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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.195 by root, Fri May 27 19:56:31 2011 UTC vs.
Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC

… …
168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '3.9'; 173 our $VERSION = '3.93';
174 174
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync aio_fsync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_fallocate
179 aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group 180 aio_rename aio_link aio_move aio_copy aio_group
180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
181 aio_chmod aio_utime aio_truncate 182 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall 183 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs); 184 aio_statvfs);
… …
222 aio_unlink $pathname, $callback->($status) 223 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status) 224 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status) 225 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status) 226 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link) 227 aio_readlink $path, $callback->($link)
228 aio_realpath $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status) 229 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status) 230 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status) 231 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries) 232 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 233 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
… …
436 438
437Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 439Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
438reading at byte offset C<$in_offset>, and starts writing at the current 440reading at byte offset C<$in_offset>, and starts writing at the current
439file offset of C<$out_fh>. Because of that, it is not safe to issue more 441file offset of C<$out_fh>. Because of that, it is not safe to issue more
440than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 442than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
441other. 443other. The same C<$in_fh> works fine though, as this function does not
444move or use the file offset of C<$in_fh>.
442 445
443Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than 446Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
444are written, and there is no way to find out how many bytes have been read 447are written, and there is no way to find out how many more bytes have been
445from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of 448read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
446bytes written to C<$out_fh>. Only if the result value equals C<$length> 449number of bytes written to C<$out_fh>. Only if the result value equals
447one can assume that C<$length> bytes have been read. 450C<$length> one can assume that C<$length> bytes have been read.
448 451
449Unlike with other C<aio_> functions, it makes a lot of sense to use 452Unlike with other C<aio_> functions, it makes a lot of sense to use
450C<aio_sendfile> on non-blocking sockets, as long as one end (typically 453C<aio_sendfile> on non-blocking sockets, as long as one end (typically
451the C<$in_fh>) is a file - the file I/O will then be asynchronous, while 454the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
452the socket I/O will be non-blocking. Note, however, that you can run into 455the socket I/O will be non-blocking. Note, however, that you can run
453a trap where C<aio_sendfile> reads some data with readahead, then fails 456into a trap where C<aio_sendfile> reads some data with readahead, then
454to write all data, and when the socket is ready the next time, the data 457fails to write all data, and when the socket is ready the next time, the
455in the cache is already lost, forcing C<aio_sendfile> to again hit the 458data in the cache is already lost, forcing C<aio_sendfile> to again hit
456disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage 459the disk. Explicit C<aio_read> + C<aio_write> let's you better control
457much better. 460resource usage.
458 461
459This call tries to make use of a native C<sendfile> syscall to provide 462This call tries to make use of a native C<sendfile>-like syscall to
460zero-copy operation. For this to work, C<$out_fh> should refer to a 463provide zero-copy operation. For this to work, C<$out_fh> should refer to
461socket, and C<$in_fh> should refer to an mmap'able file. 464a socket, and C<$in_fh> should refer to an mmap'able file.
462 465
463If a native sendfile cannot be found or it fails with C<ENOSYS>, 466If a native sendfile cannot be found or it fails with C<ENOSYS>,
464C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, 467C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
465it will be emulated, so you can call C<aio_sendfile> on any type of 468C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
466filehandle regardless of the limitations of the operating system. 469type of filehandle regardless of the limitations of the operating system.
470
471As native sendfile syscalls (as practically any non-POSIX interface hacked
472together in a hurry to improve benchmark numbers) tend to be rather buggy
473on many systems, this implementation tries to work around some known bugs
474in Linux and FreeBSD kernels (probably others, too), but that might fail,
475so you really really should check the return value of C<aio_sendfile> -
476fewre bytes than expected might have been transferred.
467 477
468 478
469=item aio_readahead $fh,$offset,$length, $callback->($retval) 479=item aio_readahead $fh,$offset,$length, $callback->($retval)
470 480
471C<aio_readahead> populates the page cache with data from a file so that 481C<aio_readahead> populates the page cache with data from a file so that
… …
635Asynchronously read the symlink specified by C<$path> and pass it to 645Asynchronously read the symlink specified by C<$path> and pass it to
636the callback. If an error occurs, nothing or undef gets passed to the 646the callback. If an error occurs, nothing or undef gets passed to the
637callback. 647callback.
638 648
639 649
650=item aio_realpath $path, $callback->($path)
651
652Asynchronously make the path absolute and resolve any symlinks in
653C<$path>. The resulting path only consists of directories (Same as
654L<Cwd::realpath>).
655
656This request can be used to get the absolute path of the current working
657directory by passing it a path of F<.> (a single dot).
658
659
640=item aio_rename $srcpath, $dstpath, $callback->($status) 660=item aio_rename $srcpath, $dstpath, $callback->($status)
641 661
642Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 662Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
643rename(2) and call the callback with the result code. 663rename(2) and call the callback with the result code.
644 664
… …
862 if ($_[0] && $! == EXDEV) { 882 if ($_[0] && $! == EXDEV) {
863 aioreq_pri $pri; 883 aioreq_pri $pri;
864 add $grp aio_copy $src, $dst, sub { 884 add $grp aio_copy $src, $dst, sub {
865 $grp->result ($_[0]); 885 $grp->result ($_[0]);
866 886
867 if (!$_[0]) { 887 unless ($_[0]) {
868 aioreq_pri $pri; 888 aioreq_pri $pri;
869 add $grp aio_unlink $src; 889 add $grp aio_unlink $src;
870 } 890 }
871 }; 891 };
872 } else { 892 } else {
… …
1781 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => 1801 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1782 \&IO::AIO::poll_cb); 1802 \&IO::AIO::poll_cb);
1783 1803
1784=head2 FORK BEHAVIOUR 1804=head2 FORK BEHAVIOUR
1785 1805
1786This module should do "the right thing" when the process using it forks: 1806Usage of pthreads in a program changes the semantics of fork
1807considerably. Specifically, only async-safe functions can be called after
1808fork. Perl doesn't know about this, so in general, you cannot call fork
1809with defined behaviour in perl. IO::AIO uses pthreads, so this applies,
1810but many other extensions and (for inexplicable reasons) perl itself often
1811is linked against pthreads, so this limitation applies.
1787 1812
1788Before the fork, IO::AIO enters a quiescent state where no requests 1813Some operating systems have extensions that allow safe use of fork, and
1789can be added in other threads and no results will be processed. After 1814this module should do "the right thing" on those, and tries on others. At
1790the fork the parent simply leaves the quiescent state and continues 1815the time of this writing (2011) only GNU/Linux supports these extensions
1791request/result processing, while the child frees the request/result queue 1816to POSIX.
1792(so that the requests started before the fork will only be handled in the
1793parent). Threads will be started on demand until the limit set in the
1794parent process has been reached again.
1795
1796In short: the parent will, after a short pause, continue as if fork had
1797not been called, while the child will act as if IO::AIO has not been used
1798yet.
1799 1817
1800=head2 MEMORY USAGE 1818=head2 MEMORY USAGE
1801 1819
1802Per-request usage: 1820Per-request usage:
1803 1821

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