ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.120 by root, Sun Dec 2 21:51:36 2007 UTC vs.
Revision 1.156 by root, Tue Jun 16 23:41:59 2009 UTC

… …
26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30 30
31 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...) 31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 32 use AnyEvent::AIO;
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34 33
35 # EV integration 34 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 35 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37 36
38 # Event integration 37 # Event integration
39 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
40 poll => 'r', 39 poll => 'r',
41 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
… …
53 \&IO::AIO::poll_cb); 52 \&IO::AIO::poll_cb);
54 53
55=head1 DESCRIPTION 54=head1 DESCRIPTION
56 55
57This module implements asynchronous I/O using whatever means your 56This module implements asynchronous I/O using whatever means your
58operating system supports. 57operating system supports. It is implemented as an interface to C<libeio>
58(L<http://software.schmorp.de/pkg/libeio.html>).
59 59
60Asynchronous means that operations that can normally block your program 60Asynchronous means that operations that can normally block your program
61(e.g. reading from disk) will be done asynchronously: the operation 61(e.g. reading from disk) will be done asynchronously: the operation
62will still block, but you can do something else in the meantime. This 62will still block, but you can do something else in the meantime. This
63is extremely useful for programs that need to stay interactive even 63is extremely useful for programs that need to stay interactive even
… …
67on a RAID volume or over NFS when you do a number of stat operations 67on a RAID volume or over NFS when you do a number of stat operations
68concurrently. 68concurrently.
69 69
70While most of this works on all types of file descriptors (for 70While most of this works on all types of file descriptors (for
71example sockets), using these functions on file descriptors that 71example sockets), using these functions on file descriptors that
72support nonblocking operation (again, sockets, pipes etc.) is very 72support nonblocking operation (again, sockets, pipes etc.) is
73inefficient. Use an event loop for that (such as the L<Event|Event> 73very inefficient. Use an event loop for that (such as the L<EV>
74module): IO::AIO will naturally fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
75 75
76In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
77requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
78in perl, and the threads created by this module will not be visible 78in perl, and the threads created by this module will not be visible
… …
88yourself, always call C<poll_cb> from within the same thread, or never 88yourself, always call C<poll_cb> from within the same thread, or never
89call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
90 90
91=head2 EXAMPLE 91=head2 EXAMPLE
92 92
93This is a simple example that uses the Event module and loads 93This is a simple example that uses the EV module and loads
94F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
95 95
96 use Fcntl; 96 use Fcntl;
97 use Event; 97 use EV;
98 use IO::AIO; 98 use IO::AIO;
99 99
100 # register the IO::AIO callback with Event 100 # register the IO::AIO callback with EV
101 Event->io (fd => IO::AIO::poll_fileno, 101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102 poll => 'r',
103 cb => \&IO::AIO::poll_cb);
104 102
105 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
106 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
107 my $fh = shift 105 my $fh = shift
108 or die "error while opening: $!"; 106 or die "error while opening: $!";
… …
120 118
121 # file contents now in $contents 119 # file contents now in $contents
122 print $contents; 120 print $contents;
123 121
124 # exit event loop and program 122 # exit event loop and program
125 Event::unloop; 123 EV::unloop;
126 }; 124 };
127 }; 125 };
128 126
129 # possibly queue up other requests, or open GUI windows, 127 # possibly queue up other requests, or open GUI windows,
130 # check for sockets etc. etc. 128 # check for sockets etc. etc.
131 129
132 # process events as long as there are some: 130 # process events as long as there are some:
133 Event::loop; 131 EV::loop;
134 132
135=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
136 134
137Every C<aio_*> function creates a request. which is a C data structure not 135Every C<aio_*> function creates a request. which is a C data structure not
138directly visible to Perl. 136directly visible to Perl.
… …
194use strict 'vars'; 192use strict 'vars';
195 193
196use base 'Exporter'; 194use base 'Exporter';
197 195
198BEGIN { 196BEGIN {
199 our $VERSION = '2.6'; 197 our $VERSION = '3.23';
200 198
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 199 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 200 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 201 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 202 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 203 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 204 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 205 aio_chmod aio_utime aio_truncate);
208 206
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 210 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 211 max_poll_time max_poll_reqs);
212
213 push @AIO_REQ, qw(aio_busy); # not exported
214 214
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 216
217 require XSLoader; 217 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 218 XSLoader::load ("IO::AIO", $VERSION);
… …
225All the C<aio_*> calls are more or less thin wrappers around the syscall 225All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 226with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 227and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 228which must be a code reference. This code reference will get called with
229the syscall return code (e.g. most syscalls return C<-1> on error, unlike 229the syscall return code (e.g. most syscalls return C<-1> on error, unlike
230perl, which usually delivers "false") as it's sole argument when the given 230perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 231syscall has been executed asynchronously.
232 232
233All functions expecting a filehandle keep a copy of the filehandle 233All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 234internally until the request has finished.
