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Revision 1.90 by root, Mon Oct 30 23:30:00 2006 UTC vs.
Revision 1.146 by root, Tue Apr 21 20:06:05 2009 UTC

5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", O_RDONLY, 0, sub {
10 my ($fh) = @_; 10 my $fh = shift
11 or die "/etc/passwd: $!";
11 ... 12 ...
12 }; 13 };
13 14
14 aio_unlink "/tmp/file", sub { }; 15 aio_unlink "/tmp/file", sub { };
15 16
25 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
26 27
27 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
28 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
29 30
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
30 # AnyEvent integration 34 # EV integration
31 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
32 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33 36
34 # Event integration 37 # Event integration
35 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
36 poll => 'r', 39 poll => 'r',
37 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
61etc.), but can also be used to easily do operations in parallel that are 64etc.), but can also be used to easily do operations in parallel that are
62normally done sequentially, e.g. stat'ing many files, which is much faster 65normally done sequentially, e.g. stat'ing many files, which is much faster
63on a RAID volume or over NFS when you do a number of stat operations 66on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 67concurrently.
65 68
66While most of this works on all types of file descriptors (for example 69While most of this works on all types of file descriptors (for
67sockets), using these functions on file descriptors that support 70example sockets), using these functions on file descriptors that
68nonblocking operation (again, sockets, pipes etc.) is very inefficient or 71support nonblocking operation (again, sockets, pipes etc.) is very
69might not work (aio_read fails on sockets/pipes/fifos). Use an event loop 72inefficient. Use an event loop for that (such as the L<Event|Event>
70for that (such as the L<Event|Event> module): IO::AIO will naturally fit 73module): IO::AIO will naturally fit into such an event loop itself.
71into such an event loop itself.
72 74
73In this version, a number of threads are started that execute your 75In this version, a number of threads are started that execute your
74requests and signal their completion. You don't need thread support 76requests and signal their completion. You don't need thread support
75in perl, and the threads created by this module will not be visible 77in perl, and the threads created by this module will not be visible
76to perl. In the future, this module might make use of the native aio 78to perl. In the future, this module might make use of the native aio
78not well-supported or restricted (GNU/Linux doesn't allow them on normal 80not well-supported or restricted (GNU/Linux doesn't allow them on normal
79files currently, for example), and they would only support aio_read and 81files currently, for example), and they would only support aio_read and
80aio_write, so the remaining functionality would have to be implemented 82aio_write, so the remaining functionality would have to be implemented
81using threads anyway. 83using threads anyway.
82 84
83Although the module will work with in the presence of other (Perl-) 85Although the module will work in the presence of other (Perl-) threads,
84threads, it is currently not reentrant in any way, so use appropriate 86it is currently not reentrant in any way, so use appropriate locking
85locking yourself, always call C<poll_cb> from within the same thread, or 87yourself, always call C<poll_cb> from within the same thread, or never
86never call C<poll_cb> (or other C<aio_> functions) recursively. 88call C<poll_cb> (or other C<aio_> functions) recursively.
87 89
88=head2 EXAMPLE 90=head2 EXAMPLE
89 91
90This is a simple example that uses the Event module and loads 92This is a simple example that uses the Event module and loads
91F</etc/passwd> asynchronously: 93F</etc/passwd> asynchronously:
99 poll => 'r', 101 poll => 'r',
100 cb => \&IO::AIO::poll_cb); 102 cb => \&IO::AIO::poll_cb);
101 103
102 # queue the request to open /etc/passwd 104 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub { 105 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = $_[0] 106 my $fh = shift
105 or die "error while opening: $!"; 107 or die "error while opening: $!";
106 108
107 # stat'ing filehandles is generally non-blocking 109 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh; 110 my $size = -s $fh;
109 111
183 185
184=cut 186=cut
185 187
186package IO::AIO; 188package IO::AIO;
187 189
190use Carp ();
191
188no warnings; 192no warnings;
189use strict 'vars'; 193use strict 'vars';
190 194
191use base 'Exporter'; 195use base 'Exporter';
192 196
193BEGIN { 197BEGIN {
194 our $VERSION = '2.1'; 198 our $VERSION = '3.19';
195 199
196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
197 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
199 aio_move aio_copy aio_group aio_nop aio_mknod); 203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate);
207
200 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
201 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
202 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
203 nreqs nready npending nthreads 211 nreqs nready npending nthreads
204 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
205 213
214 push @AIO_REQ, qw(aio_busy); # not exported
215
206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
207 217
208 require XSLoader; 218 require XSLoader;
209 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
210} 220}
216All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
217with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
218and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
219which 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
220the 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
221perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
222syscall has been executed asynchronously. 232syscall has been executed asynchronously.
