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 1.174 by root, Sun Jan 10 20:28:43 2010 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.
… …
188 186
189package IO::AIO; 187package IO::AIO;
190 188
191use Carp (); 189use Carp ();
192 190
193no warnings; 191use common::sense;
194use strict 'vars';
195 192
196use base 'Exporter'; 193use base 'Exporter';
197 194
198BEGIN { 195BEGIN {
199 our $VERSION = '2.6'; 196 our $VERSION = '3.5';
200 197
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 198 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 199 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 200 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 201 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 202 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 203 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 204 aio_chmod aio_utime aio_truncate
205 aio_msync aio_mtouch aio_statvfs);
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 sendfile fadvise);
213
214 push @AIO_REQ, qw(aio_busy); # not exported
214 215
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 217
217 require XSLoader; 218 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
… …
225All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 229which 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 230the 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 231perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 232syscall has been executed asynchronously.
232 233
233All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 235internally until the request has finished.
235 236
… …
249your pathnames to the locale (or other) encoding in effect in the user 250your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
252 253
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 254This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 255handles correctly whether it is set or not.
255 256
256=over 4 257=over 4
257 258
258=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
259 260
… …
322 323
323Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
324code. 325code.
325 326
326Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 327Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
327closing the file descriptor associated with the filehandle itself. Here is 328closing the file descriptor associated with the filehandle itself.
328what aio_close will try:
329 329
330 1. dup()licate the fd 330Therefore, C<aio_close> will not close the filehandle - instead it will
331 2. asynchronously close() the duplicated fd 331use dup2 to overwrite the file descriptor with the write-end of a pipe
332 3. dup()licate the fd once more 332(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
335 333
336The idea is that the first close() flushes stuff to disk that closing an 334Or 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 335free 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...
356 336
357=cut 337=cut
358 338
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) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
388 340
389=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
390 342
391Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 343Reads or writes C<$length> bytes from or to the specified C<$fh> and
392into the scalar given by C<$data> and offset C<$dataoffset> and calls the 344C<$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 345and calls the callback without the actual number of bytes read (or -1 on
394like the syscall). 346error, just like the syscall).
347
348C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
349offset plus the actual number of bytes read.
395 350
396If C<$offset> is undefined, then the current file descriptor offset will 351If C<$offset> is undefined, then the current file descriptor offset will
397be used (and updated), otherwise the file descriptor offset will not be 352be used (and updated), otherwise the file descriptor offset will not be
398changed by these calls. 353changed by these calls.
399 354
400If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 355If C<$length> is undefined in C<aio_write>, use the remaining length of
356C<$data>.
401 357
402If C<$dataoffset> is less than zero, it will be counted from the end of 358If C<$dataoffset> is less than zero, it will be counted from the end of
403C<$data>. 359C<$data>.
404 360
405The C<$data> scalar I<MUST NOT> be modified in any way while the request 361The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
425 381
426This call tries to make use of a native C<sendfile> syscall to provide 382This call tries to make use of a native C<sendfile> syscall to provide
427zero-copy operation. For this to work, C<$out_fh> should refer to a 383zero-copy operation. For this to work, C<$out_fh> should refer to a
428socket, and C<$in_fh> should refer to mmap'able file. 384socket, and C<$in_fh> should refer to mmap'able file.
429 385
430If the native sendfile call fails or is not implemented, it will be 386If a native sendfile cannot be found or it fails with C<ENOSYS>,
387C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
431emulated, so you can call C<aio_sendfile> on any type of filehandle 388it will be emulated, so you can call C<aio_sendfile> on any type of
432regardless of the limitations of the operating system. 389filehandle regardless of the limitations of the operating system.
433 390
434Please note, however, that C<aio_sendfile> can read more bytes from 391Please note, however, that C<aio_sendfile> can read more bytes from
435C<$in_fh> than are written, and there is no way to find out how many 392C<$in_fh> than are written, and there is no way to find out how many
436bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 393bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
437provides the number of bytes written to C<$out_fh>. Only if the result 394provides the number of bytes written to C<$out_fh>. Only if the result
… …
475 $_[0] and die "stat failed: $!"; 432 $_[0] and die "stat failed: $!";
476 print "size is ", -s _, "\n"; 433 print "size is ", -s _, "\n";
477 }; 434 };
478 435
479 436
437=item aio_statvfs $fh_or_path, $callback->($statvfs)
438
439Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
440whether a file handle or path was passed.
441
442On success, the callback is passed a hash reference with the following
443members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
444C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
445is passed.
446
447The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
448C<ST_NOSUID>.