235 235
… …
249your pathnames to the locale (or other) encoding in effect in the user 249your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 250environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 251use something else to ensure your scalar has the correct contents.
252 252
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 253This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 254handles correctly whether it is set or not.
255 255
256=over 4 256=over 4
257 257
258=item $prev_pri = aioreq_pri [$pri] 258=item $prev_pri = aioreq_pri [$pri]
259 259
… …
322 322
323Asynchronously close a file and call the callback with the result 323Asynchronously close a file and call the callback with the result
324code. 324code.
325 325
326Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 326Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
327closing the file descriptor associated with the filehandle itself. Here is 327closing the file descriptor associated with the filehandle itself.
328what aio_close will try:
329 328
330 1. dup()licate the fd 329Therefore, C<aio_close> will not close the filehandle - instead it will
331 2. asynchronously close() the duplicated fd 330use dup2 to overwrite the file descriptor with the write-end of a pipe
332 3. dup()licate the fd once more 331(the pipe fd will be created on demand and will be cached).
333 4. let perl close() the filehandle
334 5. asynchronously close the duplicated fd
335 332
336The idea is that the first close() flushes stuff to disk that closing an 333Or in other words: the file descriptor will be closed, but it will not be
337fd will flush, so when perl closes the fd, nothing much will need to be 334free for reuse until the perl filehandle is closed.
338flushed. The second async. close() will then flush stuff to disk that
339closing the last fd to the file will flush.
340
341Just FYI, SuSv3 has this to say on close:
342
343 All outstanding record locks owned by the process on the file
344 associated with the file descriptor shall be removed.
345
346 If fildes refers to a socket, close() shall cause the socket to be
347 destroyed. ... close() shall block for up to the current linger
348 interval until all data is transmitted.
349 [this actually sounds like a specification bug, but who knows]
350
351And at least Linux additionally actually flushes stuff on every close,
352even when the file itself is still open.
353
354Sounds enourmously inefficient and complicated? Yes... please show me how
355to nuke perl's fd out of existence...
356 335
357=cut 336=cut
358 337
359sub aio_close($;$) {
360 aio_block {
361 my ($fh, $cb) = @_;
362
363 my $pri = aioreq_pri;
364 my $grp = aio_group $cb;
365
366 my $fd = fileno $fh;
367
368 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
369
370 # if the dups fail we will simply get EBADF
371 my $fd2 = _dup $fd;
372 aioreq_pri $pri;
373 add $grp _aio_close $fd2, sub {
374 my $fd2 = _dup $fd;
375 close $fh;
376 aioreq_pri $pri;
377 add $grp _aio_close $fd2, sub {
378 $grp->result ($_[0]);
379 };
380 };
381
382 $grp
383 }
384}
385
386
387=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
388 339
389=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
390 341
391Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 342Reads or writes C<$length> bytes from or to the specified C<$fh> and
392into the scalar given by C<$data> and offset C<$dataoffset> and calls the 343C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
393callback without the actual number of bytes read (or -1 on error, just 344and calls the callback without the actual number of bytes read (or -1 on
394like the syscall). 345error, just like the syscall).
346
347C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
348offset plus the actual number of bytes read.
395 349
396If C<$offset> is undefined, then the current file descriptor offset will 350If C<$offset> is undefined, then the current file descriptor offset will
397be used (and updated), otherwise the file descriptor offset will not be 351be used (and updated), otherwise the file descriptor offset will not be
398changed by these calls. 352changed by these calls.
399 353
400If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 354If C<$length> is undefined in C<aio_write>, use the remaining length of
355C<$data>.
401 356
402If C<$dataoffset> is less than zero, it will be counted from the end of 357If C<$dataoffset> is less than zero, it will be counted from the end of
403C<$data>. 358C<$data>.
404 359
405The C<$data> scalar I<MUST NOT> be modified in any way while the request 360The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
577 532
578Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 533Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
579directory (i.e. opendir + readdir + closedir). The entries will not be 534directory (i.e. opendir + readdir + closedir). The entries will not be
580sorted, and will B<NOT> include the C<.> and C<..> entries. 535sorted, and will B<NOT> include the C<.> and C<..> entries.
581 536
582The callback a single argument which is either C<undef> or an array-ref 537The callback is passed a single argument which is either C<undef> or an
583with the filenames. 538array-ref with the filenames.
539
540
541=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
542
543Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
544behaviour and output format. In case of an error, C<$entries> will be
545C<undef>.
546
547The flags are a combination of the following constants, ORed together (the
548flags will also be passed to the callback, possibly modified):
549
550=over 4
551
552=item IO::AIO::READDIR_DENTS
553
554When this flag is off, then the callback gets an arrayref with of names
555only (as with C<aio_readdir>), otherwise it gets an arrayref with
556C<[$name, $type, $inode]> arrayrefs, each describing a single directory
557entry in more detail.