223 233
224All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
225internally until the request has finished. 235internally until the request has finished.
226 236
240your 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
241environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
243 253
244This 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
245handles correctly wether it is set or not. 255handles correctly whether it is set or not.
246 256
247=over 4 257=over 4
248 258
249=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
250 260
270 aio_read $_[0], ..., sub { 280 aio_read $_[0], ..., sub {
271 ... 281 ...
272 }; 282 };
273 }; 283 };
274 284
285
275=item aioreq_nice $pri_adjust 286=item aioreq_nice $pri_adjust
276 287
277Similar to C<aioreq_pri>, but subtracts the given value from the current 288Similar to C<aioreq_pri>, but subtracts the given value from the current
278priority, so the effect is cumulative. 289priority, so the effect is cumulative.
290
279 291
280=item aio_open $pathname, $flags, $mode, $callback->($fh) 292=item aio_open $pathname, $flags, $mode, $callback->($fh)
281 293
282Asynchronously open or create a file and call the callback with a newly 294Asynchronously open or create a file and call the callback with a newly
283created filehandle for the file. 295created filehandle for the file.
289list. They are the same as used by C<sysopen>. 301list. They are the same as used by C<sysopen>.
290 302
291Likewise, C<$mode> specifies the mode of the newly created file, if it 303Likewise, C<$mode> specifies the mode of the newly created file, if it
292didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 304didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
293except that it is mandatory (i.e. use C<0> if you don't create new files, 305except that it is mandatory (i.e. use C<0> if you don't create new files,
294and C<0666> or C<0777> if you do). 306and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
307by the umask in effect then the request is being executed, so better never
308change the umask.
295 309
296Example: 310Example:
297 311
298 aio_open "/etc/passwd", O_RDONLY, 0, sub { 312 aio_open "/etc/passwd", O_RDONLY, 0, sub {
299 if ($_[0]) { 313 if ($_[0]) {
302 } else { 316 } else {
303 die "open failed: $!\n"; 317 die "open failed: $!\n";
304 } 318 }
305 }; 319 };
306 320
321
307=item aio_close $fh, $callback->($status) 322=item aio_close $fh, $callback->($status)
308 323
309Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
310code. I<WARNING:> although accepted, you should not pass in a perl 325code.
311filehandle here, as perl will likely close the file descriptor another
312time when the filehandle is destroyed. Normally, you can safely call perls
313C<close> or just let filehandles go out of scope.
314 326
315This is supposed to be a bug in the API, so that might change. It's 327Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
316therefore best to avoid this function. 328closing the file descriptor associated with the filehandle itself.
329
330Therefore, C<aio_close> will not close the filehandle - instead it will
331use dup2 to overwrite the file descriptor with the write-end of a pipe
332(the pipe fd will be created on demand and will be cached).
333
334Or in other words: the file descriptor will be closed, but it will not be
335free for reuse until the perl filehandle is closed.
336
337=cut
317 338
318=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319 340
320=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321 342
322Reads 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
323into 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<$dataoffset>
324callback without the actual number of bytes read (or -1 on error, just 345and calls the callback without the actual number of bytes read (or -1 on
325like the syscall). 346error, just like the syscall).
347
348C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
349offset plus the actual number of bytes read.