449
450The following non-POSIX IO::AIO::ST_* flag masks are defined to
451their correct value when available, or to C<0> on systems that do
452not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
453C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
454C<ST_NODIRATIME> and C<ST_RELATIME>.
455
456Example: stat C</wd> and dump out the data if successful.
457
458 aio_statvfs "/wd", sub {
459 my $f = $_[0]
460 or die "statvfs: $!";
461
462 use Data::Dumper;
463 say Dumper $f;
464 };
465
466 # result:
467 {
468 bsize => 1024,
469 bfree => 4333064312,
470 blocks => 10253828096,
471 files => 2050765568,
472 flag => 4096,
473 favail => 2042092649,
474 bavail => 4333064312,
475 ffree => 2042092649,
476 namemax => 255,
477 frsize => 1024,
478 fsid => 1810
479 }
480
481
480=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 482=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
481 483
482Works like perl's C<utime> function (including the special case of $atime 484Works like perl's C<utime> function (including the special case of $atime
483and $mtime being undef). Fractional times are supported if the underlying 485and $mtime being undef). Fractional times are supported if the underlying
484syscalls support them. 486syscalls support them.
… …
577 579
578Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 580Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
579directory (i.e. opendir + readdir + closedir). The entries will not be 581directory (i.e. opendir + readdir + closedir). The entries will not be
580sorted, and will B<NOT> include the C<.> and C<..> entries. 582sorted, and will B<NOT> include the C<.> and C<..> entries.
581 583
582The callback a single argument which is either C<undef> or an array-ref 584The callback is passed a single argument which is either C<undef> or an
583with the filenames. 585array-ref with the filenames.
586
587
588=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
589
590Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
591behaviour and output format. In case of an error, C<$entries> will be
592C<undef>.
593
594The flags are a combination of the following constants, ORed together (the
595flags will also be passed to the callback, possibly modified):
596
597=over 4
598
599=item IO::AIO::READDIR_DENTS
600
601When this flag is off, then the callback gets an arrayref with of names
602only (as with C<aio_readdir>), otherwise it gets an arrayref with
603C<[$name, $type, $inode]> arrayrefs, each describing a single directory
604entry in more detail.
605
606C<$name> is the name of the entry.
607
608C<$type> is one of the C<IO::AIO::DT_xxx> constants:
609
610C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
611C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
612C<IO::AIO::DT_WHT>.
613
614C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
615know, you have to run stat yourself. Also, for speed reasons, the C<$type>
616scalars are read-only: you can not modify them.
617
618C<$inode> is the inode number (which might not be exact on systems with 64
619bit inode numbers and 32 bit perls). This field has unspecified content on
620systems that do not deliver the inode information.
621
622=item IO::AIO::READDIR_DIRS_FIRST
623
624When this flag is set, then the names will be returned in an order where
625likely directories come first. This is useful when you need to quickly
626find directories, or you want to find all directories while avoiding to
627stat() each entry.
628
629If the system returns type information in readdir, then this is used
630to find directories directly. Otherwise, likely directories are files
631beginning with ".", or otherwise files with no dots, of which files with
632short names are tried first.
633
634=item IO::AIO::READDIR_STAT_ORDER
635
636When this flag is set, then the names will be returned in an order
637suitable for stat()'ing each one. That is, when you plan to stat()
638all files in the given directory, then the returned order will likely
639be fastest.
640
641If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
642the likely dirs come first, resulting in a less optimal stat order.
643
644=item IO::AIO::READDIR_FOUND_UNKNOWN
645
646This flag should not be set when calling C<aio_readdirx>. Instead, it
647is being set by C<aio_readdirx>, when any of the C<$type>'s found were
648C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
649C<$type>'s are known, which can be used to speed up some algorithms.
650
651=back
584 652
585 653
586=item aio_load $path, $data, $callback->($status) 654=item aio_load $path, $data, $callback->($status)
587 655
588This is a composite request that tries to fully load the given file into 656This is a composite request that tries to fully load the given file into
589memory. Status is the same as with aio_read. 657memory. Status is the same as with aio_read.