558
559C<$name> is the name of the entry.
560
561C<$type> is one of the C<IO::AIO::DT_xxx> constants:
562
563C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
564C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
565C<IO::AIO::DT_WHT>.
566
567C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
568know, you have to run stat yourself. Also, for speed reasons, the C<$type>
569scalars are read-only: you can not modify them.
570
571C<$inode> is the inode number (which might not be exact on systems with 64
572bit inode numbers and 32 bit perls). This field has unspecified content on
573systems that do not deliver the inode information.
574
575=item IO::AIO::READDIR_DIRS_FIRST
576
577When this flag is set, then the names will be returned in an order where
578likely directories come first. This is useful when you need to quickly
579find directories, or you want to find all directories while avoiding to
580stat() each entry.
581
582If the system returns type information in readdir, then this is used
583to find directories directly. Otherwise, likely directories are files
584beginning with ".", or otherwise files with no dots, of which files with
585short names are tried first.
586
587=item IO::AIO::READDIR_STAT_ORDER
588
589When this flag is set, then the names will be returned in an order
590suitable for stat()'ing each one. That is, when you plan to stat()
591all files in the given directory, then the returned order will likely
592be fastest.
593
594If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
595the likely dirs come first, resulting in a less optimal stat order.
596
597=item IO::AIO::READDIR_FOUND_UNKNOWN
598
599This flag should not be set when calling C<aio_readdirx>. Instead, it
600is being set by C<aio_readdirx>, when any of the C<$type>'s found were
601C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
602C<$type>'s are known, which can be used to speed up some algorithms.
603
604=back
584 605
585 606
586=item aio_load $path, $data, $callback->($status) 607=item aio_load $path, $data, $callback->($status)
587 608
588This is a composite request that tries to fully load the given file into 609This is a composite request that tries to fully load the given file into
589memory. Status is the same as with aio_read. 610memory. Status is the same as with aio_read.
590 611
591=cut 612=cut
592 613
593sub aio_load($$;$) { 614sub aio_load($$;$) {
594 aio_block {
595 my ($path, undef, $cb) = @_; 615 my ($path, undef, $cb) = @_;
596 my $data = \$_[1]; 616 my $data = \$_[1];
597 617
598 my $pri = aioreq_pri; 618 my $pri = aioreq_pri;
599 my $grp = aio_group $cb; 619 my $grp = aio_group $cb;
620
621 aioreq_pri $pri;
622 add $grp aio_open $path, O_RDONLY, 0, sub {
623 my $fh = shift
624 or return $grp->result (-1);
600 625
601 aioreq_pri $pri; 626 aioreq_pri $pri;
602 add $grp aio_open $path, O_RDONLY, 0, sub {
603 my $fh = shift
604 or return $grp->result (-1);
605
606 aioreq_pri $pri;
607 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 627 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
608 $grp->result ($_[0]); 628 $grp->result ($_[0]);
609 };
610 }; 629 };
611
612 $grp
613 } 630 };
631
632 $grp
614} 633}
615 634
616=item aio_copy $srcpath, $dstpath, $callback->($status) 635=item aio_copy $srcpath, $dstpath, $callback->($status)
617 636
618Try to copy the I<file> (directories not supported as either source or 637Try to copy the I<file> (directories not supported as either source or
619destination) from C<$srcpath> to C<$dstpath> and call the callback with 638destination) from C<$srcpath> to C<$dstpath> and call the callback with
620the C<0> (error) or C<-1> ok. 639the C<0> (error) or C<-1> ok.
621 640
622This is a composite request that it creates the destination file with 641This is a composite request that creates the destination file with
623mode 0200 and copies the contents of the source file into it using 642mode 0200 and copies the contents of the source file into it using
624C<aio_sendfile>, followed by restoring atime, mtime, access mode and 643C<aio_sendfile>, followed by restoring atime, mtime, access mode and
625uid/gid, in that order. 644uid/gid, in that order.
626 645
627If an error occurs, the partial destination file will be unlinked, if 646If an error occurs, the partial destination file will be unlinked, if
… …
629errors are being ignored. 648errors are being ignored.
630 649
631=cut 650=cut
632 651
633sub aio_copy($$;$) { 652sub aio_copy($$;$) {
634 aio_block {
635 my ($src, $dst, $cb) = @_; 653 my ($src, $dst, $cb) = @_;
636 654
637 my $pri = aioreq_pri; 655 my $pri = aioreq_pri;
638 my $grp = aio_group $cb; 656 my $grp = aio_group $cb;
639 657
640 aioreq_pri $pri; 658 aioreq_pri $pri;
641 add $grp aio_open $src, O_RDONLY, 0, sub { 659 add $grp aio_open $src, O_RDONLY, 0, sub {
642 if (my $src_fh = $_[0]) { 660 if (my $src_fh = $_[0]) {
643 my @stat = stat $src_fh; 661 my @stat = stat $src_fh; # hmm, might bock over nfs?