350
351If C<$offset> is undefined, then the current file descriptor offset will
352be used (and updated), otherwise the file descriptor offset will not be
353changed by these calls.
354
355If C<$length> is undefined in C<aio_write>, use the remaining length of
356C<$data>.
357
358If C<$dataoffset> is less than zero, it will be counted from the end of
359C<$data>.
326 360
327The C<$data> scalar I<MUST NOT> be modified in any way while the request 361The C<$data> scalar I<MUST NOT> be modified in any way while the request
328is outstanding. Modifying it can result in segfaults or WW3 (if the 362is outstanding. Modifying it can result in segfaults or World War III (if
329necessary/optional hardware is installed). 363the necessary/optional hardware is installed).
330 364
331Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 365Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332offset C<0> within the scalar: 366offset C<0> within the scalar:
333 367
334 aio_read $fh, 7, 15, $buffer, 0, sub { 368 aio_read $fh, 7, 15, $buffer, 0, sub {
335 $_[0] > 0 or die "read error: $!"; 369 $_[0] > 0 or die "read error: $!";
336 print "read $_[0] bytes: <$buffer>\n"; 370 print "read $_[0] bytes: <$buffer>\n";
337 }; 371 };
372
338 373
339=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 374=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
340 375
341Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 376Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
342reading at byte offset C<$in_offset>, and starts writing at the current 377reading at byte offset C<$in_offset>, and starts writing at the current
356C<$in_fh> than are written, and there is no way to find out how many 391C<$in_fh> than are written, and there is no way to find out how many
357bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 392bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
358provides the number of bytes written to C<$out_fh>. Only if the result 393provides the number of bytes written to C<$out_fh>. Only if the result
359value equals C<$length> one can assume that C<$length> bytes have been 394value equals C<$length> one can assume that C<$length> bytes have been
360read. 395read.
396
361 397
362=item aio_readahead $fh,$offset,$length, $callback->($retval) 398=item aio_readahead $fh,$offset,$length, $callback->($retval)
363 399
364C<aio_readahead> populates the page cache with data from a file so that 400C<aio_readahead> populates the page cache with data from a file so that
365subsequent reads from that file will not block on disk I/O. The C<$offset> 401subsequent reads from that file will not block on disk I/O. The C<$offset>
371file. The current file offset of the file is left unchanged. 407file. The current file offset of the file is left unchanged.
372 408
373If that syscall doesn't exist (likely if your OS isn't Linux) it will be 409If that syscall doesn't exist (likely if your OS isn't Linux) it will be
374emulated by simply reading the data, which would have a similar effect. 410emulated by simply reading the data, which would have a similar effect.
375 411
412
376=item aio_stat $fh_or_path, $callback->($status) 413=item aio_stat $fh_or_path, $callback->($status)
377 414
378=item aio_lstat $fh, $callback->($status) 415=item aio_lstat $fh, $callback->($status)
379 416
380Works like perl's C<stat> or C<lstat> in void context. The callback will 417Works like perl's C<stat> or C<lstat> in void context. The callback will
393 aio_stat "/etc/passwd", sub { 430 aio_stat "/etc/passwd", sub {
394 $_[0] and die "stat failed: $!"; 431 $_[0] and die "stat failed: $!";
395 print "size is ", -s _, "\n"; 432 print "size is ", -s _, "\n";
396 }; 433 };
397 434
435
436=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437
438Works like perl's C<utime> function (including the special case of $atime
439and $mtime being undef). Fractional times are supported if the underlying
440syscalls support them.
441
442When called with a pathname, uses utimes(2) if available, otherwise
443utime(2). If called on a file descriptor, uses futimes(2) if available,
444otherwise returns ENOSYS, so this is not portable.
445
446Examples:
447
448 # set atime and mtime to current time (basically touch(1)):
449 aio_utime "path", undef, undef;
450 # set atime to current time and mtime to beginning of the epoch:
451 aio_utime "path", time, undef; # undef==0
452
453
454=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
455
456Works like perl's C<chown> function, except that C<undef> for either $uid
457or $gid is being interpreted as "do not change" (but -1 can also be used).
