[ViewVC] Annotation of: cvs/IO-AIO/Changes

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.

        - fix result status documentation of aio_copy, aio_move.

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 OS X workarounds (patch by Tokuhiro Matsuno).

3.26 Tue Jun 30 09:33:26 CEST 2009
        - os x of course claims 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.

Revision:	1.206
Committed:	Tue Aug 18 04:05:01 2009 UTC (14 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.205:	+2 -0 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.31	Revision history for IO::AIO
2	root	1.30
3	root	1.59	TODO: better autoconf.pm that can return LIBS etc.
4	root	1.114	TODO: aio_cptree/mvtree
5	root	1.106	TODO: reduce condvar fairness: schedule hot-cache-threads first?
6	root	1.176	TODO: splice/tee/vmsplice? (http://kerneltrap.org/node/6505 http://lwn.net/Articles/178199/)
7	root	1.136	TODO: aio_fcntl, at least for file-locking
8	root	1.196	TODO: fallocate, if it wouldn't be so useless.
9	root	1.100
10	root	1.206	- fix result status documentation of aio_copy, aio_move.
11
12	root	1.205	3.3 Wed Aug 5 13:52:58 CEST 2009
13	root	1.202	- use common::sense.
14			- use common schmorp.h header.
15			- allow integers (file descriptors) in addition to file handles.
16	root	1.203	- take advantage of linux' eventfd (but it seems slower on smp?).
17	root	1.204	- use poll not select on posix platforms.
18	root	1.202
19	root	1.201	3.261 Wed Jul 1 10:11:51 CEST 2009
20	root	1.200	- more OS X workarounds (patch by Tokuhiro Matsuno).
21
22	root	1.199	3.26 Tue Jun 30 09:33:26 CEST 2009
23			- os x of course claims posix 2008 but lacks posix_fadvise. try to work
24			around this horribly broken OS in a somewhat hackish way. might help
25			other os's too.
26
27	root	1.198	3.25 Sat Jun 27 05:18:26 CEST 2009
28	root	1.197	- added IO::AIO::fadvise and IO::AIO::sendfile.
29	root	1.195	- (libeio) replaced quicksort+insertion sort by a tuned radix
30			sort + insertion sort, resulting in comparable runtime (usually
31			faster) to the old version, but without any ill side effects on
32			degenerated (for quicksort) data.
33			- (libeio) correctly sort dirs by inodes if we have perfect type
34	root	1.194	knowledge and DIRS_FIRST is used.
35	root	1.195	- (libeio) internally the wrong DT_* constants were used, but no
36			known system has differing EIO_DT_/DT_ values, so not an issue.
37			- removed a (harmless) assert that was left over on the code
38			but should not have been.
39	root	1.196	- use more correct types (change IO length from IV to VAL64,
40			which makes a difference on systems without 64 bit perls).
41	root	1.194
42	root	1.193	3.23 Sat Jun 13 16:57:58 CEST 2009
43			- fix off-by-one bug in aio_readdir that was introduced in the
44			rushed 3.22 release.
45
46	root	1.192	3.22 Sat Jun 13 15:32:40 CEST 2009
47	root	1.191	- speed up readdirx sort algorithm slightly.
48	root	1.192	- bin/treescan was missing from distro tarball.
49	root	1.191
50	root	1.190	3.21 Fri Jun 12 18:45:53 CEST 2009
51	root	1.187	- new options --dirs and --files for treescan.
52	root	1.188	- install bin/treescan by default.
53	root	1.189	- (libeio) aio_readdir can now be cancelled while executing.
54	root	1.190	- fix a printf format string for 64 bit systems (could lead
55			to problems on big endian 64 bit systems).
56			- do not use qsort() but our own algorithm: glibc initialises
57			the whole locale and I/O subsystem inside qsort, causing
58			a stack overflow on 32 bit machines. The new sort uses much less
59			stack and is more than twice as fast in typical situations.