644 662
645 aioreq_pri $pri; 663 aioreq_pri $pri;
646 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 664 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
647 if (my $dst_fh = $_[0]) { 665 if (my $dst_fh = $_[0]) {
648 aioreq_pri $pri; 666 aioreq_pri $pri;
649 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 667 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
650 if ($_[0] == $stat[7]) { 668 if ($_[0] == $stat[7]) {
651 $grp->result (0); 669 $grp->result (0);
652 close $src_fh; 670 close $src_fh;
653 671
654 # those should not normally block. should. should. 672 my $ch = sub {
655 utime $stat[8], $stat[9], $dst;
656 chmod $stat[2] & 07777, $dst_fh;
657 chown $stat[4], $stat[5], $dst_fh;
658
659 aioreq_pri $pri; 673 aioreq_pri $pri;
674 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
675 aioreq_pri $pri;
676 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
677 aioreq_pri $pri;
660 add $grp aio_close $dst_fh; 678 add $grp aio_close $dst_fh;
661 } else { 679 }
662 $grp->result (-1);
663 close $src_fh;
664 close $dst_fh;
665
666 aioreq $pri; 680 };
667 add $grp aio_unlink $dst;
668 } 681 };
682
683 aioreq_pri $pri;
684 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
685 if ($_[0] < 0 && $! == ENOSYS) {
686 aioreq_pri $pri;
687 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
688 } else {
689 $ch->();
690 }
691 };
692 } else {
693 $grp->result (-1);
694 close $src_fh;
695 close $dst_fh;
696
697 aioreq $pri;
698 add $grp aio_unlink $dst;
669 }; 699 }
670 } else {
671 $grp->result (-1);
672 } 700 };
701 } else {
702 $grp->result (-1);
673 }, 703 }
674
675 } else {
676 $grp->result (-1);
677 } 704 },
705
706 } else {
707 $grp->result (-1);
678 }; 708 }
679
680 $grp
681 } 709 };
710
711 $grp
682} 712}
683 713
684=item aio_move $srcpath, $dstpath, $callback->($status) 714=item aio_move $srcpath, $dstpath, $callback->($status)
685 715
686Try to move the I<file> (directories not supported as either source or 716Try to move the I<file> (directories not supported as either source or
687destination) from C<$srcpath> to C<$dstpath> and call the callback with 717destination) from C<$srcpath> to C<$dstpath> and call the callback with
688the C<0> (error) or C<-1> ok. 718the C<0> (error) or C<-1> ok.
689 719
690This is a composite request that tries to rename(2) the file first. If 720This is a composite request that tries to rename(2) the file first; if
691rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 721rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
692that is successful, unlinking the C<$srcpath>. 722that is successful, unlinks the C<$srcpath>.
693 723
694=cut 724=cut
695 725
696sub aio_move($$;$) { 726sub aio_move($$;$) {
697 aio_block {
698 my ($src, $dst, $cb) = @_; 727 my ($src, $dst, $cb) = @_;
699 728
700 my $pri = aioreq_pri; 729 my $pri = aioreq_pri;
701 my $grp = aio_group $cb; 730 my $grp = aio_group $cb;
702 731
703 aioreq_pri $pri; 732 aioreq_pri $pri;
704 add $grp aio_rename $src, $dst, sub { 733 add $grp aio_rename $src, $dst, sub {
705 if ($_[0] && $! == EXDEV) { 734 if ($_[0] && $! == EXDEV) {
706 aioreq_pri $pri; 735 aioreq_pri $pri;
707 add $grp aio_copy $src, $dst, sub { 736 add $grp aio_copy $src, $dst, sub {
708 $grp->result ($_[0]);
709
710 if (!$_[0]) {
711 aioreq_pri $pri;
712 add $grp aio_unlink $src;
713 }
714 };
715 } else {
716 $grp->result ($_[0]); 737 $grp->result ($_[0]);
738
739 if (!$_[0]) {
740 aioreq_pri $pri;
741 add $grp aio_unlink $src;
742 }
717 } 743 };
744 } else {
745 $grp->result ($_[0]);
718 }; 746 }
719
720 $grp
721 } 747 };
748
749 $grp
722} 750}
723 751
724=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 752=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
725 753
726Scans a directory (similar to C<aio_readdir>) but additionally tries to 754Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
746 774
747Implementation notes. 775Implementation notes.
748 776
749The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 777The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
750 778
779If readdir returns file type information, then this is used directly to
780find directories.
781
751After reading the directory, the modification time, size etc. of the 782Otherwise, after reading the directory, the modification time, size etc.
