amiga-clib2/library/changes

c.lib 1.217 (10.7.2025)

- The raise() function no longer directly calls abort() because that
  function in turn would have invoked raise(SIGABRT), triggering an
  infinite loop. Instead, raise() now invokes the __abort() function
  which abort() would have called via raise(SIGABRT).

- fgets() no longer leverages the __getc() macro, which in the
  original implementation added excessive overhead for even small
  read operations. Instead, fgets() now focuses on copying data
  stored in the FILE read buffer, transferring the buffered data
  in bulk, if possible. The same kind of changes are present in
  the gets() function.

- fputs() and puts() no longer leverage the __putc() macro. As with
  the fgets() implementation, the focus is now on enabling bulk
  data transfer, eliminating the __putc() macro overhead.

- fread() and fwrite() no longer leverage the __getc() and
  __putc() macros. Their focus is on enabling bulk data transfer
  instead.

- The setvbuf() function now correctly sets the buffer size to the
  value of BUFSIZ if a buffer size of 0 is specified. Previously,
  setvbuf() would have disabled buffering for the FILE instead.
  Failure to allocate a buffer of the specified non-zero size is
  now caught and results in the setvbuf() function to indicate
  failure, setting the errno variable to ENOBUFS.

- The alloca() library function (which is a built-in function for
  gcc, for example) now calls abort() rather than returning NULL.

- Changed the numeric overflow check which the calloc() function
  uses to be simpler.
  
- The memory management debugging code in stdlib_free.c is no longer
  reusing the allocation size value to indicate that an allocation
  should never be freed. This indication is now stored in a separate
  flags field.
  
- The memory debugging code in malloc() now checks if the combined
  size of the management data structures and front/back padding
  stay within the bounds of a 32 bit integer.
  
  The list of memory nodes to be freed is now initialized first.
  Previously, the list would be left uninitialized if the attempt to
  allocate memory for memory arbitration semaphore had failed.

- The realloc() function now obtains the original size of the
  allocation from a dedicated field of the data structure which
  precedes the allocation, whose purpose is to track the
  allocation until it is freed. Previously, obtaining the relevant
  allocation size information was encapsulated by a "clever"
  macro.
  
  With memory debugging enabled, the stored allocation size no
  longer says how much memory, padding included, is being used.
  Instead, the requested allocation size is stored unchanged, with
  the total allocation size derived from this number. The idea is
  to make it harder to mistake the original allocation size for
  the padded one and vice versa.

- The use of the optional slab allocator now has to be deliberately
  enabled in the "stdlib_memory.h" header file.

- The minimum size of an allocation managed by the optional slab
  allocator is now 16 bytes instead of 8.

- The minimum size of a slab is now 4096 bytes.

- The optional slab allocator now checks for integer overflows when
  processing allocation requests, taking into account the size of
  the actual allocating, including padding. The task of figuring
  out how much padding is needed now rests in function which
  calculates the total overhead.


amiga.lib 1.216 (10.7.2025)

- Added a 'C' implementation of the pools.lib functions which were
  merged with the Kickstart/Workbench 3.0 era amiga.lib. This
  implementation provides the LibDeletePool(), LibCreatePool(),
  LibAllocPooled() and LibFreePooled() functions which had not
  been available before in clib2.
  
  Please note that these functions are largely obsolete and only
  helpful for code which must run on Kickstart 2.04. The current
  implementation performs no error checking for integer overflows,
  just like the original pools.lib implementation.


c.lib 1.216 (xxx)

- Add some wchar and multibyte-string related functions to allow gcc
  building a libstdc++ library with wide char support. For now, the
  functions are mostly stub ones only. They can be implemented on
  demand.


c.lib 1.215 (26.6.2017)

- Added -fno-aggressive-loop-optimizations option when building crtbegin.c
  to work around constructor/destructor hack with GCC 5.4.0 on AmigaOS 4.

- Added -fno-builtin option to fix conflicts with builtin memset()
  with GCC 5.4.0 on AmigaOS 4.


c.lib 1.214 (27.4.2017)

- Added integer overflow test to calloc().

- Tiny change in getopt_long() so that the value pointed to by longindex
  is always initialized to an invalid index position (that being -1),
  instead of 0. The value of 0 can break some shell commands, most notably
  GNU wget.


c.lib 1.213 (4.12.2016)

- Added the __decay_unused_slabs() function which brings all currently
  empty slabs which are still protected from reuse closer to getting
  reused or released.

- The slab-test program now exercises the memory allocation functions
  to a greater degree. Memory is allocated in random chunk sizes,
  the allocations are resized (to other random chunk sizes),
  33% of all allocations are randomly freed, empty slabs readied for
  reuse then discarded. The output in JSON format now shows a bit
  more information as to what is being done.

- Rewrote __get_slab_stats() to use setjmp() and longjmp() in the
  print() callback invocation.
  
- __get_slab_stats() now reports how many times a slab was reused
  after having stuck around in the "empty slab" list.
  
- Changing the slab size through an environment variable is now
  a feature of the debug build.

- Small changes to allow the library to be built with SAS/C again.
  This includes adding code to disable/re-enable profiling,
  fixing "stdlib_profile.h" and updating the smakefiles.

- Still not sure what it does, but _CXV45 now sits along with _CX25
  and _CX35 in "sas_cxv.asm". "sas_cxv54.asm" is not needed any
  more.

- Found the last use of MEMF_PRIVATE which should have been compiled
  only for the OS4 version.


c.lib 1.212 (27.11.2016)

- Unused slabs which get recycled are no longer reinitialized from
  scratch if their chunk size matches what the allocator needed.
  If the chunk size matches, the list of available chunks is
  left unchanged, and just the various counters are reset.

- Added __get_slab_stats() function.

- Added support for global __slab_purge_threshold tuning variable.


c.lib 1.211 (23.11.2016)

- Added more consistency checking to the slab allocator, which is
  built if DEBUG is defined in "stdlib_slab.c".

- Memory allocations are no longer guaranteed to be aligned to
  64 bit word boundaries. In fact, this has not even worked
  reliably in the past 10 years.

- Memory allocation request sizes are now rounded to multiples of
  32 bit words (the size of an address pointer) instead to the
  size of a 64 bit word.

- Reduced the memory footprint of the memory allocation management
  data structures by reusing the most significant bit of the
  memory allocation size. This allows many more allocations to fit
  into the 32 byte chunk slabs, but limits the maximum memory
  allocation size to a little less than 2 GBytes.

- Added integer overflow checks to the memory management code.

- Reduced the memory management overhead further. This cuts an
  additional 8 bytes per allocation, unless neither the slab
  allocator nor memory pools are available. With this reduction
  the slab allocator is able to use 16 byte chunks, which cover
  memory allocation requests of 1..8 bytes.

- Fixed a bug caused by returning an allocation back to a slab
  which passed the wrong pointer.


c.lib 1.210 (22.11.2016)

- Added __get_slab_allocations() function which will report information
  about each memory allocation made by the slab allocator which does
  not come from a slab.

- If the first slab in the list of slabs which share the same chunk
  size has no more room, it means that all other slabs following
  it have no room either. This speeds up the test to find a slab with
  free space, which can now abort and directly proceed to allocate
  memory for a new slab.

- If an empty slab's decay count hits zero, it is moved to the front
  of the empty slab list to be reclaimed more quickly.

- Allocations made from the slab now carry a pointer back to the
  slab which they are a part of. This speeds up deallocation but
  has the downside of making the smallest usable slab chunk size
  64 bytes, which is double what used to be the minimum before.


c.lib 1.209 (21.11.2016)

- The maximum slab size is now 2^17 bytes (= 131072). If you request
  a slab size larger than this, you will get slab sizes of 131072
  bytes instead.

- Enabling the memory management debugging code no longer produces
  compiler errors.


c.lib 1.208 (19.11.2016)

- Updated <stdlib.h> with new functions and data structures for
  use with the slab allocator.

- Added __get_slab_usage() function which can be used to query
  the slab allocator memory usage at runtime.


c.lib 1.207 (18.11.2016)

- Added a slab allocator which replaces the use of memory pools or the
  plain AllocMem() operations, respectively. In order to activate the
  slab allocator, choose a slab size (e.g. 2048 bytes or 4096 bytes)
  and declare a global variable like this:

     ULONG __slab_max_size = 2048;

  Memory allocations smaller than the slab size will be made from
  "slabs", i.e. large chunks of memory of the given size. Larger
  allocations will be managed separately.


m.lib 1.206 (24.4.2015)

- The fscanf() family failed to parse and convert %f parameters correctly
  if the respective number did not begin with a digit, but a decimal
  point. Hence ".7" would not be processed, but "0.7" would.

c.lib 1.206 (24.4.2015)

- Reworked the __putc() and putc() macros to reference the 'c' input
  parameter only once, and to be free of side-effects when tinkering
  with the buffer position.

- isatty() had the __fd_lock() call in the wrong place, which could have
  led to cleanup problems later.

- The close action in the stdio, socket and termios hook code now
  also zaps the fd pointer itself after cleaning up the file descriptor
  table entry.

- Removed the remains of all the stack extension and stack overflow/underflow
  checking code. It never actually worked. The bit that does work is the stack