- Fixed PCR-Makefile for upcoming PPCR release.
|
|
|
|
Since version 4.2:
|
|
- Fixed SPARC alignment problem with GC_DEBUG.
|
|
- Fixed Solaris threads /proc workaround. The real
|
|
problem was an interaction with mprotect.
|
|
- Incorporated fix from Patrick Beard for gc_c++.h (now gc_cpp.h).
|
|
- Slightly improved allocator space utilization by
|
|
fixing the GC_size_map mechanism.
|
|
- Integrated some Sony News and MIPS RISCos 4.51
|
|
patches. (Thanks to Nobuyuki Hikichi of
|
|
Software Research Associates, Inc. Japan)
|
|
- Fixed HP_PA alignment problem. (Thanks to
|
|
xjam@cork.cs.berkeley.edu.)
|
|
- Added GC_same_obj and friends. Changed GC_base
|
|
to return 0 for pointers past the end of large objects.
|
|
Improved GC_base performance with ALL_INTERIOR_POINTERS
|
|
on machines with a slow integer mod operation.
|
|
Added GC_PTR_ADD, GC_PTR_STORE, etc. to prepare
|
|
for preprocessor.
|
|
- changed the default on most UNIX machines to be that
|
|
signals are not disabled during critical GC operations.
|
|
This is still ANSI-conforming, though somewhat dangerous
|
|
in the presence of signal handlers. But the performance
|
|
cost of the alternative is sometimes problematic.
|
|
Can be changed back with a minor Makefile edit.
|
|
- renamed IS_STRING in gc.h, to CORD_IS_STRING, thus
|
|
following my own naming convention. Added the function
|
|
CORD_to_const_char_star.
|
|
- Fixed a gross bug in GC_finalize. Symptom: occasional
|
|
address faults in that function. (Thanks to Anselm
|
|
Baird-Smith (Anselm.BairdSmith@inria.fr)
|
|
- Added port to ICL DRS6000 running DRS/NX. Restructured
|
|
things a bit to factor out common code, and remove obsolete
|
|
code. Collector should now run under SUNOS5 with either
|
|
mprotect or /proc dirty bits. (Thanks to Douglas Steel
|
|
(doug@wg.icl.co.uk)).
|
|
- More bug fixes and workarounds for Solaris 2.X. (These were
|
|
mostly related to putting the collector in a dynamic library,
|
|
which didn't really work before. Also SOLARIS_THREADS
|
|
didn't interact well with dl_open.) Thanks to btlewis@eng.sun.com.
|
|
- Fixed a serious performance bug on the DEC Alpha. The text
|
|
segment was getting registered as part of the root set.
|
|
(Amazingly, the result was still fast enough that the bug
|
|
was not conspicuous.) The fix works on OSF/1, version 1.3.
|
|
Hopefully it also works on other versions of OSF/1 ...
|
|
- Fixed a bug in GC_clear_roots.
|
|
- Fixed a bug in GC_generic_malloc_words_small that broke
|
|
gc_inl.h. (Reported by Antoine de Maricourt. I broke it
|
|
in trying to tweak the Mac port.)
|
|
- Fixed some problems with cord/de under Linux.
|
|
- Fixed some cord problems, notably with CORD_riter4.
|
|
- Added DG/UX port.
|
|
Thanks to Ben A. Mesander (ben@piglet.cr.usgs.gov)
|
|
- Added finalization registration routines with weaker ordering
|
|
constraints. (This is necessary for C++ finalization with
|
|
multiple inheritance, since the compiler often adds self-cycles.)
|
|
- Filled the holes in the SCO port. (Thanks to Michael Arnoldus
|
|
<chime@proinf.dk>.)
|
|
- John Ellis' additions to the C++ support: From John:
|
|
|
|
* I completely rewrote the documentation in the interface gc_c++.h
|
|
(later renamed gc_cpp.h). I've tried to make it both clearer and more
|
|
precise.
|
|
|
|
* The definition of accessibility now ignores pointers from an
|
|
finalizable object (an object with a clean-up function) to itself.
|
|
This allows objects with virtual base classes to be finalizable by the
|
|
collector. Compilers typically implement virtual base classes using
|
|
pointers from an object to itself, which under the old definition of
|
|
accessibility prevented objects with virtual base classes from ever
|
|
being collected or finalized.
|
|
|
|
* gc_cleanup now includes gc as a virtual base. This was enabled by
|
|
the change in the definition of accessibility.
|
|
|
|
* I added support for operator new[]. Since most (all?) compilers
|
|
don't yet support operator new[], it is conditionalized on
|
|
-DOPERATOR_NEW_ARRAY. The code is untested, but its trivial and looks
|
|
correct.
|
|
|
|
* The test program test_gc_c++ (later renamed test_cpp.cc)
|
|
tries to test for the C++-specific functionality not tested by the
|
|
other programs.
|
|
- Added <unistd.h> include to misc.c. (Needed for ppcr.)
|
|
- Added PowerMac port. (Thanks to Patrick Beard again.)
|
|
- Fixed "srcdir"-related Makefile problems. Changed things so
|
|
that all externally visible include files always appear in the
|
|
include subdirectory of the source. Made gc.h directly
|
|
includable from C++ code. (These were at Per
|
|
Bothner's suggestion.)
|
|
- Changed Intel code to also mark from ebp (Kevin Warne's
|
|
suggestion).
|
|
- Renamed C++ related files so they could live in a FAT
|
|
file system. (Charles Fiterman's suggestion.)
|
|
- Changed Windows NT Makefile to include C++ support in
|
|
gc.lib. Added C++ test as Makefile target.
|
|
|
|
Since version 4.3:
|
|
- ASM_CLEAR_CODE was erroneously defined for HP
|
|
PA machines, resulting in a compile error.
|
|
- Fixed OS/2 Makefile to create a library. (Thanks to
|
|
Mark Boulter (mboulter@vnet.ibm.com)).
|
|
- Gc_cleanup objects didn't work if they were created on
|
|
the stack. Fixed.
|
|
- One copy of Gc_cpp.h in the distribution was out of
|
|
synch, and failed to document some known compiler
|
|
problems with explicit destructor invocation. Partially
|
|
fixed. There are probably other compilers on which
|
|
gc_cleanup is miscompiled.
|
|
- Fixed Makefile to pass C compiler flags to C++ compiler.
|
|
- Added Mac fixes.
|
|
- Fixed os_dep.c to work around what appears to be
|
|
a new and different VirtualQuery bug under newer
|
|
versions of win32S.
|
|
- GC_non_gc_bytes was not correctly maintained by
|
|
GC_free. Fixed. Thanks to James Clark (jjc@jclark.com).
|
|
- Added GC_set_max_heap_size.
|
|
- Changed allocation code to ignore blacklisting if it is preventing
|
|
use of a very large block of memory. This has the advantage
|
|
that naive code allocating very large objects is much more
|
|
likely to work. The downside is you might no
|
|
longer find out that such code should really use
|
|
GC_malloc_ignore_off_page.
|
|
- Changed GC_printf under win32 to close and reopen the file
|
|
between calls. FAT file systems otherwise make the log file
|
|
useless for debugging.
|
|
- Added GC_try_to_collect and GC_get_bytes_since_gc. These
|
|
allow starting an abortable collection during idle times.
|
|
This facility does not require special OS support. (Thanks to
|
|
Michael Spertus of Geodesic Systems for suggesting this. It was
|
|
actually an easy addition. Kumar Srikantan previously added a similar
|
|
facility to a now ancient version of the collector. At the time
|
|
this was much harder, and the result was less convincing.)
|
|
- Added some support for the Borland development environment. (Thanks
|
|
to John Ellis and Michael Spertus.)
|
|
- Removed a misfeature from checksums.c that caused unexpected
|
|
heap growth. (Thanks to Scott Schwartz.)
|
|
- Changed finalize.c to call WARN if it encounters a finalization cycle.
|
|
WARN is defined in gc_priv.h to write a message, usually to stdout.
|
|
In many environments, this may be inappropriate.
|
|
- Renamed NO_PARAMS in gc.h to GC_NO_PARAMS, thus adhering to my own
|
|
naming convention.
|
|
- Added GC_set_warn_proc to intercept warnings.
|
|
- Fixed Amiga port. (Thanks to Michel Schinz (schinz@alphanet.ch).)
|
|
- Fixed a bug in mark.c that could result in an access to unmapped
|
|
memory from GC_mark_from_mark_stack on machines with unaligned
|
|
pointers.
|
|
- Fixed a win32 specific performance bug that could result in scanning of
|
|
objects allocated with the system malloc.
|
|
- Added REDIRECT_MALLOC.
|
|
|
|
Since version 4.4:
|
|
- Fixed many minor and one major README bugs. (Thanks to Franklin Chen
|
|
(chen@adi.com) for pointing out many of them.)
|
|
- Fixed ALPHA/OSF/1 dynamic library support. (Thanks to Jonathan Bachrach
|
|
(jonathan@harlequin.com)).
|
|
- Added incremental GC support (MPROTECT_VDB) for Linux (with some
|
|
help from Bruno Haible).
|
|
- Altered SPARC recognition tests in gc.h and config.h (mostly as
|
|
suggested by Fergus Henderson).
|
|
- Added basic incremental GC support for win32, as implemented by
|
|
Windows NT and Windows 95. GC_enable_incremental is a noop
|
|
under win32s, which doesn't implement enough of the VM interface.
|
|
- Added -DLARGE_CONFIG.
|
|
- Fixed GC_..._ignore_off_page to also function without
|
|
-DALL_INTERIOR_POINTERS.
|
|
- (Hopefully) fixed RS/6000 port. (Only the test was broken.)
|
|
- Fixed a performance bug in the nonincremental collector running
|
|
on machines supporting incremental collection with MPROTECT_VDB
|
|
(e.g. SunOS 4, DEC AXP). This turned into a correctness bug under
|
|
win32s with win32 incremental collection. (Not all memory protection
|
|
was disabled.)
|
|
- Fixed some ppcr related bit rot.
|
|
- Caused dynamic libraries to be unregistered before reregistering.
|
|
The old way turned out to be a performance bug on some machines.
|
|
- GC_root_size was not properly maintained under MSWIN32.
|
|
- Added -DNO_DEBUGGING and GC_dump.
|
|
- Fixed a couple of bugs arising with SOLARIS_THREADS +
|
|
REDIRECT_MALLOC.
|
|
- Added NetBSD/M68K port. (Thanks to Peter Seebach
|
|
<seebs@taniemarie.solon.com>.)