752directory before and after the readdir is checked, and if they match (and 783of the directory before and after the readdir is checked, and if they
753isn't the current time), the link count will be used to decide how many 784match (and isn't the current time), the link count will be used to decide
754entries are directories (if >= 2). Otherwise, no knowledge of the number 785how many entries are directories (if >= 2). Otherwise, no knowledge of the
755of subdirectories will be assumed. 786number of subdirectories will be assumed.
756 787
757Then entries will be sorted into likely directories (everything without 788Then entries will be sorted into likely directories a non-initial dot
758a non-initial dot currently) and likely non-directories (everything 789currently) and likely non-directories (see C<aio_readdirx>). Then every
759else). Then every entry plus an appended C</.> will be C<stat>'ed, 790entry plus an appended C</.> will be C<stat>'ed, likely directories first,
760likely directories first. If that succeeds, it assumes that the entry 791in order of their inode numbers. If that succeeds, it assumes that the
761is a directory or a symlink to directory (which will be checked 792entry is a directory or a symlink to directory (which will be checked
762seperately). This is often faster than stat'ing the entry itself because 793seperately). This is often faster than stat'ing the entry itself because
763filesystems might detect the type of the entry without reading the inode 794filesystems might detect the type of the entry without reading the inode
764data (e.g. ext2fs filetype feature). 795data (e.g. ext2fs filetype feature), even on systems that cannot return
796the filetype information on readdir.
765 797
766If the known number of directories (link count - 2) has been reached, the 798If the known number of directories (link count - 2) has been reached, the
767rest of the entries is assumed to be non-directories. 799rest of the entries is assumed to be non-directories.
768 800
769This only works with certainty on POSIX (= UNIX) filesystems, which 801This only works with certainty on POSIX (= UNIX) filesystems, which
… …
774directory counting heuristic. 806directory counting heuristic.
775 807
776=cut 808=cut
777 809
778sub aio_scandir($$;$) { 810sub aio_scandir($$;$) {
779 aio_block {
780 my ($path, $maxreq, $cb) = @_; 811 my ($path, $maxreq, $cb) = @_;
781 812
782 my $pri = aioreq_pri; 813 my $pri = aioreq_pri;
783 814
784 my $grp = aio_group $cb; 815 my $grp = aio_group $cb;
785 816
786 $maxreq = 4 if $maxreq <= 0; 817 $maxreq = 4 if $maxreq <= 0;
787 818
788 # stat once 819 # stat once
820 aioreq_pri $pri;
821 add $grp aio_stat $path, sub {
822 return $grp->result () if $_[0];
823 my $now = time;
824 my $hash1 = join ":", (stat _)[0,1,3,7,9];
825
826 # read the directory entries
789 aioreq_pri $pri; 827 aioreq_pri $pri;
790 add $grp aio_stat $path, sub { 828 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
829 my $entries = shift
791 return $grp->result () if $_[0]; 830 or return $grp->result ();
792 my $now = time;
793 my $hash1 = join ":", (stat _)[0,1,3,7,9];
794 831
795 # read the directory entries 832 # stat the dir another time
796 aioreq_pri $pri; 833 aioreq_pri $pri;
797 add $grp aio_readdir $path, sub {
798 my $entries = shift
799 or return $grp->result ();
800
801 # stat the dir another time
802 aioreq_pri $pri;
803 add $grp aio_stat $path, sub { 834 add $grp aio_stat $path, sub {
804 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 835 my $hash2 = join ":", (stat _)[0,1,3,7,9];
805 836
806 my $ndirs; 837 my $ndirs;
807 838
808 # take the slow route if anything looks fishy 839 # take the slow route if anything looks fishy
809 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 840 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
810 $ndirs = -1; 841 $ndirs = -1;
811 } else { 842 } else {
812 # if nlink == 2, we are finished 843 # if nlink == 2, we are finished
813 # on non-posix-fs's, we rely on nlink < 2 844 # for non-posix-fs's, we rely on nlink < 2
814 $ndirs = (stat _)[3] - 2 845 $ndirs = (stat _)[3] - 2
815 or return $grp->result ([], $entries); 846 or return $grp->result ([], $entries);
816 } 847 }
817 848
818 # sort into likely dirs and likely nondirs
819 # dirs == files without ".", short entries first
820 $entries = [map $_->[0],
821 sort { $b->[1] cmp $a->[1] }
822 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
823 @$entries];
824
825 my (@dirs, @nondirs); 849 my (@dirs, @nondirs);
826 850
827 my $statgrp = add $grp aio_group sub { 851 my $statgrp = add $grp aio_group sub {
828 $grp->result (\@dirs, \@nondirs); 852 $grp->result (\@dirs, \@nondirs);
829 }; 853 };
830 854