60	root	1.187
61	root	1.186	3.2 Sun Jun 7 20:30:05 CEST 2009
62	root	1.182	- (libeio) pwrite emulation was even more flawed than intended and did
63			not restore the file offset.
64	root	1.183	- add aio_readdirx, which can return inode and filetype and sort
65			the names in various ways.
66	root	1.182	- unfortunately, utime, chmod, chown on an open file that has just
67			been written can easily block, which caused aio_copy to block the
68			process. no more!
69			- no longer rely on dst path in aio_copy when futime is available.
70
71	root	1.181	3.19 Tue Apr 21 22:05:21 CEST 2009
72			- more perl 5.10 workarounds for aio_read and write.
73			- aio_write no longer modifies the sv (if possible).
74			- aio_read now works correctly with magic values.
75
76	root	1.180	3.18 Sun Apr 19 21:17:32 CEST 2009
77	root	1.179	- better diagnostics when some aio_* functions get passed an illegal fh.
78	root	1.180	- try to avoid crashes due to incompatible 5.10 API changes. grmbl.
79	root	1.178
80	root	1.177	3.17 Thu Nov 20 08:45:36 CET 2008
81	root	1.176	- (libeio) added aio_sync_file_range (untested).
82	root	1.177	- add aio_busy to @IO::AIO::AIO_REQ.
83	root	1.175
84	root	1.174	3.16 Wed Oct 22 18:28:01 CEST 2008
85	root	1.173	- use SvREFCNT_inc instead of SvREFCNT_inc_NN in a non-speed critical
86			part to improve portability to perl 5.8 (reported by szymon).
87
88	root	1.172	3.15 Mon Oct 13 00:39:55 CEST 2008
89	root	1.171	- automatic removal of feeders was broken.
90			- (libeio) use a more robust method to detect whether a feeder
91			has added something to the group or not.
92
93	root	1.170	3.1 Thu Oct 2 13:34:40 CEST 2008
94	root	1.168	- pre-deref the passed callback object, for increased speed
95			and decreased memory usage.
96	root	1.167	- call on_next_submit callback even for aio_group - impact unknown,
97	root	1.166	but seems more correct.
98	root	1.168	- $req->cb now returns the original callback.
99	root	1.166	- (libeio) pass EIO_GROUP/aio_group requests through the queue without
100			requiring a thread switch.
101	root	1.169	- (libeio) status code of aio_futime and aio_utime was always passed 0.
102	root	1.166	- do some other µ-optimisations.
103
104	root	1.165	3.07 Sat Aug 2 16:06:13 CEST 2008
105			- do not include LIBS in autoconf tests.
106
107	root	1.164	3.06 Tue Jul 15 12:41:32 CEST 2008
108	root	1.162	- move preadwritelock definition before it's first reference,
109	root	1.164	to make it compile again on broken platforms (they still exist)
110			or badly cofngiured perls (redhat...), reported by Rob Bloodgood.
111	root	1.162
112	root	1.161	3.05 Thu Jun 19 23:23:52 CEST 2008
113	root	1.160	- work around perl overriding readdir etc. with thread-unsafe
114	root	1.161	(sic!) versions.
115	root	1.160
116	root	1.159	3.04 Wed Jun 18 01:35:38 CEST 2008
117			- (libeio) fix eio_mknod, which confused it's arguments.
118	root	1.158	- (libeio) do not use readdir_r, as Ulrich Drepper pointed out that this
119			is stupid.
120	root	1.159	- (libeio) fix eio__readahead prototype, patch by Jost Krieger.
121			- (libeio) fix a bug that could potentially cause IO::AIO
122			not to get initialised properly.
123	root	1.158
124	root	1.157	3.03 Thu May 29 05:33:30 CEST 2008
125	root	1.153	- (libeio) correctly call pthread_attr_destroy ().
126	root	1.155	- (libeio) work around broken bsd headers once more.
