Annotation of OpenXM_contrib2/asir2000/gc/doc/README.changes, Revision 1.2
1.1 noro 1: This is a rough history of garbage collector bugs and versions.
2:
3: This has been maintained with varying diligence over the years.
4:
5: I made an attempt to include recent contributors here. I apologize for any
6: omissions.
7:
8: -------------------------
9:
10: Version 1.3 and immediately preceding versions contained spurious
11: assembly language assignments to TMP_SP. Only the assignment in the PC/RT
12: code is necessary. On other machines, with certain compiler options,
13: the assignments can lead to an unsaved register being overwritten.
14: Known to cause problems under SunOS 3.5 WITHOUT the -O option. (With
15: -O the compiler recognizes it as dead code. It probably shouldn't,
16: but that's another story.)
17:
18: Version 1.4 and earlier versions used compile time determined values
19: for the stack base. This no longer works on Sun 3s, since Sun 3/80s use
20: a different stack base. We now use a straightforward heuristic on all
21: machines on which it is known to work (incl. Sun 3s) and compile-time
22: determined values for the rest. There should really be library calls
23: to determine such values.
24:
25: Version 1.5 and earlier did not ensure 8 byte alignment for objects
26: allocated on a sparc based machine.
27:
28: Version 1.8 added ULTRIX support in gc_private.h.
29:
30: Version 1.9 fixed a major bug in gc_realloc.
31:
32: Version 2.0 introduced a consistent naming convention for collector
33: routines and added support for registering dynamic library data segments
34: in the standard mark_roots.c. Most of the data structures were revamped.
35: The treatment of interior pointers was completely changed. Finalization
36: was added. Support for locking was added. Object kinds were added.
37: We added a black listing facility to avoid allocating at addresses known
38: to occur as integers somewhere in the address space. Much of this
39: was accomplished by adapting ideas and code from the PCR collector.
40: The test program was changed and expanded.
41:
42: Version 2.1 was the first stable version since 1.9, and added support
43: for PPCR.
44:
45: Version 2.2 added debugging allocation, and fixed various bugs. Among them:
46: - GC_realloc could fail to extend the size of the object for certain large object sizes.
47: - A blatant subscript range error in GC_printf, which unfortunately
48: wasn't exercised on machines with sufficient stack alignment constraints.
49: - GC_register_displacement did the wrong thing if it was called after
50: any allocation had taken place.
51: - The leak finding code would eventually break after 2048 byte
52: byte objects leaked.
53: - interface.c didn't compile.
54: - The heap size remained much too small for large stacks.
55: - The stack clearing code behaved badly for large stacks, and perhaps
56: on HP/PA machines.
57:
58: Version 2.3 added ALL_INTERIOR_POINTERS and fixed the following bugs:
59: - Missing declaration of etext in the A/UX version.
60: - Some PCR root-finding problems.
61: - Blacklisting was not 100% effective, because the plausible future
62: heap bounds were being miscalculated.
63: - GC_realloc didn't handle out-of-memory correctly.
64: - GC_base could return a nonzero value for addresses inside free blocks.
65: - test.c wasn't really thread safe, and could erroneously report failure
66: in a multithreaded environment. (The locking primitives need to be
67: replaced for other threads packages.)
68: - GC_CONS was thoroughly broken.
69: - On a SPARC with dynamic linking, signals stayed diabled while the
70: client code was running.
71: (Thanks to Manuel Serrano at INRIA for reporting the last two.)
72:
73: Version 2.4 added GC_free_space_divisor as a tuning knob, added
74: support for OS/2 and linux, and fixed the following bugs:
75: - On machines with unaligned pointers (e.g. Sun 3), every 128th word could
76: fail to be considered for marking.
77: - Dynamic_load.c erroneously added 4 bytes to the length of the data and
78: bss sections of the dynamic library. This could result in a bad memory
79: reference if the actual length was a multiple of a page. (Observed on
80: Sun 3. Can probably also happen on a Sun 4.)
81: (Thanks to Robert Brazile for pointing out that the Sun 3 version
82: was broken. Dynamic library handling is still broken on Sun 3s
83: under 4.1.1U1, but apparently not 4.1.1. If you have such a machine,
84: use -Bstatic.)
85:
86: Version 2.5 fixed the following bugs:
87: - Removed an explicit call to exit(1)
88: - Fixed calls to GC_printf and GC_err_printf, so the correct number of
89: arguments are always supplied. The OS/2 C compiler gets confused if
90: the number of actuals and the number of formals differ. (ANSI C
91: doesn't require this to work. The ANSI sanctioned way of doing things
92: causes too many compatibility problems.)
93:
94: Version 3.0 added generational/incremental collection and stubborn
95: objects.
96:
97: Version 3.1 added the following features:
98: - A workaround for a SunOS 4.X SPARC C compiler
99: misfeature that caused problems when the collector was turned into
100: a dynamic library.
101: - A fix for a bug in GC_base that could result in a memory fault.
102: - A fix for a performance bug (and several other misfeatures) pointed
103: out by Dave Detlefs and Al Dosser.
104: - Use of dirty bit information for static data under Solaris 2.X.
105: - DEC Alpha/OSF1 support (thanks to Al Dosser).
106: - Incremental collection on more platforms.
107: - A more refined heap expansion policy. Less space usage by default.
108: - Various minor enhancements to reduce space usage, and to reduce
109: the amount of memory scanned by the collector.
110: - Uncollectable allocation without per object overhead.
111: - More conscientious handling of out-of-memory conditions.
112: - Fixed a bug in debugging stubborn allocation.
113: - Fixed a bug that resulted in occasional erroneous reporting of smashed
114: objects with debugging allocation.
115: - Fixed bogus leak reports of size 4096 blocks with FIND_LEAK.
116:
117: Version 3.2 fixed a serious and not entirely repeatable bug in
118: the incremental collector. It appeared only when dirty bit info
119: on the roots was available, which is normally only under Solaris.
120: It also added GC_general_register_disappearing_link, and some
121: testing code. Interface.c disappeared.
122:
123: Version 3.3 fixes several bugs and adds new ports:
124: - PCR-specific bugs.
125: - Missing locking in GC_free, redundant FASTUNLOCK
126: in GC_malloc_stubborn, and 2 bugs in
127: GC_unregister_disappearing_link.
128: All of the above were pointed out by Neil Sharman
129: (neil@cs.mu.oz.au).
130: - Common symbols allocated by the SunOS4.X dynamic loader
131: were not included in the root set.
132: - Bug in GC_finalize (reported by Brian Beuning and Al Dosser)
133: - Merged Amiga port from Jesper Peterson (untested)
134: - Merged NeXT port from Thomas Funke (significantly
135: modified and untested)
136:
137: Version 3.4:
138: - Fixed a performance bug in GC_realloc.
139: - Updated the amiga port.
140: - Added NetBSD and 386BSD ports.
141: - Added cord library.
142: - Added trivial performance enhancement for
143: ALL_INTERIOR_POINTERS. (Don't scan last word.)
144:
145: Version 3.5
146: - Minor collections now mark from roots only once, if that
147: doesn't cause an excessive pause.
148: - The stack clearing heuristic was refined to prevent anomalies
149: with very heavily recursive programs and sparse stacks.
150: - Fixed a bug that prevented mark stack growth in some cases.
151: GC_objects_are_marked should be set to TRUE after a call
152: to GC_push_roots and as part of GC_push_marked, since
153: both can now set mark bits. I think this is only a performance
154: bug, but I wouldn't bet on it. It's certainly very hard to argue
155: that the old version was correct.
156: - Fixed an incremental collection bug that prevented it from
157: working at all when HBLKSIZE != getpagesize()
158: - Changed dynamic_loading.c to include gc_priv.h before testing
159: DYNAMIC_LOADING. SunOS dynamic library scanning
160: must have been broken in 3.4.
161: - Object size rounding now adapts to program behavior.
162: - Added a workaround (provided by Manuel Serrano and
163: colleagues) to a long-standing SunOS 4.X (and 3.X?) ld bug
164: that I had incorrectly assumed to have been squished.
165: The collector was broken if the text segment size was within
166: 32 bytes of a multiple of 8K bytes, and if the beginning of
167: the data segment contained interesting roots. The workaround
168: assumes a demand-loadable executable. The original may have
169: have "worked" in some other cases.
170: - Added dynamic library support under IRIX5.
171: - Added support for EMX under OS/2 (thanks to Ari Huttunen).
172:
173: Version 3.6:
174: - fixed a bug in the mark stack growth code that was introduced
175: in 3.4.
176: - fixed Makefile to work around DEC AXP compiler tail recursion
177: bug.
178:
179: Version 3.7:
180: - Added a workaround for an HP/UX compiler bug.
181: - Fixed another stack clearing performance bug. Reworked
182: that code once more.
183:
184: Version 4.0:
185: - Added support for Solaris threads (which was possible
186: only by reimplementing some fraction of Solaris threads,
187: since Sun doesn't currently make the thread debugging
188: interface available).
189: - Added non-threads win32 and win32S support.
190: - (Grudgingly, with suitable muttering of obscenities) renamed
191: files so that the collector distribution could live on a FAT
192: file system. Files that are guaranteed to be useless on
193: a PC still have long names. Gc_inline.h and gc_private.h
194: still exist, but now just include gc_inl.h and gc_priv.h.
195: - Fixed a really obscure bug in finalization that could cause
196: undetected mark stack overflows. (I would be surprised if
197: any real code ever tickled this one.)
198: - Changed finalization code to dynamically resize the hash
199: tables it maintains. (This probably does not matter for well-
200: -written code. It no doubt does for C++ code that overuses
201: destructors.)
202: - Added typed allocation primitives. Rewrote the marker to
203: accommodate them with more reasonable efficiency. This
204: change should also speed up marking for GC_malloc allocated
205: objects a little. See gc_typed.h for new primitives.
206: - Improved debugging facilities slightly. Allocation time
207: stack traces are now kept by default on SPARC/SUNOS4.
208: (Thanks to Scott Schwartz.)
209: - Added better support for small heap applications.
210: - Significantly extended cord package. Fixed a bug in the
211: implementation of lazily read files. Printf and friends now
212: have cord variants. Cord traversals are a bit faster.
213: - Made ALL_INTERIOR_POINTERS recognition the default.
214: - Fixed de so that it can run in constant space, independent
215: of file size. Added simple string searching to cords and de.
216: - Added the Hull-Ellis C++ interface.
217: - Added dynamic library support for OSF/1.
218: (Thanks to Al Dosser and Tim Bingham at DEC.)
219: - Changed argument to GC_expand_hp to be expressed
220: in units of bytes instead of heap blocks. (Necessary
221: since the heap block size now varies depending on
222: configuration. The old version was never very clean.)
223: - Added GC_get_heap_size(). The previous "equivalent"
224: was broken.
225: - Restructured the Makefile a bit.
226:
227: Since version 4.0:
228: - Changed finalization implementation to guarantee that
229: finalization procedures are called outside of the allocation
230: lock, making direct use of the interface a little less dangerous.
231: MAY BREAK EXISTING CLIENTS that assume finalizers
232: are protected by a lock. Since there seem to be few multithreaded
233: clients that use finalization, this is hopefully not much of
234: a problem.
235: - Fixed a gross bug in CORD_prev.
236: - Fixed a bug in blacklst.c that could result in unbounded
237: heap growth during startup on machines that do not clear
238: memory obtained from the OS (e.g. win32S).
239: - Ported de editor to win32/win32S. (This is now the only
240: version with a mouse-sensitive UI.)
241: - Added GC_malloc_ignore_off_page to allocate large arrays
242: in the presence of ALL_INTERIOR_POINTERS.
243: - Changed GC_call_with_alloc_lock to not disable signals in
244: the single-threaded case.
245: - Reduced retry count in GC_collect_or_expand for garbage
246: collecting when out of memory.
247: - Made uncollectable allocations bypass black-listing, as they
248: should.
249: - Fixed a bug in typed_test in test.c that could cause (legitimate)
250: GC crashes.
251: - Fixed some potential synchronization problems in finalize.c
252: - Fixed a real locking problem in typd_mlc.c.
253: - Worked around an AIX 3.2 compiler feature that results in
254: out of bounds memory references.
255: - Partially worked around an IRIX5.2 beta problem (which may
256: or may not persist to the final release).
257: - Fixed a bug in the heap integrity checking code that could
258: result in explicitly deallocated objects being identified as
259: smashed. Fixed a bug in the dbg_mlc stack saving code
260: that caused old argument pointers to be considered live.
261: - Fixed a bug in CORD_ncmp (and hence CORD_str).
262: - Repaired the OS2 port, which had suffered from bit rot
263: in 4.0. Worked around what appears to be CSet/2 V1.0
264: optimizer bug.
265: - Fixed a Makefile bug for target "c++".
266:
267: Since version 4.1:
268: - Multiple bug fixes/workarounds in the Solaris threads version.
269: (It occasionally failed to locate some register contents for
270: marking. It also turns out that thr_suspend and friends are
271: unreliable in Solaris 2.3. Dirty bit reads appear
272: to be unreliable under some weird
273: circumstances. My stack marking code
274: contained a serious performance bug. The new code is
275: extremely defensive, and has not failed in several cpu
276: hours of testing. But no guarantees ...)
277: - Added MacOS support (thanks to Patrick Beard.)
278: - Fixed several syntactic bugs in gc_c++.h and friends. (These
279: didn't bother g++, but did bother most other compilers.)
280: Fixed gc_c++.h finalization interface. (It didn't.)
281: - 64 bit alignment for allocated objects was not guaranteed in a
282: few cases in which it should have been.
283: - Added GC_malloc_atomic_ignore_off_page.
284: - Added GC_collect_a_little.