831 limit $statgrp $maxreq; 855 limit $statgrp $maxreq;
832 feed $statgrp sub { 856 feed $statgrp sub {
833 return unless @$entries; 857 return unless @$entries;
834 my $entry = pop @$entries; 858 my $entry = shift @$entries;
835 859
836 aioreq_pri $pri; 860 aioreq_pri $pri;
837 add $statgrp aio_stat "$path/$entry/.", sub { 861 add $statgrp aio_stat "$path/$entry/.", sub {
838 if ($_[0] < 0) { 862 if ($_[0] < 0) {
839 push @nondirs, $entry; 863 push @nondirs, $entry;
840 } else { 864 } else {
841 # need to check for real directory 865 # need to check for real directory
842 aioreq_pri $pri; 866 aioreq_pri $pri;
843 add $statgrp aio_lstat "$path/$entry", sub { 867 add $statgrp aio_lstat "$path/$entry", sub {
844 if (-d _) { 868 if (-d _) {
845 push @dirs, $entry; 869 push @dirs, $entry;
846 870
847 unless (--$ndirs) { 871 unless (--$ndirs) {
848 push @nondirs, @$entries; 872 push @nondirs, @$entries;
849 feed $statgrp; 873 feed $statgrp;
850 }
851 } else {
852 push @nondirs, $entry;
853 } 874 }
875 } else {
876 push @nondirs, $entry;
854 } 877 }
855 } 878 }
856 }; 879 }
857 }; 880 };
858 }; 881 };
859 }; 882 };
860 }; 883 };
861
862 $grp
863 } 884 };
885
886 $grp
864} 887}
865 888
866=item aio_rmtree $path, $callback->($status) 889=item aio_rmtree $path, $callback->($status)
867 890
868Delete a directory tree starting (and including) C<$path>, return the 891Delete a directory tree starting (and including) C<$path>, return the
… …
872 895
873=cut 896=cut
874 897
875sub aio_rmtree; 898sub aio_rmtree;
876sub aio_rmtree($;$) { 899sub aio_rmtree($;$) {
877 aio_block {
878 my ($path, $cb) = @_; 900 my ($path, $cb) = @_;
879 901
880 my $pri = aioreq_pri; 902 my $pri = aioreq_pri;
881 my $grp = aio_group $cb; 903 my $grp = aio_group $cb;
882 904
883 aioreq_pri $pri; 905 aioreq_pri $pri;
884 add $grp aio_scandir $path, 0, sub { 906 add $grp aio_scandir $path, 0, sub {
885 my ($dirs, $nondirs) = @_; 907 my ($dirs, $nondirs) = @_;
886 908
887 my $dirgrp = aio_group sub { 909 my $dirgrp = aio_group sub {
888 add $grp aio_rmdir $path, sub { 910 add $grp aio_rmdir $path, sub {
889 $grp->result ($_[0]); 911 $grp->result ($_[0]);
890 };
891 }; 912 };
892
893 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
894 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
895
896 add $grp $dirgrp;
897 }; 913 };
898 914
899 $grp 915 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
916 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
917
918 add $grp $dirgrp;
900 } 919 };
920
921 $grp
901} 922}
902 923
903=item aio_sync $callback->($status) 924=item aio_sync $callback->($status)
904 925
905Asynchronously call sync and call the callback when finished. 926Asynchronously call sync and call the callback when finished.
… …
915callback with the fdatasync result code. 936callback with the fdatasync result code.
916 937
917If this call isn't available because your OS lacks it or it couldn't be 938If this call isn't available because your OS lacks it or it couldn't be
918detected, it will be emulated by calling C<fsync> instead. 939detected, it will be emulated by calling C<fsync> instead.
919 940
941=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
942
943Sync the data portion of the file specified by C<$offset> and C<$length>
944to disk (but NOT the metadata), by calling the Linux-specific
945sync_file_range call. If sync_file_range is not available or it returns
946ENOSYS, then fdatasync or fsync is being substituted.
947
948C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
949C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
950C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
951manpage for details.
952
920=item aio_pathsync $path, $callback->($status) 953=item aio_pathsync $path, $callback->($status)
921 954
922This request tries to open, fsync and close the given path. This is a 955This request tries to open, fsync and close the given path. This is a
923composite request intended tosync directories after directory operations 956composite request intended to sync directories after directory operations
924(E.g. rename). This might not work on all operating systems or have any 957(E.g. rename). This might not work on all operating systems or have any
925specific effect, but usually it makes sure that directory changes get 958specific effect, but usually it makes sure that directory changes get
926written to disc. It works for anything that can be opened for read-only, 959written to disc. It works for anything that can be opened for read-only,
927not just directories. 960not just directories.
928 961
929Passes C<0> when everything went ok, and C<-1> on error. 962Passes C<0> when everything went ok, and C<-1> on error.