|
|
- Fixed a serious realloc bug. For certain object sizes, the collector
|
|
wouldn't scan the expanded part of the object. (Thanks to Clay Spence
|
|
(cds@peanut.sarnoff.com) for noticing the problem, and helping me to
|
|
track it down.)
|
|
|
|
Since version 4.5:
|
|
- Added Linux ELF support. (Thanks to Arrigo Triulzi <arrigo@ic.ac.uk>.)
|
|
- GC_base crashed if it was called before any other GC_ routines.
|
|
This could happen if a gc_cleanup object was allocated outside the heap
|
|
before any heap allocation.
|
|
- The heap expansion heuristic was not stable if all objects had finalization
|
|
enabled. Fixed finalize.c to count memory in finalization queue and
|
|
avoid explicit deallocation. Changed alloc.c to also consider this count.
|
|
(This is still not recommended. It's expensive if nothing else.) Thanks
|
|
to John Ellis for pointing this out.
|
|
- GC_malloc_uncollectable(0) was broken. Thanks to Phong Vo for pointing
|
|
this out.
|
|
- The collector didn't compile under Linux 1.3.X. (Thanks to Fred Gilham for
|
|
pointing this out.) The current workaround is ugly, but expected to be
|
|
temporary.
|
|
- Fixed a formatting problem for SPARC stack traces.
|
|
- Fixed some '=='s in os_dep.c that should have been assignments.
|
|
Fortunately these were in code that should never be executed anyway.
|
|
(Thanks to Fergus Henderson.)
|
|
- Fixed the heap block allocator to only drop blacklisted blocks in small
|
|
chunks. Made BL_LIMIT self adjusting. (Both of these were in response
|
|
to heap growth observed by Paul Graham.)
|
|
- Fixed the Metrowerks/68K Mac code to also mark from a6. (Thanks
|
|
to Patrick Beard.)
|
|
- Significantly updated README.debugging.
|
|
- Fixed some problems with longjmps out of signal handlers, especially under
|
|
Solaris. Added a workaround for the fact that siglongjmp doesn't appear to
|
|
do the right thing with -lthread under Solaris.
|
|
- Added MSDOS/djgpp port. (Thanks to Mitch Harris (maharri@uiuc.edu).)
|
|
- Added "make reserved_namespace" and "make user_namespace". The
|
|
first renames ALL "GC_xxx" identifiers as "_GC_xxx". The second is the
|
|
inverse transformation. Note that doing this is guaranteed to break all
|
|
clients written for the other names.
|
|
- descriptor field for kind NORMAL in GC_obj_kinds with ADD_BYTE_AT_END
|
|
defined should be -ALIGNMENT not WORDS_TO_BYTES(-1). This is
|
|
a serious bug on machines with pointer alignment of less than a word.
|
|
- GC_ignore_self_finalize_mark_proc didn't handle pointers to very near the
|
|
end of the object correctly. Caused failures of the C++ test on a DEC Alpha
|
|
with g++.
|
|
- gc_inl.h still had problems. Partially fixed. Added warnings at the
|
|
beginning to hopefully specify the remaining dangers.
|
|
- Added DATAEND definition to config.h.
|
|
- Fixed some of the .h file organization. Fixed "make floppy".
|
|
|
|
Since version 4.6:
|
|
- Fixed some compilation problems with -DCHECKSUMS (thanks to Ian Searle)
|
|
- Updated some Mac specific files to synchronize with Patrick Beard.
|
|
- Fixed a serious bug for machines with non-word-aligned pointers.
|
|
(Thanks to Patrick Beard for pointing out the problem. The collector
|
|
should fail almost any conceivable test immediately on such machines.)
|
|
|
|
Since version 4.7:
|
|
- Changed a "comment" in a MacOS specific part of mach-dep.c that caused
|
|
gcc to fail on other platforms.
|
|
|
|
Since version 4.8
|
|
- More README.debugging fixes.
|
|
- Objects ready for finalization, but not finalized in the same GC
|
|
cycle, could be prematurely collected. This occasionally happened
|
|
in test_cpp.
|
|
- Too little memory was obtained from the system for very large
|
|
objects. That could cause a heap explosion if these objects were
|
|
not contiguous (e.g. under PCR), and too much of them was blacklisted.
|
|
- Due to an improper initialization, the collector was too hesitant to
|
|
allocate blacklisted objects immediately after system startup.
|
|
- Moved GC_arrays from the data into the bss segment by not explicitly
|
|
initializing it to zero. This significantly
|
|
reduces the size of executables, and probably avoids some disk accesses
|
|
on program startup. It's conceivable that it might break a port that I
|
|
didn't test.
|
|
- Fixed EMX_MAKEFILE to reflect the gc_c++.h to gc_cpp.h renaming which
|
|
occurred a while ago.
|
|
|
|
Since 4.9:
|
|
- Fixed a typo around a call to GC_collect_or_expand in alloc.c. It broke
|
|
handling of out of memory. (Thanks to Patrick Beard for noticing.)
|
|
|
|
Since 4.10:
|
|
- Rationalized (hopefully) GC_try_to_collect in an incremental collection
|
|
environment. It appeared to not handle a call while a collection was in
|
|
progress, and was otherwise too conservative.
|
|
- Merged GC_reclaim_or_delete_all into GC_reclaim_all to get rid of some
|
|
code.
|
|
- Added Patrick Beard's Mac fixes, with substantial completely untested
|
|
modifications.
|
|
- Fixed the MPROTECT_VDB code to deal with large pages and imprecise
|
|
fault addresses (as on an UltraSPARC running Solaris 2.5). Note that this
|
|
was not a problem in the default configuration, which uses PROC_VDB.
|
|
- The DEC Alpha assembly code needed to restore $gp between calls.
|
|
Thanks to Fergus Henderson for tracking this down and supplying a
|
|
patch.
|
|
- The write command for "de" was completely broken for large files.
|
|
I used the easiest portable fix, which involved changing the semantics
|
|
so that f.new is written instead of overwriting f. That's safer anyway.
|
|
- Added README.solaris2 with a discussion of the possible problems of
|
|
mixing the collector's sbrk allocation with malloc/realloc.
|
|
- Changed the data segment starting address for SGI machines. The
|
|
old code failed under IRIX6.
|
|
- Required double word alignment for MIPS.
|
|
- Various minor fixes to remove warnings.
|
|
- Attempted to fix some Solaris threads problems reported by Zhiying Chen.
|
|
In particular, the collector could try to fork a thread with the
|
|
world stopped as part of GC_thr_init. It also failed to deal with
|
|
the case in which the original thread terminated before the whole
|
|
process did.
|
|
- Added -DNO_EXECUTE_PERMISSION. This has a major performance impact
|
|
on the incremental collector under Irix, and perhaps under other
|
|
operating systems.
|
|
- Added some code to support allocating the heap with mmap. This may
|
|
be preferable under some circumstances.
|
|
- Integrated dynamic library support for HP.
|
|
(Thanks to Knut Tvedten <knuttv@ifi.uio.no>.)
|
|
- Integrated James Clark's win32 threads support, and made a number
|
|
of changes to it, many of which were suggested by Pontus Rydin.
|
|
This is still not 100% solid.
|
|
- Integrated Alistair Crooks' support for UTS4 running on an Amdahl
|
|
370-class machine.
|
|
- Fixed a serious bug in explicitly typed allocation. Objects requiring
|
|
large descriptors where handled in a way that usually resulted in
|
|
a segmentation fault in the marker. (Thanks to Jeremy Fitzhardinge
|
|
for helping to track this down.)
|
|
- Added partial support for GNU win32 development. (Thanks to Fergus
|
|
Henderson.)
|
|
- Added optional support for Java-style finalization semantics. (Thanks
|
|
to Patrick Bridges.) This is recommended only for Java implementations.
|
|
- GC_malloc_uncollectable faulted instead of returning 0 when out of
|
|
memory. (Thanks to dan@math.uiuc.edu for noticing.)
|
|
- Calls to GC_base before the collector was initialized failed on a
|
|
DEC Alpha. (Thanks to Matthew Flatt.)
|
|
- Added base pointer checking to GC_REGISTER_FINALIZER in debugging
|
|
mode, at the suggestion of Jeremy Fitzhardinge.
|
|
- GC_debug_realloc failed for uncollectable objects. (Thanks to
|
|
Jeremy Fitzhardinge.)
|
|
- Explicitly typed allocation could crash if it ran out of memory.
|
|
(Thanks to Jeremy Fitzhardinge.)
|
|
- Added minimal support for a DEC Alpha running Linux.
|
|
- Fixed a problem with allocation of objects whose size overflowed
|
|
ptrdiff_t. (This now fails unconditionally, as it should.)
|
|
- Added the beginning of Irix pthread support.
|
|
- Integrated Xiaokun Zhu's fixes for djgpp 2.01.
|
|
- Added SGI-style STL allocator support (gc_alloc.h).
|
|
- Fixed a serious bug in README.solaris2. Multithreaded programs must include
|
|
gc.h with SOLARIS_THREADS defined.
|
|
- Changed GC_free so it actually deallocates uncollectable objects.
|
|
(Thanks to Peter Chubb for pointing out the problem.)
|
|
- Added Linux ELF support for dynamic libararies. (Thanks again to
|
|
Patrick Bridges.)
|
|
- Changed the Borland cc configuration so that the assembler is not
|
|
required.
|
|
- Fixed a bug in the C++ test that caused it to fail in 64-bit
|
|
environments.
|
|
|
|
Since 4.11:
|
|
- Fixed ElfW definition in dyn_load.c. (Thanks to Fergus Henderson.)
|
|
This prevented the dynamic library support from compiling on some
|
|
older ELF Linux systems.
|
|
- Fixed UTS4 port (which I apparently mangled during the integration)
|
|
(Thanks to again to Alistair Crooks.)
|
|
- "Make C++" failed on Suns with SC4.0, due to a problem with "bool".
|
|
Fixed in gc_priv.h.
|
|
- Added more pieces for GNU win32. (Thanks to Timothy N. Newsham.)
|
|
The current state of things should suffice for at least some
|
|
applications.
|
|
- Changed the out of memory retry count handling as suggested by
|
|
Kenjiro Taura. (This matters only if GC_max_retries > 0, which
|
|
is no longer the default.)
|
|
- If a /proc read failed repeatedly, GC_written_pages was not updated
|
|
correctly. (Thanks to Peter Chubb for diagnosing this.)
|
|
- Under unlikely circumstances, the allocator could infinite loop in
|
|
an out of memory situation. (Thanks again to Kenjiro Taura for
|
|
identifying the problem and supplying a fix.)