458
459Examples:
460
461 # same as "chown root path" in the shell:
462 aio_chown "path", 0, -1;
463 # same as above:
464 aio_chown "path", 0, undef;
465
466
467=item aio_truncate $fh_or_path, $offset, $callback->($status)
468
469Works like truncate(2) or ftruncate(2).
470
471
472=item aio_chmod $fh_or_path, $mode, $callback->($status)
473
474Works like perl's C<chmod> function.
475
476
398=item aio_unlink $pathname, $callback->($status) 477=item aio_unlink $pathname, $callback->($status)
399 478
400Asynchronously unlink (delete) a file and call the callback with the 479Asynchronously unlink (delete) a file and call the callback with the
401result code. 480result code.
402 481
482
403=item aio_mknod $path, $mode, $dev, $callback->($status) 483=item aio_mknod $path, $mode, $dev, $callback->($status)
404 484
405[EXPERIMENTAL] 485[EXPERIMENTAL]
406 486
407Asynchronously create a device node (or fifo). See mknod(2). 487Asynchronously create a device node (or fifo). See mknod(2).
408 488
409The only (POSIX-) portable way of calling this function is: 489The only (POSIX-) portable way of calling this function is:
410 490
411 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 491 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
492
412 493
413=item aio_link $srcpath, $dstpath, $callback->($status) 494=item aio_link $srcpath, $dstpath, $callback->($status)
414 495
415Asynchronously create a new link to the existing object at C<$srcpath> at 496Asynchronously create a new link to the existing object at C<$srcpath> at
416the path C<$dstpath> and call the callback with the result code. 497the path C<$dstpath> and call the callback with the result code.
417 498
499
418=item aio_symlink $srcpath, $dstpath, $callback->($status) 500=item aio_symlink $srcpath, $dstpath, $callback->($status)
419 501
420Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 502Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
421the path C<$dstpath> and call the callback with the result code. 503the path C<$dstpath> and call the callback with the result code.
504
422 505
423=item aio_readlink $path, $callback->($link) 506=item aio_readlink $path, $callback->($link)
424 507
425Asynchronously read the symlink specified by C<$path> and pass it to 508Asynchronously read the symlink specified by C<$path> and pass it to
426the callback. If an error occurs, nothing or undef gets passed to the 509the callback. If an error occurs, nothing or undef gets passed to the
427callback. 510callback.
428 511
512
429=item aio_rename $srcpath, $dstpath, $callback->($status) 513=item aio_rename $srcpath, $dstpath, $callback->($status)
430 514
431Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 515Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432rename(2) and call the callback with the result code. 516rename(2) and call the callback with the result code.
433 517
518
519=item aio_mkdir $pathname, $mode, $callback->($status)
520
521Asynchronously mkdir (create) a directory and call the callback with
522the result code. C<$mode> will be modified by the umask at the time the
523request is executed, so do not change your umask.
524
525
434=item aio_rmdir $pathname, $callback->($status) 526=item aio_rmdir $pathname, $callback->($status)
435 527
436Asynchronously rmdir (delete) a directory and call the callback with the 528Asynchronously rmdir (delete) a directory and call the callback with the
437result code. 529result code.
530
438 531
439=item aio_readdir $pathname, $callback->($entries) 532=item aio_readdir $pathname, $callback->($entries)
440 533
441Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 534Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
442directory (i.e. opendir + readdir + closedir). The entries will not be 535directory (i.e. opendir + readdir + closedir). The entries will not be
443sorted, and will B<NOT> include the C<.> and C<..> entries. 536sorted, and will B<NOT> include the C<.> and C<..> entries.
444 537
445The callback a single argument which is either C<undef> or an array-ref 538The callback a single argument which is either C<undef> or an array-ref
446with the filenames. 539with the filenames.
447 540
541
542=item aio_load $path, $data, $callback->($status)
543
544This is a composite request that tries to fully load the given file into
545memory. Status is the same as with aio_read.
546
547=cut
548
549sub aio_load($$;$) {
550 my ($path, undef, $cb) = @_;
551 my $data = \$_[1];
552
553 my $pri = aioreq_pri;
554 my $grp = aio_group $cb;
555
556 aioreq_pri $pri;
557 add $grp aio_open $path, O_RDONLY, 0, sub {
558 my $fh = shift
559 or return $grp->result (-1);
560
561 aioreq_pri $pri;
562 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
563 $grp->result ($_[0]);
564 };
565 };
566
567 $grp
568}
569
448=item aio_copy $srcpath, $dstpath, $callback->($status) 570=item aio_copy $srcpath, $dstpath, $callback->($status)
449 571
450Try to copy the I<file> (directories not supported as either source or 572Try to copy the I<file> (directories not supported as either source or
451destination) from C<$srcpath> to C<$dstpath> and call the callback with 573destination) from C<$srcpath> to C<$dstpath> and call the callback with
452the C<0> (error) or C<-1> ok. 574the C<0> (error) or C<-1> ok.
453 575
454This is a composite request that it creates the destination file with 576This is a composite request that creates the destination file with
455mode 0200 and copies the contents of the source file into it using 577mode 0200 and copies the contents of the source file into it using
456C<aio_sendfile>, followed by restoring atime, mtime, access mode and 578C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457uid/gid, in that order. 579uid/gid, in that order.
458 580
459If an error occurs, the partial destination file will be unlinked, if 581If an error occurs, the partial destination file will be unlinked, if
484 606
485 # those should not normally block. should. should. 607 # those should not normally block. should. should.
486 utime $stat[8], $stat[9], $dst; 608 utime $stat[8], $stat[9], $dst;
487 chmod $stat[2] & 07777, $dst_fh; 609 chmod $stat[2] & 07777, $dst_fh;
488 chown $stat[4], $stat[5], $dst_fh; 610 chown $stat[4], $stat[5], $dst_fh;
611
612 aioreq_pri $pri;
489 close $dst_fh; 613 add $grp aio_close $dst_fh;
490 } else { 614 } else {
491 $grp->result (-1); 615 $grp->result (-1);
492 close $src_fh; 616 close $src_fh;
493 close $dst_fh; 617 close $dst_fh;
494 618
513 637
514Try to move the I<file> (directories not supported as either source or 638Try to move the I<file> (directories not supported as either source or
515destination) from C<$srcpath> to C<$dstpath> and call the callback with 639destination) from C<$srcpath> to C<$dstpath> and call the callback with
516the C<0> (error) or C<-1> ok. 640the C<0> (error) or C<-1> ok.
517 641
518This is a composite request that tries to rename(2) the file first. If 642This is a composite request that tries to rename(2) the file first; if
519rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 643rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520that is successful, unlinking the C<$srcpath>. 644that is successful, unlinks the C<$srcpath>.
521 645
522=cut 646=cut
523 647
524sub aio_move($$;$) { 648sub aio_move($$;$) {
525 my ($src, $dst, $cb) = @_; 649 my ($src, $dst, $cb) = @_;
599as those tend to return 0 or 1 as link counts, which disables the 723as those tend to return 0 or 1 as link counts, which disables the
600directory counting heuristic. 724directory counting heuristic.
601 725
602=cut 726=cut
603 727
604sub aio_scandir($$$) { 728sub aio_scandir($$;$) {
605 my ($path, $maxreq, $cb) = @_; 729 my ($path, $maxreq, $cb) = @_;
606 730
607 my $pri = aioreq_pri; 731 my $pri = aioreq_pri;
608 732
609 my $grp = aio_group $cb; 733 my $grp = aio_group $cb;
685 }; 809 };
686 810
687 $grp 811 $grp
688} 812}
689 813
814=item aio_rmtree $path, $callback->($status)
815
816Delete a directory tree starting (and including) C<$path>, return the
817status of the final C<rmdir> only. This is a composite request that
818uses C<aio_scandir> to recurse into and rmdir directories, and unlink
819everything else.
