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Revision 1.27 by root, Sat Oct 6 14:05:37 2007 UTC vs.
Revision 1.29 by root, Wed Apr 16 16:45:30 2008 UTC

24 $req->cancel; # cancel request if still in queue 24 $req->cancel; # cancel request if still in queue
25 25
26 my $grp = aio_group sub { print "all stats done\n" }; 26 my $grp = aio_group sub { print "all stats done\n" };
27 add $grp aio_stat "..." for ...; 27 add $grp aio_stat "..." for ...;
28 28
29 # AnyEvent integration 29 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...)
30 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 30 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
31 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); 31 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
32
33 # EV integration
34 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
32 35
33 # Event integration 36 # Event integration
34 Event->io (fd => IO::AIO::poll_fileno, 37 Event->io (fd => IO::AIO::poll_fileno,
35 poll => 'r', 38 poll => 'r',
36 cb => \&IO::AIO::poll_cb); 39 cb => \&IO::AIO::poll_cb);
262 Asynchronously close a file and call the callback with the result 265 Asynchronously close a file and call the callback with the result
263 code. 266 code.
264 267
265 Unfortunately, you can't do this to perl. Perl *insists* very 268 Unfortunately, you can't do this to perl. Perl *insists* very
266 strongly on closing the file descriptor associated with the 269 strongly on closing the file descriptor associated with the
267 filehandle itself. Here is what aio_close will try: 270 filehandle itself.
268 271
269 1. dup()licate the fd 272 Therefore, "aio_close" will not close the filehandle - instead it
270 2. asynchronously close() the duplicated fd 273 will use dup2 to overwrite the file descriptor with the write-end of
271 3. dup()licate the fd once more 274 a pipe (the pipe fd will be created on demand and will be cached).
272 4. let perl close() the filehandle
273 5. asynchronously close the duplicated fd
274 275
275 The idea is that the first close() flushes stuff to disk that 276 Or in other words: the file descriptor will be closed, but it will
276 closing an fd will flush, so when perl closes the fd, nothing much 277 not be free for reuse until the perl filehandle is closed.
277 will need to be flushed. The second async. close() will then flush
278 stuff to disk that closing the last fd to the file will flush.
279
280 Just FYI, SuSv3 has this to say on close:
281
282 All outstanding record locks owned by the process on the file
283 associated with the file descriptor shall be removed.
284
285 If fildes refers to a socket, close() shall cause the socket to be
286 destroyed. ... close() shall block for up to the current linger
287 interval until all data is transmitted.
288 [this actually sounds like a specification bug, but who knows]
289
290 And at least Linux additionally actually flushes stuff on every
291 close, even when the file itself is still open.
292
293 Sounds enourmously inefficient and complicated? Yes... please show
294 me how to nuke perl's fd out of existence...
295 278
296 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 279 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
297 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 280 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
298 Reads or writes $length bytes from the specified $fh and $offset 281 Reads or writes $length bytes from the specified $fh and $offset
299 into the scalar given by $data and offset $dataoffset and calls the 282 into the scalar given by $data and offset $dataoffset and calls the
546 Delete a directory tree starting (and including) $path, return the 529 Delete a directory tree starting (and including) $path, return the
547 status of the final "rmdir" only. This is a composite request that 530 status of the final "rmdir" only. This is a composite request that
548 uses "aio_scandir" to recurse into and rmdir directories, and unlink 531 uses "aio_scandir" to recurse into and rmdir directories, and unlink
549 everything else. 532 everything else.
550 533
534 aio_sync $callback->($status)
535 Asynchronously call sync and call the callback when finished.
536
551 aio_fsync $fh, $callback->($status) 537 aio_fsync $fh, $callback->($status)
552 Asynchronously call fsync on the given filehandle and call the 538 Asynchronously call fsync on the given filehandle and call the
553 callback with the fsync result code. 539 callback with the fsync result code.
554 540
555 aio_fdatasync $fh, $callback->($status) 541 aio_fdatasync $fh, $callback->($status)
556 Asynchronously call fdatasync on the given filehandle and call the 542 Asynchronously call fdatasync on the given filehandle and call the
557 callback with the fdatasync result code. 543 callback with the fdatasync result code.
558 544
559 If this call isn't available because your OS lacks it or it couldn't 545 If this call isn't available because your OS lacks it or it couldn't
560 be detected, it will be emulated by calling "fsync" instead. 546 be detected, it will be emulated by calling "fsync" instead.
547
548 aio_pathsync $path, $callback->($status)
549 This request tries to open, fsync and close the given path. This is
550 a composite request intended tosync directories after directory
551 operations (E.g. rename). This might not work on all operating
552 systems or have any specific effect, but usually it makes sure that
553 directory changes get written to disc. It works for anything that
554 can be opened for read-only, not just directories.
555
556 Passes 0 when everything went ok, and -1 on error.
561 557
562 aio_group $callback->(...) 558 aio_group $callback->(...)
563 This is a very special aio request: Instead of doing something, it 559 This is a very special aio request: Instead of doing something, it
564 is a container for other aio requests, which is useful if you want 560 is a container for other aio requests, which is useful if you want
565 to bundle many requests into a single, composite, request with a 561 to bundle many requests into a single, composite, request with a
647 }; 643 };
648 644
649 This makes it very easy to create composite requests (see the source of 645 This makes it very easy to create composite requests (see the source of
650 "aio_move" for an application) that work and feel like simple requests. 646 "aio_move" for an application) that work and feel like simple requests.
651 647
652 * The IO::AIO::GRP objects will be cleaned up during calls to 648 * The IO::AIO::GRP objects will be cleaned up during calls to
653 "IO::AIO::poll_cb", just like any other request. 649 "IO::AIO::poll_cb", just like any other request.
650
654 * They can be canceled like any other request. Canceling will cancel not 651 * They can be canceled like any other request. Canceling will cancel
655 only the request itself, but also all requests it contains. 652 not only the request itself, but also all requests it contains.
653
656 * They can also can also be added to other IO::AIO::GRP objects. 654 * They can also can also be added to other IO::AIO::GRP objects.
655
657 * You must not add requests to a group from within the group callback 656 * You must not add requests to a group from within the group callback
658 (or any later time). 657 (or any later time).
659 658
660 Their lifetime, simplified, looks like this: when they are empty, they 659 Their lifetime, simplified, looks like this: when they are empty, they
661 will finish very quickly. If they contain only requests that are in the 660 will finish very quickly. If they contain only requests that are in the
662 "done" state, they will also finish. Otherwise they will continue to 661 "done" state, they will also finish. Otherwise they will continue to
663 exist. 662 exist.
680 request itself. Useful when you queued a lot of events but got a 679 request itself. Useful when you queued a lot of events but got a
681 result early. 680 result early.
682 681
683 $grp->result (...) 682 $grp->result (...)
684 Set the result value(s) that will be passed to the group callback 683 Set the result value(s) that will be passed to the group callback
685 when all subrequests have finished and set thre groups errno to the 684 when all subrequests have finished and set the groups errno to the
686 current value of errno (just like calling "errno" without an error 685 current value of errno (just like calling "errno" without an error
687 number). By default, no argument will be passed and errno is zero. 686 number). By default, no argument will be passed and errno is zero.
688 687
689 $grp->errno ([$errno]) 688 $grp->errno ([$errno])
690 Sets the group errno value to $errno, or the current value of errno 689 Sets the group errno value to $errno, or the current value of errno

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