|
|
- Fixed a syntactic error in the DJGPP code. (Thanks to Fergus
|
|
Henderson for finding this by inspection.) Also fixed a test program
|
|
problem with DJGPP (Thanks to Peter Monks.)
|
|
- Atomic uncollectable objects were not treated correctly by the
|
|
incremental collector. This resulted in weird log statistics and
|
|
occasional performance problems. (Thanks to Peter Chubb for pointing
|
|
this out.)
|
|
- Fixed some problems resulting from compilers that dont define
|
|
__STDC__. In this case void * and char * were used inconsistently
|
|
in some cases. (Void * should not have been used at all. If
|
|
you have an ANSI superset compiler that does not define __STDC__,
|
|
please compile with -D__STDC__=0. Thanks to Manuel Serrano and others
|
|
for pointing out the problem.)
|
|
- Fixed a compilation problem on Irix with -n32 and -DIRIX_THREADS.
|
|
Also fixed some other IRIX_THREADS problems which may or may not have
|
|
had observable symptoms.
|
|
- Fixed an HP PA compilation problem in dyn_load.c. (Thanks to
|
|
Philippe Queinnec.)
|
|
- SEGV fault handlers sometimes did not get reset correctly. (Thanks
|
|
to David Pickens.)
|
|
- Added a fix for SOLARIS_THREADS on Intel. (Thanks again to David
|
|
Pickens.) This probably needs more work to become functional.
|
|
- Fixed struct sigcontext_struct in os_dep.c for compilation under
|
|
Linux 2.1.X. (Thanks to Fergus Henderson.)
|
|
- Changed the DJGPP STACKBOTTOM and DATASTART values to those suggested
|
|
by Kristian Kristensen. These may still not be right, but it is
|
|
it is likely to work more often than what was there before. They may
|
|
even be exactly right.
|
|
- Added a #include <string.h> to test_cpp.cc. This appears to help
|
|
with HP/UX and gcc. (Thanks to assar@sics.se.)
|
|
- Version 4.11 failed to run in incremental mode on recent 64-bit Irix
|
|
kernels. This was a problem related to page unaligned heap segments.
|
|
Changed the code to page align heap sections on all platforms.
|
|
(I had mistakenly identified this as a kernel problem earlier.
|
|
It was not.)
|
|
- Version 4.11 did not make allocated storage executable, except on
|
|
one or two platforms, due to a bug in a #if test. (Thanks to Dave
|
|
Grove for pointing this out.)
|
|
- Added sparc_sunos4_mach_dep.s to support Sun's compilers under SunOS4.
|
|
- Added GC_exclude_static_roots.
|
|
- Fixed the object size mapping algorithm. This shouldn't matter,
|
|
but the old code was ugly.
|
|
- Heap checking code could die if one of the allocated objects was
|
|
larger than its base address. (Unsigned underflow problem. Thanks
|
|
to Clay Spence for isolating the problem.)
|
|
- Added RS6000 (AIX) dynamic library support and fixed STACK_BOTTOM.
|
|
(Thanks to Fred Stearns.)
|
|
- Added Fergus Henderson's patches for improved robustness with large
|
|
heaps and lots of blacklisting.
|
|
- Added Peter Chubb's changes to support Solaris Pthreads, to support
|
|
MMAP allocation in Solaris, to allow Solaris to find dynamic libraries
|
|
through /proc, to add malloc_typed_ignore_off_page, and a few other
|
|
minor features and bug fixes.
|
|
- The Solaris 2 port should not use sbrk. I received confirmation from
|
|
Sun that the use of sbrk and malloc in the same program is not
|
|
supported. The collector now defines USE_MMAP by default on Solaris.
|
|
- Replaced the djgpp makefile with Gary Leavens' version.
|
|
- Fixed MSWIN32 detection test.
|
|
- Added Fergus Henderson's patches to allow putting the collector into
|
|
a DLL under GNU win32.
|
|
- Added Ivan V. Demakov's port to Watcom C on X86.
|
|
- Added Ian Piumarta's Linux/PowerPC port.
|
|
- On Brian Burton's suggestion added PointerFreeGC to the placement
|
|
options in gc_cpp.h. This is of course unsafe, and may be controversial.
|
|
On the other hand, it seems to be needed often enough that it's worth
|
|
adding as a standard facility.
|
|
|
|
Since 4.12:
|
|
- Fixed a crucial bug in the Watcom port. There was a redundant decl
|
|
of GC_push_one in gc_priv.h.
|
|
- Added FINALIZE_ON_DEMAND.
|
|
- Fixed some pre-ANSI cc problems in test.c.
|
|
- Removed getpagesize() use for Solaris. It seems to be missing in one
|
|
or two versions.
|
|
- Fixed bool handling for SPARCCompiler version 4.2.
|
|
- Fixed some files in include that had gotten unlinked from the main
|
|
copy.
|
|
- Some RS/6000 fixes (missing casts). Thanks to Toralf Foerster.
|
|
- Fixed several problems in GC_debug_realloc, affecting mostly the
|
|
FIND_LEAK case.
|
|
- GC_exclude_static_roots contained a buggy unsigned comparison to
|
|
terminate a loop. (Thanks to Wilson Ho.)
|
|
- CORD_str failed if the substring occurred at the last possible position.
|
|
(Only affects cord users.)
|
|
- Fixed Linux code to deal with RedHat 5.0 and integrated Peter Bigot's
|
|
os_dep.c code for dealing with various Linux versions.
|
|
- Added workaround for Irix pthreads sigaction bug and possible signal
|
|
misdirection problems.
|
|
Since alpha1:
|
|
- Changed RS6000 STACKBOTTOM.
|
|
- Integrated Patrick Beard's Mac changes.
|
|
- Alpha1 didn't compile on Irix m.n, m < 6.
|
|
- Replaced Makefile.dj with a new one from Gary Leavens.
|
|
- Added Andrew Stitcher's changes to support SCO OpenServer.
|
|
- Added PRINT_BLACK_LIST, to allow debugging of high densities of false
|
|
pointers.
|
|
- Added code to debug allocator to keep track of return address
|
|
in GC_malloc caller, thus giving a bit more context.
|
|
- Changed default behavior of large block allocator to more
|
|
aggressively avoid fragmentation. This is likely to slow down the
|
|
collector when it succeeds at reducing space cost.
|
|
- Integrated Fergus Henderson's CYGWIN32 changes. They are untested,
|
|
but needed for newer versions.
|
|
- USE_MMAP had some serious bugs. This caused the collector to fail
|
|
consistently on Solaris with -DSMALL_CONFIG.
|
|
- Added Linux threads support, thanks largely to Fergus Henderson.
|
|
Since alpha2:
|
|
- Fixed more Linux threads problems.
|
|
- Changed default GC_free_space_divisor to 3 with new large block allocation.
|
|
(Thanks to Matthew Flatt for some measurements that suggest the old
|
|
value sometimes favors space too much over time.)
|
|
- More CYGWIN32 fixes.
|
|
- Integrated Tyson-Dowd's Linux-M68K port.
|
|
- Minor HP PA and DEC UNIX fixes from Fergus Henderson.
|
|
- Integrated Christoffe Raffali's Linux-SPARC changes.
|
|
- Allowed for one more GC fixup iteration after a full GC in incremental
|
|
mode. Some quick measurements suggested that this significantly
|
|
reduces pause times even with smaller GC_RATE values.
|
|
- Moved some more GC data structures into GC_arrays. This decreases
|
|
pause times and GC overhead, but makes debugging slightly less convenient.
|
|
- Fixed namespace pollution problem ("excl_table").
|
|
- Made GC_incremental a constant for -DSMALL_CONFIG, hopefully shrinking
|
|
that slightly.
|
|
- Added some win32 threads fixes.
|
|
- Integrated Ivan Demakov and David Stes' Watcom fixes.
|
|
- Various other minor fixes contributed by many people.
|
|
- Renamed config.h to gcconfig.h, since config.h tends to be used for
|
|
many other things.
|
|
- Integrated Matthew Flatt's support for 68K MacOS "far globals".
|
|
- Fixed up some of the dynamic library Makefile targets for consistency
|
|
across platforms.
|
|
- Fixed a USE_MMAP typo that caused out-of-memory handling to fail
|
|
on Solaris.
|
|
- Added code to test.c to test thread creation a bit more.
|
|
- Integrated GC_win32_free_heap, as suggested by Ivan Demakov.
|
|
- Fixed Solaris 2.7 stack base finding problem. (This may actually
|
|
have been done in an earlier alpha release.)
|
|
Since alpha3:
|
|
- Fixed MSWIN32 recognition test, which interfered with cygwin.
|
|
- Removed unnecessary gc_watcom.asm from distribution. Removed
|
|
some obsolete README.win32 text.
|
|
- Added Alpha Linux incremental GC support. (Thanks to Philipp Tomsich
|
|
for code for retrieving the fault address in a signal handler.)
|
|
Changed Linux signal handler context argument to be a pointer.
|
|
- Took care of some new warnings generated by the 7.3 SGI compiler.
|
|
- Integrated Phillip Musumeci's FreeBSD/ELF fixes.
|
|
- -DIRIX_THREADS was broken with the -o32 ABI (typo in gc_priv.h>
|
|
|
|
Since 4.13:
|
|
- Fixed GC_print_source_ptr to not use a prototype.
|
|
- generalized CYGWIN test.
|
|
- gc::new did the wrong thing with PointerFreeGC placement.
|
|
(Thanks to Rauli Ruohonen.)
|
|
- In the ALL_INTERIOR_POINTERS (default) case, some callee-save register
|
|
values could fail to be scanned if the register was saved and
|
|
reused in a GC frame. This showed up in verbose mode with gctest
|
|
compiled with an unreleased SGI compiler. I vaguely recall an old
|
|
bug report that may have been related. The bug was probably quite old.
|
|
(The problem was that the stack scanning could be deferred until
|
|
after the relevant frame was overwritten, and the new save location
|
|
might be outside the scanned area. Fixed by more eager stack scanning.)
|
|
- PRINT_BLACK_LIST had some problems. A few source addresses were garbage.
|
|
- Replaced Makefile.dj and added -I flags to cord make targets.
|
|
(Thanks to Gary Leavens.)
|
|
- GC_try_to_collect was broken with the nonincremental collector.
|
|
- gc_cleanup destructors could pass the wrong address to
|
|
GC_register_finalizer_ignore_self in the presence of multiple
|
|
inheritance. (Thanks to Darrell Schiebel.)