127	root	1.154	- reduce shared library size again by not including wrappers.
128	root	1.156	- max_outstanding could cause poll to enter a busy-waiting loop.
129			- document the new IO::AIO::poll_cb result value.
130	root	1.153
131	root	1.152	3.02 Mon May 12 02:32:02 CEST 2008
132	root	1.150	- fix a memory leak on aio_readlink.
133			- bring back working fchmod.
134	root	1.151	- nop and busy now set result to 0.
135			- set errno to ENOMEM when allocation fails.
136	root	1.150
137	root	1.149	3.01 Sun May 11 03:07:03 CEST 2008
138			- (libeio) make it compile on systems without readahead or readdir_r.
139	root	1.148	- (libeio) improve configure check for readahead availability.
140			- do not try to link against -lrt.
141	root	1.147	- use a separate configure script for IO::AIO (not the libeio one).
142
143	root	1.146	3.0 Sun May 11 00:57:14 CEST 2008
144	root	1.145	- added bin/treescan to the distribution.
145			- switched to using libeio.
146			- LOTS OF INCOMPATIBLE CHANGES:
147			- remove signal functionality, it is not worth the effort.
148			- max_outstanding no longer returns the previous number of requests.
149			- poll_cb no longer returns number of requests.
150	root	1.143
151	root	1.142	2.62 Sat Apr 26 13:59:33 CEST 2008
152	root	1.141	- port to solaris perls configured for old posix
153			(analysed by Jost Krieger).
154	root	1.142	- keep a reference to the perl filehandle object in aio_close,
155			so it doesn't get closed prematurely, leading to ugly races.
156	root	1.141
157	root	1.140	2.61 Wed Apr 16 18:45:02 CEST 2008
158	root	1.137	- fix treescan output duplication and improve output ordering.
159			also display files given on the commandline.
160	root	1.140	- use a different algorithm for aio_close that is faster
161			and probably has even lower chances of blocking.
162	root	1.138	- do our own stack memory management for threads - linux
163			allocates outrageous amounts of VM (not so bad unless you
164			use mlockall...), which severely limits the number of threads
165	root	1.139	on 32-bit arches: stack size is the larger of PTHREAD_STACK_MIN
166			and 4096 * sizeof (long) (usually this is 16..64k).
167	root	1.137
168	root	1.136	2.6 Sun Mar 30 08:28:11 CEST 2008
169	root	1.134	- added aio_sync.
170	root	1.135	- added aio_pathsync.
171	root	1.136	- fix prototypes of (void) functions.
172	root	1.134
173	root	1.133	2.51 Sat Oct 6 16:04:54 CEST 2007
174			- perlio isn't generally threadsafe, so aio_close could not work reliably.
175			aio_close now tries a safe hack that might not be that asynchronous
176			(see the manpage for details).
177			- discard callback return values as to not grow the stack endlessly
178			when poll_cb handles many requests without returning.
179			- minor code cleanups.
180
181	root	1.132	2.5 Thu Oct 4 14:49:08 CEST 2007
182	root	1.131	- replaced _fd2fh with faster xs code.
183			- aio_close will now try to do "the right thing" and thus might
184			work sensibly for the very first time.
185
186	root	1.130	2.41 Mon Sep 24 21:28:21 CEST 2007
187	root	1.129	- after fork, invest some work to make sure that the poll_fileno
188			stays stable (by dup2'ing the new fd over the old one), to make
189			it easier for programs/libs that don't control their forking
190			behaviour and cannot recreate their watchers.
191
192	root	1.128	2.4 Sun Aug 5 18:44:22 CEST 2007
193	root	1.127	- add aio_truncate, aio_chmod, aio_chown, aio_utime (linux
194			successfully demonstrated that you can block on futimes...).
195	root	1.124	- allow undef as fileoffset for aio_read/write and use read/write(2)
196			internally (useful for sockets or O_APPEND handles).