285: - Added some prototypes to gc.h.
286: - Some other minor bug fixes (notably in Makefile).
287: - Fixed OS/2 / EMX port (thanks to Ari Huttunen).
288: - Fixed AmigaDOS port. (thanks to Michel Schinz).
289: - Fixed the DATASTART definition under Solaris. There
290: was a 1 in 16K chance of the collector missing the first
291: 64K of static data (and thus crashing).
292: - Fixed some blatant anachronisms in the README file.
293: - Fixed PCR-Makefile for upcoming PPCR release.
294:
295: Since version 4.2:
296: - Fixed SPARC alignment problem with GC_DEBUG.
297: - Fixed Solaris threads /proc workaround. The real
298: problem was an interaction with mprotect.
299: - Incorporated fix from Patrick Beard for gc_c++.h (now gc_cpp.h).
300: - Slightly improved allocator space utilization by
301: fixing the GC_size_map mechanism.
302: - Integrated some Sony News and MIPS RISCos 4.51
303: patches. (Thanks to Nobuyuki Hikichi of
304: Software Research Associates, Inc. Japan)
305: - Fixed HP_PA alignment problem. (Thanks to
306: xjam@cork.cs.berkeley.edu.)
307: - Added GC_same_obj and friends. Changed GC_base
308: to return 0 for pointers past the end of large objects.
309: Improved GC_base performance with ALL_INTERIOR_POINTERS
310: on machines with a slow integer mod operation.
311: Added GC_PTR_ADD, GC_PTR_STORE, etc. to prepare
312: for preprocessor.
313: - changed the default on most UNIX machines to be that
314: signals are not disabled during critical GC operations.
315: This is still ANSI-conforming, though somewhat dangerous
316: in the presence of signal handlers. But the performance
317: cost of the alternative is sometimes problematic.
318: Can be changed back with a minor Makefile edit.
319: - renamed IS_STRING in gc.h, to CORD_IS_STRING, thus
320: following my own naming convention. Added the function
321: CORD_to_const_char_star.
322: - Fixed a gross bug in GC_finalize. Symptom: occasional
323: address faults in that function. (Thanks to Anselm
324: Baird-Smith (Anselm.BairdSmith@inria.fr)
325: - Added port to ICL DRS6000 running DRS/NX. Restructured
326: things a bit to factor out common code, and remove obsolete
327: code. Collector should now run under SUNOS5 with either
328: mprotect or /proc dirty bits. (Thanks to Douglas Steel
329: (doug@wg.icl.co.uk)).
330: - More bug fixes and workarounds for Solaris 2.X. (These were
331: mostly related to putting the collector in a dynamic library,
332: which didn't really work before. Also SOLARIS_THREADS
333: didn't interact well with dl_open.) Thanks to btlewis@eng.sun.com.
334: - Fixed a serious performance bug on the DEC Alpha. The text
335: segment was getting registered as part of the root set.
336: (Amazingly, the result was still fast enough that the bug
337: was not conspicuous.) The fix works on OSF/1, version 1.3.
338: Hopefully it also works on other versions of OSF/1 ...
339: - Fixed a bug in GC_clear_roots.
340: - Fixed a bug in GC_generic_malloc_words_small that broke
341: gc_inl.h. (Reported by Antoine de Maricourt. I broke it
342: in trying to tweak the Mac port.)
343: - Fixed some problems with cord/de under Linux.
344: - Fixed some cord problems, notably with CORD_riter4.
345: - Added DG/UX port.
346: Thanks to Ben A. Mesander (ben@piglet.cr.usgs.gov)
347: - Added finalization registration routines with weaker ordering
348: constraints. (This is necessary for C++ finalization with
349: multiple inheritance, since the compiler often adds self-cycles.)
350: - Filled the holes in the SCO port. (Thanks to Michael Arnoldus
351: <chime@proinf.dk>.)
352: - John Ellis' additions to the C++ support: From John:
353:
354: * I completely rewrote the documentation in the interface gc_c++.h
355: (later renamed gc_cpp.h). I've tried to make it both clearer and more
356: precise.
357:
358: * The definition of accessibility now ignores pointers from an
359: finalizable object (an object with a clean-up function) to itself.
360: This allows objects with virtual base classes to be finalizable by the
361: collector. Compilers typically implement virtual base classes using
362: pointers from an object to itself, which under the old definition of
363: accessibility prevented objects with virtual base classes from ever
364: being collected or finalized.
365:
366: * gc_cleanup now includes gc as a virtual base. This was enabled by
367: the change in the definition of accessibility.
368:
369: * I added support for operator new[]. Since most (all?) compilers
370: don't yet support operator new[], it is conditionalized on
371: -DOPERATOR_NEW_ARRAY. The code is untested, but its trivial and looks
372: correct.
373:
374: * The test program test_gc_c++ (later renamed test_cpp.cc)
375: tries to test for the C++-specific functionality not tested by the
376: other programs.
377: - Added <unistd.h> include to misc.c. (Needed for ppcr.)
378: - Added PowerMac port. (Thanks to Patrick Beard again.)
379: - Fixed "srcdir"-related Makefile problems. Changed things so
380: that all externally visible include files always appear in the
381: include subdirectory of the source. Made gc.h directly
382: includable from C++ code. (These were at Per
383: Bothner's suggestion.)
384: - Changed Intel code to also mark from ebp (Kevin Warne's
385: suggestion).
386: - Renamed C++ related files so they could live in a FAT
387: file system. (Charles Fiterman's suggestion.)
388: - Changed Windows NT Makefile to include C++ support in
389: gc.lib. Added C++ test as Makefile target.
390:
391: Since version 4.3:
392: - ASM_CLEAR_CODE was erroneously defined for HP
393: PA machines, resulting in a compile error.
394: - Fixed OS/2 Makefile to create a library. (Thanks to
395: Mark Boulter (mboulter@vnet.ibm.com)).
396: - Gc_cleanup objects didn't work if they were created on
397: the stack. Fixed.
398: - One copy of Gc_cpp.h in the distribution was out of
399: synch, and failed to document some known compiler
400: problems with explicit destructor invocation. Partially
401: fixed. There are probably other compilers on which
402: gc_cleanup is miscompiled.
403: - Fixed Makefile to pass C compiler flags to C++ compiler.
404: - Added Mac fixes.
405: - Fixed os_dep.c to work around what appears to be
406: a new and different VirtualQuery bug under newer
407: versions of win32S.
408: - GC_non_gc_bytes was not correctly maintained by
409: GC_free. Fixed. Thanks to James Clark (jjc@jclark.com).
410: - Added GC_set_max_heap_size.
411: - Changed allocation code to ignore blacklisting if it is preventing
412: use of a very large block of memory. This has the advantage
413: that naive code allocating very large objects is much more
414: likely to work. The downside is you might no
415: longer find out that such code should really use
416: GC_malloc_ignore_off_page.
417: - Changed GC_printf under win32 to close and reopen the file
418: between calls. FAT file systems otherwise make the log file
419: useless for debugging.
420: - Added GC_try_to_collect and GC_get_bytes_since_gc. These
421: allow starting an abortable collection during idle times.
422: This facility does not require special OS support. (Thanks to
423: Michael Spertus of Geodesic Systems for suggesting this. It was
424: actually an easy addition. Kumar Srikantan previously added a similar
425: facility to a now ancient version of the collector. At the time
426: this was much harder, and the result was less convincing.)
427: - Added some support for the Borland development environment. (Thanks
428: to John Ellis and Michael Spertus.)
429: - Removed a misfeature from checksums.c that caused unexpected
430: heap growth. (Thanks to Scott Schwartz.)
431: - Changed finalize.c to call WARN if it encounters a finalization cycle.
432: WARN is defined in gc_priv.h to write a message, usually to stdout.
433: In many environments, this may be inappropriate.
434: - Renamed NO_PARAMS in gc.h to GC_NO_PARAMS, thus adhering to my own
435: naming convention.
436: - Added GC_set_warn_proc to intercept warnings.
437: - Fixed Amiga port. (Thanks to Michel Schinz (schinz@alphanet.ch).)
438: - Fixed a bug in mark.c that could result in an access to unmapped
439: memory from GC_mark_from_mark_stack on machines with unaligned
440: pointers.
441: - Fixed a win32 specific performance bug that could result in scanning of
442: objects allocated with the system malloc.
443: - Added REDIRECT_MALLOC.
444:
445: Since version 4.4:
446: - Fixed many minor and one major README bugs. (Thanks to Franklin Chen
447: (chen@adi.com) for pointing out many of them.)
448: - Fixed ALPHA/OSF/1 dynamic library support. (Thanks to Jonathan Bachrach
449: (jonathan@harlequin.com)).
450: - Added incremental GC support (MPROTECT_VDB) for Linux (with some
451: help from Bruno Haible).
452: - Altered SPARC recognition tests in gc.h and config.h (mostly as
453: suggested by Fergus Henderson).
454: - Added basic incremental GC support for win32, as implemented by
455: Windows NT and Windows 95. GC_enable_incremental is a noop
456: under win32s, which doesn't implement enough of the VM interface.
457: - Added -DLARGE_CONFIG.
458: - Fixed GC_..._ignore_off_page to also function without
459: -DALL_INTERIOR_POINTERS.
460: - (Hopefully) fixed RS/6000 port. (Only the test was broken.)
461: - Fixed a performance bug in the nonincremental collector running
462: on machines supporting incremental collection with MPROTECT_VDB
463: (e.g. SunOS 4, DEC AXP). This turned into a correctness bug under
464: win32s with win32 incremental collection. (Not all memory protection
465: was disabled.)
466: - Fixed some ppcr related bit rot.
467: - Caused dynamic libraries to be unregistered before reregistering.
468: The old way turned out to be a performance bug on some machines.
469: - GC_root_size was not properly maintained under MSWIN32.
470: - Added -DNO_DEBUGGING and GC_dump.
471: - Fixed a couple of bugs arising with SOLARIS_THREADS +
472: REDIRECT_MALLOC.
473: - Added NetBSD/M68K port. (Thanks to Peter Seebach
474: <seebs@taniemarie.solon.com>.)
475: - Fixed a serious realloc bug. For certain object sizes, the collector
476: wouldn't scan the expanded part of the object. (Thanks to Clay Spence
477: (cds@peanut.sarnoff.com) for noticing the problem, and helping me to
478: track it down.)
479:
480: Since version 4.5:
481: - Added Linux ELF support. (Thanks to Arrigo Triulzi <arrigo@ic.ac.uk>.)
482: - GC_base crashed if it was called before any other GC_ routines.
483: This could happen if a gc_cleanup object was allocated outside the heap
484: before any heap allocation.
485: - The heap expansion heuristic was not stable if all objects had finalization
486: enabled. Fixed finalize.c to count memory in finalization queue and
487: avoid explicit deallocation. Changed alloc.c to also consider this count.
488: (This is still not recommended. It's expensive if nothing else.) Thanks
489: to John Ellis for pointing this out.
490: - GC_malloc_uncollectable(0) was broken. Thanks to Phong Vo for pointing
491: this out.
492: - The collector didn't compile under Linux 1.3.X. (Thanks to Fred Gilham for
493: pointing this out.) The current workaround is ugly, but expected to be
494: temporary.
495: - Fixed a formatting problem for SPARC stack traces.
496: - Fixed some '=='s in os_dep.c that should have been assignments.
497: Fortunately these were in code that should never be executed anyway.
498: (Thanks to Fergus Henderson.)
499: - Fixed the heap block allocator to only drop blacklisted blocks in small
500: chunks. Made BL_LIMIT self adjusting. (Both of these were in response
501: to heap growth observed by Paul Graham.)
502: - Fixed the Metrowerks/68K Mac code to also mark from a6. (Thanks
503: to Patrick Beard.)
504: - Significantly updated README.debugging.
505: - Fixed some problems with longjmps out of signal handlers, especially under
506: Solaris. Added a workaround for the fact that siglongjmp doesn't appear to
507: do the right thing with -lthread under Solaris.
508: - Added MSDOS/djgpp port. (Thanks to Mitch Harris (maharri@uiuc.edu).)
509: - Added "make reserved_namespace" and "make user_namespace". The
510: first renames ALL "GC_xxx" identifiers as "_GC_xxx". The second is the
511: inverse transformation. Note that doing this is guaranteed to break all
512: clients written for the other names.
513: - descriptor field for kind NORMAL in GC_obj_kinds with ADD_BYTE_AT_END
514: defined should be -ALIGNMENT not WORDS_TO_BYTES(-1). This is
515: a serious bug on machines with pointer alignment of less than a word.
516: - GC_ignore_self_finalize_mark_proc didn't handle pointers to very near the
517: end of the object correctly. Caused failures of the C++ test on a DEC Alpha
518: with g++.
519: - gc_inl.h still had problems. Partially fixed. Added warnings at the
520: beginning to hopefully specify the remaining dangers.
521: - Added DATAEND definition to config.h.
522: - Fixed some of the .h file organization. Fixed "make floppy".
523:
524: Since version 4.6:
525: - Fixed some compilation problems with -DCHECKSUMS (thanks to Ian Searle)
526: - Updated some Mac specific files to synchronize with Patrick Beard.
527: - Fixed a serious bug for machines with non-word-aligned pointers.
528: (Thanks to Patrick Beard for pointing out the problem. The collector
529: should fail almost any conceivable test immediately on such machines.)
530:
531: Since version 4.7:
532: - Changed a "comment" in a MacOS specific part of mach-dep.c that caused
533: gcc to fail on other platforms.
534:
535: Since version 4.8
536: - More README.debugging fixes.
537: - Objects ready for finalization, but not finalized in the same GC
538: cycle, could be prematurely collected. This occasionally happened
539: in test_cpp.