|
|
- Changed PowerPC Linux stack finding code.
|
|
|
|
Since 4.14alpha1
|
|
- -DSMALL_CONFIG did not work reliably with large (> 4K) pages.
|
|
Recycling the mark stack during expansion could result in a size
|
|
zero heap segment, which confused things. (This was probably also an
|
|
issue with the normal config and huge pages.)
|
|
- Did more work to make sure that callee-save registers were scanned
|
|
completely, even with the setjmp-based code. Added USE_GENERIC_PUSH_REGS
|
|
macro to facilitate testing on machines I have access to.
|
|
- Added code to explicitly push register contents for win32 threads.
|
|
This seems to be necessary. (Thanks to Pierre de Rop.)
|
|
|
|
Since 4.14alpha2
|
|
- changed STACKBOTTOM for DJGPP (Thanks to Salvador Eduardo Tropea).
|
|
|
|
Since 4.14
|
|
- Reworked large block allocator. Now uses multiple doubly linked free
|
|
lists to approximate best fit.
|
|
- Changed heap expansion heuristic. Entirely free blocks are no longer
|
|
counted towards the heap size. This seems to have a major impact on
|
|
heap size stability; the old version could expand the heap way too
|
|
much in the presence of large block fragmentation.
|
|
- added -DGC_ASSERTIONS and some simple assertions inside the collector.
|
|
This is mainlyt for collector debugging.
|
|
- added -DUSE_MUNMAP to allow the heap to shrink. Suupported on only
|
|
a few UNIX-like platforms for now.
|
|
- added GC_dump_regions() for debugging of fragmentation issues.
|
|
- Changed PowerPC pointer alignment under Linux to 4. (This needs
|
|
checking by someone who has one. The suggestions came to me via a
|
|
rather circuitous path.)
|
|
- Changed the Linux/Alpha port to walk the data segment backwards until
|
|
it encounters a SIGSEGV. The old way to find the start of the data
|
|
segment broke with a recent release.
|
|
- cordxtra.c needed to call GC_REGISTER_FINALIZER instead of
|
|
GC_register_finalizer, so that it would continue to work with GC_DEBUG.
|
|
- allochblk sometimes cleared the wrong block for debugging purposes
|
|
when it dropped blacklisted blocks. This could result in spurious
|
|
error reports with GC_DEBUG.
|
|
- added MACOS X Server support. (Thanks to Andrew Stone.)
|
|
- Changed the Solaris threads code to ignore stack limits > 8 MB with
|
|
a warning. Empirically, it is not safe to access arbitrary pages
|
|
in such large stacks. And the dirty bit implementation does not
|
|
guarantee that none of them will be accessed.
|
|
- Integrated Martin Tauchmann's Amiga changes.
|
|
- Integrated James Dominy's OpenBSD/SPARC port.
|
|
|
|
Since 5.0alpha1
|
|
- Fixed bugs introduced in alpha1 (OpenBSD & large block initialization).
|
|
- Added -DKEEP_BACK_PTRS and backptr.h interface. (The implementation
|
|
idea came from Al Demers.)
|
|
|
|
Since 5.0alpha2
|
|
- Added some highly incomplete code to support a copied young generation.
|
|
Comments on nursery.h are appreciated.
|
|
- Changed -DFIND_LEAK, -DJAVA_FINALIZATION, and -DFINALIZE_ON_DEMAND,
|
|
so the same effect could be obtained with a runtime switch. This is
|
|
a step towards standardizing on a single dynamic GC library.
|
|
- Significantly changed the way leak detection is handled, as a consequence
|
|
of the above.
|
|
|
|
Since 5.0 alpha3
|
|
- Added protection fault handling patch for Linux/M68K from Fergus
|
|
Henderson and Roman Hodek.
|
|
- Removed the tests for SGI_SOURCE in new_gc_alloc.h. This was causing that
|
|
interface to fail on nonSGI platforms.
|
|
- Changed the Linux stack finding code to use /proc, after changing it
|
|
to use HEURISTIC1. (Thanks to David Mossberger for pointing out the
|
|
/proc hook.)
|
|
- Added HP/UX incremental GC support and HP/UX 11 thread support.
|
|
Thread support is currently still flakey.
|
|
- Added basic Linux/IA64 support.
|
|
- Integrated Anthony Green's PicoJava support.
|
|
- Integrated Scott Ananian's StrongARM/NetBSD support.
|
|
- Fixed some fairly serious performance bugs in the incremental
|
|
collector. These have probably been there essentially forever.
|
|
(Mark bits were sometimes set before scanning dirty pages.
|
|
The reclaim phase unnecessarily dirtied full small object pages.)
|
|
- Changed the reclaim phase to ignore nearly full pages to avoid
|
|
touching them.
|
|
- Limited GC_black_list_spacing to roughly the heap growth increment.
|
|
- Changed full collection triggering heuristic to decrease full GC
|
|
frequency by default, but to explicitly trigger full GCs during
|
|
heap growth. This doesn't always improve things, but on average it's
|
|
probably a win.
|
|
- GC_debug_free(0, ...) failed. Thanks to Fergus Henderson for the
|
|
bug report and fix.
|
|
|
|
Since 5.0 alpha4
|
|
- GC_malloc_explicitly_typed and friends sometimes failed to
|
|
initialize first word.
|
|
- Added allocation routines and support in the marker for mark descriptors
|
|
in a type structure referenced by the first word of an object. This was
|
|
introduced to support gcj, but hopefully in a way that makes it
|
|
generically useful.
|
|
- Added GC_requested_heapsize, and inhibited collections in nonincremental
|
|
mode if the actual used heap size is less than what was explicitly
|
|
requested.
|
|
- The Solaris pthreads version of GC_pthread_create didn't handle a NULL
|
|
attribute pointer. Solaris thread support used the wrong default thread
|
|
stack size. (Thanks to Melissa O'Neill for the patch.)
|
|
- Changed PUSH_CONTENTS macro to no longer modify first parameter.
|
|
This usually doesn't matter, but it was certainly an accident waiting
|
|
to happen ...
|
|
- Added GC_register_finalizer_no_order and friends to gc.h. They're
|
|
needed by Java implementations.
|
|
- Integrated a fix for a win32 deadlock resulting from clock() calling
|
|
malloc. (Thanks to Chris Dodd.)
|
|
- Integrated Hiroshi Kawashima's port to Linux/MIPS. This was designed
|
|
for a handheld platform, and may or may not be sufficient for other
|
|
machines.
|
|
- Fixed a va_arg problem with the %c specifier in cordprnt.c. It appears
|
|
that this was always broken, but recent versions of gcc are the first to
|
|
report the (statically detectable) bug.
|
|
- Added an attempt at a more general solution to dlopen races/deadlocks.
|
|
GC_dlopen now temporarily disables collection. Still not ideal, but ...
|
|
- Added -DUSE_I686_PREFETCH, -DUSE_3DNOW_PREFETCH, and support for IA64
|
|
prefetch instructions. May improve performance measurably, but I'm not
|
|
sure the code will run correctly on processors that don't support the
|
|
instruction. Won't build except with very recent gcc.
|
|
- Added caching for header lookups in the marker. This seems to result
|
|
in a barely measurable performance gain. Added support for interleaved
|
|
lookups of two pointers, but unconfigured that since the performance
|
|
gain is currently near zero, and it adds to code size.
|
|
- Changed Linux DATA_START definition to check both data_start and
|
|
__data_start, since nothing else seems to be portable.
|
|
- Added -DUSE_LD_WRAP to optionally take advantage of the GNU ld function
|
|
wrapping mechanism. Probably currently useful only on Linux.
|
|
- Moved some variables for the scratch allocator into GC_arrays, on
|
|
Martin Hirzel's suggestion.
|
|
- Fixed a win32 threads bug that caused the collector to not look for
|
|
interior pointers from one of the thread stacks without
|
|
ALL_INTERIOR_POINTERS. (Thanks to Jeff Sturm.)
|
|
- Added Mingw32 support. (Thanks again to Jeff Sturm for the patch.)
|
|
- Changed the alpha port to use the generic register scanning code instead
|
|
of alpha_mach_dep.s. Alpha_mach_dep.s doesn't look for pointers in fp
|
|
registers, but gcc sometimes spills pointers there. (Thanks to Manuel
|
|
Serrano for helping me debug this by email.) Changed the IA64 code to
|
|
do something similar for similar reasons.
|
|
|
|
[5.0alpha5 doesn't really exist, but it may have escaped.]
|
|
|
|
Since 5.0alpha6:
|
|
- -DREDIRECT_MALLOC was broken in alpha6. Fixed.
|
|
- Cleaned up gc_ccp.h slightly, thus also causing the HP C++ compiler to
|
|
accept it.
|
|
- Removed accidental reference to dbg_mlc.c, which caused dbg_mlc.o to be
|
|
linked into every executable.
|
|
- Added PREFETCH to bitmap marker. Changed it to use the header cache.
|
|
- GC_push_marked sometimes pushed one object too many, resulting in a
|
|
segmentation fault in GC_mark_from_mark_stack. This was probably an old
|
|
bug. It finally showed up in gctest on win32.
|
|
- Gc_priv.h erroneously #defined GC_incremental to be TRUE instead of FALSE
|
|
when SMALL_CONFIG was defined. This was no doubt a major performance bug for
|
|
the default win32 configuration.
|
|
- Removed -DSMALL_CONFIG from NT_MAKEFILE. It seemed like an anchronism now
|
|
that the average PC has 64MB or so.
|
|
- Integrated Bryce McKinley's patches for linux threads and dynamic loading
|
|
from the libgcj tree. Turned on dynamic loading support for Linux/PPC.
|
|
- Changed the stack finding code to use environ on HP/UX. (Thanks
|
|
to Gustavo Rodriguez-Rivera for the suggestion.) This should probably
|
|
be done on other platforms, too. Since I can't test those, that'll
|
|
wait until after 5.0.
|
|
|
|
Since 5.0alpha7:
|
|
- Fixed threadlibs.c for linux threads. -DUSE_LD_WRAP was broken and
|
|
-ldl was omitted. Fixed Linux stack finding code to handle
|
|
-DUSE_LD_WRAP correctly.
|
|
- Added MSWIN32 exception handler around marker, so that the collector
|
|
can recover from root segments that are unmapped during the collection.
|
|
This caused occasional failures under Windows 98, and may also be
|
|
an issue under Windows NT/2000.