197	root	1.126	- allow undef for length in aio_write.
198			- negative dataoffsets work as expected now in aio_read/aio_write.
199	root	1.124	- use NV instead of UV for 32 bit perls and file offsets, as NVs
200	root	1.125	have a larger range then.
201	root	1.120	- shared code between BDB and IO::AIO.
202	root	1.127	- aio_busy was completely broken. now fixed.
203			- readahead emulation now returns something.
204	root	1.121	- correctly set errno to ENOSYS on unimplemented functions
205			(should never happen, though).
206	root	1.127	- large changes to make it partially compile and run on win32,
207			but win32 lacks too much functionality, and perl overrides way
208			too many functions with crashing versions.
209	root	1.120
210	root	1.119	2.33 Tue Jan 23 23:55:41 CET 2007
211			- fix install path (Andreas J. Koenig).
212
213	root	1.118	2.32 Mon Jan 22 16:56:23 CET 2007
214	root	1.114	- added aio_rmtree.
215	root	1.115	- wow, aio_mkdir was missing.
216	root	1.116	- aio_load did return undef on error, not -1.
217	root	1.117	- use prefixexp not prefix in autoconf.pm
218			(suggested by ... rt.cpan.org unreachable).
219	root	1.118	- avoid installing autoconf.pm.
220	root	1.114
221	root	1.113	2.31 Sat Jan 6 03:46:02 CET 2007
222	root	1.112	- added aio_load.
223
224	root	1.111	2.3 Sat Dec 23 05:48:07 CET 2006
225			- fix off-by-one bug in aio_read, causing memory corruption
226			or crashes.
227
228	root	1.110	2.21 Fri Dec 22 05:03:38 CET 2006
229	root	1.108	- minor doc updates.
230	root	1.107	- minor cleanups.
231			- IO::AIO::poll returns request count.
232	root	1.109	- undocumented and unfinished async-signal-reporting.
233	root	1.107
234	root	1.103	2.2 Tue Oct 31 00:31:00 CET 2006
235	root	1.100	- minor doc updates.
236	root	1.101	- added aio_readlink.
237			- properly zero-terminate aio_read buffer.
238			- fix aio_read/write with nonzero dataoffset.
239	root	1.104	- reduced size of aio request structure.
240	root	1.106	- better diagnostics when pathnames etc. are not byte-encoded;
241	root	1.105	do not leak request in that case, either.
242	root	1.94
243	root	1.99	2.1 Sun Oct 29 02:01:57 CET 2006
244	root	1.98	- INCOMPATIBLE CHANGE: replace IO::AIO::poll_some by
245			IO::AIO::max_poll_reqs and IO::AIO::max_poll_time.
246	root	1.95	- fix a bug in aio_move where it would fail everytime
247			it would have to copy files manually.
248	root	1.98	- doc updates.
249	root	1.94	- start threads only on (very low) demand.
250	root	1.97	- end superfluous threads automatically after 10s idling.
251	root	1.98	- add IO::AIO::max_idle to control this.
252	root	1.94	- some tuning applied to random places.
253	root	1.95	- add aio_mknod.
254	root	1.59
255	root	1.92	2.0 Thu Oct 26 18:27:58 CEST 2006
256	root	1.90	- minor incompatibility: max_outstanding semantics have changed.
257	root	1.86	- major rewrite, consider all functionality EXPERIMENTAL.
258	root	1.68	- aio requests can be cancelled.
259	root	1.81	- callbacks can be (re-)set later.
260	root	1.93	- aio requests can choose between 9 priorities.
261	root	1.83	- add aio_group: aio requests can be grouped
262			into composite requests.
263			- generator interface for groups.
264	root	1.89	- add IO::AIO::poll_some.
265	root	1.72	- major documentation improvements.
266			- very minor bugfixes.
267	root	1.76	- add aio_nop for dummy requests.
268	root	1.84	- add aio_busy mainly for benchmarking and debugging.