540: - Too little memory was obtained from the system for very large
541: objects. That could cause a heap explosion if these objects were
542: not contiguous (e.g. under PCR), and too much of them was blacklisted.
543: - Due to an improper initialization, the collector was too hesitant to
544: allocate blacklisted objects immediately after system startup.
545: - Moved GC_arrays from the data into the bss segment by not explicitly
546: initializing it to zero. This significantly
547: reduces the size of executables, and probably avoids some disk accesses
548: on program startup. It's conceivable that it might break a port that I
549: didn't test.
550: - Fixed EMX_MAKEFILE to reflect the gc_c++.h to gc_cpp.h renaming which
551: occurred a while ago.
552:
553: Since 4.9:
554: - Fixed a typo around a call to GC_collect_or_expand in alloc.c. It broke
555: handling of out of memory. (Thanks to Patrick Beard for noticing.)
556:
557: Since 4.10:
558: - Rationalized (hopefully) GC_try_to_collect in an incremental collection
559: environment. It appeared to not handle a call while a collection was in
560: progress, and was otherwise too conservative.
561: - Merged GC_reclaim_or_delete_all into GC_reclaim_all to get rid of some
562: code.
563: - Added Patrick Beard's Mac fixes, with substantial completely untested
564: modifications.
565: - Fixed the MPROTECT_VDB code to deal with large pages and imprecise
566: fault addresses (as on an UltraSPARC running Solaris 2.5). Note that this
567: was not a problem in the default configuration, which uses PROC_VDB.
568: - The DEC Alpha assembly code needed to restore $gp between calls.
569: Thanks to Fergus Henderson for tracking this down and supplying a
570: patch.
571: - The write command for "de" was completely broken for large files.
572: I used the easiest portable fix, which involved changing the semantics
573: so that f.new is written instead of overwriting f. That's safer anyway.
574: - Added README.solaris2 with a discussion of the possible problems of
575: mixing the collector's sbrk allocation with malloc/realloc.
576: - Changed the data segment starting address for SGI machines. The
577: old code failed under IRIX6.
578: - Required double word alignment for MIPS.
579: - Various minor fixes to remove warnings.
580: - Attempted to fix some Solaris threads problems reported by Zhiying Chen.
581: In particular, the collector could try to fork a thread with the
582: world stopped as part of GC_thr_init. It also failed to deal with
583: the case in which the original thread terminated before the whole
584: process did.
585: - Added -DNO_EXECUTE_PERMISSION. This has a major performance impact
586: on the incremental collector under Irix, and perhaps under other
587: operating systems.
588: - Added some code to support allocating the heap with mmap. This may
589: be preferable under some circumstances.
590: - Integrated dynamic library support for HP.
591: (Thanks to Knut Tvedten <knuttv@ifi.uio.no>.)
592: - Integrated James Clark's win32 threads support, and made a number
593: of changes to it, many of which were suggested by Pontus Rydin.
594: This is still not 100% solid.
595: - Integrated Alistair Crooks' support for UTS4 running on an Amdahl
596: 370-class machine.
597: - Fixed a serious bug in explicitly typed allocation. Objects requiring
598: large descriptors where handled in a way that usually resulted in
599: a segmentation fault in the marker. (Thanks to Jeremy Fitzhardinge
600: for helping to track this down.)
601: - Added partial support for GNU win32 development. (Thanks to Fergus
602: Henderson.)
603: - Added optional support for Java-style finalization semantics. (Thanks
604: to Patrick Bridges.) This is recommended only for Java implementations.
605: - GC_malloc_uncollectable faulted instead of returning 0 when out of
606: memory. (Thanks to dan@math.uiuc.edu for noticing.)
607: - Calls to GC_base before the collector was initialized failed on a
608: DEC Alpha. (Thanks to Matthew Flatt.)
609: - Added base pointer checking to GC_REGISTER_FINALIZER in debugging
610: mode, at the suggestion of Jeremy Fitzhardinge.
611: - GC_debug_realloc failed for uncollectable objects. (Thanks to
612: Jeremy Fitzhardinge.)
613: - Explicitly typed allocation could crash if it ran out of memory.
614: (Thanks to Jeremy Fitzhardinge.)
615: - Added minimal support for a DEC Alpha running Linux.
616: - Fixed a problem with allocation of objects whose size overflowed
617: ptrdiff_t. (This now fails unconditionally, as it should.)
618: - Added the beginning of Irix pthread support.
619: - Integrated Xiaokun Zhu's fixes for djgpp 2.01.
620: - Added SGI-style STL allocator support (gc_alloc.h).
621: - Fixed a serious bug in README.solaris2. Multithreaded programs must include
622: gc.h with SOLARIS_THREADS defined.
623: - Changed GC_free so it actually deallocates uncollectable objects.
624: (Thanks to Peter Chubb for pointing out the problem.)
625: - Added Linux ELF support for dynamic libararies. (Thanks again to
626: Patrick Bridges.)
627: - Changed the Borland cc configuration so that the assembler is not
628: required.
629: - Fixed a bug in the C++ test that caused it to fail in 64-bit
630: environments.
631:
632: Since 4.11:
633: - Fixed ElfW definition in dyn_load.c. (Thanks to Fergus Henderson.)
634: This prevented the dynamic library support from compiling on some
635: older ELF Linux systems.
636: - Fixed UTS4 port (which I apparently mangled during the integration)
637: (Thanks to again to Alistair Crooks.)
638: - "Make C++" failed on Suns with SC4.0, due to a problem with "bool".
639: Fixed in gc_priv.h.
640: - Added more pieces for GNU win32. (Thanks to Timothy N. Newsham.)
641: The current state of things should suffice for at least some
642: applications.
643: - Changed the out of memory retry count handling as suggested by
644: Kenjiro Taura. (This matters only if GC_max_retries > 0, which
645: is no longer the default.)
646: - If a /proc read failed repeatedly, GC_written_pages was not updated
647: correctly. (Thanks to Peter Chubb for diagnosing this.)
648: - Under unlikely circumstances, the allocator could infinite loop in
649: an out of memory situation. (Thanks again to Kenjiro Taura for
650: identifying the problem and supplying a fix.)
651: - Fixed a syntactic error in the DJGPP code. (Thanks to Fergus
652: Henderson for finding this by inspection.) Also fixed a test program
653: problem with DJGPP (Thanks to Peter Monks.)
654: - Atomic uncollectable objects were not treated correctly by the
655: incremental collector. This resulted in weird log statistics and
656: occasional performance problems. (Thanks to Peter Chubb for pointing
657: this out.)
658: - Fixed some problems resulting from compilers that dont define
659: __STDC__. In this case void * and char * were used inconsistently
660: in some cases. (Void * should not have been used at all. If
661: you have an ANSI superset compiler that does not define __STDC__,
662: please compile with -D__STDC__=0. Thanks to Manuel Serrano and others
663: for pointing out the problem.)
664: - Fixed a compilation problem on Irix with -n32 and -DIRIX_THREADS.
665: Also fixed some other IRIX_THREADS problems which may or may not have
666: had observable symptoms.
667: - Fixed an HP PA compilation problem in dyn_load.c. (Thanks to
668: Philippe Queinnec.)
669: - SEGV fault handlers sometimes did not get reset correctly. (Thanks
670: to David Pickens.)
671: - Added a fix for SOLARIS_THREADS on Intel. (Thanks again to David
672: Pickens.) This probably needs more work to become functional.
673: - Fixed struct sigcontext_struct in os_dep.c for compilation under
674: Linux 2.1.X. (Thanks to Fergus Henderson.)
675: - Changed the DJGPP STACKBOTTOM and DATASTART values to those suggested
676: by Kristian Kristensen. These may still not be right, but it is
677: it is likely to work more often than what was there before. They may
678: even be exactly right.
679: - Added a #include <string.h> to test_cpp.cc. This appears to help
680: with HP/UX and gcc. (Thanks to assar@sics.se.)
681: - Version 4.11 failed to run in incremental mode on recent 64-bit Irix
682: kernels. This was a problem related to page unaligned heap segments.
683: Changed the code to page align heap sections on all platforms.
684: (I had mistakenly identified this as a kernel problem earlier.
685: It was not.)
686: - Version 4.11 did not make allocated storage executable, except on
687: one or two platforms, due to a bug in a #if test. (Thanks to Dave
688: Grove for pointing this out.)
689: - Added sparc_sunos4_mach_dep.s to support Sun's compilers under SunOS4.
690: - Added GC_exclude_static_roots.
691: - Fixed the object size mapping algorithm. This shouldn't matter,
692: but the old code was ugly.
693: - Heap checking code could die if one of the allocated objects was
694: larger than its base address. (Unsigned underflow problem. Thanks
695: to Clay Spence for isolating the problem.)
696: - Added RS6000 (AIX) dynamic library support and fixed STACK_BOTTOM.
697: (Thanks to Fred Stearns.)
698: - Added Fergus Henderson's patches for improved robustness with large
699: heaps and lots of blacklisting.
700: - Added Peter Chubb's changes to support Solaris Pthreads, to support
701: MMAP allocation in Solaris, to allow Solaris to find dynamic libraries
702: through /proc, to add malloc_typed_ignore_off_page, and a few other
703: minor features and bug fixes.
704: - The Solaris 2 port should not use sbrk. I received confirmation from
705: Sun that the use of sbrk and malloc in the same program is not
706: supported. The collector now defines USE_MMAP by default on Solaris.
707: - Replaced the djgpp makefile with Gary Leavens' version.
708: - Fixed MSWIN32 detection test.
709: - Added Fergus Henderson's patches to allow putting the collector into
710: a DLL under GNU win32.
711: - Added Ivan V. Demakov's port to Watcom C on X86.
712: - Added Ian Piumarta's Linux/PowerPC port.
713: - On Brian Burton's suggestion added PointerFreeGC to the placement
714: options in gc_cpp.h. This is of course unsafe, and may be controversial.
715: On the other hand, it seems to be needed often enough that it's worth
716: adding as a standard facility.
717:
718: Since 4.12:
719: - Fixed a crucial bug in the Watcom port. There was a redundant decl
720: of GC_push_one in gc_priv.h.
721: - Added FINALIZE_ON_DEMAND.
722: - Fixed some pre-ANSI cc problems in test.c.
723: - Removed getpagesize() use for Solaris. It seems to be missing in one
724: or two versions.
725: - Fixed bool handling for SPARCCompiler version 4.2.
726: - Fixed some files in include that had gotten unlinked from the main
727: copy.
728: - Some RS/6000 fixes (missing casts). Thanks to Toralf Foerster.
729: - Fixed several problems in GC_debug_realloc, affecting mostly the
730: FIND_LEAK case.
731: - GC_exclude_static_roots contained a buggy unsigned comparison to
732: terminate a loop. (Thanks to Wilson Ho.)
733: - CORD_str failed if the substring occurred at the last possible position.
734: (Only affects cord users.)
735: - Fixed Linux code to deal with RedHat 5.0 and integrated Peter Bigot's
736: os_dep.c code for dealing with various Linux versions.
737: - Added workaround for Irix pthreads sigaction bug and possible signal
738: misdirection problems.
739: Since alpha1:
740: - Changed RS6000 STACKBOTTOM.
741: - Integrated Patrick Beard's Mac changes.
742: - Alpha1 didn't compile on Irix m.n, m < 6.
743: - Replaced Makefile.dj with a new one from Gary Leavens.
744: - Added Andrew Stitcher's changes to support SCO OpenServer.
745: - Added PRINT_BLACK_LIST, to allow debugging of high densities of false
746: pointers.
747: - Added code to debug allocator to keep track of return address
748: in GC_malloc caller, thus giving a bit more context.
749: - Changed default behavior of large block allocator to more
750: aggressively avoid fragmentation. This is likely to slow down the
751: collector when it succeeds at reducing space cost.
752: - Integrated Fergus Henderson's CYGWIN32 changes. They are untested,
753: but needed for newer versions.
754: - USE_MMAP had some serious bugs. This caused the collector to fail
755: consistently on Solaris with -DSMALL_CONFIG.
756: - Added Linux threads support, thanks largely to Fergus Henderson.
757: Since alpha2:
758: - Fixed more Linux threads problems.
759: - Changed default GC_free_space_divisor to 3 with new large block allocation.
760: (Thanks to Matthew Flatt for some measurements that suggest the old
761: value sometimes favors space too much over time.)
762: - More CYGWIN32 fixes.
763: - Integrated Tyson-Dowd's Linux-M68K port.
764: - Minor HP PA and DEC UNIX fixes from Fergus Henderson.
765: - Integrated Christoffe Raffali's Linux-SPARC changes.
766: - Allowed for one more GC fixup iteration after a full GC in incremental
767: mode. Some quick measurements suggested that this significantly
768: reduces pause times even with smaller GC_RATE values.
769: - Moved some more GC data structures into GC_arrays. This decreases
770: pause times and GC overhead, but makes debugging slightly less convenient.
771: - Fixed namespace pollution problem ("excl_table").
772: - Made GC_incremental a constant for -DSMALL_CONFIG, hopefully shrinking
773: that slightly.
774: - Added some win32 threads fixes.
775: - Integrated Ivan Demakov and David Stes' Watcom fixes.
776: - Various other minor fixes contributed by many people.
777: - Renamed config.h to gcconfig.h, since config.h tends to be used for
778: many other things.
779: - Integrated Matthew Flatt's support for 68K MacOS "far globals".
780: - Fixed up some of the dynamic library Makefile targets for consistency
781: across platforms.
782: - Fixed a USE_MMAP typo that caused out-of-memory handling to fail
783: on Solaris.
784: - Added code to test.c to test thread creation a bit more.
785: - Integrated GC_win32_free_heap, as suggested by Ivan Demakov.