590 658
591=cut 659=cut
592 660
593sub aio_load($$;$) { 661sub aio_load($$;$) {
594 aio_block {
595 my ($path, undef, $cb) = @_; 662 my ($path, undef, $cb) = @_;
596 my $data = \$_[1]; 663 my $data = \$_[1];
597 664
598 my $pri = aioreq_pri; 665 my $pri = aioreq_pri;
599 my $grp = aio_group $cb; 666 my $grp = aio_group $cb;
667
668 aioreq_pri $pri;
669 add $grp aio_open $path, O_RDONLY, 0, sub {
670 my $fh = shift
671 or return $grp->result (-1);
600 672
601 aioreq_pri $pri; 673 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), $$data, 0, sub { 674 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
608 $grp->result ($_[0]); 675 $grp->result ($_[0]);
609 };
610 }; 676 };
611
612 $grp
613 } 677 };
678
679 $grp
614} 680}
615 681
616=item aio_copy $srcpath, $dstpath, $callback->($status) 682=item aio_copy $srcpath, $dstpath, $callback->($status)
617 683
618Try to copy the I<file> (directories not supported as either source or 684Try to copy the I<file> (directories not supported as either source or
619destination) from C<$srcpath> to C<$dstpath> and call the callback with 685destination) from C<$srcpath> to C<$dstpath> and call the callback with
620the C<0> (error) or C<-1> ok. 686a status of C<0> (ok) or C<-1> (error, see C<$!>).
621 687
622This is a composite request that it creates the destination file with 688This is a composite request that creates the destination file with
623mode 0200 and copies the contents of the source file into it using 689mode 0200 and copies the contents of the source file into it using
624C<aio_sendfile>, followed by restoring atime, mtime, access mode and 690C<aio_sendfile>, followed by restoring atime, mtime, access mode and
625uid/gid, in that order. 691uid/gid, in that order.
626 692
627If an error occurs, the partial destination file will be unlinked, if 693If an error occurs, the partial destination file will be unlinked, if
… …
629errors are being ignored. 695errors are being ignored.
630 696
631=cut 697=cut
632 698
633sub aio_copy($$;$) { 699sub aio_copy($$;$) {
634 aio_block {
635 my ($src, $dst, $cb) = @_; 700 my ($src, $dst, $cb) = @_;
636 701
637 my $pri = aioreq_pri; 702 my $pri = aioreq_pri;
638 my $grp = aio_group $cb; 703 my $grp = aio_group $cb;
639 704
640 aioreq_pri $pri; 705 aioreq_pri $pri;
641 add $grp aio_open $src, O_RDONLY, 0, sub { 706 add $grp aio_open $src, O_RDONLY, 0, sub {
642 if (my $src_fh = $_[0]) { 707 if (my $src_fh = $_[0]) {
643 my @stat = stat $src_fh; 708 my @stat = stat $src_fh; # hmm, might block over nfs?
644 709
645 aioreq_pri $pri; 710 aioreq_pri $pri;
646 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 711 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
647 if (my $dst_fh = $_[0]) { 712 if (my $dst_fh = $_[0]) {
648 aioreq_pri $pri; 713 aioreq_pri $pri;
649 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 714 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
650 if ($_[0] == $stat[7]) { 715 if ($_[0] == $stat[7]) {
651 $grp->result (0); 716 $grp->result (0);
652 close $src_fh; 717 close $src_fh;
653 718
654 # those should not normally block. should. should. 719 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; 720 aioreq_pri $pri;
721 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
722 aioreq_pri $pri;
723 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
724 aioreq_pri $pri;
660 add $grp aio_close $dst_fh; 725 add $grp aio_close $dst_fh;
661 } else { 726 }
662 $grp->result (-1);
663 close $src_fh;
664 close $dst_fh;
665
666 aioreq $pri; 727 };
667 add $grp aio_unlink $dst;
668 } 728 };
729
730 aioreq_pri $pri;
731 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
732 if ($_[0] < 0 && $! == ENOSYS) {
733 aioreq_pri $pri;
734 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
735 } else {
736 $ch->();
737 }
738 };
739 } else {
740 $grp->result (-1);
741 close $src_fh;
742 close $dst_fh;
743
744 aioreq $pri;
745 add $grp aio_unlink $dst;
669 }; 746 }
670 } else {
671 $grp->result (-1);
672 } 747 };
748 } else {
749 $grp->result (-1);
673 }, 750 }
674
675 } else {
676 $grp->result (-1);
677 } 751 },
752
753 } else {
754 $grp->result (-1);
678 }; 755 }
679
680 $grp
681 } 756 };
757
758 $grp
682} 759}
683 760
684=item aio_move $srcpath, $dstpath, $callback->($status) 761=item aio_move $srcpath, $dstpath, $callback->($status)
685 762
686Try to move the I<file> (directories not supported as either source or 763Try to move the I<file> (directories not supported as either source or
687destination) from C<$srcpath> to C<$dstpath> and call the callback with 764destination) from C<$srcpath> to C<$dstpath> and call the callback with
688the C<0> (error) or C<-1> ok. 765a status of C<0> (ok) or C<-1> (error, see C<$!>).
