[ViewVC] Contents 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

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