269	root	1.79	- use "fast" mutexes on linux.
270	root	1.80	- use dynamic (and larger) buffers instead of
271			putting them onto the stack.
272			- optimise x86 and amd64 a bit.
273			- better error checking when ENOMEM.
274	root	1.85	- hopefully fix mem and dirp leaks on fork.
275	root	1.92	- warn about broken perl malloc.
276	root	1.88	- compiles on cygwin (but pread is broken on cygwin
277			which is not detected by autoconf, so you have to
278			edit autoconf/config.h yourself to enable emulation).
279	root	1.68
280	root	1.67	1.8 Sat Jun 24 22:20:44 CEST 2006
281	root	1.66	- add and/or document aio_rename, aio_link, aio_symlink and aio_move.
282
283	root	1.65	1.73 Wed Mar 1 22:49:32 CET 2006
284			- codename "jost"
285			- AIX/Solaris(?) aren't being helpful again, hardcode a value
286			for NAME_MAX and drive with your eyes closed (reported by
287			wcooley@nakedape.cc).
288	root	1.63
289	root	1.62	1.72 Thu Feb 2 00:40:44 CET 2006
290	root	1.61	- another minor bug in aio_scandir, again, the callback was called
291			twice when the directory can't be stat'ed.
292
293	root	1.60	1.71 Mon Dec 26 20:20:03 CET 2005
294			- grr, another minor bug in aio_scandir, this time resulting
295			in a runtime error.
296
297	root	1.59	1.7 Mon Dec 26 19:29:48 CET 2005
298	root	1.58	- aio_scandir errornously called callback twice in some cases.
299	root	1.57	- added AnyEvent example.
300
301	root	1.55	1.61 Wed Sep 7 19:40:42 CEST 2005
302	root	1.54	- no longer include $Config{libs}, as distros include too much
303	root	1.56	garbage in there that is not installed on typical systems
304	root	1.54	(for example, debian links perl against -lgdbm and many more
305			libraries despite perl not needing it, slowing down startup and
306			wasting memory).
307
308	root	1.53	1.6 Tue Aug 30 17:44:44 CEST 2005
309			- added aio_readdir, aio_scandir.
310	root	1.51	- added aio_sendfile, including sendfile emulation when sendfile
311			isn't available. Linux, FreeBSD and HP-UX might work (sendfilev
312			support is unavailable on my solaris 8 machine, but preliminary
313			code is there. What's lacking is configury stuff and testing...).
314	root	1.46
315	root	1.44	1.5 Sat Aug 20 02:32:19 CEST 2005
316	root	1.51	- create the aio threads on demand only (good after forking).
317	root	1.41	- somebody nagged about C89 compatibility, so this release should
318	root	1.42	be C89 compatible, but no guarantees for future ones.
319	root	1.43	- abort when the configure script fails.
320	root	1.41
321	root	1.40	1.4 Wed Aug 17 08:07:27 CEST 2005
322	root	1.93	- forgot to recreate the pipe after forking, this could cause
323	root	1.40	deadlocks.
324
325	root	1.39	1.3 Wed Aug 17 07:25:54 CEST 2005
326	root	1.33	- properly propagate exceptions from callbacks, instead of silently
327			eating them.
328	root	1.38	- use a different fork algorithm that avoids recursive callback
329			invocations and reduces fork latency in busy processes.
330	root	1.37	- fix a bug where the buffer scalar in aio_read got assigned the wrong
331			length after reading.
332			- fix a bug where the child would process some outstanding requests
333			from the parent.
334			- make a copy of the callback scalar, to avoid some very uncommon
335			(but valid) usages where the callback scalar changes.
336			- the callback was never freed in aio_read/aio_write.
337	root	1.38	- aio_read/aio_write will now set the readonly flag on the data
338			scalar for better error reporting.
