Revision history for IO::AIO

TODO: better autoconf.pm that can return LIBS etc.
TODO: aio_cptree/mvtree
TODO: reduce condvar fairness: schedule hot-cache-threads first?
TODO: splice/tee/vmsplice? (http://kerneltrap.org/node/6505 http://lwn.net/Articles/178199/)
TODO: aio_fcntl, at least for file-locking
TODO: fallocate, if it wouldn't be so useless.
TODO: aio_mincore?
TODO: add? also linux-specific stuff?
TODO: O_EXEC O_SEARCH O_CLOEXEC O_DIRECTORY O_DSYNC O_NOCTTY O_NOFOLLOW O_NONBLOCK O_RSYNC O_SYNC O_TTY_INIT O_DIRECT O_LARGEFILE O_NOATIME O_ASYNC

3.8  Sun Mar 27 12:25:33 CEST 2011
	- use nonstandard but maybe-working-on-bsd fork technique.
	- support a max_idle value of 0.
	- support setting of idle timeout value (IO::AIO::idle_timeout).

3.72 Fri Feb 11 04:25:38 CET 2011
	- use _POSIX_MEMLOCK_RANGE to detetc mlock/munlock.
        - aio_mknod always used a dev_t value of 0.
        - new treescan option: --grep.
        - add more S_IF macros, and major/minor/makedev "macros".

3.71 Thu Dec 30 08:18:46 CET 2010
	- the numerical result value passed to callbacks did not stringify
          correctly, due to internal reuse and failure to reset the sv flags.
	- actually test for posix_[mf]advise, as at least uClibc defines
          _POSIX_ADVISORY_INFO without actually having any of the required
          funcitonality. ugh.

3.7  Mon Nov  1 23:00:34 CET 2010
        - implement/add madvise, mmap, munmap, aio_mlockall, munlockall,
          aio_mlock, munlock, msync and mtouch to @EXPORT_OK.
        - document the sad state of affairs w.r.t. pthread on many bsds.
	- do not enable mmap on systems without _POSIX_MAPPED_FILES
          (openbsd 4.8).
        - do not leak memory in IO::AIO::mmap when the scalar already
          had string-data.
	- add O_RDWR, O_APPEND and O_EXCL symbols and semi-document
          them.
        - cache the result IV, for a minor speedup in the common case.
        - croak when an mmapped-scalar changes location, to detect
          user-errors better.
        - fix aio_readlink prototype.

3.65 Wed Mar 31 02:45:05 CEST 2010
	- actually use PATH_MAX instead of NAME_MAX for readlink, as to not
          cut off long pathnames in aio_readlink (based on patch by
          Rasmus Andersson).
	- a double fork partially killed the event pipe (great testcase
          by dormando). affects IO::AIO, BDB and Async::Interrupt.
        - suck steve's dick and rename our symbols to avoid colliding
          with nonstandard identifier spam on the broken os x pseudo-os.
          affects IO::AIO and BDB.

3.6  Mon Jan 11 00:43:39 CET 2010
	- (libeio) more fixes for the freebsd/apple sendfile - broken by
          manpage standards, but apparently correct accoridng to actual
          kernel sources.
        - add IO::AIO::mmap/munmap support.
        - add IO::AIO::m(un)lockall support.
        - clean up manpage.

3.5  Thu Jan  7 21:25:04 CET 2010
	- (liebio) fix freebsd sendfile (Vanilla Hsu).
        - (libeio) also fix darwin sendfile that suffered from a similar bug.
        - add aio_statvfs as interface to statvfs/fstatvfs.
        - work around buggy symlink() on cygwin in the testsuite.
        - wtf. freebsd-8.0 actually passes the testsuite! I knew
          they could implement fork and semaphores one day! cheers!

3.4  Sat Jan  2 15:13:04 CET 2010
	- (libeio) max_poll_time was not properly converted to ticks.
        - clarify cancel_subs description.
        - IO::AIO::sendfile did not actually return the return value
          from the sendfile call.
        - implement aio_msync, aio_mtouch.
        - (libeio) tentatively support darwin in sendfile.

3.31 Thu Nov 12 02:14:29 CET 2009
	- fix result status documentation of aio_copy, aio_move.
        - speed up object creation considerably by avoiding
          hash lookups.