930 963
931=cut 964=cut
932 965
933sub aio_pathsync($;$) { 966sub aio_pathsync($;$) {
934 aio_block {
935 my ($path, $cb) = @_; 967 my ($path, $cb) = @_;
936 968
937 my $pri = aioreq_pri; 969 my $pri = aioreq_pri;
938 my $grp = aio_group $cb; 970 my $grp = aio_group $cb;
939 971
940 aioreq_pri $pri; 972 aioreq_pri $pri;
941 add $grp aio_open $path, O_RDONLY, 0, sub { 973 add $grp aio_open $path, O_RDONLY, 0, sub {
942 my ($fh) = @_; 974 my ($fh) = @_;
943 if ($fh) { 975 if ($fh) {
976 aioreq_pri $pri;
977 add $grp aio_fsync $fh, sub {
978 $grp->result ($_[0]);
979
944 aioreq_pri $pri; 980 aioreq_pri $pri;
945 add $grp aio_fsync $fh, sub {
946 $grp->result ($_[0]);
947
948 aioreq_pri $pri;
949 add $grp aio_close $fh; 981 add $grp aio_close $fh;
950 };
951 } else {
952 $grp->result (-1);
953 } 982 };
983 } else {
984 $grp->result (-1);
954 }; 985 }
955
956 $grp
957 } 986 };
987
988 $grp
958} 989}
959 990
960=item aio_group $callback->(...) 991=item aio_group $callback->(...)
961 992
962This is a very special aio request: Instead of doing something, it is a 993This is a very special aio request: Instead of doing something, it is a
… …
1013=item cancel $req 1044=item cancel $req
1014 1045
1015Cancels the request, if possible. Has the effect of skipping execution 1046Cancels the request, if possible. Has the effect of skipping execution
1016when entering the B<execute> state and skipping calling the callback when 1047when entering the B<execute> state and skipping calling the callback when
1017entering the the B<result> state, but will leave the request otherwise 1048entering the the B<result> state, but will leave the request otherwise
1018untouched. That means that requests that currently execute will not be 1049untouched (with the exception of readdir). That means that requests that
1019stopped and resources held by the request will not be freed prematurely. 1050currently execute will not be stopped and resources held by the request
1051will not be freed prematurely.
1020 1052
1021=item cb $req $callback->(...) 1053=item cb $req $callback->(...)
1022 1054
1023Replace (or simply set) the callback registered to the request. 1055Replace (or simply set) the callback registered to the request.
1024 1056
… …
1075Their lifetime, simplified, looks like this: when they are empty, they 1107Their lifetime, simplified, looks like this: when they are empty, they
1076will finish very quickly. If they contain only requests that are in the 1108will finish very quickly. If they contain only requests that are in the
1077C<done> state, they will also finish. Otherwise they will continue to 1109C<done> state, they will also finish. Otherwise they will continue to
1078exist. 1110exist.
1079 1111
1080That means after creating a group you have some time to add requests. And 1112That means after creating a group you have some time to add requests
1081in the callbacks of those requests, you can add further requests to the 1113(precisely before the callback has been invoked, which is only done within
1082group. And only when all those requests have finished will the the group 1114the C<poll_cb>). And in the callbacks of those requests, you can add
1083itself finish. 1115further requests to the group. And only when all those requests have
1116finished will the the group itself finish.
1084 1117
1085=over 4 1118=over 4
1086 1119
1087=item add $grp ... 1120=item add $grp ...
1088 1121
… …
1121=item feed $grp $callback->($grp) 1154=item feed $grp $callback->($grp)
1122 1155
1123Sets a feeder/generator on this group: every group can have an attached 1156Sets a feeder/generator on this group: every group can have an attached
1124generator that generates requests if idle. The idea behind this is that, 1157generator that generates requests if idle. The idea behind this is that,
1125although you could just queue as many requests as you want in a group, 1158although you could just queue as many requests as you want in a group,
1126this might starve other requests for a potentially long time. For 1159this might starve other requests for a potentially long time. For example,
1127example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1160C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1128requests, delaying any later requests for a long time. 1161delaying any later requests for a long time.
1129 1162
1130To avoid this, and allow incremental generation of requests, you can 1163To avoid this, and allow incremental generation of requests, you can
1131instead a group and set a feeder on it that generates those requests. The 1164instead a group and set a feeder on it that generates those requests. The
1132feed callback will be called whenever there are few enough (see C<limit>, 1165feed callback will be called whenever there are few enough (see C<limit>,
1133below) requests active in the group itself and is expected to queue more 1166below) requests active in the group itself and is expected to queue more
… …
1137not impose any limits). 1170not impose any limits).
1138 1171
1139If the feed does not queue more requests when called, it will be 1172If the feed does not queue more requests when called, it will be
1140automatically removed from the group. 1173automatically removed from the group.
1141 1174
1142If the feed limit is C<0>, it will be set to C<2> automatically. 1175If the feed limit is C<0> when this method is called, it will be set to
1176C<2> automatically.
1143 1177
1144Example: 1178Example:
1145 1179
1146 # stat all files in @files, but only ever use four aio requests concurrently: 1180 # stat all files in @files, but only ever use four aio requests concurrently:
1147 1181
… …
1159Sets the feeder limit for the group: The feeder will be called whenever 1193Sets the feeder limit for the group: The feeder will be called whenever
1160the group contains less than this many requests. 1194the group contains less than this many requests.