786: - Fixed Solaris 2.7 stack base finding problem. (This may actually
787: have been done in an earlier alpha release.)
788: Since alpha3:
789: - Fixed MSWIN32 recognition test, which interfered with cygwin.
790: - Removed unnecessary gc_watcom.asm from distribution. Removed
791: some obsolete README.win32 text.
792: - Added Alpha Linux incremental GC support. (Thanks to Philipp Tomsich
793: for code for retrieving the fault address in a signal handler.)
794: Changed Linux signal handler context argument to be a pointer.
795: - Took care of some new warnings generated by the 7.3 SGI compiler.
796: - Integrated Phillip Musumeci's FreeBSD/ELF fixes.
797: - -DIRIX_THREADS was broken with the -o32 ABI (typo in gc_priv.h>
798:
799: Since 4.13:
800: - Fixed GC_print_source_ptr to not use a prototype.
801: - generalized CYGWIN test.
802: - gc::new did the wrong thing with PointerFreeGC placement.
803: (Thanks to Rauli Ruohonen.)
804: - In the ALL_INTERIOR_POINTERS (default) case, some callee-save register
805: values could fail to be scanned if the register was saved and
806: reused in a GC frame. This showed up in verbose mode with gctest
807: compiled with an unreleased SGI compiler. I vaguely recall an old
808: bug report that may have been related. The bug was probably quite old.
809: (The problem was that the stack scanning could be deferred until
810: after the relevant frame was overwritten, and the new save location
811: might be outside the scanned area. Fixed by more eager stack scanning.)
812: - PRINT_BLACK_LIST had some problems. A few source addresses were garbage.
813: - Replaced Makefile.dj and added -I flags to cord make targets.
814: (Thanks to Gary Leavens.)
815: - GC_try_to_collect was broken with the nonincremental collector.
816: - gc_cleanup destructors could pass the wrong address to
817: GC_register_finalizer_ignore_self in the presence of multiple
818: inheritance. (Thanks to Darrell Schiebel.)
819: - Changed PowerPC Linux stack finding code.
820:
821: Since 4.14alpha1
822: - -DSMALL_CONFIG did not work reliably with large (> 4K) pages.
823: Recycling the mark stack during expansion could result in a size
824: zero heap segment, which confused things. (This was probably also an
825: issue with the normal config and huge pages.)
826: - Did more work to make sure that callee-save registers were scanned
827: completely, even with the setjmp-based code. Added USE_GENERIC_PUSH_REGS
828: macro to facilitate testing on machines I have access to.
829: - Added code to explicitly push register contents for win32 threads.
830: This seems to be necessary. (Thanks to Pierre de Rop.)
831:
832: Since 4.14alpha2
833: - changed STACKBOTTOM for DJGPP (Thanks to Salvador Eduardo Tropea).
834:
835: Since 4.14
836: - Reworked large block allocator. Now uses multiple doubly linked free
837: lists to approximate best fit.
838: - Changed heap expansion heuristic. Entirely free blocks are no longer
839: counted towards the heap size. This seems to have a major impact on
840: heap size stability; the old version could expand the heap way too
841: much in the presence of large block fragmentation.
842: - added -DGC_ASSERTIONS and some simple assertions inside the collector.
843: This is mainlyt for collector debugging.
844: - added -DUSE_MUNMAP to allow the heap to shrink. Suupported on only
845: a few UNIX-like platforms for now.
846: - added GC_dump_regions() for debugging of fragmentation issues.
847: - Changed PowerPC pointer alignment under Linux to 4. (This needs
848: checking by someone who has one. The suggestions came to me via a
849: rather circuitous path.)
850: - Changed the Linux/Alpha port to walk the data segment backwards until
851: it encounters a SIGSEGV. The old way to find the start of the data
852: segment broke with a recent release.
853: - cordxtra.c needed to call GC_REGISTER_FINALIZER instead of
854: GC_register_finalizer, so that it would continue to work with GC_DEBUG.
855: - allochblk sometimes cleared the wrong block for debugging purposes
856: when it dropped blacklisted blocks. This could result in spurious
857: error reports with GC_DEBUG.
858: - added MACOS X Server support. (Thanks to Andrew Stone.)
859: - Changed the Solaris threads code to ignore stack limits > 8 MB with
860: a warning. Empirically, it is not safe to access arbitrary pages
861: in such large stacks. And the dirty bit implementation does not
862: guarantee that none of them will be accessed.
863: - Integrated Martin Tauchmann's Amiga changes.
864: - Integrated James Dominy's OpenBSD/SPARC port.
865:
866: Since 5.0alpha1
867: - Fixed bugs introduced in alpha1 (OpenBSD & large block initialization).
868: - Added -DKEEP_BACK_PTRS and backptr.h interface. (The implementation
869: idea came from Al Demers.)
870:
871: Since 5.0alpha2
872: - Added some highly incomplete code to support a copied young generation.
873: Comments on nursery.h are appreciated.
874: - Changed -DFIND_LEAK, -DJAVA_FINALIZATION, and -DFINALIZE_ON_DEMAND,
875: so the same effect could be obtained with a runtime switch. This is
876: a step towards standardizing on a single dynamic GC library.
877: - Significantly changed the way leak detection is handled, as a consequence
878: of the above.
879:
880: Since 5.0 alpha3
881: - Added protection fault handling patch for Linux/M68K from Fergus
882: Henderson and Roman Hodek.
883: - Removed the tests for SGI_SOURCE in new_gc_alloc.h. This was causing that
884: interface to fail on nonSGI platforms.
885: - Changed the Linux stack finding code to use /proc, after changing it
886: to use HEURISTIC1. (Thanks to David Mossberger for pointing out the
887: /proc hook.)
888: - Added HP/UX incremental GC support and HP/UX 11 thread support.
889: Thread support is currently still flakey.
890: - Added basic Linux/IA64 support.
891: - Integrated Anthony Green's PicoJava support.
892: - Integrated Scott Ananian's StrongARM/NetBSD support.
893: - Fixed some fairly serious performance bugs in the incremental
894: collector. These have probably been there essentially forever.
895: (Mark bits were sometimes set before scanning dirty pages.
896: The reclaim phase unnecessarily dirtied full small object pages.)
897: - Changed the reclaim phase to ignore nearly full pages to avoid
898: touching them.
899: - Limited GC_black_list_spacing to roughly the heap growth increment.
900: - Changed full collection triggering heuristic to decrease full GC
901: frequency by default, but to explicitly trigger full GCs during
902: heap growth. This doesn't always improve things, but on average it's
903: probably a win.
904: - GC_debug_free(0, ...) failed. Thanks to Fergus Henderson for the
905: bug report and fix.
906:
907: Since 5.0 alpha4
908: - GC_malloc_explicitly_typed and friends sometimes failed to
909: initialize first word.
910: - Added allocation routines and support in the marker for mark descriptors
911: in a type structure referenced by the first word of an object. This was
912: introduced to support gcj, but hopefully in a way that makes it
913: generically useful.
914: - Added GC_requested_heapsize, and inhibited collections in nonincremental
915: mode if the actual used heap size is less than what was explicitly
916: requested.
917: - The Solaris pthreads version of GC_pthread_create didn't handle a NULL
918: attribute pointer. Solaris thread support used the wrong default thread
919: stack size. (Thanks to Melissa O'Neill for the patch.)
920: - Changed PUSH_CONTENTS macro to no longer modify first parameter.
921: This usually doesn't matter, but it was certainly an accident waiting
922: to happen ...
923: - Added GC_register_finalizer_no_order and friends to gc.h. They're
924: needed by Java implementations.
925: - Integrated a fix for a win32 deadlock resulting from clock() calling
926: malloc. (Thanks to Chris Dodd.)
927: - Integrated Hiroshi Kawashima's port to Linux/MIPS. This was designed
928: for a handheld platform, and may or may not be sufficient for other
929: machines.
930: - Fixed a va_arg problem with the %c specifier in cordprnt.c. It appears
931: that this was always broken, but recent versions of gcc are the first to
932: report the (statically detectable) bug.
933: - Added an attempt at a more general solution to dlopen races/deadlocks.
934: GC_dlopen now temporarily disables collection. Still not ideal, but ...
935: - Added -DUSE_I686_PREFETCH, -DUSE_3DNOW_PREFETCH, and support for IA64
936: prefetch instructions. May improve performance measurably, but I'm not
937: sure the code will run correctly on processors that don't support the
938: instruction. Won't build except with very recent gcc.
939: - Added caching for header lookups in the marker. This seems to result
940: in a barely measurable performance gain. Added support for interleaved
941: lookups of two pointers, but unconfigured that since the performance
942: gain is currently near zero, and it adds to code size.
943: - Changed Linux DATA_START definition to check both data_start and
944: __data_start, since nothing else seems to be portable.
945: - Added -DUSE_LD_WRAP to optionally take advantage of the GNU ld function
946: wrapping mechanism. Probably currently useful only on Linux.
947: - Moved some variables for the scratch allocator into GC_arrays, on
948: Martin Hirzel's suggestion.
949: - Fixed a win32 threads bug that caused the collector to not look for
950: interior pointers from one of the thread stacks without
951: ALL_INTERIOR_POINTERS. (Thanks to Jeff Sturm.)
952: - Added Mingw32 support. (Thanks again to Jeff Sturm for the patch.)
953: - Changed the alpha port to use the generic register scanning code instead
954: of alpha_mach_dep.s. Alpha_mach_dep.s doesn't look for pointers in fp
955: registers, but gcc sometimes spills pointers there. (Thanks to Manuel
956: Serrano for helping me debug this by email.) Changed the IA64 code to
957: do something similar for similar reasons.
958:
959: [5.0alpha5 doesn't really exist, but it may have escaped.]
960:
961: Since 5.0alpha6:
962: - -DREDIRECT_MALLOC was broken in alpha6. Fixed.
963: - Cleaned up gc_ccp.h slightly, thus also causing the HP C++ compiler to
964: accept it.
965: - Removed accidental reference to dbg_mlc.c, which caused dbg_mlc.o to be
966: linked into every executable.
967: - Added PREFETCH to bitmap marker. Changed it to use the header cache.
968: - GC_push_marked sometimes pushed one object too many, resulting in a
969: segmentation fault in GC_mark_from_mark_stack. This was probably an old
970: bug. It finally showed up in gctest on win32.
971: - Gc_priv.h erroneously #defined GC_incremental to be TRUE instead of FALSE
972: when SMALL_CONFIG was defined. This was no doubt a major performance bug for
973: the default win32 configuration.
974: - Removed -DSMALL_CONFIG from NT_MAKEFILE. It seemed like an anchronism now
975: that the average PC has 64MB or so.
976: - Integrated Bryce McKinley's patches for linux threads and dynamic loading
977: from the libgcj tree. Turned on dynamic loading support for Linux/PPC.
978: - Changed the stack finding code to use environ on HP/UX. (Thanks
979: to Gustavo Rodriguez-Rivera for the suggestion.) This should probably
980: be done on other platforms, too. Since I can't test those, that'll
981: wait until after 5.0.
982:
983: Since 5.0alpha7:
984: - Fixed threadlibs.c for linux threads. -DUSE_LD_WRAP was broken and
985: -ldl was omitted. Fixed Linux stack finding code to handle
986: -DUSE_LD_WRAP correctly.
987: - Added MSWIN32 exception handler around marker, so that the collector
988: can recover from root segments that are unmapped during the collection.
989: This caused occasional failures under Windows 98, and may also be
990: an issue under Windows NT/2000.
991:
992: Since 5.0
993: - Fixed a gc.h header bug which showed up under Irix. (Thanks to
994: Dan Sullivan.)
995: - Fixed a typo in GC_double_descr in typd_mlc.c.
996: This probably could result in objects described by array descriptors not
997: getting traced correctly. (Thanks to Ben Hutchings for pointing this out.)
998: - The block nearly full tests in reclaim.c were not correct for 64 bit
999: environments. This could result in unnecessary heap growth under unlikely
1000: conditions.
1001:
1002: Since 5.1
1003: - dyn_load.c declared GC_scratch_last_end_ptr as an extern even if it
1004: was defined as a macro. This prevented the collector from building on
1005: Irix.
1006: - We quietly assumed that indirect mark descriptors were never 0.
1007: Our own typed allocation interface violated that. This could result
1008: in segmentation faults in the marker with typed allocation.
1009: - Fixed a _DUSE_MUNMAP bug in the heap block allocation code.
1010: (Thanks to Ben Hutchings for the patch.)
1011: - Taught the collector about VC++ handling array operator new.
1012: (Thanks again to Ben Hutchings for the patch.)
1013: - The two copies of gc_hdrs.h had diverged. Made one a link to the other
1014: again.
1015:
1016: Since 5.2 (A few 5.2 patches are not in 6.0alpha1)
1017: - Fixed _end declaration for OSF1.
1018: - There were lots of spurious leak reports in leak detection mode, caused
1019: by the fact that some pages were not being swept, and hence unmarked
1020: objects weren't making it onto free lists. (This bug dated back to 5.0.)
1021: - Fixed a typo in the liblinuxgc.so Makefile rule.
1022: - Added the GetExitCodeThread to Win32 GC_stop_world to (mostly) work
1023: around a Windows 95 GetOpenFileName problem. (Thanks to Jacob Navia.)
1024:
1025: Since 5.3
1026: - Fixed a typo that prevented compilation with -DUSE_3DNOW_PREFETCH.
1027: (Thanks to Shawn Wagner for actually testing this.)
1028: - Fixed GC_is_thread_stack in solaris_threads.c. It forgot to return a value
1029: in the common case. I wonder why nobody noticed?
1030: - Fixed another silly syntax problem in GC_double_descr. (Thanks to
1031: Fergus Henderson for finding it.)
