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Diffstat (limited to '')
| -rw-r--r-- | gc/doc/README | 2 | ||||
| -rw-r--r-- | gc/doc/README.changes | 67 | ||||
| -rw-r--r-- | gc/doc/README.environment | 23 | ||||
| -rw-r--r-- | gc/doc/README.ews4800 | 75 | ||||
| -rw-r--r-- | gc/doc/README.win32 | 13 | ||||
| -rw-r--r-- | gc/doc/debugging.html | 2 |
6 files changed, 171 insertions, 11 deletions
diff --git a/gc/doc/README b/gc/doc/README index c6b48c3..702bdd0 100644 --- a/gc/doc/README +++ b/gc/doc/README @@ -27,7 +27,7 @@ are GPL'ed, but with an exception that should cover all uses in the collector. (If you are concerned about such things, I recommend you look at the notice in config.guess or ltmain.sh.) -This is version 6.0 of a conservative garbage collector for C and C++. +This is version 6.1alpha2 of a conservative garbage collector for C and C++. You might find a more recent version of this at diff --git a/gc/doc/README.changes b/gc/doc/README.changes index c018c8b..4478da7 100644 --- a/gc/doc/README.changes +++ b/gc/doc/README.changes @@ -1360,7 +1360,7 @@ Since 6.0alpha8: it on untested platforms. - Integrated initial GNU HURD port. (Thanks to Chris Lingard and Igor Khavkine.) - - A few more fixes for Digital Mars compiler. + - A few more fixes for Digital Mars compiler (Walter Bright). - Fixed gcc version recognition. Renamed OPERATOR_NEW_ARRAY to GC_OPERATOR_NEW_ARRAY. Changed GC_OPERATOR_NEW_ARRAY to be the default. It can be overridden with -DGC_NO_OPERATOR_NEW_ARRAY. (Thanks to @@ -1378,16 +1378,71 @@ Since 6.0alpha9: - Fixed a stack clearing problem that resulted in SIGILL with a misaligned stack pointer for multithreaded SPARC builds. - Integrated another HURD patch (thanks to Igor Khavkine). + +Since 6.0: + - Non-debug, atomic allocations could result in bogus smashed object + reports with debugging on. (Thanks to Patrick Doyle for the small + test case.) + - Fixed GC_get_register_stack_base (Itanium only) to work around a glibc + 2.2.4 bug. + - Initial port to HP/UX on Itanium. Thread support and both 32 and 64 + bit ABIs appear to work. Parallel mark support doesn't yet, due to + some inline assembly code issues. Thread local allocation does appear + to work. + - ifdef'ed out glibc2.1/Itanium workaround. I suspect nobody is using + that combination anymore. + - Added a patch to make new_gc_alloc.h usable with gcc3.0. (Thanks to + Dimitris Vyzovitis for the patch.) + - Debugged 64-bit support on HP/UX PA-RISC. + - Turned on dynamic loading support for FreeBSD/ELF. (Thanks to Peter + Housel.) + - Unregistering of finalizers with debugging allocation was broken. + (Thanks to Jani Kajala for the test case.) + - Old finalizers were not returned correctly from GC_debug_register_finalizer. + - Disabled MPROTECT_VDB for Linux/M68K based on a report that it doesn't work. + - Cleaned up some statistics gathering code in reclaim.c (Thanks to Walter + Bright.) + - Added some support for OpenBSD/ELF/Linux. (Thanks to Suzuki Toshiya.) + - Added Jakub Jelinek's patch to use dl_iterate_phdr for dynamic library + traversal to dyn_load.c. Changed it to weakly reference dl_iterate_phdr, + so that the old code is stilll used with old versions of glibc. + - Cleaned up feature test macros for various threads packages and + integrated (partially functional) FreeBSD threads code from Loren Rittle. + It's likely that the cleanup broke something, since it touched lots of + code. It's also likelly that it fixed some unreported bugs in the + less common thread implementations, since some of the original code + didn't stand up to close scrutiny. Support for the next pthreads + implementation should be easier to add. +Since 6.0alpha1: + - No longer wrap read by default in multithreaded applications. It was + pointed out on the libgcj list that this holds the allocation lock for + way too long if the read blocks. For now, reads into the heap are + broken with