1161 1195
1162Setting the limit to C<0> will pause the feeding process. 1196Setting the limit to C<0> will pause the feeding process.
1163 1197
1198The default value for the limit is C<0>, but note that setting a feeder
1199automatically bumps it up to C<2>.
1200
1164=back 1201=back
1165 1202
1166=head2 SUPPORT FUNCTIONS 1203=head2 SUPPORT FUNCTIONS
1167 1204
1168=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1205=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1170=over 4 1207=over 4
1171 1208
1172=item $fileno = IO::AIO::poll_fileno 1209=item $fileno = IO::AIO::poll_fileno
1173 1210
1174Return the I<request result pipe file descriptor>. This filehandle must be 1211Return the I<request result pipe file descriptor>. This filehandle must be
1175polled for reading by some mechanism outside this module (e.g. Event or 1212polled for reading by some mechanism outside this module (e.g. EV, Glib,
1176select, see below or the SYNOPSIS). If the pipe becomes readable you have 1213select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1177to call C<poll_cb> to check the results. 1214you have to call C<poll_cb> to check the results.
1178 1215
1179See C<poll_cb> for an example. 1216See C<poll_cb> for an example.
1180 1217
1181=item IO::AIO::poll_cb 1218=item IO::AIO::poll_cb
1182 1219
1183Process some outstanding events on the result pipe. You have to call this 1220Process some outstanding events on the result pipe. You have to call this
1184regularly. Returns the number of events processed. Returns immediately 1221regularly. Returns C<0> if all events could be processed, or C<-1> if it
1222returned earlier for whatever reason. Returns immediately when no events
1185when no events are outstanding. The amount of events processed depends on 1223are outstanding. The amount of events processed depends on the settings of
1186the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1224C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1187 1225
1188If not all requests were processed for whatever reason, the filehandle 1226If not all requests were processed for whatever reason, the filehandle
1189will still be ready when C<poll_cb> returns. 1227will still be ready when C<poll_cb> returns, so normally you don't have to
1228do anything special to have it called later.
1190 1229
1191Example: Install an Event watcher that automatically calls 1230Example: Install an Event watcher that automatically calls
1192IO::AIO::poll_cb with high priority: 1231IO::AIO::poll_cb with high priority (more examples can be found in the
1232SYNOPSIS section, at the top of this document):
1193 1233
1194 Event->io (fd => IO::AIO::poll_fileno, 1234 Event->io (fd => IO::AIO::poll_fileno,
1195 poll => 'r', async => 1, 1235 poll => 'r', async => 1,
1196 cb => \&IO::AIO::poll_cb); 1236 cb => \&IO::AIO::poll_cb);
1197 1237
… …
1308 1348
1309The default is probably ok in most situations, especially if thread 1349The default is probably ok in most situations, especially if thread
1310creation is fast. If thread creation is very slow on your system you might 1350creation is fast. If thread creation is very slow on your system you might
1311want to use larger values. 1351want to use larger values.
1312 1352
1313=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1353=item IO::AIO::max_outstanding $maxreqs
1314 1354
1315This is a very bad function to use in interactive programs because it 1355This is a very bad function to use in interactive programs because it
1316blocks, and a bad way to reduce concurrency because it is inexact: Better 1356blocks, and a bad way to reduce concurrency because it is inexact: Better
1317use an C<aio_group> together with a feed callback. 1357use an C<aio_group> together with a feed callback.
1318 1358
… …
1323 1363
1324The default value is very large, so there is no practical limit on the 1364The default value is very large, so there is no practical limit on the
1325number of outstanding requests. 1365number of outstanding requests.
1326 1366
1327You can still queue as many requests as you want. Therefore, 1367You can still queue as many requests as you want. Therefore,
1328C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1368C<max_outstanding> is mainly useful in simple scripts (with low values) or
1329as a stop gap to shield against fatal memory overflow (with large values). 1369as a stop gap to shield against fatal memory overflow (with large values).
1330 1370
1331=back 1371=back
1332 1372
1333=head3 STATISTICAL INFORMATION 1373=head3 STATISTICAL INFORMATION
… …
1403 1443
1404Known bugs will be fixed in the next release. 1444Known bugs will be fixed in the next release.
1405 1445
1406=head1 SEE ALSO 1446=head1 SEE ALSO
1407 1447
1408L<Coro::AIO>. 1448L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1449more natural syntax.
1409 1450
1410=head1 AUTHOR 1451=head1 AUTHOR
1411 1452
1412 Marc Lehmann <schmorp@schmorp.de> 1453 Marc Lehmann <schmorp@schmorp.de>
1413 http://home.schmorp.de/ 1454 http://home.schmorp.de/

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines