Revision history for Perl extension IPC::Shareable.

1.14 UNREL
    - Modify remove() to properly catch a non "0 but true" case when trying
      to destroy segments and semaphores so warnings are displayed properly
    - remove() now leaves the global and process registers intact if the destroy
      operation fails
    - Rename _mg_tie() to _magic_tie()
    - Rename _is_kid() to _is_child()
    - In IPC::SharedMem, removed leading underscore from object attributes
    - Parameter list in IPC::SharedMem::new() is now in the form of a hash
    - Code refactoring in IPC::SharedMem
    - Add POD for IPC::SharedMem
    - SharedMem::remove() now returns 1 on '0 but true' and 0 otherwise
      that was preventing matches from happening, and broke JSON
    - ipcs() now ignores lines that don't include an actual key
    - Add data() method to SharedMem. This strips off the NULL pad bytes from
      shmread()
    - Added key_hex() to SharedMem. Will allow for easier troubleshooting when
      using ipcs (closes #32)
    - Added SharedMem::stat(); returns a new object that contains the related
      info about the actual shared memory segment
    - Fixes #49; Logic error from old implementation of JSON
    - Fixes #47; Clean up broken code in old _decode_json()
    - Fixes #41; JSON serializer not handling nested data structures properly
    - Closes #52; Add tests and POD for SharedMem::stat struct methods
    - Added SharedMem::stats(), return an href of all segment stats
    - Closes #48; All tests now run unconditionally; there is no more
      CI_TESTING flag required
    - Greatly simplify the FIRSTKEY and NEXTKEY shared hash ops; removed the
      _iterating flag complexity and replaced it with an _hkey_list instead
    - Fixes #38; Fixed issue where the global_register was not being populated
      if a data access hadn't happened yet, causing leaked segments upon
      cleanup. This fix eliminated the weird 'Dumper' hack
    - Add new scripts/flush_ipc.sh script that cleans out all segments and
      semaphores from the system for the current user
    - Closes #28; Add link to Script::Singleton in singleton() POD
    - Closes #24; lock() now allows a cref parameter. If a LOCK_EX lock can be
      acquired, we will set the lock, execute the subroutine, then release the
      lock
    - 'tidy' attribute now defaults to true
    - All unit tests do a check for leaked segments and semaphores at their
      conclusion. Also, when running 'make test' it compares the numbers before
      and after and doubly makes sure there are no leaks
    - Closes #51; Better document that the 'size' attribute is for each segment,
      and not the overall size of all the data. Also emphasize that each nested
      data structure requires an additional segment, they aren't all stashed
      into a single one
    - Added uuid(), sets an internal UUID for each tied object (primarily used
      for troubleshooting)
    - Fixes #50; Added enforced locking, with optional warning
    - Correct five areas in clean/delete routines where segments may have been
      able to leak
    - Removed redundant _global_register checks in STORE, FETCH, PUSH; _tie()
      already registers unconditionally
    - Add ref() check before _is_child(); skips the function call reftype()
      entirely for plain scalar values in FETCH, CLEAR, and DELETE
    - Add ref() check before _need_tie(); same pattern in all three STORE
      branches
    - _type_int numeric dispatch; string eq comparisons on every operation
      replaced with == against integer constants in STORE, FETCH, and CLEAR
    - Major POD enhancements/cleanup

1.13    2022-10-11
    - In singleton(), do a check whether class was sent in. There was a shifting
      issue if called with IPC::Shareable::singleton() as opposed to
      IPC::Shareable->singleton()
    - When an exclusive collision occurs and both 'graceful' and 'warn' are set,
      the warning thrown now includes the segment/semaphore key in use. This
      makes it easier to clean things up with 'ipcrm'

1.12    2022-03-13
    - Add tests in t/07-new.t to test how using tied() against a dereferenced
      variable returned from new() allows access to the underlying
      IPC::Shareable object
    - Reworked how spawn() and unspawn() manage things internally
    - POD updates, fixes and clarifications
    - Removed spawn() and unspawn(). There's really no need for these as one
      can simply create but not destroy

1.11    2022-03-07
    - Fix certain tests so they don't throw if we bail early

1.10    2022-03-07
    - Fix issue where if segments were created underneath of a parent by an
      external process other than the process that created the parent, the
      global register wasn't being updated, therefore those segments weren't
      being removed when calling clean_up_all()
    - All test files now check number of segments before and after the entire
      script has run, verifying that all segments were cleaned up ok
    - The test suite itself in its entirety makes sure that all segments
      created during the suite run are cleaned up properly
    - Added CI_TESTING=1 to coverage CI tests

1.09    2022-03-06
    - Made 81-fork_dup_rand_keys.t developer only (but still need to figure out
      why it only fails on FreeBSD)

1.08    2022-03-04
    - Added 'protected' option and clean_up_protected(). If set, the cleanup
      methods, nor the automatic 'destroy' functionality will remove the segment
      the option was set in, nor any children created underneath of it. A call
      to clean_up_protected() is required to remove them
    - Updated attribute tests to include all available options
    - _shm_key_rand() now checks EXCLUSIVE_CHECK_LIMIT times to find a key for
      a free segment. It croaks if not
    - Added _shm_key_rand_int() so we can mock it to test the dup random key
      checks
    - Added build prereq of Mock::Sub to test the random key function

1.07    2022-03-04
    - When running in forked environments, _shm_key_rand() was consistently
      returning the same 'random' key to each forked process. We've fixed this
      issue, and added tests for it (fixed by adding a call to srand() before
      rand)
    - Move $SIG{CHLD} handlers to spawn() and unspawn() instead of having them
      global (fixes #15)
    - t/65-seg_size.t fails on 32-bit perls; Add a check and bail if we're on
      a perl < 64-bit (fixes #14)

1.06    2021-09-08
    - Fix significant bug where at least on MacOS, if we generated a CRC of a
      key that was greater than 0x80000000, it would round down the key to that
      number exactly, causing duplicates, and incorrect segment access
    - Added new() method, returns a reference (default hash) without having to
      do the tie() directly
    - Fix issue in JSON decoder where an empty JSON string may have caused
      decode failure
    - Modify t/65-seg_size.t beyond RAM max test to cover varying error messages
      on differing OSs
    - Renamed t/67-out_of_memory.t as the tests are related to exhausting SHM
      slots, not RAM

1.05    2021-07-16
    - Bump prereq version of Test::SharedFork to 0.35
    - Added ability to use JSON as the serializer
    - Added ipcs()
    - Added test to ensure we croak if data size is greater than segment size
    - Added 'tidy' attribute, removes unneeded nested structure segments
    - In SharedMem, added _key attribute, and added set/get methods
    - Changed key generation from using padding, pack and unpack to using
      String::CRC32's crc32(), which allows arbitrary, unpadded strings
    - Added attributes() allows fetching one, or all of the object's atttributes
    - Added 'limit' attribute, by setting false, allows a user to set a segment
      size larger than our internal 1GB default
    - Cleaned up exception throwing (particularly if seg size eats up all
      memory, we throw an appropriate message)
    - Display proper exception if we try to exhaust all available shared memory
      segments (fixes #3)

1.04    2021-06-28
    - Skip unspawn tests for perls with -Duselongdouble, as Storable is not
      compatible storing/retrieving such numbers (closes #5)

1.03    2021-06-25
    - Add newline to singleton() warn so that it doesn't print out trace info

1.02    2021-06-25
    - Remove erroneous listing from MANIFEST
    - Work around issue in t/65-seg_size.t where MacOS and FreeBSD don't have
      the -i flag to ipcs (thanks for the PR, Roland Walker!)
    - Added singleton(), ensures that only a single instance of a script can
      run at any given time
    - Added tests to ensure we croak() if create is not set and the segment
      doesn't yet exist
    - Fix POD issue where we stated exclusive returns undef instead of croaking
      (fixes #10)
    - Change 'perl' shell call to $^X in t/71-unspawn.t (fixes #6)

1.01    2021-06-24
    - Added 'graceful' flag option. With exclusive, if a second process
      attempts to tie an exclusive segment, we exit gracefully instead of
      croaking

1.00    2021-06-09
    - Project adopted by Steve Bertrand
    - Added global_register() and process_register() to return the
      registries of active segments and semaphores
    - Added seg() and sem() methods, returns the structure of a shared
      memory segment and a sempahore respectively
    - Added initial "persist" hash variables. Separate processes (even
      multiple files in multiple windows) can share a variable, and it'll
      remain available even after all processes exit. The variable will be
      re-attached if the same shared segment key is used in subsequent runs
    - Reversed order of Changes file
    - Removed trace() and debug() code for ease of reading
    - Improved exception/error messages, added exception testing, reduced
      and minimized the number of exceptions actually uncaught
    - Significant POD cleanup
    - 100% rewrite of all test files, and added a slew of new ones, all
      using Test::More
    - Add build requirement of Test::SharedFork to handle the out of
      sequence fork() tests in t/35-clean.t and t/30-lock_operations
    - Major POD updates
    - Added tests to prove that RT 123057 isn't really an issue (ie. segment
      size parameter works correctly)

0.61  Mon Oct  8 00:27:39 2012
    - Added patch from Frank Lichtenheld fixing IPC::Shareable's dependence
      on the presence of a perl bug which is no longer present in
      perl >= 5.10
    - Fixed bug reported by Dan Harbin where the FETCH operation on a tie()d
      string containing HASH, ARRAY, or SCALAR fails because it was using
      the stringification of the data to determine what kind of reference
      it was.  Now using Scalar::Util::reftype
    - Added missing dependency on IPC::Semaphore to Makefile.PL (reported
      by Adrian Issott)
    - Added a 'sleep 1' in a test that was hanging on certain systems
      due (possibly) to two alarm signals coming too quickly to the
      child process.  From Ton Voon.