689 766
690This is a composite request that tries to rename(2) the file first. If 767This is a composite request that tries to rename(2) the file first; if
691rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 768rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
692that is successful, unlinking the C<$srcpath>. 769that is successful, unlinks the C<$srcpath>.
693 770
694=cut 771=cut
695 772
696sub aio_move($$;$) { 773sub aio_move($$;$) {
697 aio_block {
698 my ($src, $dst, $cb) = @_; 774 my ($src, $dst, $cb) = @_;
699 775
700 my $pri = aioreq_pri; 776 my $pri = aioreq_pri;
701 my $grp = aio_group $cb; 777 my $grp = aio_group $cb;
702 778
703 aioreq_pri $pri; 779 aioreq_pri $pri;
704 add $grp aio_rename $src, $dst, sub { 780 add $grp aio_rename $src, $dst, sub {
705 if ($_[0] && $! == EXDEV) { 781 if ($_[0] && $! == EXDEV) {
706 aioreq_pri $pri; 782 aioreq_pri $pri;
707 add $grp aio_copy $src, $dst, sub { 783 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]); 784 $grp->result ($_[0]);
785
786 if (!$_[0]) {
787 aioreq_pri $pri;
788 add $grp aio_unlink $src;
789 }
717 } 790 };
791 } else {
792 $grp->result ($_[0]);
718 }; 793 }
719
720 $grp
721 } 794 };
795
796 $grp
722} 797}
723 798
724=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 799=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
725 800
726Scans a directory (similar to C<aio_readdir>) but additionally tries to 801Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
746 821
747Implementation notes. 822Implementation notes.
748 823
749The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 824The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
750 825
826If readdir returns file type information, then this is used directly to
827find directories.
828
751After reading the directory, the modification time, size etc. of the 829Otherwise, after reading the directory, the modification time, size etc.
752directory before and after the readdir is checked, and if they match (and 830of 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 831match (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 832how many entries are directories (if >= 2). Otherwise, no knowledge of the
755of subdirectories will be assumed. 833number of subdirectories will be assumed.
756 834
757Then entries will be sorted into likely directories (everything without 835Then entries will be sorted into likely directories a non-initial dot
758a non-initial dot currently) and likely non-directories (everything 836currently) and likely non-directories (see C<aio_readdirx>). Then every
759else). Then every entry plus an appended C</.> will be C<stat>'ed, 837entry plus an appended C</.> will be C<stat>'ed, likely directories first,
760likely directories first. If that succeeds, it assumes that the entry 838in order of their inode numbers. If that succeeds, it assumes that the
761is a directory or a symlink to directory (which will be checked 839entry is a directory or a symlink to directory (which will be checked
762seperately). This is often faster than stat'ing the entry itself because 840seperately). This is often faster than stat'ing the entry itself because
763filesystems might detect the type of the entry without reading the inode 841filesystems might detect the type of the entry without reading the inode
764data (e.g. ext2fs filetype feature). 842data (e.g. ext2fs filetype feature), even on systems that cannot return
843the filetype information on readdir.
765 844
766If the known number of directories (link count - 2) has been reached, the 845If the known number of directories (link count - 2) has been reached, the
767rest of the entries is assumed to be non-directories. 846rest of the entries is assumed to be non-directories.
768 847
769This only works with certainty on POSIX (= UNIX) filesystems, which 848This only works with certainty on POSIX (= UNIX) filesystems, which
… …
774directory counting heuristic. 853directory counting heuristic.