1032: - Fixed a GC_gcj_malloc bug: It tended to release the allocator lock twice.
1033:
1034: Since 5.4 (A few 5.3 patches are not in 6.0alpha2)
1035: - Added HP/PA prefetch support.
1036: - Added -DDBG_HDRS_ALL and -DSHORT_DBG_HDRS to reduce the cost and improve
1037: the reliability of generating pointer backtrace information, e.g. in
1038: the Bigloo environment.
1039: - Added parallel marking support (-DPARALLEL_MARK). This currently
1040: works only under IA32 and IA64 Linux, but it shouldn't be hard to adapt
1041: to other platforms. This is intended to be a lighter-weight (less
1042: new code, probably not as scalable) solution than the work by Toshio Endo
1043: et al, at the University of Tokyo. A number of their ideas were
1044: reused, though the code wasn't, and the underlying data structure
1045: is significantly different. In particular, we keep the global mark
1046: stack as a single shared data structure, but most of the work is done
1047: on smaller thread-local mark stacks.
1048: - Changed GC_malloc_many to be cheaper, and to require less mutual exclusion
1049: with -DPARALLEL_MARK.
1050: - Added full support for thread local allocation under Linux
1051: (-DTHREAD_LOCAL_ALLOC). This is a thin veneer on GC_malloc_many, and
1052: should be easily portable to other platforms, especially those that
1053: support pthreads.
1054: - CLEAR_DOUBLE was not always getting invoked when it should have been.
1055: - GC_gcj_malloc and friends used different out of memory handling than
1056: everything else, probably because I forgot about one when I implemented
1057: the other. They now both call GC_oom_fn(), not GC_oom_action().
1058: - Integrated Jakub Jelinek's fixes for Linux/SPARC.
1059: - Moved GC_objfreelist, GC_aobjfreelist, and GC_words_allocd out of
1060: GC_arrays, and separately registered the first two as excluded roots.
1061: This makes code compiled with gc_inl.h less dependent on the
1062: collector version. (It would be nice to remove the inclusion of
1063: gc_priv.h by gc_inl.h completely, but we're not there yet. The
1064: locking definitions in gc_priv.h are still referenced.)
1065: This change was later coniditoned on SEPARATE_GLOBALS, which
1066: is not defined by default, since it involves a performance hit.
1067: - Register GC_obj_kinds separately as an excluded root region. The
1068: attempt to register it with GC_arrays was usually failing. (This wasn't
1069: serious, but seemed to generate some confusion.)
1070: - Moved backptr.h to gc_backptr.h.
1071:
1072: Since 6.0alpha1
1073: - Added USE_MARK_BYTES to reduce the need for compare-and-swap on platforms
1074: for which that's expensive.
1075: - Fixed a locking bug ib GC_gcj_malloc and some locking assertion problems.
1076: - Added a missing volatile to OR_WORD and renamed the parameter to
1077: GC_compare_and_swap so it's not a C++ reserved word. (Thanks to
1078: Toshio Endo for pointing out both of those.)
1079: - Changed Linux dynamic library registration code to look at /proc/self/maps
1080: instead of the rld data structures when REDIRECT_MALLOC is defined.
1081: Otherwise some of the rld data data structures may be prematurely garbage
1082: collected. (Thanks to Eric Benson for helping to track this down.)
1083: - Fixed USE_LD_WRAP a bit more, so it should now work without threads.
1084: - Renamed XXX_THREADS macros to GC_XXX_THREADS for namespace correctness.
1085: Tomporarily added some backward compatibility definitions. Renamed
1086: USE_LD_WRAP to GC_USE_LD_WRAP.
1087: - Many MACOSX POWERPC changes, some additions to the gctest output, and
1088: a few minor generic bug fixes. (Thanks to Dietmar Planitzer.)
1089:
1090: Since 6.0 alpha2
1091: - Fixed the /proc/self/maps code to not seek, since that apparently is not
1092: reliable across all interesting kernels.
1093: - Fixed some compilation problems in the absence of PARALLEL_MARK
1094: (introduced in alpha2).
1095: - Fixed an algorithmic problem with PARALLEL_MARK. If work needs to
1096: be given back to the main mark "stack", the BOTTOM entries of the local
1097: stack should be given away, not the top ones. This has substantial
1098: performance impact, especially for > 2 processors, from what I can tell.
1099: - Extracted gc_lock.h from gc_priv.h. This should eventually make it a
1100: bit easier to avoid including gc_priv.h in clients.
1101: - Moved all include files to include/ and removed duplicate links to the
1102: same file. The old scheme was a bad idea because it was too easy to get the
1103: copies out of sync, and many systems don't support hard links.
1104: Unfortunately, it's likely that I broke some of the non-Unix Makefiles in
1105: the process, although I tried to update them appropriately.
1106: - Removed the partial support for a copied nursery. It's not clear that
1107: this would be a tremendous win, since we don't consistently lose to
1108: generational copying collectors. And it would significantly complicate
1109: many things. May be reintroduced if/when it really turns out to win.
1110: - Removed references to IRIX_JDK_THREADS, since I believe there never
1111: were and never will be any clients.
1112: - Added some code to linux_threads.c to possibly support HPUX threads
1113: using the Linux code. Unfortunately, it doesn't work yet, and is
1114: currently disabled.
1115: - Added support under Linux/X86 for saving the call chain, both in (debug)
1116: objects for client debugging, and in GC_arrays._last_stack for GC
1117: debugging. This was previously supported only under Solaris. It is
1118: not enabled by default under X86, since it requires that code be compiled
1119: to explicitly dave frame pointers on the call stack. (With gcc this
1120: currently happens by default, but is often turned off explicitly.)
1121: To turn it on, define SAVE_CALL_CHAIN.
1122:
1123: Since 6.0 alpha3
1124: - Moved up the detection of mostly full blocks to the initiatiation of the
1125: sweep phase. This eliminates some lock conention in the PARALLEL_MARK case,
1126: as multiple threads try to look at mostly full blocks concurrently.
1127: - Restored the code in GC_malloc_many that grabs a prefix of the global
1128: free list. This avoids the case in which every GC_malloc_many call
1129: tries and fails to allocate a new heap block, and the returns a single
1130: object from the global free list.
1131: - Some minor fixes in new_hblk.c. (Attempted to build free lists in order
1132: of increasing addresses instead of decreasing addresses for cache performance
1133: reasons. But this seems to be only a very minor gain with -DEAGER_SWEEP,
1134: and a loss in other cases. So the change was backed out.)
1135: - Fixed some of the documentation. (Thanks in large part to Fergus
1136: Henderson.)
1137: - Fixed the Linux USE_PROC_FOR_LIBRARIES code to deal with apps that perform
1138: large numbers of mmaps. (Thanks to Eric Benson.) Also fixed that code to
1139: deal with short reads.
1140: - Added GC_get_total_bytes().
1141: - Fixed leak detection mode to avoid spurious messages under linuxthreads.
1142: (This should also now be easy for the other supported threads packages.
1143: But the code is tricky enough that I'm hesitant to do it without being able
1144: to test. Everything allocated in the GC thread support itself should be
1145: explicitly deallocated.)
1146: - Made it possible (with luck) to redirect malloc to GC_local_malloc.
1147:
1148: Since 6.0 alpha4
1149: - Changed the definition of GC_pause in linux_threads.c to use a volatile
1150: asm. Some versions of gcc apparently optimize away writes to local volatile
1151: variables. This caused poor locking behaviour starting at about
1152: 4 processors.
1153: - Added GC_start_blocking(), GC_end_blocking() calls and wrapper for sleep
1154: to linux_threads.c.
1155: The first two calls could be used to generally avoid sending GC signals to
1156: blocked threads, avoiding both premature wakeups and unnecessary overhead.
1157: - Fixed a serious bug in thread-local allocation. At thread termination,
1158: GC_free could get called on small integers. Changed the code for thread
1159: termination to more efficiently return left-over free-lists.
1160: - Integrated Kjetil Matheussen's BeOS support.
1161: - Rearranged the directory structure to create the doc and tests
1162: subdirectories.
1163: - Sort of integrated Eric Benson's patch for OSF1. This provided basic
1164: OSF1 thread support by suitably extending hpux_irix_threads.c. Based
1165: on earlier email conversations with David Butenhof, I suspect that it
1166: will be more reliable in the long run to base this on linux_threads.c
1167: instead. Thus I attempted to patch up linux_threads.c based on Eric's code.
1168: The result is almost certainly broken, but hopefully close enough that
1169: someone with access to a machine can pick it up.
1170: - Integrated lots of minor changes from the NetBSD distribution. (These
1171: were supplied by David Brownlee. I'm not sure about the original
1172: authors.)
1173: - Hacked a bit more on the HP/UX thread-support in linux_threads.c. It
1174: now appears to work in the absence of incremental collection. Renamed
1175: hpux_irix_threads.c back to irix_threads.c, and removed the attempt to
1176: support HPUX there.
1177: - Changed gc.h to define _REENTRANT in cases in which it should already
1178: have been defined. It is still safer to also define it on the command
1179: line.
1180:
1181: Since 6.0alpha5:
1182: - Changed the definition of DATASTART on ALPHA and IA64, where data_start
1183: and __data_start are not defined by earlier versions of glibc. This might
1184: need to be fixed on other platforms as well.
1185: - Changed the way the stack base and backing store base are found on IA64.
1186: This should now remain reliable on future kernels. But since it relies
1187: on /proc, it will no longer work in the simulated NUE environment.
1188: - Made the call to random() in dbg_mlc.c with -DKEEP_BACK_PTRS dependent
1189: on the OS. On non-Unix systems, rand() should be used instead. Handled
1190: small RAND_MAX. (Thanks to Peter Ross for pointing this out.)
1191: - Fixed the cord make rules to create the cord subdirectory, if necessary.
1192: (Thanks to Doug Moen.)
1193: - Changed fo_object_size calculation in finalize.c. Turned finalization
1194: of nonheap object into a no-op. Removed anachronism from GC_size()
1195: implementation.
1196: - Changed GC_push_dirty call in solaris_threads.c to GC_push_selected.
1197: It was missed in a previous renaming. (Thanks to Vladimir Tsichevski
1198: for pointing this out.)
1199: - Arranged to not not mask SIGABRT in linux_threads.c. (Thanks to Bryce
1200: McKinlay.)
1201: - Added GC_no_dls hook for applications that want to register their own
1202: roots.
1203: - Integrated Kjetil Matheussen's Amiga changes.
1204: - Added FREEBSD_STACKBOTTOM. Changed the X86/FreeBSD port to use it.
1205: (Thanks to Matthew Flatt.)
1206: - Added pthread_detach interception for platforms supported by linux_threads.c
1207: and irix_threads.c. Should also be added for Solaris?
1208: - Changed the USE_MMAP code to check for the case in which we got the
1209: high end of the address space, i.e. mem_ptr + mem_sz == 0. It appears
1210: that this can happen under Solaris 7. It seems to be allowed by what
1211: I would claim is an oversight in the mmap specification. (Thanks to Toshio
1212: Endo for pointing out the problem.)
1213: - Cleanup of linux_threads.c. Some code was originally cloned from
1214: irix_threads.c and now unnecessary. Some comments were obviously wrong.
1215: - (Mostly) fixed a longstanding problem with setting of dirty bits from
1216: a signal handler. In the presence of threads, dirty bits could get lost,
1217: since the etting of a bit in the bit vector was not atomic with respect
1218: to other updates. The fix is 100% correct only for platforms for which
1219: GC_test_and_set is defined. The goal is to make that all platforms with
1220: thread support. Matters only if incremental GC and threads are both
1221: enabled.
1222: - made GC_all_interior_pointers (a.k.a. ALL_INTERIOR_POINTERS) an
1223: initialization time, instead of build-time option. This is a
1224: nontrivial, high risk change. It should slow down the code measurably
1225: only if MERGE_SIZES is not defined, which is a very nonstandard
1226: configuration.
1227: - Added doc/README.environment, and implemented what it describes. This
1228: allows a number of additional configuration options to be set through
1229: the environment. It documents a few previously undocumented options.
1230: - Integrated Eric Benson's leak testing improvements.
1231: - Removed the option to throw away the beginning of each page (DISCARD_WORDS).
1232: This became less and less useful as processors enforce stricter alignment.
1233: And it hadn't been tested in ages, and was thus probably broken anyway.
1234:
1235: Since 6.0alpha6:
1236: - Added GC_finalizer_notifier. Fixed GC_finalize_on_demand. (The variable
1237: actually wasn't being tested at the right points. The build-time flag
1238: was.)
1239: - Added Tom Tromey's S390 Linux patch.
1240: - Added code to push GC_finalize_now in GC_push_finalizer_structures.
1241: (Thanks to Matthew Flatt.)
1242: - Added GC_push_gc_structures() to push all GC internal roots.
1243: - Integrated some FreeBSD changes from Matthew Flatt.
1244: - It looks like USRSTACK is not always correctly defined under Solaris.
1245: Hacked gcconfig.h to attempt to work around the problem. The result
1246: is not well tested. (Thanks again to Matthew Flatt for pointing this
1247: out. The gross hack is mine. - HB)
1248: - Added Ji-Yong Chung's win32 threads and C++ fixes.
1249: - Arranged for hpux_test_and_clear.s to no longer be needed or built.
1250: It was causing build problems with gas, and it's not clear this is
1251: better than the pthreads alternative on this platform.
1252: - Some MINGW32 fixes from Hubert Garavel.
1253: - Added Initial Hitachi SH4 port from Kaz Kojima.
1254: - Ported thread-local allocation and parallel mark code to HP/UX on PA_RISC.
1255: - Made include/gc_mark.h more public and separated out the really private
1256: pieces. This is probably still not quite sufficient for clients that
1257: want to supply their own kind of type information. But it's a start.
1258: This involved lots of identifier renaming to make it namespace clean.
1259: - Added GC_dont_precollect for clients that need complete control over
1260: the root set.
1261: - GC_is_visible didn't do the right thing with gcj objects. (Not that
1262: many people are likely to care, but ...)
1263: - Don't redefine read with GC_USE_LD_WRAP.
1264: - Initial port to LINUX/HP_PA. Incremental collection and threads are not
1265: yet supported. (Incremental collection should work if you have the
1266: right kernel. Threads may work with a sufficiently patched pthread
1267: library.)
1268: - Changed gcconfig.h to recognize __i386__ as an alternative to i386 in
1269: many places. (Thanks to Benjamin Lerman.)
1270: - Made win32_threads.c more tolerant of detaching a thread that it didn't
1271: know about. (Thanks to Paul Nash.)
1272: - Added Makefile.am and configure.in from gcc to the distribution, with
1273: minimal changes. For the moment, those are just placeholders. In the
1274: future, we're planning to switch to a GNU-style build environment for
1275: Un*x-like systems, though the old Makefile will remain as a backup.
1276: - Turned off STUBBORN_ALLOC by default, and added it back as a Makefile
1277: option.
1278: - Redistributed some functions between malloc.c and mallocx.c, so that
1279: simple statically linked apps no longer pull in mallocx.o.
1280: - Changed large object allocation to clear the first and last few words
1281: of each block before releassing the lock. Otherwise the marker could see
1282: objects with nonsensical type descriptors.
1283: - Fixed a couple of subtle problems that could result in not recognizing
1284: interior pointers from the stack. (I believe these were introduced
1285: in 6.0alpha6.)
1286: - GC_debug_free_inner called GC_free, which tried to reacquire the
1287: allocator lock, and hence deadlocked. (DBG_HDRS_ALL probably never worked
1288: with threads?)
1289: - Fixed several problems with back traces. Accidental references to a free
1290: list could cause the free list pointer to be overwritten by a back pointer.
1291: There seemed to be some problems with the encoding of root and finalizer
1292: references.
1293:
1294: Since 6.0alpha7:
1295: - Changed GC_debug_malloc_replacement and GC_debug_realloc_replacement
1296: so that they compile under Irix. (Thanks to Dave Love.)
1297: - Updated powerpc_macosx_mach_dep.s so that it works if the collector
1298: is in a dynamic library. (Thanks to Andrew Begel.)
1299: - Transformed README.debugging into debugging.html, updating and
1300: expanding it in the process. Added gcdescr.html and tree.html
1301: from the web site to the GC distribution.
1302: - Fixed several problems related to PRINT_BLACK_LIST. This involved
1303: restructuring some of the marker macros.
1304: - Fixed some problems with the sizing of objects with debug information.
1305: Finalization was broken KEEP_BACK_PTRS or PRINT_BLACK_LIST. Reduced the
1306: object size with SHORT_DEBUG_HDRS by another word.
1307: - The "Needed to allocate blacklisted ..." warning had inadvertently
1308: been turned off by default, due to a buggy test in allchblk.c. Turned
1309: it back on.
1310: - Removed the marker macros to deal with 2 pointers in interleaved fashion.
1311: They were messy and the performance improvement seemed minimal. We'll
1312: leave such scheduling issues to the compiler.
1313: - Changed Linux/PowerPC test to also check for __powerpc__ in response
1314: to a discussion on the gcc mailing list.
1315: - On Matthew Flatt's suggestion removed the "static" from the jmp_buf
1316: declaration in GC_generic_push_regs. This was causing problems in
1317: systems that register all of their own roots. It looks far more correct
1318: to me without the "static" anyway.
1319: - Fixed several problems with thread local allocation of pointerfree or
1320: typed objects. The collector was reclaiming thread-local free lists, since
1321: it wasn't following the link fields.
1322: - There was apparently a long-standing race condition related to multithreaded
1323: incremental collection. A collection could be started and a thread stopped
1324: between the memory unprotect system call and the setting of the
1325: corresponding dirt bit. I believe this did not affect Solaris or PCR, which
1326: use a different dirty-bit implementation. Fixed this by installing
1327: signal handlers with sigaction instead of signal, and disabling the thread
1328: suspend signal while in the write-protect handler. (It is unclear
1329: whether this scenario ever actually occurred. I found it while tracking
1330: down the following:)
1331: - Incremental collection did not cooperate correctly with the PARALLEL_MARK
1332: implementation of GC_malloc_many or the local_malloc primitves. It still
1333: doesn't work well, but it shouldn't lose memory anymore.
1334: - Integrated some changes from the gcc source tree that I had previously
1335: missed. (Thanks to Bryce McKinley for the reminder/diff.)
1336: - Added Makefile.direct as a copy of the default Makefile, which would
1337: normally be overwritten if configure is run.
1338: - Changed the gc.tar target in Makefile.direct to embed the version number
1339: in the gc directory name. This will affect future tar file distributions.
1340: - Changed the Irix dynamic library finding code to no longer try to
1341: eliminate writable text segments under Irix6.x, since that is probably no
1342: longer necessary, and can apparently be unsafe on occasion. (Thanks to
1343: Shiro Kawai for pointing this out.)
1344: - GC_cleanup with GC_DEBUG enabled passed a real object base address to
1345: GC_debug_register_finalizer_ignore_self, which expected a pointer past the
1346: debug header. Call GC_register_finalizer_ignore_self instead, even with
1347: debugging enabled. (Thanks to Jean-Daniel Fekete for catching this.)
1348: - The collector didn't build with call chain saving enabled but NARGS=0.
1349: (Thanks to Maarten Thibaut.)
1350: - Fixed up the GNU-style build files enough so that they work in some
1351: obvious cases.
1352: - Added initial port to Digital Mars compiler for win32. (Thanks to Walter
1353: Bright.)
1354:
1355: Since 6.0alpha8:
1356: - added README.macros.
1357: - Made gc.mak a symbolic link to work around winzip's tendency to ignore
1358: hard links.
1359: - Simplified the setting of NEED_FIND_LIMIT in os_dep.c, possibly breaking
1360: it on untested platforms.
1361: - Integrated initial GNU HURD port. (Thanks to Chris Lingard and Igor
1362: Khavkine.)
1363: - A few more fixes for Digital Mars compiler (Walter Bright).
1364: - Fixed gcc version recognition. Renamed OPERATOR_NEW_ARRAY to
1365: GC_OPERATOR_NEW_ARRAY. Changed GC_OPERATOR_NEW_ARRAY to be the default.
1366: It can be overridden with -DGC_NO_OPERATOR_NEW_ARRAY. (Thanks to
1367: Cesar Eduardo Barros.)
1368: - Changed the byte size to free-list mapping in thread local allocation
1369: so that size 0 allocations are handled correctly.
1370: - Fixed Linux/MIPS stackbottom for new toolchain. (Thanks to Ryan Murray.)
1371: - Changed finalization registration to invoke GC_oom_fn when it runs out
1372: of memory.
1373: - Removed lvalue cast in finalize.c. This caused some debug configurations
1374: not to build with some non-gcc compilers.
1375:
1376: Since 6.0alpha9:
1377: - Two more bug fixes for KEEP_BACK_PTRS and DBG_HDRS_ALL.
1378: - Fixed a stack clearing problem that resulted in SIGILL with a
1379: misaligned stack pointer for multithreaded SPARC builds.
1380: - Integrated another HURD patch (thanks to Igor Khavkine).
1381:
1382: Since 6.0:
1383: - Non-debug, atomic allocations could result in bogus smashed object
1384: reports with debugging on. (Thanks to Patrick Doyle for the small
1385: test case.)
1386: - Fixed GC_get_register_stack_base (Itanium only) to work around a glibc
1387: 2.2.4 bug.
1388: - Initial port to HP/UX on Itanium. Thread support and both 32 and 64
1389: bit ABIs appear to work. Parallel mark support doesn't yet, due to
1390: some inline assembly code issues. Thread local allocation does appear
1391: to work.
1392: - ifdef'ed out glibc2.1/Itanium workaround. I suspect nobody is using
1393: that combination anymore.
1394: - Added a patch to make new_gc_alloc.h usable with gcc3.0. (Thanks to
1395: Dimitris Vyzovitis for the patch.)
1396: - Debugged 64-bit support on HP/UX PA-RISC.
1397: - Turned on dynamic loading support for FreeBSD/ELF. (Thanks to Peter
1398: Housel.)
1399: - Unregistering of finalizers with debugging allocation was broken.
1400: (Thanks to Jani Kajala for the test case.)
1401: - Old finalizers were not returned correctly from GC_debug_register_finalizer.
1402: - Disabled MPROTECT_VDB for Linux/M68K based on a report that it doesn't work.
1403: - Cleaned up some statistics gathering code in reclaim.c (Thanks to Walter
1404: Bright.)
1405: - Added some support for OpenBSD/ELF/Linux. (Thanks to Suzuki Toshiya.)
1406: - Added Jakub Jelinek's patch to use dl_iterate_phdr for dynamic library
1407: traversal to dyn_load.c. Changed it to weakly reference dl_iterate_phdr,
1408: so that the old code is stilll used with old versions of glibc.
1409: - Cleaned up feature test macros for various threads packages and
1410: integrated (partially functional) FreeBSD threads code from Loren Rittle.
1411: It's likely that the cleanup broke something, since it touched lots of
1412: code. It's also likelly that it fixed some unreported bugs in the
1413: less common thread implementations, since some of the original code
1414: didn't stand up to close scrutiny. Support for the next pthreads
1415: implementation should be easier to add.
1416:
1417: Since 6.1alpha1:
1418: - No longer wrap read by default in multithreaded applications. It was
1419: pointed out on the libgcj list that this holds the allocation lock for
1420: way too long if the read blocks. For now, reads into the heap are
1421: broken with incremental collection. It's possible to turn this back on
1422: if you make sure that read calls don't block (e.g. by calling select
1423: first).
1424: - Fix ifdef in Solaris_threads.h to refer to GC_SOLARIS_THREADS.
1425: - Added check for environment variable GC_IGNORE_GCJ_INFO.
1426: - Added printing of stop-the-world GC times if GC_PRINT_STATS environment
1427: variable is set.
1428: - The calloc definition in leak_detector.h was missing parentheses, and
1429: realloc was missing a second argument to GC_REALLOC.
1430: (Thanks to Elrond (elrond<at>samba-tng.org).)
1431: - Added GC_PRINT_BACK_HEIGHT environment variable and associated
1432: code, mostly in the new file backgraph.c. See doc/README.environment.
1433: - Added -DUSE_GLOBAL_ALLOC to work around a Windows NT issue. (Thanks to
1434: Jonathan Clark.)
1435: - Integrated port to NEC EWS4800 (MIPS-based workstation, with somewhat
1436: different address-space layout). This may help for other machines with
1437: holes in the data segment. (Thanks to Hironori Sakamoto.)
1438: - Changed the order in which GC_push_roots and friends push things onto
1439: the mark stack. GC_push_all calls need to come first, since we can't
1440: necessarily recovere if those overflow the mark stack. (Thanks to
1441: Matthew Flatt for tracking down the problem.)
1442: - Some minor cleanups to mostly support the Intel compiler on Linux/IA64.
1443:
1444: Since 6.1 alpha2:
1445: - Minor cleanup on the gcconfig.h section for SPARC.
1446: - Minor fix to support Intel compiler for I386/Linux. (Thanks to Sven
1447: Hartrumpf.)
1448: - Added SPARC V9 (64-bit) support. (Thanks to Jeff Sturm.)
1449: - Restructured the way in which we determine whether or not to keep
1450: call stacks for debug allocation. By default SAVE_CALL_COUNT is
1451: now zero on all platforms. Added SAVE_CALL_NARGS parameters.
1452: If possible, use execinfo.h to capture call stack. (This should
1453: add support for a number of new platforms, though often at
1454: considerable runtime expense.)
1455: - Try to print symbolic information for call stacks. On Linux, we
1456: do this with a combination of execinfo.h and running addr2line in
1457: a separate process. This is both much more expensive and much more
1458: useful. Amazingly, it seems to be fast enough for most purposes.
1459: - Redefined strdup if -DREDIRECT_MALLOC is given.
1460: - Changed incremental collector and MPROTECT_VDB implementation so that,
1461: under favorable conditions, pointerfree objects are not protected.
1462: Added GC_incremental_protection_needs() to determine ahead of time whether
1463: pointerfree objects may be protected. Replaced GC_write_hint() with
1464: GC_remove_protection().
1465: - Added test for GC_ENABLE_INCREMENTAL environment variable.
1466: - Made GC_time_limit runtime configurable. Added GC_PAUSE_TIME_TARGET
1467: environment variable.
1468: - Eliminated GC_page_sz, a duplicate of GC_page_size.
1469: - Caused the Solaris and Irix thread creation primitives to call
1470: GC_init_inner().
1471:
1472: Since 6.1alpha3:
1473: - Fixed typo in sparc_mach_dep.S, preventing the 64-bit version from
1474: building. Increased 64-bit heap size limit in test.c slightly, since
1475: a functional SPARC collector seems to slightly exceed the old limits.
1476: (Thanks again to Jeff Sturm.)
1477: - Use NPRGREG in solaris_threads.c, thus printing all registers if things
1478: go wrong.
1479: - Added GC_MARKERS environment variable to allow use of a single marker
1480: thread on an MP without confusing the lock implementation.
1481: - Collect much less aggressively in incremental mode with GC_TIME_UNLIMITED.
1482: This is really a purely generational mode, and we can afford to
1483: postpone the collection until the heap is (nearly) full.
1484: - Remove read() wrapper for MPROTECT_VDB. It was causing more harm than
1485: good. It is often no longer needed if system calls avoid writing to
1486: pointerfull heap objects.
1487: - Fix MACOSX test in gcconfig.h. (Thanks to John Clements.)
1488: - Change GC_test_and_set so that it consistently has one argument.
1489: Add spaces to ::: in powerpc assembly code in gc_locks.h.
1490: (Thanks to Ryan Murray.)
1491: - Fixed a formatting error in dbg_mlc.c. Added prototype to GC_abort()
1492: declaration. (Thanks to Michael Smith.)
1493: - Removed "source" argument to GC_find_start(). Eliminate GC_FIND_START().
1494: - Added win32 recognition code in configure.in. Changed some of the
1495: dllimport/export defines in gc.h. (Thanks to Adam Megacz.)
1496: - GC_malloc_many didn't set hb_last_reclaimed when it called
1497: GC_reclaim_generic. (I'm not sure this matters much, but ...)
1498: - Allocating uncollectable objects with debug information sometimes
1499: allocated objects that were one byte too small, since uncollectable
1500: objects don't have the extra byte added at the end. (Thanks to
1501: Wink Saville for pointing this out.)
1502: - Added a bit more assertion checking to make sure that gcj objects
1503: on free lists never have a nonzero second word.
1504: - Replaced BCC_MAKEFILE with an up-to-date one. (Thanks to
1505: Andre Leiradella.)
1506: - Upgraded libtool, cinfigure.in and some related files to hopefully
1507: support NetBSD/SPARC. (Thanks to Adrian Bunk.) Unfortunately,
1508: libtool 1.4.2 seemed to be buggy due to missing quotes in several
1509: "test" invocations. Fixed those in the ltmain.sh script.
1510: - Some win32-specific patches, including the introduction of
1511: GC_CreateThread. (Thanks to Adam Megacz.)
1512: - Merged in gcj changes from Anthony Green to support embedded systems.
1513: - Tried to consistently rename preprocessed assembly files with a capital
1514: .S extension.
1515: - Use alpha_mach_dep.S on ALPHA again. It doesn't really matter, but this
1516: makes our distribution consistent with the gcc one, avoiding future merge
1517: problems.
1518: - Move GET_MEM definition into gcconfig.h. Include gcconfig.h slightly
1519: later in gc_priv.h to avoid forward references to ptr_t.
1520: - Add some testing of local allocation to test.c.
1521: - Change definition of INVALID_QTID in specific.h. The -1 value was used
1522: inconsistently, and too likely to collide with a valid stack address.
1523: Some general clean-up of specific.[ch]. Added assertions. (Thanks
1524: to Michael Smith for tracking down an intermittent bug to this
1525: general area. I'm not sure it has been squashed yet, however.)
1526: - On Pthread systems it was not safe to call GC_malloc() between fork()
1527: and exec(). According to the applicable standards, it doesn't appear
1528: to be safe to call malloc() or many other libc functions either, thus
1529: it's not clear this is fixable. Added experimental support for
1530: -DHANDLE_FORK in linux_threads.c which tries to support it. It may
1531: succeed if libc does the right thing. I'm not sure whether it does.
1532: (Thanks to Kenneth Schalk for pointing out this issue.)
1533: - Documented thread local allocation primitives to require an
1534: explicit GC_init call. GC_init_parallel is no longer declared to
1535: be a constructor function, since that isn't portable and often
1536: seems to lead to initialization order problems.
1537: - Changed gc_cpp.cc and gc_cpp.h in one more attempt to make them
1538: compatible with Visual C++ 6. (Thanks to Wink Saville for the
1539: patch.)
1540: - Some more patches for Linux on HP PA-RISC.
1541: - Added include/gc_allocator.h. It implements (hopefully) standard
1542: conforming (as opposed to SGI-style) allocators that allocate
1543: collectable (gc_allocator) or GC-traceable, but not collectable
1544: (traceable_allocator) objects. This borrows heavily from libstc++,
1545: which borrows heavily from the SGI implementation, this part of
1546: which was written by Matt Austern. Changed test_cpp.cc to very
1547: minimally test this.
1548: - On Linux/X86, retry mmap with a different start argument. That should
1549: allow the collector to use more (closer to 3GB) of the address space.
1550: (Thanks to Jeffrey Mark Siskind for tracking this down.)
1551: - Force 64 bit alignment with GCJ support. (Reflects Bryce McKinley's
1552: patch to the gcc tree.)
1553: - Refined the choice of sa_handler vs. sa_sigaction in GC_dirty_init
1554: to accomodate some glibc5 systems. (Thanks to Dan Fandrich for the
1555: patch.)
1556: - Compensated for the fact that current versions of glibc set
1557: __libc_stack_end incorrectly on Linux/IA64 while initialization code
1558: is running. This could cause the collector to miss 16 bytes of
1559: the memory stack if GC_malloc or friends where called before main().
1560: - Mostly integrated Takis Psarogiannakopoulos' port to DG/UX Inix 86.
1561: This will probably take another iteration to work, since his
1562: patch conflicted with the libtool upgrade.
1563: - Added README.arm.cross containing some information about cross-
1564: compiling to an ARM processor from Margaret Fleck.
1565:
1566: Since 6.1alpha4:
1567: - Added GC_finalizer_mem_freed, and changed some of the code that
1568: decided on heap expansion to look at it. Memory explicitly
1569: deallocated by finalizers essentially needs to be counted as reclaimed
1570: by the GC. Otherwise there are cases in which the heap can grow
1571: unboundedly. (Thanks to Mark Reichert for the test case.)
1572: - Integrated Adam Megacz patches to not scan dynamic libraries if
1573: we are compiling with gcc on win32. Otherwise we need structured
1574: exception handling to deal with asynchronously unmapped root
1575: segments, and gcc doesn't directly support that.
1576: - Integrated Anthony Green's patch to support Wine.
1577: - GC_OPERATOR_NEW_ARRAY was misspelled OPERATOR_NEW_ARRAY in several
1578: places, including gc_cpp.cc. (Thanks to Wink Saville for pointing
1579: this out.)
1580: - Integrated Loren James Rittle's Alpha FreeBSD patches. In
1581: response to Richard Henderson's suggestion, these also
1582: changed the declarations of symbols like _end on many platforms to
1583: that they wouldn't mistakenly be declared as short data symbols.
1584: - Integrated changes from the Debian distribution. (Thanks to Ryan Murray
1585: for pointing these out.) Fix C++ comments in POWERPC port. Add ARM32
1586: incremental GC support. Get rid of USE_GENERIC_PUSH_REGS for alpha/Linux,
1587: this time for real. Use va_copy to get rid of cord printf problems
1588: (finally).
1589: - Close file descriptor used to count cpus. Thanks to Jeff Sturm for
1590: pointing out the omission.
1591: - Don't just drop gcj free lists in GC_start_reclaim, since that can
1592: eventually cause the marker to see a bogus mark descriptor in the
1593: dropped objects. The usual symptom was a very intermittent segmentation
1594: fault in the marker. This mattered only if one of the GC_gcj_malloc
1595: variants was used. (Thanks to Michael Smith, Jeff Sturm, Bryce
1596: McKinley and Tom Tromey for helping to track this down.)
1597: - Fixed Linux and Solaris/64 SPARC configuration. (Thanks to David Miller,
1598: Jeff Sturm, Tom Tromey, and Christian Joensson.)
1599: - Fixed a typo in strdup definition. (Thanks to Gerard A Allan.)
1600: - Changed Makefile.direct to invoke $(CC) to assemble alpha_mach_dep.S.
1601: This is needed on Linux. I'm not sure whether it's better or worse
1602: on Tru64.
1603: - Changed gc_cpp.h once more to declare operator new and friends only in
1604: a Microsoft environment. This may need further fine tuning. (Thanks to
1605: Johannes Schmidt for pointing out that the older code breaks on gcc3.0.4.)
1606: - Don't ever override strdup if it's already macro defined. (Thanks to
1607: Adnan Ali for pointing out the problem.)
1608: - Changed gc_cpp.h yet again to also overload placement new. Due to the
1609: C++ overloading rules, the other overloaded new operations otherwise hide
1610: placement new, which causes many STL uses to break. (Thanks to Reza
1611: Shahidi for reporting this, and to Matt Austern for proposing a fix.)
1612: - Integrated cygwin pthreads support from Dan Bonachea.
1613: - Turn on DYNAMIC_LOADING for NetBSD. (Thanks to Krister Walfridsson.)
1614: - Changed printing code to print more complete GC times.
1615: - Applied Mark Mitchell's Irix patch to correct some bitrot.
1616: - Clarified which object-printing routines in dbg_mlc.c should hold
1617: the allocation lock. Restructured the code to allow reasonable object
1618: printing with -DREDIRECT_MALLOC.
1619: - Fix the Linux mmap code to always start with 0x1000 as the initial hint.
1620: Minor patches for 64-bit AIX, particularly to STACKBOTTOM.
1621: (Thanks again to Jeffrey Mark Siskind.)
1622: - Renamed "SUSPENDED" flag for Solaris threads support to avoid a conflict
1623: with a system header. (Thanks to Philp Brown.)
1.2 ! noro 1624: - Cause win32_threads.c to handle an out of range stack pointer correctly,
! 1625: though currently with a warning. (Thanks to Jonathan Clark for
! 1626: observing that win32 applications may temporarily use the stack
! 1627: pointer for other purposes, and suggesting a fix. Unfortunately, it's
! 1628: not clear that there is a complete solution to this problem.)
! 1629:
! 1630: Since 6.1alpha5:
! 1631: - Added GC_MAXIMUM_HEAP_SIZE environment variable.
! 1632: - Fix configure.in for MIPS/LINUX. (Thanks to H.J. Lu.)
! 1633: - Double page hash table size for -DLARGE_CONFIG.
! 1634: - Integrated Bo Thorsen's X86-64 support.
! 1635: - STACKBOTTOM definition for LINUX/MIPS was partially changed back.
! 1636: (Thanks to H.J. Lu and Hiroshi Kawashima for resolving this.)
! 1637: - Replaced all occurrences of LINUX_DATA_START in gcconfig.h with
! 1638: SEARCH_FOR_DATA_START. It doesn't hurt to falll back to a search.
! 1639: And __data_start doesn't seem to get defined correctly of the GC
! 1640: library is loaded with LD_PRELOAD, e.g. for leak detection.
! 1641: - If the GC_find_leak environment variable is set, do a
! 1642: atexit(GC_gcollect) to give us at least one chance to detect leaks.
! 1643: This may report some very benign leaks, but ...
! 1644: - Addeded REDIRECT_FREE. It's necessary if we want leak detection with
! 1645: LD_PRELOAD.
! 1646: - Defer printing of leaked objects, as for smashed objects.
! 1647: - Fixed process and descriptor leak in GC_print_callers. Try for
! 1648: line number even if we got function name.)
! 1649: - Ported parallel GC support and thread local allocation to Alpha.
! 1650: Not yet well-tested.
! 1651: - Added GC_DUMP_REGULARLY and added finalization statistics to GC_dump().
! 1652: - Fixed Makefile.am to mention alpha_mach_dep.S instead of the defunct
! 1653: alpha_mach_dep.s. (Thanks to Fergus Henderson.)
! 1654: - Incorporated a change to new_gc_alloc.h, suggested by Johannes Schmidt,
! 1655: which should make it work with gcc3.1. (I would still like to encourage
! 1656: use of gc_allocator.h instead.)
! 1657: - Use alpha_mach_dep.S only on Linux. (It's not clear that this is
! 1658: optimal, but it otherwise didn't build on Tru64. Thanks to Fergus
! 1659: Henderson.)
! 1660: - Added ifdef to guard free() in os_dep.c. Otherwise we get a
! 1661: compilation error on Irix. (Thanks to Dai Sato.)
! 1662: - Added an experimental version of GC_memalign to mallocx.c. This can't
! 1663: always work, since we don't handle alignment requests in the hblk-level
! 1664: allocator, and we can't handle arbitrary pointer displacements unless
! 1665: GC_all_interior_pointers is enabled. But it should work for alignment
! 1666: requests up to HBLKSIZE. This is not yet documented in the standard
! 1667: places.
! 1668: - Finally debugged the OSF1/Tru64 thread support. This needs more testing,
! 1669: since I needed to add a somewhat unconvincing workaround for signal
! 1670: delivery issues that I don't yet completely understand. But it does
! 1671: pass my tests, even in parallel GC mode. Incremental GC support is
! 1672: disabled if thread support is enabled, due to the signal issues.
! 1673: - Eliminated name-space-incorrect definition of _cdecl from gc_cpp.h.
! 1674: - Added GC_debug_malloc_replacement and GC_debug_realloc_replacement
! 1675: declarations to gc.h. On IA64, this is required for REDIRECT_MALLOC
! 1676: to work correctly with these.
! 1677: - Fixed Linux USE_PROC_FOR_LIBRARIES to work with a 64-bit /proc format.
! 1678:
! 1679: Since 6.1:
! 1680: - Guard the test for GC_DUMP_REGULARLY in misc.c with
! 1681: "#ifndef NO_DEBUGGING". Otherwise it fails to build with NO_DEBUGGING
! 1682: defined. (Thanks to Manuel Serrano.)
! 1683: - Message about retrying suspend signals was incorrectly generated even when
! 1684: flag was not set.
! 1685: - Cleaned up MACOSX/NEXT root registration code. There was apparently a
! 1686: separate ifdef case in GC_register_data_segments() for no reason.
! 1687: - Removed MPROTECT_VDB for MACOSX port, based on one negative report.