0.60  Mon Mar  5 15:20:18 EST 2001
    - Lee Lindley (lee.lindley@bigfoot.com) added the _was_changed
      optimization, improved the locking functionality, fixed
      numerous bugs, and generally cleaned things up; thanks.
    - Removed support for "no" as a false value in arguments;
      thanks to Dave Rolsky <autarch@urth.org>

0.54  Mon Jan  8 11:52:28 EST 2001
    - Fix to allow IPC::Shareable to work with 1.0.* versions of
      Storable

0.53  Tue Nov 14 00:33:35 EST 2000
    - Fixed race condition in test suite causing intermitent
      failures.
    - Better checking for success of calls to Storable::thaw();
      thanks to Raphael Manfredi <Raphael_Manfredi@pobox.com>.

0.52  Thu Sep 14 12:30:17 EDT 2000
    - Now STORE, PUSH, POP, etc all call _thaw() before doing
      their business.
    - Refined SIGALRM handlers in test scripts
    - Fixed concurrency issues affecting tied arrays and hashes;
      thanks to thanks to Robert Emmery <roberte@netscape.com>,
      Terry Ewing <terry@intevo.com>, Tim Fries
      <timf@dicecorp.com>, and Joe Thomas <jthomas@women.com>.
    - Doc fixes thanks to Paul Makepeace
      <Paul.Makepeace@realprogrammers.com>

0.51  Fri May  5 23:47:06 EDT 2000
    - Fixed bug that would cause IPC::Shareable::BUF_SIZ to be
      ignored; thanks to Robert Emmery <roberte@netscape.com> and
      Mohammed J. Kabir <kabir@intevo.com> for reporting.
    - Stopped tests from leaking shm segments
    - Added test of argument parsing
    - doc fixes

0.50 Tue Mar 21 11:56:32 EST 2000
    - Complete rewrite incorporating the following changes.
    - Requires 5.00503.  This allowed the module to get rid of the
      global cache for shared memory segments; each Shareable
      object now carries around its own data.
    - 5.00503 also allowed tied arrays to be implemented
    - Shared memory segments can no longer be of infinite length
      thereby reducing the amount of code in the module by a
      factor of 2.
    - Uses IPC::Shareable::SharedMem class for accessing
      shared memory.
    - Uses IPC::Semaphore module for accessing semaphores.
    - Completely revisited the way references are dealed with: all
      referenced thingies are now automagically tied to shared
      memory.
    - Constants now imported from IPC::SysV; Shareable.xs is gone
    - Rewrote test suite and moved into t subdirectory
    - Updated man page

 0.30 Mon Jan 19 11:13:41 EST 1998
    - Added SEM_UNDO to semop() calls; Maurice Aubrey.
    - Fixed some bugs in the locking code; Maurice Aubrey.
    - Made calls to debug() conditional for efficency; Maurice Aubrey.
    - Fixed a signal handler in test.pl; Maurice Aubrey.

0.29  Mon Jan 12 13:49:42 EST 1998
    - $MAXVER patch for when the version semaphore reaches its limit
      and rolls back over to 0; Maurice Aubrey <maurice@hevanet.com>.
    - patch to quieten things down under -w; Doug MacEachern
      <dougm@telebusiness.co.nz>

0.28  Wed Oct 22 14:59:08 EDT 1997
    - cleaned up the way thingys are magically tied; Ben Sugars.
    - moved many subroutines so that they are auto-loaded; Ben
      Sugars.
    - updated man page; Ben Sugars.

0.26  Mon Oct 20 10:06:43 EDT 1997
    - fixed bug regarding assigning a reference to an empty
      hash to a tied variable.  Thanks to Jason Stevens.

0.25  Tue Oct  7 14:41:49 EDT 1997
    - added more checking of sem*() and shm*() return values;
      Michael Stevens and Ben Sugars.
    - added shlock and shunlock; Ben Sugars.
    - fixed bug that would cause modifications of magically
      referenced thingys to fail.  Thanks to Maurice Aubrey

0.20  Thu Aug 28 15:13:46 EDT 1997
    - added ability to magically create ties to implicitly
      referenced thingys; Ben Sugars.

0.18  Thu Aug 28 09:12:30 EDT 1997
    - fixed garbage collection bug; Ben Sugars.  Thanks to
      Michael Stevens <michael@imaginet.co.uk> for the patch.

0.17  Wed Aug 27 15:57:11 EDT 1997
    - fixed some bugs in &parse_argument_hash; Ben Sugars.

0.16  Mon Aug 11 16:10:54 EDT 1997
    - new shared memory segments now initialized with null
      values; Ben Sugars.

0.15  Fri Aug  8 15:45:29 EDT 1997
    - implemented locking using semaphores; Ben Sugars.

0.12  Thu Aug  7 14:47:42 EDT 1997
    - various bug fixes; Ben Sugars.

0.11  Wed Aug  6 10:14:49 EDT 1997
    - initial implementation of semaphores for versioning and
      caching; Ben Sugars.

0.10  Fri Aug  1 13:32:52 EDT 1997
    - can now tie both scalars and hashes of arbitrary length;
      Ben Sugars.

0.05  Wed Jul 30 15:02:31 EDT 1997
    - scalars can now be tied; Ben Sugars.

0.01  Wed Jul 30 09:00:53 1997
    - original version; created by h2xs 1.18.