775 854
776=cut 855=cut
777 856
778sub aio_scandir($$;$) { 857sub aio_scandir($$;$) {
779 aio_block {
780 my ($path, $maxreq, $cb) = @_; 858 my ($path, $maxreq, $cb) = @_;
781 859
782 my $pri = aioreq_pri; 860 my $pri = aioreq_pri;
783 861
784 my $grp = aio_group $cb; 862 my $grp = aio_group $cb;
785 863
786 $maxreq = 4 if $maxreq <= 0; 864 $maxreq = 4 if $maxreq <= 0;
787 865
788 # stat once 866 # stat once
867 aioreq_pri $pri;
868 add $grp aio_stat $path, sub {
869 return $grp->result () if $_[0];
870 my $now = time;
871 my $hash1 = join ":", (stat _)[0,1,3,7,9];
872
873 # read the directory entries
789 aioreq_pri $pri; 874 aioreq_pri $pri;
790 add $grp aio_stat $path, sub { 875 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
876 my $entries = shift
791 return $grp->result () if $_[0]; 877 or return $grp->result ();
792 my $now = time;
793 my $hash1 = join ":", (stat _)[0,1,3,7,9];
794 878
795 # read the directory entries 879 # stat the dir another time
796 aioreq_pri $pri; 880 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 { 881 add $grp aio_stat $path, sub {
804 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 882 my $hash2 = join ":", (stat _)[0,1,3,7,9];
805 883
806 my $ndirs; 884 my $ndirs;
807 885
808 # take the slow route if anything looks fishy 886 # take the slow route if anything looks fishy
809 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 887 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
810 $ndirs = -1; 888 $ndirs = -1;
811 } else { 889 } else {
812 # if nlink == 2, we are finished 890 # if nlink == 2, we are finished
813 # on non-posix-fs's, we rely on nlink < 2 891 # for non-posix-fs's, we rely on nlink < 2
814 $ndirs = (stat _)[3] - 2 892 $ndirs = (stat _)[3] - 2
815 or return $grp->result ([], $entries); 893 or return $grp->result ([], $entries);
816 } 894 }
817 895
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); 896 my (@dirs, @nondirs);
826 897
827 my $statgrp = add $grp aio_group sub { 898 my $statgrp = add $grp aio_group sub {
828 $grp->result (\@dirs, \@nondirs); 899 $grp->result (\@dirs, \@nondirs);
829 }; 900 };
830 901
831 limit $statgrp $maxreq; 902 limit $statgrp $maxreq;
832 feed $statgrp sub { 903 feed $statgrp sub {
833 return unless @$entries; 904 return unless @$entries;
834 my $entry = pop @$entries; 905 my $entry = shift @$entries;
835 906
836 aioreq_pri $pri; 907 aioreq_pri $pri;
837 add $statgrp aio_stat "$path/$entry/.", sub { 908 add $statgrp aio_stat "$path/$entry/.", sub {
838 if ($_[0] < 0) { 909 if ($_[0] < 0) {
839 push @nondirs, $entry; 910 push @nondirs, $entry;
840 } else { 911 } else {
841 # need to check for real directory 912 # need to check for real directory
842 aioreq_pri $pri; 913 aioreq_pri $pri;
843 add $statgrp aio_lstat "$path/$entry", sub { 914 add $statgrp aio_lstat "$path/$entry", sub {
844 if (-d _) { 915 if (-d _) {
845 push @dirs, $entry; 916 push @dirs, $entry;
846 917
847 unless (--$ndirs) { 918 unless (--$ndirs) {
848 push @nondirs, @$entries; 919 push @nondirs, @$entries;
849 feed $statgrp; 920 feed $statgrp;
850 }
851 } else {
852 push @nondirs, $entry;
853 } 921 }
922 } else {
923 push @nondirs, $entry;
854 } 924 }
855 } 925 }
856 }; 926 }
857 }; 927 };
858 }; 928 };
859 }; 929 };
860 }; 930 };
861
862 $grp
863 } 931 };
932
933 $grp
864} 934}
865 935
866=item aio_rmtree $path, $callback->($status) 936=item aio_rmtree $path, $callback->($status)
867 937
868Delete a directory tree starting (and including) C<$path>, return the 938Delete a directory tree starting (and including) C<$path>, return the
… …
872 942
873=cut 943=cut
874 944
875sub aio_rmtree; 945sub aio_rmtree;
876sub aio_rmtree($;$) { 946sub aio_rmtree($;$) {
877 aio_block {
878 my ($path, $cb) = @_; 947 my ($path, $cb) = @_;
879 948
880 my $pri = aioreq_pri; 949 my $pri = aioreq_pri;
881 my $grp = aio_group $cb; 950 my $grp = aio_group $cb;
882 951
883 aioreq_pri $pri; 952 aioreq_pri $pri;
884 add $grp aio_scandir $path, 0, sub { 953 add $grp aio_scandir $path, 0, sub {
885 my ($dirs, $nondirs) = @_; 954 my ($dirs, $nondirs) = @_;
886 955
887 my $dirgrp = aio_group sub { 956 my $dirgrp = aio_group sub {
888 add $grp aio_rmdir $path, sub { 957 add $grp aio_rmdir $path, sub {
889 $grp->result ($_[0]); 958 $grp->result ($_[0]);
890 };
891 }; 959 };
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 }; 960 };
898 961
899 $grp 962 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
963 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
964
965 add $grp $dirgrp;
900 } 966 };
967
968 $grp
901} 969}
902 970
903=item aio_sync $callback->($status) 971=item aio_sync $callback->($status)
904 972
905Asynchronously call sync and call the callback when finished. 973Asynchronously call sync and call the callback when finished.
… …
915callback with the fdatasync result code. 983callback with the fdatasync result code.
916 984
917If this call isn't available because your OS lacks it or it couldn't be 985If 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. 986detected, it will be emulated by calling C<fsync> instead.
919 987
988=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
989
990Sync the data portion of the file specified by C<$offset> and C<$length>
991to disk (but NOT the metadata), by calling the Linux-specific
992sync_file_range call. If sync_file_range is not available or it returns
993ENOSYS, then fdatasync or fsync is being substituted.
994
995C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
996C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
997C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
998manpage for details.
999
920=item aio_pathsync $path, $callback->($status) 1000=item aio_pathsync $path, $callback->($status)
921 1001
922This request tries to open, fsync and close the given path. This is a 1002This request tries to open, fsync and close the given path. This is a
923composite request intended tosync directories after directory operations 1003composite request intended to sync directories after directory operations
924(E.g. rename). This might not work on all operating systems or have any 1004(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 1005specific effect, but usually it makes sure that directory changes get
926written to disc. It works for anything that can be opened for read-only, 1006written to disc. It works for anything that can be opened for read-only,
927not just directories. 1007not just directories.
928 1008
1009Future versions of this function might fall back to other methods when
1010C<fsync> on the directory fails (such as calling C<sync>).
1011
929Passes C<0> when everything went ok, and C<-1> on error. 1012Passes C<0> when everything went ok, and C<-1> on error.
930 1013
931=cut 1014=cut
932 1015
933sub aio_pathsync($;$) { 1016sub aio_pathsync($;$) {
934 aio_block {
935 my ($path, $cb) = @_; 1017 my ($path, $cb) = @_;
936 1018
937 my $pri = aioreq_pri; 1019 my $pri = aioreq_pri;
938 my $grp = aio_group $cb; 1020 my $grp = aio_group $cb;
939 1021
940 aioreq_pri $pri; 1022 aioreq_pri $pri;
941 add $grp aio_open $path, O_RDONLY, 0, sub { 1023 add $grp aio_open $path, O_RDONLY, 0, sub {
942 my ($fh) = @_; 1024 my ($fh) = @_;
943 if ($fh) { 1025 if ($fh) {
1026 aioreq_pri $pri;
1027 add $grp aio_fsync $fh, sub {
1028 $grp->result ($_[0]);
1029
944 aioreq_pri $pri; 1030 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; 1031 add $grp aio_close $fh;
950 };
951 } else {
952 $grp->result (-1);
953 } 1032 };
1033 } else {
1034 $grp->result (-1);
954 }; 1035 }
955
956 $grp
957 } 1036 };
1037
1038 $grp
958} 1039}
1040
1041=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1042
1043This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1044scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
1045that the scalar must only be modified in-place while an aio operation is
1046pending on it).
1047
1048It calls the C<msync> function of your OS, if available, with the memory
1049area starting at C<$offset> in the string and ending C<$length> bytes
1050later. If C<$length> is negative, counts from the end, and if C<$length>
1051is C<undef>, then it goes till the end of the string. The flags can be
1052a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1053C<IO::AIO::MS_SYNC>.
1054
1055=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1056
1057This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1058scalars.
1059
1060It touches (reads or writes) all memory pages in the specified
1061range inside the scalar. All caveats and parameters are the same
1062as for C<aio_msync>, above, except for flags, which must be either
1063C<0> (which reads all pages and ensures they are instantiated) or
1064C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1065writing an octet from it, which dirties the page).
959 1066
960=item aio_group $callback->(...) 1067=item aio_group $callback->(...)
961 1068
962This is a very special aio request: Instead of doing something, it is a 1069This is a very special aio request: Instead of doing something, it is a
963container for other aio requests, which is useful if you want to bundle 1070container for other aio requests, which is useful if you want to bundle
… …
1013=item cancel $req 1120=item cancel $req
1014 1121
1015Cancels the request, if possible. Has the effect of skipping execution 1122Cancels the request, if possible. Has the effect of skipping execution
1016when entering the B<execute> state and skipping calling the callback when 1123when entering the B<execute> state and skipping calling the callback when
1017entering the the B<result> state, but will leave the request otherwise 1124entering the the B<result> state, but will leave the request otherwise
1018untouched. That means that requests that currently execute will not be 1125untouched (with the exception of readdir). That means that requests that
1019stopped and resources held by the request will not be freed prematurely. 1126currently execute will not be stopped and resources held by the request
1127will not be freed prematurely.
1020 1128
1021=item cb $req $callback->(...) 1129=item cb $req $callback->(...)
1022 1130
1023Replace (or simply set) the callback registered to the request. 1131Replace (or simply set) the callback registered to the request.