3.3  Wed Aug  5 13:52:58 CEST 2009
	- use common::sense.
        - use common schmorp.h header.
        - allow integers (file descriptors) in addition to file handles.
        - take advantage of linux' eventfd (but it seems slower on smp?).
        - use poll not select on posix platforms.

3.261 Wed Jul  1 10:11:51 CEST 2009
	- more 0S X workarounds (patch by Tokuhiro Matsuno).

3.26 Tue Jun 30 09:33:26 CEST 2009
        - 0S X of course claims to be posix 2008 but lacks posix_fadvise.
          try to work around this horribly broken OS in a somewhat hackish
          way. might help other os's too.

3.25 Sat Jun 27 05:18:26 CEST 2009
        - added IO::AIO::fadvise and IO::AIO::sendfile.
        - (libeio) replaced quicksort+insertion sort by a tuned radix
          sort + insertion sort, resulting in comparable runtime (usually
          faster) to the old version, but without any ill side effects on
          degenerated (for quicksort) data.
        - (libeio) correctly sort dirs by inodes if we have perfect type
          knowledge and DIRS_FIRST is used.
        - (libeio) internally the wrong DT_* constants were used, but no
          known system has differing EIO_DT_*/DT_* values, so not an issue.
        - removed a (harmless) assert that was left over on the code
          but should not have been.
        - use more correct types (change IO length from IV to VAL64,
          which makes a difference on systems without 64 bit perls).

3.23 Sat Jun 13 16:57:58 CEST 2009
	- fix off-by-one bug in aio_readdir that was introduced in the
          rushed 3.22 release.

3.22 Sat Jun 13 15:32:40 CEST 2009
	- speed up readdirx sort algorithm slightly.
        - bin/treescan was missing from distro tarball.

3.21 Fri Jun 12 18:45:53 CEST 2009
	- new options --dirs and --files for treescan.
        - install bin/treescan by default.
        - (libeio) aio_readdir can now be cancelled while executing.
        - fix a printf format string for 64 bit systems (could lead
          to problems on big endian 64 bit systems).
        - do not use qsort() but our own algorithm: glibc initialises
          the whole locale and I/O subsystem inside qsort, causing
          a stack overflow on 32 bit machines. The new sort uses much less
          stack and is more than twice as fast in typical situations.

3.2  Sun Jun  7 20:30:05 CEST 2009
	- (libeio) pwrite emulation was even more flawed than intended and did
          not restore the file offset.
        - add aio_readdirx, which can return inode and filetype and sort
          the names in various ways.
        - unfortunately, utime, chmod, chown on an open file that has just
          been written can easily block, which caused aio_copy to block the
          process. no more!
        - no longer rely on dst path in aio_copy when futime is available.

3.19 Tue Apr 21 22:05:21 CEST 2009
	- more perl 5.10 workarounds for aio_read and write.
        - aio_write no longer modifies the sv (if possible).
        - aio_read now works correctly with magic values.

3.18 Sun Apr 19 21:17:32 CEST 2009
	- better diagnostics when some aio_* functions get passed an illegal fh.
        - try to avoid crashes due to incompatible 5.10 API changes. grmbl.

3.17 Thu Nov 20 08:45:36 CET 2008
	- (libeio) added aio_sync_file_range (untested).
        - add aio_busy to @IO::AIO::AIO_REQ.

3.16 Wed Oct 22 18:28:01 CEST 2008
	- use SvREFCNT_inc instead of SvREFCNT_inc_NN in a non-speed critical
          part to improve portability to perl 5.8 (reported by szymon).

3.15 Mon Oct 13 00:39:55 CEST 2008
	- automatic removal of feeders was broken.
	- (libeio) use a more robust method to detect whether a feeder
          has added something to the group or not.

3.1  Thu Oct  2 13:34:40 CEST 2008
	- pre-deref the passed callback object, for increased speed
          and decreased memory usage.
	- call on_next_submit callback even for aio_group - impact unknown,
          but seems more correct.
        - $req->cb now returns the original callback.
        - (libeio) pass EIO_GROUP/aio_group requests through the queue without
          requiring a thread switch.
        - (libeio) status code of aio_futime and aio_utime was always passed 0.
        - do some other µ-optimisations.

3.07 Sat Aug  2 16:06:13 CEST 2008
	- do not include LIBS in autoconf tests.

3.06 Tue Jul 15 12:41:32 CEST 2008
	- move preadwritelock definition before it's first reference,
          to make it compile again on broken platforms (they still exist)
          or badly cofngiured perls (redhat...), reported by Rob Bloodgood.