|
|
|
|
Since 5.0
|
|
- Fixed a gc.h header bug which showed up under Irix. (Thanks to
|
|
Dan Sullivan.)
|
|
- Fixed a typo in GC_double_descr in typd_mlc.c.
|
|
This probably could result in objects described by array descriptors not
|
|
getting traced correctly. (Thanks to Ben Hutchings for pointing this out.)
|
|
- The block nearly full tests in reclaim.c were not correct for 64 bit
|
|
environments. This could result in unnecessary heap growth under unlikely
|
|
conditions.
|
|
|
|
Since 5.1
|
|
- dyn_load.c declared GC_scratch_last_end_ptr as an extern even if it
|
|
was defined as a macro. This prevented the collector from building on
|
|
Irix.
|
|
- We quietly assumed that indirect mark descriptors were never 0.
|
|
Our own typed allocation interface violated that. This could result
|
|
in segmentation faults in the marker with typed allocation.
|
|
- Fixed a _DUSE_MUNMAP bug in the heap block allocation code.
|
|
(Thanks to Ben Hutchings for the patch.)
|
|
- Taught the collector about VC++ handling array operator new.
|
|
(Thanks again to Ben Hutchings for the patch.)
|
|
- The two copies of gc_hdrs.h had diverged. Made one a link to the other
|
|
again.
|
|
|
|
Since 5.2 (A few 5.2 patches are not in 6.0alpha1)
|
|
- Fixed _end declaration for OSF1.
|
|
- There were lots of spurious leak reports in leak detection mode, caused
|
|
by the fact that some pages were not being swept, and hence unmarked
|
|
objects weren't making it onto free lists. (This bug dated back to 5.0.)
|
|
- Fixed a typo in the liblinuxgc.so Makefile rule.
|
|
- Added the GetExitCodeThread to Win32 GC_stop_world to (mostly) work
|
|
around a Windows 95 GetOpenFileName problem. (Thanks to Jacob Navia.)
|
|
|
|
Since 5.3
|
|
- Fixed a typo that prevented compilation with -DUSE_3DNOW_PREFETCH.
|
|
(Thanks to Shawn Wagner for actually testing this.)
|
|
- Fixed GC_is_thread_stack in solaris_threads.c. It forgot to return a value
|
|
in the common case. I wonder why nobody noticed?
|
|
- Fixed another silly syntax problem in GC_double_descr. (Thanks to
|
|
Fergus Henderson for finding it.)
|
|
- Fixed a GC_gcj_malloc bug: It tended to release the allocator lock twice.
|
|
|
|
Since 5.4 (A few 5.3 patches are not in 6.0alpha2)
|
|
- Added HP/PA prefetch support.
|
|
- Added -DDBG_HDRS_ALL and -DSHORT_DBG_HDRS to reduce the cost and improve
|
|
the reliability of generating pointer backtrace information, e.g. in
|
|
the Bigloo environment.
|
|
- Added parallel marking support (-DPARALLEL_MARK). This currently
|
|
works only under IA32 and IA64 Linux, but it shouldn't be hard to adapt
|
|
to other platforms. This is intended to be a lighter-weight (less
|
|
new code, probably not as scalable) solution than the work by Toshio Endo
|
|
et al, at the University of Tokyo. A number of their ideas were
|
|
reused, though the code wasn't, and the underlying data structure
|
|
is significantly different. In particular, we keep the global mark
|
|
stack as a single shared data structure, but most of the work is done
|
|
on smaller thread-local mark stacks.
|
|
- Changed GC_malloc_many to be cheaper, and to require less mutual exclusion
|
|
with -DPARALLEL_MARK.
|
|
- Added full support for thread local allocation under Linux
|
|
(-DTHREAD_LOCAL_ALLOC). This is a thin veneer on GC_malloc_many, and
|
|
should be easily portable to other platforms, especially those that
|
|
support pthreads.
|
|
- CLEAR_DOUBLE was not always getting invoked when it should have been.
|
|
- GC_gcj_malloc and friends used different out of memory handling than
|
|
everything else, probably because I forgot about one when I implemented
|
|
the other. They now both call GC_oom_fn(), not GC_oom_action().
|
|
- Integrated Jakub Jelinek's fixes for Linux/SPARC.
|
|
- Moved GC_objfreelist, GC_aobjfreelist, and GC_words_allocd out of
|
|
GC_arrays, and separately registered the first two as excluded roots.
|
|
This makes code compiled with gc_inl.h less dependent on the
|
|
collector version. (It would be nice to remove the inclusion of
|
|
gc_priv.h by gc_inl.h completely, but we're not there yet. The
|
|
locking definitions in gc_priv.h are still referenced.)
|
|
This change was later coniditoned on SEPARATE_GLOBALS, which
|
|
is not defined by default, since it involves a performance hit.
|
|
- Register GC_obj_kinds separately as an excluded root region. The
|
|
attempt to register it with GC_arrays was usually failing. (This wasn't
|
|
serious, but seemed to generate some confusion.)
|
|
- Moved backptr.h to gc_backptr.h.
|
|
|
|
Since 6.0alpha1
|
|
- Added USE_MARK_BYTES to reduce the need for compare-and-swap on platforms
|
|
for which that's expensive.
|
|
- Fixed a locking bug ib GC_gcj_malloc and some locking assertion problems.
|
|
- Added a missing volatile to OR_WORD and renamed the parameter to
|
|
GC_compare_and_swap so it's not a C++ reserved word. (Thanks to
|
|
Toshio Endo for pointing out both of those.)
|
|
- Changed Linux dynamic library registration code to look at /proc/self/maps
|
|
instead of the rld data structures when REDIRECT_MALLOC is defined.
|
|
Otherwise some of the rld data data structures may be prematurely garbage
|
|
collected. (Thanks to Eric Benson for helping to track this down.)
|
|
- Fixed USE_LD_WRAP a bit more, so it should now work without threads.
|
|
- Renamed XXX_THREADS macros to GC_XXX_THREADS for namespace correctness.
|
|
Tomporarily added some backward compatibility definitions. Renamed
|
|
USE_LD_WRAP to GC_USE_LD_WRAP.
|
|
- Many MACOSX POWERPC changes, some additions to the gctest output, and
|
|
a few minor generic bug fixes. (Thanks to Dietmar Planitzer.)
|
|
|
|
Since 6.0 alpha2
|
|
- Fixed the /proc/self/maps code to not seek, since that apparently is not
|
|
reliable across all interesting kernels.
|
|
- Fixed some compilation problems in the absence of PARALLEL_MARK
|
|
(introduced in alpha2).
|
|
- Fixed an algorithmic problem with PARALLEL_MARK. If work needs to
|
|
be given back to the main mark "stack", the BOTTOM entries of the local
|
|
stack should be given away, not the top ones. This has substantial
|
|
performance impact, especially for > 2 processors, from what I can tell.
|
|
- Extracted gc_lock.h from gc_priv.h. This should eventually make it a
|
|
bit easier to avoid including gc_priv.h in clients.
|
|
- Moved all include files to include/ and removed duplicate links to the
|
|
same file. The old scheme was a bad idea because it was too easy to get the
|
|
copies out of sync, and many systems don't support hard links.
|
|
Unfortunately, it's likely that I broke some of the non-Unix Makefiles in
|
|
the process, although I tried to update them appropriately.
|
|
- Removed the partial support for a copied nursery. It's not clear that
|
|
this would be a tremendous win, since we don't consistently lose to
|
|
generational copying collectors. And it would significantly complicate
|
|
many things. May be reintroduced if/when it really turns out to win.
|
|
- Removed references to IRIX_JDK_THREADS, since I believe there never
|
|
were and never will be any clients.
|
|
- Added some code to linux_threads.c to possibly support HPUX threads
|
|
using the Linux code. Unfortunately, it doesn't work yet, and is
|
|
currently disabled.
|
|
- Added support under Linux/X86 for saving the call chain, both in (debug)
|
|
objects for client debugging, and in GC_arrays._last_stack for GC
|
|
debugging. This was previously supported only under Solaris. It is
|
|
not enabled by default under X86, since it requires that code be compiled
|
|
to explicitly dave frame pointers on the call stack. (With gcc this
|
|
currently happens by default, but is often turned off explicitly.)
|
|
To turn it on, define SAVE_CALL_CHAIN.
|
|
|
|
Since 6.0 alpha3
|
|
- Moved up the detection of mostly full blocks to the initiatiation of the
|
|
sweep phase. This eliminates some lock conention in the PARALLEL_MARK case,
|
|
as multiple threads try to look at mostly full blocks concurrently.
|
|
- Restored the code in GC_malloc_many that grabs a prefix of the global
|
|
free list. This avoids the case in which every GC_malloc_many call
|
|
tries and fails to allocate a new heap block, and the returns a single
|
|
object from the global free list.
|
|
- Some minor fixes in new_hblk.c. (Attempted to build free lists in order
|
|
of increasing addresses instead of decreasing addresses for cache performance
|
|
reasons. But this seems to be only a very minor gain with -DEAGER_SWEEP,
|
|
and a loss in other cases. So the change was backed out.)
|
|
- Fixed some of the documentation. (Thanks in large part to Fergus
|
|
Henderson.)
|
|
- Fixed the Linux USE_PROC_FOR_LIBRARIES code to deal with apps that perform
|
|
large numbers of mmaps. (Thanks to Eric Benson.) Also fixed that code to
|
|
deal with short reads.
|
|
- Added GC_get_total_bytes().
|
|
- Fixed leak detection mode to avoid spurious messages under linuxthreads.
|
|
(This should also now be easy for the other supported threads packages.
|
|
But the code is tricky enough that I'm hesitant to do it without being able
|
|
to test. Everything allocated in the GC thread support itself should be
|
|
explicitly deallocated.)
|
|
- Made it possible (with luck) to redirect malloc to GC_local_malloc.
|
|
|
|
Since 6.0 alpha4
|
|
- Changed the definition of GC_pause in linux_threads.c to use a volatile
|
|
asm. Some versions of gcc apparently optimize away writes to local volatile
|
|
variables. This caused poor locking behaviour starting at about
|
|
4 processors.
|
|
- Added GC_start_blocking(), GC_end_blocking() calls and wrapper for sleep
|
|
to linux_threads.c.
|
|
The first two calls could be used to generally avoid sending GC signals to
|
|
blocked threads, avoiding both premature wakeups and unnecessary overhead.
|
|
- Fixed a serious bug in thread-local allocation. At thread termination,
|
|
GC_free could get called on small integers. Changed the code for thread
|
|
termination to more efficiently return left-over free-lists.
|
|
- Integrated Kjetil Matheussen's BeOS support.
|
|
- Rearranged the directory structure to create the doc and tests
|
|
subdirectories.
|
|
- Sort of integrated Eric Benson's patch for OSF1. This provided basic
|
|
OSF1 thread support by suitably extending hpux_irix_threads.c. Based
|
|
on earlier email conversations with David Butenhof, I suspect that it
|
|
will be more reliable in the long run to base this on linux_threads.c
|
|
instead. Thus I attempted to patch up linux_threads.c based on Eric's code.
|
|
The result is almost certainly broken, but hopefully close enough that
|
|
someone with access to a machine can pick it up.
|
|
- Integrated lots of minor changes from the NetBSD distribution. (These
|
|
were supplied by David Brownlee. I'm not sure about the original
|
|
authors.)
|
|
- Hacked a bit more on the HP/UX thread-support in linux_threads.c. It
|
|
now appears to work in the absence of incremental collection. Renamed
|
|
hpux_irix_threads.c back to irix_threads.c, and removed the attempt to
|
|
support HPUX there.
|
|
- Changed gc.h to define _REENTRANT in cases in which it should already
|
|
have been defined. It is still safer to also define it on the command
|
|
line.
|
|
|
|
Since 6.0alpha5:
|
|
- Changed the definition of DATASTART on ALPHA and IA64, where data_start
|
|
and __data_start are not defined by earlier versions of glibc. This might
|
|
need to be fixed on other platforms as well.
|
|
- Changed the way the stack base and backing store base are found on IA64.
|
|
This should now remain reliable on future kernels. But since it relies
|
|
on /proc, it will no longer work in the simulated NUE environment.
|
|
- Made the call to random() in dbg_mlc.c with -DKEEP_BACK_PTRS dependent
|
|
on the OS. On non-Unix systems, rand() should be used instead. Handled
|
|
small RAND_MAX. (Thanks to Peter Ross for pointing this out.)
|
|
- Fixed the cord make rules to create the cord subdirectory, if necessary.
|
|
(Thanks to Doug Moen.)
|
|
- Changed fo_object_size calculation in finalize.c. Turned finalization
|
|
of nonheap object into a no-op. Removed anachronism from GC_size()
|
|
implementation.
|
|
- Changed GC_push_dirty call in solaris_threads.c to GC_push_selected.
|
|
It was missed in a previous renaming. (Thanks to Vladimir Tsichevski
|
|
for pointing this out.)
|
|
- Arranged to not not mask SIGABRT in linux_threads.c. (Thanks to Bryce
|
|
McKinlay.)
|
|
- Added GC_no_dls hook for applications that want to register their own
|
|
roots.
|
|
- Integrated Kjetil Matheussen's Amiga changes.
|
|
- Added FREEBSD_STACKBOTTOM. Changed the X86/FreeBSD port to use it.
|
|
(Thanks to Matthew Flatt.)
|
|
- Added pthread_detach interception for platforms supported by linux_threads.c
|
|
and irix_threads.c. Should also be added for Solaris?
|
|
- Changed the USE_MMAP code to check for the case in which we got the
|
|
high end of the address space, i.e. mem_ptr + mem_sz == 0. It appears
|
|
that this can happen under Solaris 7. It seems to be allowed by what
|
|
I would claim is an oversight in the mmap specification. (Thanks to Toshio
|
|
Endo for pointing out the problem.)
|
|
- Cleanup of linux_threads.c. Some code was originally cloned from
|
|
irix_threads.c and now unnecessary. Some comments were obviously wrong.
|
|
- (Mostly) fixed a longstanding problem with setting of dirty bits from
|
|
a signal handler. In the presence of threads, dirty bits could get lost,
|
|
since the etting of a bit in the bit vector was not atomic with respect
|
|
to other updates. The fix is 100% correct only for platforms for which
|
|
GC_test_and_set is defined. The goal is to make that all platforms with
|
|
thread support. Matters only if incremental GC and threads are both
|
|
enabled.
|
|
- made GC_all_interior_pointers (a.k.a. ALL_INTERIOR_POINTERS) an
|
|
initialization time, instead of build-time option. This is a
|
|
nontrivial, high risk change. It should slow down the code measurably
|
|
only if MERGE_SIZES is not defined, which is a very nonstandard
|
|
configuration.
|
|
- Added doc/README.environment, and implemented what it describes. This
|
|
allows a number of additional configuration options to be set through
|
|
the environment. It documents a few previously undocumented options.
|
|
- Integrated Eric Benson's leak testing improvements.
|
|
- Removed the option to throw away the beginning of each page (DISCARD_WORDS).
|
|
This became less and less useful as processors enforce stricter alignment.
|
|
And it hadn't been tested in ages, and was thus probably broken anyway.
|
|
|
|
Since 6.0alpha6:
|
|
- Added GC_finalizer_notifier. Fixed GC_finalize_on_demand. (The variable
|
|
actually wasn't being tested at the right points. The build-time flag
|
|
was.)
|
|
- Added Tom Tromey's S390 Linux patch.
|
|
- Added code to push GC_finalize_now in GC_push_finalizer_structures.
|
|
(Thanks to Matthew Flatt.)
|
|
- Added GC_push_gc_structures() to push all GC internal roots.
|
|
- Integrated some FreeBSD changes from Matthew Flatt.
|
|
- It looks like USRSTACK is not always correctly defined under Solaris.
|
|
Hacked gcconfig.h to attempt to work around the problem. The result
|
|
is not well tested. (Thanks again to Matthew Flatt for pointing this
|
|
out. The gross hack is mine. - HB)
|
|
- Added Ji-Yong Chung's win32 threads and C++ fixes.
|
|
- Arranged for hpux_test_and_clear.s to no longer be needed or built.
|
|
It was causing build problems with gas, and it's not clear this is
|
|
better than the pthreads alternative on this platform.
|
|
- Some MINGW32 fixes from Hubert Garavel.
|
|
- Added Initial Hitachi SH4 port from Kaz Kojima.
|
|
- Ported thread-local allocation and parallel mark code to HP/UX on PA_RISC.
|
|
- Made include/gc_mark.h more public and separated out the really private
|
|
pieces. This is probably still not quite sufficient for clients that
|
|
want to supply their own kind of type information. But it's a start.
|
|
This involved lots of identifier renaming to make it namespace clean.
|
|
- Added GC_dont_precollect for clients that need complete control over
|
|
the root set.
|
|
- GC_is_visible didn't do the right thing with gcj objects. (Not that
|
|
many people are likely to care, but ...)
|
|
- Don't redefine read with GC_USE_LD_WRAP.
|
|
- Initial port to LINUX/HP_PA. Incremental collection and threads are not
|
|
yet supported. (Incremental collection should work if you have the
|
|
right kernel. Threads may work with a sufficiently patched pthread
|
|
library.)
|
|
- Changed gcconfig.h to recognize __i386__ as an alternative to i386 in
|
|
many places. (Thanks to Benjamin Lerman.)
|
|
- Made win32_threads.c more tolerant of detaching a thread that it didn't
|
|
know about. (Thanks to Paul Nash.)
|
|
- Added Makefile.am and configure.in from gcc to the distribution, with
|
|
minimal changes. For the moment, those are just placeholders. In the
|
|
future, we're planning to switch to a GNU-style build environment for
|
|
Un*x-like systems, though the old Makefile will remain as a backup.
|
|
- Turned off STUBBORN_ALLOC by default, and added it back as a Makefile
|
|
option.
|
|
- Redistributed some functions between malloc.c and mallocx.c, so that
|
|
simple statically linked apps no longer pull in mallocx.o.
|
|
- Changed large object allocation to clear the first and last few words
|
|
of each block before releassing the lock. Otherwise the marker could see
|
|
objects with nonsensical type descriptors.
|
|
- Fixed a couple of subtle problems that could result in not recognizing
|
|
interior pointers from the stack. (I believe these were introduced
|
|
in 6.0alpha6.)
|
|
- GC_debug_free_inner called GC_free, which tried to reacquire the
|
|
allocator lock, and hence deadlocked. (DBG_HDRS_ALL probably never worked
|
|
with threads?)
|
|
- Fixed several problems with back traces. Accidental references to a free
|
|
list could cause the free list pointer to be overwritten by a back pointer.
|
|
There seemed to be some problems with the encoding of root and finalizer
|
|
references.
|
|
|
|
Since 6.0alpha7:
|
|
- Changed GC_debug_malloc_replacement and GC_debug_realloc_replacement
|
|
so that they compile under Irix. (Thanks to Dave Love.)
|
|
- Updated powerpc_macosx_mach_dep.s so that it works if the collector
|
|
is in a dynamic library. (Thanks to Andrew Begel.)
|
|
- Transformed README.debugging into debugging.html, updating and
|
|
expanding it in the process. Added gcdescr.html and tree.html
|
|
from the web site to the GC distribution.
|
|
- Fixed several problems related to PRINT_BLACK_LIST. This involved
|
|
restructuring some of the marker macros.
|
|
- Fixed some problems with the sizing of objects with debug information.
|
|
Finalization was broken KEEP_BACK_PTRS or PRINT_BLACK_LIST. Reduced the
|
|
object size with SHORT_DEBUG_HDRS by another word.
|
|
- The "Needed to allocate blacklisted ..." warning had inadvertently
|
|
been turned off by default, due to a buggy test in allchblk.c. Turned
|
|
it back on.
|
|
- Removed the marker macros to deal with 2 pointers in interleaved fashion.
|
|
They were messy and the performance improvement seemed minimal. We'll
|
|
leave such scheduling issues to the compiler.
|
|
- Changed Linux/PowerPC test to also check for __powerpc__ in response
|
|
to a discussion on the gcc mailing list.
|
|
- On Matthew Flatt's suggestion removed the "static" from the jmp_buf
|
|
declaration in GC_generic_push_regs. This was causing problems in
|
|
systems that register all of their own roots. It looks far more correct
|
|
to me without the "static" anyway.
|
|
- Fixed several problems with thread local allocation of pointerfree or
|
|
typed objects. The collector was reclaiming thread-local free lists, since
|
|
it wasn't following the link fields.
|
|
- There was apparently a long-standing race condition related to multithreaded
|
|
incremental collection. A collection could be started and a thread stopped
|
|
between the memory unprotect system call and the setting of the
|
|
corresponding dirt bit. I believe this did not affect Solaris or PCR, which
|
|
use a different dirty-bit implementation. Fixed this by installing
|
|
signal handlers with sigaction instead of signal, and disabling the thread
|
|
suspend signal while in the write-protect handler. (It is unclear
|
|
whether this scenario ever actually occurred. I found it while tracking
|
|
down the following:)
|
|
- Incremental collection did not cooperate correctly with the PARALLEL_MARK
|
|
implementation of GC_malloc_many or the local_malloc primitves. It still
|
|
doesn't work well, but it shouldn't lose memory anymore.
|
|
- Integrated some changes from the gcc source tree that I had previously
|
|
missed. (Thanks to Bryce McKinley for the reminder/diff.)
|
|
- Added Makefile.direct as a copy of the default Makefile, which would
|
|
normally be overwritten if configure is run.
|
|
- Changed the gc.tar target in Makefile.direct to embed the version number
|
|
in the gc directory name. This will affect future tar file distributions.
|
|
- Changed the Irix dynamic library finding code to no longer try to
|
|
eliminate writable text segments under Irix6.x, since that is probably no
|
|
longer necessary, and can apparently be unsafe on occasion. (Thanks to
|
|
Shiro Kawai for pointing this out.)
|
|
- GC_cleanup with GC_DEBUG enabled passed a real object base address to
|
|
GC_debug_register_finalizer_ignore_self, which expected a pointer past the
|
|
debug header. Call GC_register_finalizer_ignore_self instead, even with
|
|
debugging enabled. (Thanks to Jean-Daniel Fekete for catching this.)
|
|
- The collector didn't build with call chain saving enabled but NARGS=0.
|
|
(Thanks to Maarten Thibaut.)
|
|
- Fixed up the GNU-style build files enough so that they work in some
|
|
obvious cases.
|
|
- Added initial port to Digital Mars compiler for win32. (Thanks to Walter
|
|
Bright.)
|
|
|
|
Since 6.0alpha8:
|
|
- added README.macros.
|
|
- Made gc.mak a symbolic link to work around winzip's tendency to ignore
|
|
hard links.
|
|
- Simplified the setting of NEED_FIND_LIMIT in os_dep.c, possibly breaking
|
|
it on untested platforms.
|
|
- Integrated initial GNU HURD port. (Thanks to Chris Lingard and Igor
|
|
Khavkine.)
|
|
- A few more fixes for Digital Mars compiler (Walter Bright).
|
|
- Fixed gcc version recognition. Renamed OPERATOR_NEW_ARRAY to
|
|
GC_OPERATOR_NEW_ARRAY. Changed GC_OPERATOR_NEW_ARRAY to be the default.
|
|
It can be overridden with -DGC_NO_OPERATOR_NEW_ARRAY. (Thanks to
|
|
Cesar Eduardo Barros.)
|
|
- Changed the byte size to free-list mapping in thread local allocation
|
|
so that size 0 allocations are handled correctly.
|
|
- Fixed Linux/MIPS stackbottom for new toolchain. (Thanks to Ryan Murray.)
|
|
- Changed finalization registration to invoke GC_oom_fn when it runs out
|
|
of memory.
|
|
- Removed lvalue cast in finalize.c. This caused some debug configurations
|
|
not to build with some non-gcc compilers.
|
|
|
|
Since 6.0alpha9:
|
|
- Two more bug fixes for KEEP_BACK_PTRS and DBG_HDRS_ALL.
|
|
- Fixed a stack clearing problem that resulted in SIGILL with a
|
|
misaligned stack pointer for multithreaded SPARC builds.
|
|
- Integrated another HURD patch (thanks to Igor Khavkine).
|
|
|
|
Since 6.0:
|
|
- Non-debug, atomic allocations could result in bogus smashed object
|
|
reports with debugging on. (Thanks to Patrick Doyle for the small
|
|
test case.)
|
|
- Fixed GC_get_register_stack_base (Itanium only) to work around a glibc
|
|
2.2.4 bug.
|
|
- Initial port to HP/UX on Itanium. Thread support and both 32 and 64
|
|
bit ABIs appear to work. Parallel mark support doesn't yet, due to
|
|
some inline assembly code issues. Thread local allocation does appear
|
|
to work.
|
|
- ifdef'ed out glibc2.1/Itanium workaround. I suspect nobody is using
|
|
that combination anymore.
|
|
- Added a patch to make new_gc_alloc.h usable with gcc3.0. (Thanks to
|
|
Dimitris Vyzovitis for the patch.)
|
|
- Debugged 64-bit support on HP/UX PA-RISC.
|
|
- Turned on dynamic loading support for FreeBSD/ELF. (Thanks to Peter
|
|
Housel.)
|
|
- Unregistering of finalizers with debugging allocation was broken.
|
|
(Thanks to Jani Kajala for the test case.)
|
|
- Old finalizers were not returned correctly from GC_debug_register_finalizer.
|
|
- Disabled MPROTECT_VDB for Linux/M68K based on a report that it doesn't work.
|
|
- Cleaned up some statistics gathering code in reclaim.c (Thanks to Walter
|
|
Bright.)
|
|
- Added some support for OpenBSD/ELF/Linux. (Thanks to Suzuki Toshiya.)
|
|
- Added Jakub Jelinek's patch to use dl_iterate_phdr for dynamic library
|
|
traversal to dyn_load.c. Changed it to weakly reference dl_iterate_phdr,
|
|
so that the old code is stilll used with old versions of glibc.
|
|
- Cleaned up feature test macros for various threads packages and
|
|
integrated (partially functional) FreeBSD threads code from Loren Rittle.
|
|
It's likely that the cleanup broke something, since it touched lots of
|
|
code. It's also likelly that it fixed some unreported bugs in the
|
|
less common thread implementations, since some of the original code
|
|
didn't stand up to close scrutiny. Support for the next pthreads
|
|
implementation should be easier to add.
|
|
|
|
Since 6.1alpha1:
|
|
- No longer wrap read by default in multithreaded applications. It was
|
|
pointed out on the libgcj list that this holds the allocation lock for
|
|
way too long if the read blocks. For now, reads into the heap are
|
|
broken with incremental collection. It's possible to turn this back on
|
|
if you make sure that read calls don't block (e.g. by calling select
|
|
first).
|
|
- Fix ifdef in Solaris_threads.h to refer to GC_SOLARIS_THREADS.
|
|
- Added check for environment variable GC_IGNORE_GCJ_INFO.
|
|
- Added printing of stop-the-world GC times if GC_PRINT_STATS environment
|
|
variable is set.
|
|
- The calloc definition in leak_detector.h was missing parentheses, and
|
|
realloc was missing a second argument to GC_REALLOC.
|
|
(Thanks to Elrond (elrond<at>samba-tng.org).)
|
|
- Added GC_PRINT_BACK_HEIGHT environment variable and associated
|
|
code, mostly in the new file backgraph.c. See doc/README.environment.
|
|
- Added -DUSE_GLOBAL_ALLOC to work around a Windows NT issue. (Thanks to
|
|
Jonathan Clark.)
|
|
- Integrated port to NEC EWS4800 (MIPS-based workstation, with somewhat
|
|
different address-space layout). This may help for other machines with
|
|
holes in the data segment. (Thanks to Hironori Sakamoto.)
|
|
- Changed the order in which GC_push_roots and friends push things onto
|
|
the mark stack. GC_push_all calls need to come first, since we can't
|
|
necessarily recovere if those overflow the mark stack. (Thanks to
|
|
Matthew Flatt for tracking down the problem.)
|
|
- Some minor cleanups to mostly support the Intel compiler on Linux/IA64.
|
|
|
|
Since 6.1 alpha2:
|
|
- Minor cleanup on the gcconfig.h section for SPARC.
|
|
- Minor fix to support Intel compiler for I386/Linux. (Thanks to Sven
|
|
Hartrumpf.)
|
|
- Added SPARC V9 (64-bit) support. (Thanks to Jeff Sturm.)
|
|
- Restructured the way in which we determine whether or not to keep
|
|
call stacks for debug allocation. By default SAVE_CALL_COUNT is
|
|
now zero on all platforms. Added SAVE_CALL_NARGS parameters.
|
|
If possible, use execinfo.h to capture call stack. (This should
|
|
add support for a number of new platforms, though often at
|
|
considerable runtime expense.)
|
|
- Try to print symbolic information for call stacks. On Linux, we
|
|
do this with a combination of execinfo.h and running addr2line in
|
|
a separate process. This is both much more expensive and much more
|
|
useful. Amazingly, it seems to be fast enough for most purposes.
|
|
- Redefined strdup if -DREDIRECT_MALLOC is given.
|
|
- Changed incremental collector and MPROTECT_VDB implementation so that,
|
|
under favorable conditions, pointerfree objects are not protected.
|
|
Added GC_incremental_protection_needs() to determine ahead of time whether
|
|
pointerfree objects may be protected. Replaced GC_write_hint() with
|
|
GC_remove_protection().
|
|
- Added test for GC_ENABLE_INCREMENTAL environment variable.
|
|
- Made GC_time_limit runtime configurable. Added GC_PAUSE_TIME_TARGET
|
|
environment variable.
|
|
- Eliminated GC_page_sz, a duplicate of GC_page_size.
|
|
- Caused the Solaris and Irix thread creation primitives to call
|
|
GC_init_inner().
|
|
|
|
Since 6.1alpha3:
|
|
- Fixed typo in sparc_mach_dep.S, preventing the 64-bit version from
|
|
building. Increased 64-bit heap size limit in test.c slightly, since
|
|
a functional SPARC collector seems to slightly exceed the old limits.
|
|
(Thanks again to Jeff Sturm.)
|
|
- Use NPRGREG in solaris_threads.c, thus printing all registers if things
|
|
go wrong.
|
|
- Added GC_MARKERS environment variable to allow use of a single marker
|
|
thread on an MP without confusing the lock implementation.
|
|
- Collect much less aggressively in incremental mode with GC_TIME_UNLIMITED.
|
|
This is really a purely generational mode, and we can afford to
|
|
postpone the collection until the heap is (nearly) full.
|
|
- Remove read() wrapper for MPROTECT_VDB. It was causing more harm than
|
|
good. It is often no longer needed if system calls avoid writing to
|
|
pointerfull heap objects.
|
|
- Fix MACOSX test in gcconfig.h. (Thanks to John Clements.)
|
|
- Change GC_test_and_set so that it consistently has one argument.
|
|
Add spaces to ::: in powerpc assembly code in gc_locks.h.
|
|
(Thanks to Ryan Murray.)
|
|
- Fixed a formatting error in dbg_mlc.c. Added prototype to GC_abort()
|
|
declaration. (Thanks to Michael Smith.)
|
|
- Removed "source" argument to GC_find_start(). Eliminate GC_FIND_START().
|
|
- Added win32 recognition code in configure.in. Changed some of the
|
|
dllimport/export defines in gc.h. (Thanks to Adam Megacz.)
|
|
- GC_malloc_many didn't set hb_last_reclaimed when it called
|
|
GC_reclaim_generic. (I'm not sure this matters much, but ...)
|
|
- Allocating uncollectable objects with debug information sometimes
|
|
allocated objects that were one byte too small, since uncollectable
|
|
objects don't have the extra byte added at the end. (Thanks to
|
|
Wink Saville for pointing this out.)
|
|
- Added a bit more assertion checking to make sure that gcj objects
|
|
on free lists never have a nonzero second word.
|
|
- Replaced BCC_MAKEFILE with an up-to-date one. (Thanks to
|
|
Andre Leiradella.)
|
|
- Upgraded libtool, cinfigure.in and some related files to hopefully
|
|
support NetBSD/SPARC. (Thanks to Adrian Bunk.) Unfortunately,
|
|
libtool 1.4.2 seemed to be buggy due to missing quotes in several
|
|
"test" invocations. Fixed those in the ltmain.sh script.
|
|
- Some win32-specific patches, including the introduction of
|
|
GC_CreateThread. (Thanks to Adam Megacz.)
|
|
- Merged in gcj changes from Anthony Green to support embedded systems.
|
|
- Tried to consistently rename preprocessed assembly files with a capital
|
|
.S extension.
|
|
- Use alpha_mach_dep.S on ALPHA again. It doesn't really matter, but this
|
|
makes our distribution consistent with the gcc one, avoiding future merge
|
|
problems.
|
|
- Move GET_MEM definition into gcconfig.h. Include gcconfig.h slightly
|
|
later in gc_priv.h to avoid forward references to ptr_t.
|
|
- Add some testing of local allocation to test.c.
|
|
- Change definition of INVALID_QTID in specific.h. The -1 value was used
|
|
inconsistently, and too likely to collide with a valid stack address.
|
|
Some general clean-up of specific.[ch]. Added assertions. (Thanks
|
|
to Michael Smith for tracking down an intermittent bug to this
|
|
general area. I'm not sure it has been squashed yet, however.)
|
|
- On Pthread systems it was not safe to call GC_malloc() between fork()
|
|
and exec(). According to the applicable standards, it doesn't appear
|
|
to be safe to call malloc() or many other libc functions either, thus
|
|
it's not clear this is fixable. Added experimental support for
|
|
-DHANDLE_FORK in linux_threads.c which tries to support it. It may
|
|
succeed if libc does the right thing. I'm not sure whether it does.
|
|
(Thanks to Kenneth Schalk for pointing out this issue.)
|
|
- Documented thread local allocation primitives to require an
|
|
explicit GC_init call. GC_init_parallel is no longer declared to
|
|
be a constructor function, since that isn't portable and often
|
|
seems to lead to initialization order problems.
|
|
- Changed gc_cpp.cc and gc_cpp.h in one more attempt to make them
|
|
compatible with Visual C++ 6. (Thanks to Wink Saville for the
|
|
patch.)
|
|
- Some more patches for Linux on HP PA-RISC.
|
|
- Added include/gc_allocator.h. It implements (hopefully) standard
|
|
conforming (as opposed to SGI-style) allocators that allocate
|
|
collectable (gc_allocator) or GC-traceable, but not collectable
|
|
(traceable_allocator) objects. This borrows heavily from libstc++,
|
|
which borrows heavily from the SGI implementation, this part of
|
|
which was written by Matt Austern. Changed test_cpp.cc to very
|
|
minimally test this.
|
|
- On Linux/X86, retry mmap with a different start argument. That should
|
|
allow the collector to use more (closer to 3GB) of the address space.
|
|
(Thanks to Jeffrey Mark Siskind for tracking this down.)
|
|
- Force 64 bit alignment with GCJ support. (Reflects Bryce McKinley's
|
|
patch to the gcc tree.)
|
|
- Refined the choice of sa_handler vs. sa_sigaction in GC_dirty_init
|
|
to accomodate some glibc5 systems. (Thanks to Dan Fandrich for the
|
|
patch.)
|
|
- Compensated for the fact that current versions of glibc set
|
|
__libc_stack_end incorrectly on Linux/IA64 while initialization code
|
|
is running. This could cause the collector to miss 16 bytes of
|
|
the memory stack if GC_malloc or friends where called before main().
|
|
- Mostly integrated Takis Psarogiannakopoulos' port to DG/UX Inix 86.
|
|
This will probably take another iteration to work, since his
|
|
patch conflicted with the libtool upgrade.
|
|
- Added README.arm.cross containing some information about cross-
|
|
compiling to an ARM processor from Margaret Fleck.
|
|
|
|
Since 6.1alpha4:
|
|
- Added GC_finalizer_mem_freed, and changed some of the code that
|
|
decided on heap expansion to look at it. Memory explicitly
|
|
deallocated by finalizers essentially needs to be counted as reclaimed
|
|
by the GC. Otherwise there are cases in which the heap can grow
|
|
unboundedly. (Thanks to Mark Reichert for the test case.)
|
|
- Integrated Adam Megacz patches to not scan dynamic libraries if
|
|
we are compiling with gcc on win32. Otherwise we need structured
|
|
exception handling to deal with asynchronously unmapped root
|
|
segments, and gcc doesn't directly support that.
|
|
- Integrated Anthony Green's patch to support Wine.
|
|
- GC_OPERATOR_NEW_ARRAY was misspelled OPERATOR_NEW_ARRAY in several
|
|
places, including gc_cpp.cc. (Thanks to Wink Saville for pointing
|
|
this out.)
|
|
- Integrated Loren James Rittle's Alpha FreeBSD patches. In
|
|
response to Richard Henderson's suggestion, these also
|
|
changed the declarations of symbols like _end on many platforms to
|
|
that they wouldn't mistakenly be declared as short data symbols.
|
|
- Integrated changes from the Debian distribution. (Thanks to Ryan Murray
|
|
for pointing these out.) Fix C++ comments in POWERPC port. Add ARM32
|
|
incremental GC support. Get rid of USE_GENERIC_PUSH_REGS for alpha/Linux,
|
|
this time for real. Use va_copy to get rid of cord printf problems
|
|
(finally).
|
|
- Close file descriptor used to count cpus. Thanks to Jeff Sturm for
|
|
pointing out the omission.
|
|
- Don't just drop gcj free lists in GC_start_reclaim, since that can
|
|
eventually cause the marker to see a bogus mark descriptor in the
|
|
dropped objects. The usual symptom was a very intermittent segmentation
|
|
fault in the marker. This mattered only if one of the GC_gcj_malloc
|
|
variants was used. (Thanks to Michael Smith, Jeff Sturm, Bryce
|
|
McKinley and Tom Tromey for helping to track this down.)
|
|
- Fixed Linux and Solaris/64 SPARC configuration. (Thanks to David Miller,
|
|
Jeff Sturm, Tom Tromey, and Christian Joensson.)
|
|
- Fixed a typo in strdup definition. (Thanks to Gerard A Allan.)
|
|
- Changed Makefile.direct to invoke $(CC) to assemble alpha_mach_dep.S.
|
|
This is needed on Linux. I'm not sure whether it's better or worse
|
|
on Tru64.
|
|
- Changed gc_cpp.h once more to declare operator new and friends only in
|
|
a Microsoft environment. This may need further fine tuning. (Thanks to
|
|
Johannes Schmidt for pointing out that the older code breaks on gcc3.0.4.)
|
|
- Don't ever override strdup if it's already macro defined. (Thanks to
|
|
Adnan Ali for pointing out the problem.)
|
|
- Changed gc_cpp.h yet again to also overload placement new. Due to the
|
|
C++ overloading rules, the other overloaded new operations otherwise hide
|
|
placement new, which causes many STL uses to break. (Thanks to Reza
|
|
Shahidi for reporting this, and to Matt Austern for proposing a fix.)
|
|
- Integrated cygwin pthreads support from Dan Bonachea.
|
|
- Turn on DYNAMIC_LOADING for NetBSD. (Thanks to Krister Walfridsson.)
|
|
- Changed printing code to print more complete GC times.
|
|
- Applied Mark Mitchell's Irix patch to correct some bitrot.
|
|
- Clarified which object-printing routines in dbg_mlc.c should hold
|
|
the allocation lock. Restructured the code to allow reasonable object
|
|
printing with -DREDIRECT_MALLOC.
|
|
- Fix the Linux mmap code to always start with 0x1000 as the initial hint.
|
|
Minor patches for 64-bit AIX, particularly to STACKBOTTOM.
|
|
(Thanks again to Jeffrey Mark Siskind.)
|
|
- Renamed "SUSPENDED" flag for Solaris threads support to avoid a conflict
|
|
with a system header. (Thanks to Philp Brown.)
|
|
|
|
|
|
To do:
|
|
- --enable-redirect-malloc is mostly untested and known not to work
|
|
on some platforms.
|
|
- The win32 collector ends up tracing some (most?) objects allocated with
|
|
the system allocator, in spite if the fact that it tries not to.
|
|
This costs time and space, though it remains correct.
|
|
We need a way to identify memory regions used by the system malloc(),
|
|
or an alternate way to locate dll data areas. A very partial
|
|
workaround is to use GC_malloc_atomic_uncollectable() instead of
|
|
the system malloc() for most allocation.
|
|
- There seem to be outstanding issues on Solaris/X86, possibly with
|
|
finding the data segment starting address. Information/patches would
|
|
be appreciated.
|
|
- Very large root set sizes (> 16 MB or so) could cause the collector
|
|
to abort with an unexpected mark stack overflow. (Thanks again to
|
|
Peter Chubb.) NOT YET FIXED. Workaround is to increase the initial
|
|
size.
|
|
- The SGI version of the collector marks from mmapped pages, even
|
|
if they are not part of dynamic library static data areas. This
|
|
causes performance problems with some SGI libraries that use mmap
|
|
as a bitmap allocator. NOT YET FIXED. It may be possible to turn
|
|
off DYNAMIC_LOADING in the collector as a workaround. It may also
|
|
be possible to conditionally intercept mmap and use GC_exclude_static_roots.
|
|
The real fix is to walk rld data structures, which looks possible.
|
|
- Incremental collector should handle large objects better. Currently,
|
|
it looks like the whole object is treated as dirty if any part of it
|
|
is.
|
|
|