1024 1132
… …
1075Their lifetime, simplified, looks like this: when they are empty, they 1183Their lifetime, simplified, looks like this: when they are empty, they
1076will finish very quickly. If they contain only requests that are in the 1184will finish very quickly. If they contain only requests that are in the
1077C<done> state, they will also finish. Otherwise they will continue to 1185C<done> state, they will also finish. Otherwise they will continue to
1078exist. 1186exist.
1079 1187
1080That means after creating a group you have some time to add requests. And 1188That 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 1189(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 1190the C<poll_cb>). And in the callbacks of those requests, you can add
1083itself finish. 1191further requests to the group. And only when all those requests have
1192finished will the the group itself finish.
1084 1193
1085=over 4 1194=over 4
1086 1195
1087=item add $grp ... 1196=item add $grp ...
1088 1197
… …
1096 1205
1097=item $grp->cancel_subs 1206=item $grp->cancel_subs
1098 1207
1099Cancel all subrequests and clears any feeder, but not the group request 1208Cancel all subrequests and clears any feeder, but not the group request
1100itself. Useful when you queued a lot of events but got a result early. 1209itself. Useful when you queued a lot of events but got a result early.
1210
1211The group request will finish normally (you cannot add requests to the
1212group).
1101 1213
1102=item $grp->result (...) 1214=item $grp->result (...)
1103 1215
1104Set the result value(s) that will be passed to the group callback when all 1216Set the result value(s) that will be passed to the group callback when all
1105subrequests have finished and set the groups errno to the current value 1217subrequests have finished and set the groups errno to the current value
… …
1121=item feed $grp $callback->($grp) 1233=item feed $grp $callback->($grp)
1122 1234
1123Sets a feeder/generator on this group: every group can have an attached 1235Sets a feeder/generator on this group: every group can have an attached
1124generator that generates requests if idle. The idea behind this is that, 1236generator 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, 1237although you could just queue as many requests as you want in a group,
1126this might starve other requests for a potentially long time. For 1238this might starve other requests for a potentially long time. For example,
1127example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1239C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1128requests, delaying any later requests for a long time. 1240delaying any later requests for a long time.
1129 1241
1130To avoid this, and allow incremental generation of requests, you can 1242To avoid this, and allow incremental generation of requests, you can
1131instead a group and set a feeder on it that generates those requests. The 1243instead 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>, 1244feed 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 1245below) requests active in the group itself and is expected to queue more
… …
1137not impose any limits). 1249not impose any limits).
1138 1250
1139If the feed does not queue more requests when called, it will be 1251If the feed does not queue more requests when called, it will be
1140automatically removed from the group. 1252automatically removed from the group.
1141 1253
1142If the feed limit is C<0>, it will be set to C<2> automatically. 1254If the feed limit is C<0> when this method is called, it will be set to
1255C<2> automatically.
1143 1256
1144Example: 1257Example:
1145 1258
1146 # stat all files in @files, but only ever use four aio requests concurrently: 1259 # stat all files in @files, but only ever use four aio requests concurrently:
1147 1260
… …
1159Sets the feeder limit for the group: The feeder will be called whenever 1272Sets the feeder limit for the group: The feeder will be called whenever
1160the group contains less than this many requests. 1273the group contains less than this many requests.
1161 1274
1162Setting the limit to C<0> will pause the feeding process. 1275Setting the limit to C<0> will pause the feeding process.
1163 1276
1277The default value for the limit is C<0>, but note that setting a feeder
1278automatically bumps it up to C<2>.
1279
1164=back 1280=back
1165 1281
1166=head2 SUPPORT FUNCTIONS 1282=head2 SUPPORT FUNCTIONS
1167 1283
1168=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1284=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1170=over 4 1286=over 4
1171 1287
1172=item $fileno = IO::AIO::poll_fileno 1288=item $fileno = IO::AIO::poll_fileno
1173 1289
1174Return the I<request result pipe file descriptor>. This filehandle must be 1290Return the I<request result pipe file descriptor>. This filehandle must be
1175polled for reading by some mechanism outside this module (e.g. Event or 1291polled 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 1292select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1177to call C<poll_cb> to check the results. 1293you have to call C<poll_cb> to check the results.
1178 1294
1179See C<poll_cb> for an example. 1295See C<poll_cb> for an example.