! 1688: - Arrange for gc.h and friends to be correctly installed with GNU-style
! 1689: "make install".
! 1690: - Enable the GNU-style build facility include C++ support in the library
! 1691: with --enable-cplusplus. (Thanks to Thomas Maier for some of the patch.)
! 1692: - Mark from GC_thread_key in linux_threads.c, in case that's allocated
! 1693: from the garbage collected heap, as it is with our own thread-specific
! 1694: storage implementation. (Thanks to Jeff Sturm.)
! 1695: - Mark all free list header blocks if they are heap allocated. This avoids
! 1696: some unnecessary tracing. And it remains correct if we clear the
! 1697: root set. (Thanks to Jeff Sturm for identifying the bug.)
! 1698: - Improved S390/Linux support. Add S390/Linux 64-bit support. (Thanks
! 1699: to Ulrich Weigand.)
! 1700: - Corrected the spelling of GC_{M,C}ALLOC_EXPLICTLY_TYPED to
! 1701: GC_{M,C}ALLOC_EXPLICITLY_TYPED in gc_typed.h. This is technically
! 1702: an interface change. Based on the fact that nobody reported this,
! 1703: I suspect/hope there were no clients.
! 1704: - Cleaned up gc_typed.h so that (1) it adds an extern "C" declaration
! 1705: when appropriate, (2) doesn't generate references to undefined internal
! 1706: macros, and (3) allows easier manual construction of descriptors.
! 1707: - Close the file descriptor used by GC_print_address_map().
! 1708: - Set the "close-on-exec" bit for various file descriptors maintained
! 1709: for the collector's internal use.
! 1710: - Added a hack to find memory segments owned by the system allocator
! 1711: under win32. Based on my tests, this tends to eventually find all
! 1712: segments, though it may take a while. There appear to be cleaner,
! 1713: but slower solutions under NT/XP. But they rely on an API that's
! 1714: unsupported under 9X.
! 1715: - Changed Linux PowerPC stack finding to LINUX_STACKBOTTOM. (Thanks
! 1716: to Akira Tagoh for pointing out that HEURISTIC1 doesn't work on
! 1717: 64-bit kernels.)
! 1718: - Added GC_set_free_space_divisor to avoid some Windows dll issues.
! 1719: - Added FIXUP_POINTER, POINTER_SHIFT, POINTER_MASK to allow preprocessing
! 1720: of candidate pointers for tagging, etc.
! 1721: - Always lock around GC_notify_full_gc(). Simplified code for
! 1722: invoking GC_notify_full_gc().
! 1723: - Changed the way DATASTART is defined on FreeBSD to be robust against
! 1724: an unmapped page after etext. (Thanks to Hironori Sakamoto for
! 1725: tracking down the intermittent failure.)
! 1726: - Made GC_enable() and GC_disable() official. Deprecated direct update
! 1727: of GC_dont_gc. Changed GC_gcollect to be a noop when garbage collection
! 1728: is disabled.
! 1729: - Call GC_register_dynamic_libraries before stopping the world on Linux,
! 1730: in order to avoid a potential deadlock due to the dl_iterate_phdr lock.
! 1731: - Introduced a more general mechanism for platform-dependent code to
! 1732: decide whether the main data segment should be handled separately
! 1733: from dynamic libraries, or registered by GC_register_dynamic_libraries.
! 1734: The latter is more reliable and easier on Linux with dl_iterate_phdr.
! 1735:
! 1736: Since 6.2alpha1:
! 1737: - Fixed the completely broken FreeBSD code in 6.2alpha1. (Thanks to
! 1738: Hironori Sakamoto for the patch.)
! 1739: - Changed IRIX reference in dbg_mlc.c to IRIX5. (Thanks to Marcus Herbert.)
! 1740: - Attempted to work around the problems with .S filenames and the SGI
! 1741: compiler. (Reported by several people. Untested.)
! 1742: - Worked around an HP/UX make issue with the GNU-style build process.
! 1743: - Fixed the --enable-cplusplus build machinery to allow builds without
! 1744: a C++ compiler. (That was always the intent ...)
! 1745: - Changed the debugging allocation macros to explicitly pass the return
! 1746: address for Linux and XXXBSD on hardware for which we can't get stack
! 1747: traces. Use __builtin_return_address(0) to generate it when possible.
! 1748: Some of the configuration work was cleaned up (good) and moved to gc.h
! 1749: (bad, but necessary). This should make leak detection more useful
! 1750: on a number of platforms. (Thanks to Fabian Thylman for the suggestion.)
! 1751: - Fixed compilation problems in dbg_mlc.c with GC_ADD_CALLER.
! 1752: - Bumped revision number for dynamic library.
! 1753:
! 1754: Since 6.2alpha2:
! 1755: - Don't include execinfo.h in os_dep.c when it's not needed, and may not exist.
! 1756:
! 1757: Since 6.2alpha3:
! 1758: - Use LINUX_STACKBOTTOM for >= glibc2.2 on Linux/MIPS. (See Debian bug
! 1759: # 177204)
! 1760: - Integrated Jeff Sturm and Jesse Rosenstock's MACOSX threads patches.
! 1761: - Integrated Grzegorz Jakacki's substantial GNU build patch. "Make dist"
! 1762: should now work for the GNU build process. Documentation files
! 1763: are installed under share/gc.
! 1764: - Tweaked gc_cpp.h to again support the Borland compiler. (Thanks to
! 1765: Rene Girard for pointing out the problems.)
! 1766: - Updated BCC_MAKEFILE (thanks to Rene Girard).
! 1767: - Added GC_ASSERT check for minimum thread stack size.
! 1768: - Added --enable-gc-assertions.
! 1769: - Added some web documentation to the distribution. Updated it in the
! 1770: process.
! 1771: - Separate gc_conf_macros.h from gc.h.
! 1772: - Added generic GC_THREADS client-defined macro to set the appropriate
! 1773: GC_XXX_THREADS internal macro. (gc_config_macros.h.)
! 1774: - Add debugging versions of _ignore_off_page allocation primitves.
! 1775: - Moved declarations of GC_make_closure and GC_debug_invoke_finalizer
! 1776: from gc.h to gc_priv.h.
! 1777: - Reset GC_fail_count even if only a small allocation succeeds.
! 1778: - Integrated Brian Alliet's patch for dynamic library support on Darwin.
! 1779: - gc_cpp.h's gc_cleanup destructor called GC_REGISTER_FINALIZER_IGNORE_SELF
! 1780: when it should have called the lower case version, since it was
! 1781: explicitly computing a base pointer.
! 1782:
! 1783: Since 6.2alpha4:
! 1784: - GC_invoke_finalizers could, under rare conditions, set
! 1785: GC_finalizer_mem_freed to an essentially random value. This could
! 1786: possibly cause unbounded heap growth for long-running applications
! 1787: under some conditions. (The bug was introduced in 6.1alpha5, and
! 1788: is not in gcc3.3. Thanks to Ben Hutchings for finding it.)
! 1789: - Attempted to sanitize the various DLL macros. GC_USE_DLL disappeared.
! 1790: GC_DLL is used instead. All internal tests are now on GC_DLL.
! 1791: README.macros is now more precise about the intended meaning.
! 1792: - Include DllMain in the multithreaded win32 version only if the
! 1793: collector is actually built as a dll. (Thanks to Mohan Embar for
! 1794: a version of the patch.)
! 1795: - Hide the cygwin threadAttach/Detach functions. They were violating our
! 1796: namespace rules.
! 1797: - Fixed an assertion in GC_check_heap_proc. Added GC_STATIC_ASSERT.
! 1798: (Thanks again to Ben Hutchings.)
! 1799: - Removed some obsolete definitions for Linux/PowerPC in gcconfig.h.
! 1800: - CORD_cat was not rebalancing unbalanced trees in some cases, violating
! 1801: a CORD invariant. Also tweaked the rebalancing rule for
! 1802: CORD_cat_char_star. (Thanks to Alexandr Petrosian for the bug report
! 1803: and patch.)
! 1804: - Added hand-coded structured exception handling support to mark.c.
! 1805: This should enable support of dynamic libraries under win32 with
! 1806: gcc-compiled code. (Thanks to Ranjit Mathew for the patch.)
! 1807: Turned on dynamic library scanning for win32/gcc.
! 1808: - Removed some remnants of read wrapping. (Thanks to Kenneth Schalk.)
! 1809: GC_USE_LD_WRAP ws probably broken in recent versions.
! 1810: - The build could fail on some platforms since gcconfig.h could include
! 1811: declarations mentioning ptr_t, which was not defined, e.g. when if_mach
! 1812: was built. (Thanks to Yann Dirson for pointing this out.) Also
! 1813: cleaned up tests for GC_PRIVATE_H in gcconfig.h a bit.
! 1814: - The GC_LOOP_ON_ABORT environment variable interfered with incremental
! 1815: collection, since the write fault handler was erroneously overridden.
! 1816: Handlers are now set up in the correct order.
! 1817: - It used to be possible to call GC_mark_thread_local_free_lists() while
! 1818: the world was not stopped during an incremental GC. This was not safe.
! 1819: Fortunately, it was also unnecessary. Added GC_world_stopped flag
! 1820: to avoid it. (This caused occasional crashes in GC_set_fl_marks
! 1821: with thread local allocation and incremental GC. This probably happened
! 1822: primarily on old, slow multiprocessors.)
! 1823: - Allowed overriding of MAX_THREADS in win32_threads.c from the build
! 1824: command line. (Patch from Yannis Bres.)
! 1825: - Taught the IA64/linux code to determine the register backing store base from
! 1826: /proc/self/maps after checking the __libc symbol, but before guessing.
! 1827: (__libc symbols are on the endangered list, and the guess is likely to not
! 1828: always be right for 2.6 kernels.) Restructured the code to read and parse
! 1829: /proc/self/maps so it only exists in one place (all platforms).
! 1830: - The -DUSE_PROC_FOR_LIBRARIES code was broken on Linux. It claimed that it
! 1831: also registered the main data segment, but didn't actually do so. (I don't
! 1832: think anyone actually uses this configuration, but ...)
! 1833: - Made another attempt to get --enablecplusplus to do the right thing.
! 1834: Since there are unavoidable problems with C programs linking against a
! 1835: dynamic library that includes C++ code, I separated out the c++ code into
! 1836: libgccpp.
! 1837:
! 1838: Since 6.2alpha5:
! 1839: - There was extra underscore in the name of GC_save_registers_in_stack
! 1840: for NetBSD/SPARC. (Thanks to Jaap Boender for the patch.)
! 1841: - Integrated Brian Alliet's patch for Darwin. This restructured the
! 1842: linuxthreads/pthreads support to separate generic pthreads support
! 1843: from more the system-dependent thread-stopping code. I believe this
! 1844: should make it easier to eliminate the code duplication between
! 1845: pthreads platforms in the future. The patch included some other
! 1846: code cleanups.
! 1847: - Integrated Dan Bonachea's patch to support AIX threads. This required
! 1848: substantial manual integration, mostly due to conflicts with other
! 1849: recent threads changes. It may take another iteration to
! 1850: get it to work.
! 1851: - Removed HPUX/PA-RISC support from aix_irix_threads.c. It wasn't used
! 1852: anyway and it cluttered up the code. And anything we can do to migrate
! 1853: towards generic pthreads support is a good thing.
! 1854: - Added a more explicit test for tracing of function arguments to test.c.
! 1855: (Thanks to Dan Grayson.)
! 1856: - Added Akira Tagoh's PowerPC64 patch.
! 1857: - Fixed some bit rot in the Cygwin port. (Thanks to Dan Bonachea for
! 1858: pointing it out.) Gc.h now includes just windows.h, not winbase.h.
! 1859: - Declared GC_save_regs_in_stack() in gc_priv.h. Remove other declarations.
! 1860: - Changed --enable-cplusplus to use automake consitionals. The old way
! 1861: confused libtool. "Make install" didn't work correctly for the old version.
! 1862: Previously --enable-cplusplus was broken on cygwin.
! 1863: - Changed the C version of GC_push_regs to fail at compile time if it is
! 1864: generated with an empty body. This seems to have been the cause of one
! 1865: or two subtle failures on unusual platforms. Those failures should
! 1866: now occur at build time and be easily fixable.
! 1867:
1.1 noro 1868:
1869: To do:
1.2 ! noro 1870: - A dynamic libgc.so references dlopen unconditionally, but doesn't link
! 1871: against libdl.
! 1872: - GC_proc_fd for Solaris is not correctly updated in response to a
! 1873: fork() call. Thus incremental collection in the child won't work
! 1874: correctly. (Thanks to Ben Cottrell for pointing this out.)
1.1 noro 1875: - --enable-redirect-malloc is mostly untested and known not to work
1876: on some platforms.
1877: - There seem to be outstanding issues on Solaris/X86, possibly with
1878: finding the data segment starting address. Information/patches would
1879: be appreciated.
1880: - Very large root set sizes (> 16 MB or so) could cause the collector
1881: to abort with an unexpected mark stack overflow. (Thanks again to
1882: Peter Chubb.) NOT YET FIXED. Workaround is to increase the initial
1883: size.
1884: - The SGI version of the collector marks from mmapped pages, even
1885: if they are not part of dynamic library static data areas. This
1886: causes performance problems with some SGI libraries that use mmap
1887: as a bitmap allocator. NOT YET FIXED. It may be possible to turn
1888: off DYNAMIC_LOADING in the collector as a workaround. It may also
1889: be possible to conditionally intercept mmap and use GC_exclude_static_roots.
1890: The real fix is to walk rld data structures, which looks possible.
1891: - Incremental collector should handle large objects better. Currently,
1892: it looks like the whole object is treated as dirty if any part of it
1893: is.
1894:
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