339	root	1.33
340	root	1.32	1.2 Wed Aug 17 01:22:58 CEST 2005
341			- verified on cygwin, linux/amd64+ia32+alpha, solaris.
342	root	1.31	- use SvPVbyte for filenames now. You need to encode your strings to
343			the external filename encoding first.
344	root	1.32	- fix the bug where filehandles could leak (again).
345	root	1.31	- clarify freebsd situation: make it work and tell me how, or go away
346			with your underdocumented, broken and outdated OS.
347			- fork'ing should now be officially supported (where linux and
348			posix contradict each other, I followed posix).
349	root	1.32	- only call read() once per poll, not twice (speedup).
350			- new functions: aio_rmdir, aio_symlink.
351	root	1.31	- force callback arguments to be undef or a reference, for better
352			error catching.
353	root	1.1
354	root	1.29	1.1 Sun Aug 7 05:27:23 CEST 2005
355	root	1.25	- added configure script to detect availability of some calls.
356	root	1.27	(imperfect, as we cannot detect things like -lrt due to missing
357	root	1.23	feedback yet).
358	root	1.27	- emulate fdatasync via fsync, pread/pwrite via unsafe read/write
359			and readahead via manual reading on platforms lacking those.
360	root	1.19	- ported t/03_errors.t+framework by Brad Fitzpatrick
361			from Linux::AIO.
362	root	1.18	- removed XOPEN_SOURCE because stupid solaris 9 doesn't
363			compile with it enabled. Probably breaks others. Oh well.
364	root	1.24	- try to be more careful with errno on non-threaded perls.
365	root	1.26	- cygwins perl insisted on a matching open mode when morphing
366			the fd to an fh.
367	root	1.28	- convert sv's to "byte" encoding in aio_read/aio_write. Might
368			do that for pathnames, too, in the future, so make sure you
369			properly encode your pathnames.
370	root	1.18
371	root	1.17	1.0 Fri Jul 22 10:43:30 CEST 2005
372			- aio_open did not reliably deliver (open) filehandles.
373	root	1.16	- all aio_*-functions keep a reference to the filehandle so
374			it doesn't go away while the aio requests is working on it.
375			- disable warnings in AIO.pm.
376
377	root	1.15	0.9 Wed Jul 20 23:55:04 CEST 2005
378			- allow recursive calls to poll_cb, use less locking calls, too.
379			- fix the Gtk2-example in the SYNOPSIS.
380	root	1.14	- use pread/pwrite not pread64/pwrite64. this was simply a leftover
381			from Linux::AIO.
382			(found by compiling on cygwin. Unfortunately, cygwin declares but
383			does not implement pread/pwrite).
384			- only include <sys/syscall.h> on linux.
385
386	root	1.13	0.5 Tue Jul 12 13:03:09 CEST 2005
387	root	1.12	- removed #include <endian.h>, it's not portable, and we don't
388			need it anyway.
389			- link against -lrt, as it might contain goodies such as fdatasync,
390			and often aio_read, which we do not use yet, but it shouldn't hurt.
391
392	root	1.11	0.4 Mon Jul 11 05:28:25 CEST 2005
393	root	1.9	- added IO::AIO::flush, IO::AIO::poll.
394	root	1.10	- make callback argument optional for all calls.
395	root	1.8
396	root	1.7	0.3 Mon Jul 11 01:42:37 CEST 2005
397	root	1.5	- restructured manpage.
398	root	1.7	- added SYNOPSIS with examples for Event, Glib, Tk.
399			- remove explicit context support so I don't have to maintain
400			it for threaded perls (i.e. it should work now :).
401	root	1.5
402	root	1.4	0.2 Sun Jul 10 22:57:12 CEST 2005
403	root	1.2	- return immediately from poll_wait if nreqs==0.
404			- get rid of the request pipe and use faster thread-thread
405	root	1.3	communications for most requests and responses.
406	root	1.2
407	root	1.1	0.1
408			- cloned from Linux::AIO, which is very similar.
409