1180 1296
1181=item IO::AIO::poll_cb 1297=item IO::AIO::poll_cb
1182 1298
1183Process some outstanding events on the result pipe. You have to call this 1299Process some outstanding events on the result pipe. You have to call this
1184regularly. Returns the number of events processed. Returns immediately 1300regularly. Returns C<0> if all events could be processed, or C<-1> if it
1301returned earlier for whatever reason. Returns immediately when no events
1185when no events are outstanding. The amount of events processed depends on 1302are 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>. 1303C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1187 1304
1188If not all requests were processed for whatever reason, the filehandle 1305If not all requests were processed for whatever reason, the filehandle
1189will still be ready when C<poll_cb> returns. 1306will still be ready when C<poll_cb> returns, so normally you don't have to
1307do anything special to have it called later.
1190 1308
1191Example: Install an Event watcher that automatically calls 1309Example: Install an Event watcher that automatically calls
1192IO::AIO::poll_cb with high priority: 1310IO::AIO::poll_cb with high priority (more examples can be found in the
1311SYNOPSIS section, at the top of this document):
1193 1312
1194 Event->io (fd => IO::AIO::poll_fileno, 1313 Event->io (fd => IO::AIO::poll_fileno,
1195 poll => 'r', async => 1, 1314 poll => 'r', async => 1,
1196 cb => \&IO::AIO::poll_cb); 1315 cb => \&IO::AIO::poll_cb);
1197 1316
… …
1308 1427
1309The default is probably ok in most situations, especially if thread 1428The default is probably ok in most situations, especially if thread
1310creation is fast. If thread creation is very slow on your system you might 1429creation is fast. If thread creation is very slow on your system you might
1311want to use larger values. 1430want to use larger values.
1312 1431
1313=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1432=item IO::AIO::max_outstanding $maxreqs
1314 1433
1315This is a very bad function to use in interactive programs because it 1434This 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 1435blocks, and a bad way to reduce concurrency because it is inexact: Better
1317use an C<aio_group> together with a feed callback. 1436use an C<aio_group> together with a feed callback.
1318 1437
… …
1323 1442
1324The default value is very large, so there is no practical limit on the 1443The default value is very large, so there is no practical limit on the
1325number of outstanding requests. 1444number of outstanding requests.
1326 1445
1327You can still queue as many requests as you want. Therefore, 1446You can still queue as many requests as you want. Therefore,
1328C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1447C<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). 1448as a stop gap to shield against fatal memory overflow (with large values).
1330 1449
1331=back 1450=back
1332 1451
1333=head3 STATISTICAL INFORMATION 1452=head3 STATISTICAL INFORMATION
… …
1351 1470
1352=item IO::AIO::npending 1471=item IO::AIO::npending
1353 1472
1354Returns the number of requests currently in the pending state (executed, 1473Returns the number of requests currently in the pending state (executed,
1355but not yet processed by poll_cb). 1474but not yet processed by poll_cb).
1475
1476=back
1477
1478=head3 MISCELLANEOUS FUNCTIONS
1479
1480IO::AIO implements some functions that might be useful, but are not
1481asynchronous.
1482
1483=over 4
1484
1485=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1486
1487Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1488but is blocking (this makes most sense if you know the input data is
1489likely cached already and the output filehandle is set to non-blocking
1490operations).
1491
1492Returns the number of bytes copied, or C<-1> on error.
1493
1494=item IO::AIO::fadvise $fh, $offset, $len, $advice
1495
1496Simply calls the C<posix_fadvise> function (see it's
1497manpage for details). The following advice constants are
1498avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1499C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1500C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1501
1502On systems that do not implement C<posix_fadvise>, this function returns
1503ENOSYS, otherwise the return value of C<posix_fadvise>.
1504
1505=item IO::AIO::mlockall $flags
1506
1507Calls the C<mlockall> function with the given C<$flags> (a combination of
1508C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1509
1510On systems that do not implement C<mlockall>, this function returns
1511ENOSYS, otherwise the return value of C<mlockall>.
1512
1513=item IO::AIO::munlockall
1514
1515Calls the C<munlockall> function.
1516
1517On systems that do not implement C<munlockall>, this function returns
1518ENOSYS, otherwise the return value of C<munlockall>.
1356 1519
1357=back 1520=back
1358 1521
1359=cut 1522=cut
1360 1523
… …
1403 1566
1404Known bugs will be fixed in the next release. 1567Known bugs will be fixed in the next release.
1405 1568
1406=head1 SEE ALSO 1569=head1 SEE ALSO
1407 1570
1408L<Coro::AIO>. 1571L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1572more natural syntax.
1409 1573
1410=head1 AUTHOR 1574=head1 AUTHOR
1411 1575
1412 Marc Lehmann <schmorp@schmorp.de> 1576 Marc Lehmann <schmorp@schmorp.de>
1413 http://home.schmorp.de/ 1577 http://home.schmorp.de/

Diff Legend

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