3.05 Thu Jun 19 23:23:52 CEST 2008
	- work around perl overriding readdir etc. with thread-unsafe
          (sic!) versions.

3.04 Wed Jun 18 01:35:38 CEST 2008
	- (libeio) fix eio_mknod, which confused it's arguments.
	- (libeio) do not use readdir_r, as Ulrich Drepper pointed out that this
          is stupid.
        - (libeio) fix eio__readahead prototype, patch by Jost Krieger.
        - (libeio) fix a bug that could potentially cause IO::AIO
          not to get initialised properly.

3.03 Thu May 29 05:33:30 CEST 2008
	- (libeio) correctly call pthread_attr_destroy ().
        - (libeio) work around broken bsd headers once more.
        - reduce shared library size again by not including wrappers.
        - max_outstanding could cause poll to enter a busy-waiting loop.
        - document the new IO::AIO::poll_cb result value.

3.02 Mon May 12 02:32:02 CEST 2008
	- fix a memory leak on aio_readlink.
        - bring back working fchmod.
        - nop and busy now set result to 0.
        - set errno to ENOMEM when allocation fails.

3.01 Sun May 11 03:07:03 CEST 2008
	- (libeio) make it compile on systems without readahead or readdir_r.
        - (libeio) improve configure check for readahead availability.
        - do not try to link against -lrt.
	- use a separate configure script for IO::AIO (not the libeio one).

3.0  Sun May 11 00:57:14 CEST 2008
	- added bin/treescan to the distribution.
        - switched to using libeio.
	- LOTS OF INCOMPATIBLE CHANGES:
          - remove signal functionality, it is not worth the effort.
          - max_outstanding no longer returns the previous number of requests.
          - poll_cb no longer returns number of requests.

2.62 Sat Apr 26 13:59:33 CEST 2008
	- port to solaris perls configured for old posix
          (analysed by Jost Krieger).
        - keep a reference to the perl filehandle object in aio_close,
          so it doesn't get closed prematurely, leading to ugly races.

2.61 Wed Apr 16 18:45:02 CEST 2008
	- fix treescan output duplication and improve output ordering.
          also display files given on the commandline.
        - use a different algorithm for aio_close that is faster
          and probably has even lower chances of blocking.
        - do our own stack memory management for threads - linux
          allocates outrageous amounts of VM (not so bad unless you
          use mlockall...), which severely limits the number of threads
          on 32-bit arches: stack size is the larger of PTHREAD_STACK_MIN
          and 4096 * sizeof (long) (usually this is 16..64k).

2.6  Sun Mar 30 08:28:11 CEST 2008
	- added aio_sync.
        - added aio_pathsync.
        - fix prototypes of (void) functions.

2.51 Sat Oct  6 16:04:54 CEST 2007
	- perlio isn't generally threadsafe, so aio_close could not work reliably.
          aio_close now tries a safe hack that might not be that asynchronous
          (see the manpage for details).
        - discard callback return values as to not grow the stack endlessly
          when poll_cb handles many requests without returning.
        - minor code cleanups.

2.5  Thu Oct  4 14:49:08 CEST 2007
	- replaced _fd2fh with faster xs code.
        - aio_close will now try to do "the right thing" and thus might
          work sensibly for the very first time.

2.41 Mon Sep 24 21:28:21 CEST 2007
	- after fork, invest some work to make sure that the poll_fileno
          stays stable (by dup2'ing the new fd over the old one), to make
          it easier for programs/libs that don't control their forking
          behaviour and cannot recreate their watchers.

2.4  Sun Aug  5 18:44:22 CEST 2007
        - add aio_truncate, aio_chmod, aio_chown, aio_utime (linux
          successfully demonstrated that you can block on futimes...).
        - allow undef as fileoffset for aio_read/write and use read/write(2)
          internally (useful for sockets or O_APPEND handles).
        - allow undef for length in aio_write.
        - negative dataoffsets work as expected now in aio_read/aio_write.
        - use NV instead of UV for 32 bit perls and file offsets, as NVs
          have a larger range then.
	- shared code between BDB and IO::AIO.
        - aio_busy was completely broken. now fixed.
        - readahead emulation now returns something.
        - correctly set errno to ENOSYS on unimplemented functions
          (should never happen, though).
        - large changes to make it partially compile and run on win32,
          but win32 lacks too much functionality, and perl overrides way
          too many functions with crashing versions.

2.33 Tue Jan 23 23:55:41 CET 2007
	- fix install path (Andreas J. Koenig).

2.32 Mon Jan 22 16:56:23 CET 2007
	- added aio_rmtree.
        - wow, aio_mkdir was missing.
        - aio_load did return undef on error, not -1.
        - use prefixexp not prefix in autoconf.pm
          (suggested by ... rt.cpan.org unreachable).
        - avoid installing autoconf.pm.

2.31 Sat Jan  6 03:46:02 CET 2007
	- added aio_load.

2.3  Sat Dec 23 05:48:07 CET 2006
	- fix off-by-one bug in aio_read, causing memory corruption
          or crashes.

2.21  Fri Dec 22 05:03:38 CET 2006
	- minor doc updates.
	- minor cleanups.
        - IO::AIO::poll returns request count.
        - undocumented and unfinished async-signal-reporting.

2.2  Tue Oct 31 00:31:00 CET 2006
	- minor doc updates.
        - added aio_readlink.
        - properly zero-terminate aio_read buffer.
        - fix aio_read/write with nonzero dataoffset.
        - reduced size of aio request structure.
        - better diagnostics when pathnames etc. are not byte-encoded;
          do not leak request in that case, either.

2.1  Sun Oct 29 02:01:57 CET 2006
        - INCOMPATIBLE CHANGE: replace IO::AIO::poll_some by
          IO::AIO::max_poll_reqs and IO::AIO::max_poll_time.
	- fix a bug in aio_move where it would fail everytime
          it would have to copy files manually.
	- doc updates.
	- start threads only on (very low) demand.
        - end superfluous threads automatically after 10s idling.
        - add IO::AIO::max_idle to control this.
	- some tuning applied to random places.
        - add aio_mknod.

2.0  Thu Oct 26 18:27:58 CEST 2006
	- minor incompatibility: max_outstanding semantics have changed.
	- major rewrite, consider all functionality EXPERIMENTAL.
        - aio requests can be cancelled.
        - callbacks can be (re-)set later.
        - aio requests can choose between 9 priorities.
        - add aio_group: aio requests can be grouped
          into composite requests.
        - generator interface for groups.
        - add IO::AIO::poll_some.
        - major documentation improvements.
        - very minor bugfixes.
        - add aio_nop for dummy requests.
        - add aio_busy mainly for benchmarking and debugging.
        - use "fast" mutexes on linux.
        - use dynamic (and larger) buffers instead of
          putting them onto the stack.
        - optimise x86 and amd64 a bit.
        - better error checking when ENOMEM.
        - hopefully fix mem and dirp leaks on fork.
        - warn about broken perl malloc.
        - compiles on cygwin (but pread is broken on cygwin
          which is not detected by autoconf, so you have to
          edit autoconf/config.h yourself to enable emulation).

1.8  Sat Jun 24 22:20:44 CEST 2006
	- add and/or document aio_rename, aio_link, aio_symlink and aio_move.

1.73 Wed Mar  1 22:49:32 CET 2006
	- codename "jost"
        - AIX/Solaris(?) aren't being helpful again, hardcode a value
          for NAME_MAX and drive with your eyes closed (reported by
          wcooley@nakedape.cc).

1.72 Thu Feb  2 00:40:44 CET 2006
	- another minor bug in aio_scandir, again, the callback was called
          twice when the directory can't be stat'ed.

1.71 Mon Dec 26 20:20:03 CET 2005
	- grr, another minor bug in aio_scandir, this time resulting
          in a runtime error.

1.7  Mon Dec 26 19:29:48 CET 2005
        - aio_scandir errornously called callback twice in some cases.
	- added AnyEvent example.

1.61 Wed Sep  7 19:40:42 CEST 2005
	- no longer include $Config{libs}, as distros include too much
          garbage in there that is not installed on typical systems
          (for example, debian links perl against -lgdbm and many more
          libraries despite perl not needing it, slowing down startup and
          wasting memory).

1.6  Tue Aug 30 17:44:44 CEST 2005
        - added aio_readdir, aio_scandir.
        - added aio_sendfile, including sendfile emulation when sendfile
          isn't available. Linux, FreeBSD and HP-UX might work (sendfilev
          support is unavailable on my solaris 8 machine, but preliminary
          code is there. What's lacking is configury stuff and testing...).

1.5  Sat Aug 20 02:32:19 CEST 2005
	- create the aio threads on demand only (good after forking).
	- somebody nagged about C89 compatibility, so this release should
          be C89 compatible, but no guarantees for future ones.
        - abort when the configure script fails.

1.4  Wed Aug 17 08:07:27 CEST 2005
	- forgot to recreate the pipe after forking, this could cause
          deadlocks.

1.3  Wed Aug 17 07:25:54 CEST 2005
	- properly propagate exceptions from callbacks, instead of silently
          eating them.
        - use a different fork algorithm that avoids recursive callback
          invocations and reduces fork latency in busy processes.
        - fix a bug where the buffer scalar in aio_read got assigned the wrong
          length after reading.
        - fix a bug where the child would process some outstanding requests
          from the parent.
        - make a copy of the callback scalar, to avoid some very uncommon
          (but valid) usages where the callback scalar changes.
        - the callback was never freed in aio_read/aio_write.
        - aio_read/aio_write will now set the readonly flag on the data
          scalar for better error reporting.

1.2  Wed Aug 17 01:22:58 CEST 2005
	- verified on cygwin, linux/amd64+ia32+alpha, solaris.
        - use SvPVbyte for filenames now. You *need* to encode your strings to
          the external filename encoding first.
	- fix the bug where filehandles could leak (again).
        - clarify freebsd situation: make it work and tell me how, or go away
          with your underdocumented, broken and outdated OS.
        - fork'ing should now be officially supported (where linux and
          posix contradict each other, I followed posix).
        - only call read() once per poll, not twice (speedup).
        - new functions: aio_rmdir, aio_symlink.
        - force callback arguments to be undef or a reference, for better
          error catching.

1.1  Sun Aug  7 05:27:23 CEST 2005
	- added configure script to detect availability of some calls.
          (imperfect, as we cannot detect things like -lrt due to missing
          feedback yet).
        - emulate fdatasync via fsync, pread/pwrite via unsafe read/write
          and readahead via manual reading on platforms lacking those.
	- ported t/03_errors.t+framework by Brad Fitzpatrick
          from Linux::AIO.
	- removed XOPEN_SOURCE because stupid solaris 9 doesn't
          compile with it enabled. Probably breaks others. Oh well.
        - try to be more careful with errno on non-threaded perls.
        - cygwins perl insisted on a matching open mode when morphing
          the fd to an fh.
        - convert sv's to "byte" encoding in aio_read/aio_write. Might
          do that for pathnames, too, in the future, so make sure you
          properly encode your pathnames.

1.0  Fri Jul 22 10:43:30 CEST 2005
        - aio_open did not reliably deliver (open) filehandles.
        - all aio_*-functions keep a reference to the filehandle so
          it doesn't go away while the aio requests is working on it.
	- disable warnings in AIO.pm.

0.9  Wed Jul 20 23:55:04 CEST 2005
        - allow recursive calls to poll_cb, use less locking calls, too.
        - fix the Gtk2-example in the SYNOPSIS.
	- use pread/pwrite not pread64/pwrite64. this was simply a leftover
          from Linux::AIO.
          (found by compiling on cygwin. Unfortunately, cygwin declares but
          does not implement pread/pwrite).
	- only include <sys/syscall.h> on linux.

0.5  Tue Jul 12 13:03:09 CEST 2005
	- removed #include <endian.h>, it's not portable, and we don't
          need it anyway.
        - link against -lrt, as it might contain goodies such as fdatasync,
          and often aio_read, which we do not use yet, but it shouldn't hurt.

0.4  Mon Jul 11 05:28:25 CEST 2005
	- added IO::AIO::flush, IO::AIO::poll.
        - make callback argument optional for all calls.

0.3  Mon Jul 11 01:42:37 CEST 2005
	- restructured manpage.
        - added SYNOPSIS with examples for Event, Glib, Tk.
        - remove explicit context support so I don't have to maintain
          it for threaded perls (i.e. it should work now :).

0.2  Sun Jul 10 22:57:12 CEST 2005
	- return immediately from poll_wait if nreqs==0.
        - get rid of the request pipe and use faster thread-thread
          communications for most requests and responses.

0.1
	- cloned from Linux::AIO, which is very similar.