incremental collection. It's possible to turn this back on + if you make sure that read calls don't block (e.g. by calling select + first). + - Fix ifdef in Solaris_threads.h to refer to GC_SOLARIS_THREADS. + - Added check for environment variable GC_IGNORE_GCJ_INFO. + - Added printing of stop-the-world GC times if GC_PRINT_STATS environment + variable is set. + - The calloc definition in leak_detector.h was missing parentheses, and + realloc was missing a second argument to GC_REALLOC. (Thanks to Elrond.) + - Added GC_PRINT_BACK_HEIGHT environment variable and associated + code, mostly in the new file backgraph.c. See doc/README.environment. + - Added -DUSE_GLOBAL_ALLOC to work around a Windows NT issue. (Thanks to + Jonathan Clark.) + - Integrated port to NEC EWS4800 (MIPS-based workstation, with somewhat + different address-space layout). This may help for other machines with + holes in the data segment. (Thanks to Hironori Sakamoto.) + - Changed the order in which GC_push_roots and friends push things onto + the mark stack. GC_push_all calls need to come first, since we can't + necessarily recovere if thos overflow the mark stack. (Thanks to + Matthew Flatt for tracking down the problem.) To do: - There seem to be outstanding issues on Solaris/X86, possibly with finding the data segment starting address. Information/patches would - ne appreciated. - - New_gc_alloc.h is apparently no longer compatible with the latest C++ - standard library in gcc3.0. (This isn't technically a bug, since it only - claimed compatibility with the SGI STL. But we may need a new C++ STL - allocator interface.) + be appreciated. - Very large root set sizes (> 16 MB or so) could cause the collector to abort with an unexpected mark stack overflow. (Thanks again to Peter Chubb.) NOT YET FIXED. Workaround is to increase the initial diff --git a/gc/doc/README.environment b/gc/doc/README.environment index 5760342..f540692 100644 --- a/gc/doc/README.environment +++ b/gc/doc/README.environment @@ -1,5 +1,5 @@ The garbage collector looks at a number of environment variables which are -the used to affect its operation. These are examined only on Un*x-like +then used to affect its operation. These are examined only on Un*x-like platforms. GC_INITIAL_HEAP_SIZE=<bytes> - Initial heap size in bytes. May speed up @@ -32,6 +32,27 @@ GC_NPROCS=<n> - Linux w/threads only. Explicitly sets the number of processors GC_NO_BLACKLIST_WARNING - Prevents the collector from issuing "Needed to allocate blacklisted block at ..." warnings. +GC_IGNORE_GCJ_INFO - Ignore the type descriptors implicitly supplied by + GC_gcj_malloc and friends. This is useful for debugging + descriptor generation problems, and possibly for + temporarily working around such problems. It forces a + fully conservative scan of all heap objects except + those known to be pointerfree, and may thus have other + adverse effects. + +GC_PRINT_BACK_HEIGHT - Print max length of chain through unreachable objects + ending in a reachable one. If this number remains + bounded, then the program is "GC robust". This ensures + that a fixed number of misidentified pointers can only + result in a bounded space leak. This currently only + works if debugging allocation is used throughout. + It increases GC space and time requirements appreciably. + This feature is still somewhat experimental, and requires + that the collector have been built with MAKE_BACK_GRAPH + defined. For details, see Boehm, "Bounding Space Usage + of Conservative Garbage Collectors", POPL 2001, or + http://lib.hpl.hp.com/techpubs/2001/HPL-2001-251.html . + The following turn on runtime flags that are also program settable. Checked only during initialization. We expect that they will usually be set through other means, but this may help with debugging and testing: diff --git a/gc/doc/README.ews4800 b/gc/doc/README.ews4800 new file mode 100644 index 0000000..bced243 --- /dev/null +++ b/gc/doc/README.ews4800 @@ -0,0 +1,75 @@ +GC on EWS4800 +------------- + +1. About EWS4800 + EWS4800 is 32bit/64bit workstation. + + Vender: NEC Corporation + OS: UX/4800 R9.* - R13.* (SystemV R4.2) + CPU: R4000, R4400, R10000 (MIPS) + +2. Compiler + + 32bit: + Use ANSI C compiler. + CC = /usr/abiccs/bin/cc + + 64bit: + Use 64bit ANSI C compiler. + CC = /usr/ccs64/bin/cc + AR = /usr/ccs64/bin/ar + +3. ELF file format + *** Caution: The following infomation is empirical. *** + + 32bit: + ELF file has an unique format. (See a.out(4) and end(3C).) + + &_start + : text segment + &etext + DATASTART + : data segment (initialized) + &edata + DATASTART2 + : data segment (uninitialized) + &end + + Here, DATASTART and DATASTART2 are macros of GC, and are defined as + the following equations. (See include/private/gcconfig.h.) + The algorithm for DATASTART is similar with the function + GC_SysVGetDataStart() in os_dep.c. + + DATASTART = ((&etext + 0x3ffff) & ~0x3ffff) + (&etext & 0xffff) + + Dynamically linked: + DATASTART2 = (&_gp + 0x8000 + 0x3ffff) & ~0x3ffff + + Statically linked: + DATASTART2 = &edata + + GC has to check addresses both between DATASTART and &edata, and + between DATASTART2 and &end. If a program accesses between &etext + and DATASTART, or between &edata and DATASTART2, the segmentation + error occurs and the program stops. + + If a program is statically linked, there is not a gap between + &edata and DATASTART2. The global symbol &_DYNAMIC_LINKING is used + for the detection. + + 64bit: + ELF file has a simple format. (See end(3C).) + + _ftext + : text segment + _etext + _fdata = DATASTART + : data segment (initialized) + _edata + _fbss + : data segment (uninitialized) + _end = DATAEND + +-- +Hironori SAKAMOTO <hsaka@mth.biglobe.ne.jp> + diff --git a/gc/doc/README.win32 b/gc/doc/README.win32 index 417281d..b1a6ec5 100644 --- a/gc/doc/README.win32 +++ b/gc/doc/README.win32 @@ -1,8 +1,8 @@ The collector has at various times been compiled under Windows 95 & NT, with the original Microsoft SDK, with Visual C++ 2.0, 4.0, and 6, with -the GNU win32 environment, with Borland 4.5, and recently with -Watcom C. It is likely that some of these have been broken in the -meantime. Patches are appreciated. +the GNU win32 environment, with Borland 4.5, with Watcom C, and recently +with the Digital Mars compiler. It is likely that some of these have been +broken in the meantime. Patches are appreciated. It runs under both win32s and win32, but with different semantics. Under win32, all writable pages outside of the heaps and stack are @@ -45,6 +45,13 @@ window colors.) In general -DREDIRECT_MALLOC is unlikely to work unless the application is completely statically linked. +The collector normally allocates memory from the OS with VirtualAlloc. +This appears to cause problems under Windows NT and Windows 2000 (but +not Windows 95/98) if the memory is later passed to CreateDIBitmap. +To work around this problem, build the collector with -DUSE_GLOBAL_ALLOC. +This is currently incompatible with -DUSE_MUNMAP. (Thanks to Jonathan +Clark for tracking this down.) + For Microsoft development tools, rename NT_MAKEFILE as MAKEFILE. (Make sure that the CPU environment variable is defined to be i386.) In order to use the gc_cpp.h C++ interface, all diff --git a/gc/doc/debugging.html b/gc/doc/debugging.html index a186ff5..04773fa 100644 --- a/gc/doc/debugging.html +++ b/gc/doc/debugging.html @@ -209,6 +209,8 @@ down the problem: <OL> <LI> If you are using the incremental collector try turning it off for debugging. +<LI> If you are using shared libraries, try linking statically. If that works, +ensure that DYNAMIC_LOADING is defined on your platform. <LI> Try to reproduce the problem with fully debuggable unoptimized code. This will eliminate the last possibility, as well as making debugging easier. <LI> Try replacing any suspect typed allocation and <TT>GC_malloc_atomic</tt> |