820
821=cut
822
823sub aio_rmtree;
824sub aio_rmtree($;$) {
825 my ($path, $cb) = @_;
826
827 my $pri = aioreq_pri;
828 my $grp = aio_group $cb;
829
830 aioreq_pri $pri;
831 add $grp aio_scandir $path, 0, sub {
832 my ($dirs, $nondirs) = @_;
833
834 my $dirgrp = aio_group sub {
835 add $grp aio_rmdir $path, sub {
836 $grp->result ($_[0]);
837 };
838 };
839
840 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
841 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
842
843 add $grp $dirgrp;
844 };
845
846 $grp
847}
848
849=item aio_sync $callback->($status)
850
851Asynchronously call sync and call the callback when finished.
852
690=item aio_fsync $fh, $callback->($status) 853=item aio_fsync $fh, $callback->($status)
691 854
692Asynchronously call fsync on the given filehandle and call the callback 855Asynchronously call fsync on the given filehandle and call the callback
693with the fsync result code. 856with the fsync result code.
694 857
697Asynchronously call fdatasync on the given filehandle and call the 860Asynchronously call fdatasync on the given filehandle and call the
698callback with the fdatasync result code. 861callback with the fdatasync result code.
699 862
700If this call isn't available because your OS lacks it or it couldn't be 863If this call isn't available because your OS lacks it or it couldn't be
701detected, it will be emulated by calling C<fsync> instead. 864detected, it will be emulated by calling C<fsync> instead.
865
866=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
867
868Sync the data portion of the file specified by C<$offset> and C<$length>
869to disk (but NOT the metadata), by calling the Linux-specific
870sync_file_range call. If sync_file_range is not available or it returns
871ENOSYS, then fdatasync or fsync is being substituted.
872
873C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
874C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
875C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
876manpage for details.
877
878=item aio_pathsync $path, $callback->($status)
879
880This request tries to open, fsync and close the given path. This is a
881composite request intended to sync directories after directory operations
882(E.g. rename). This might not work on all operating systems or have any
883specific effect, but usually it makes sure that directory changes get
884written to disc. It works for anything that can be opened for read-only,
885not just directories.
886
887Passes C<0> when everything went ok, and C<-1> on error.
888
889=cut
890
891sub aio_pathsync($;$) {
892 my ($path, $cb) = @_;
893
894 my $pri = aioreq_pri;
895 my $grp = aio_group $cb;
896
897 aioreq_pri $pri;
898 add $grp aio_open $path, O_RDONLY, 0, sub {
899 my ($fh) = @_;
900 if ($fh) {
901 aioreq_pri $pri;
902 add $grp aio_fsync $fh, sub {
903 $grp->result ($_[0]);
904
905 aioreq_pri $pri;
906 add $grp aio_close $fh;
907 };
908 } else {
909 $grp->result (-1);
910 }
911 };
912
913 $grp
914}
702 915
703=item aio_group $callback->(...) 916=item aio_group $callback->(...)
704 917
705This is a very special aio request: Instead of doing something, it is a 918This is a very special aio request: Instead of doing something, it is a
706container for other aio requests, which is useful if you want to bundle 919container for other aio requests, which is useful if you want to bundle
818Their lifetime, simplified, looks like this: when they are empty, they 1031Their lifetime, simplified, looks like this: when they are empty, they
819will finish very quickly. If they contain only requests that are in the 1032will finish very quickly. If they contain only requests that are in the
820C<done> state, they will also finish. Otherwise they will continue to 1033C<done> state, they will also finish. Otherwise they will continue to
821exist. 1034exist.
822 1035
823That means after creating a group you have some time to add requests. And 1036That means after creating a group you have some time to add requests
824in the callbacks of those requests, you can add further requests to the 1037(precisely before the callback has been invoked, which is only done within
825group. And only when all those requests have finished will the the group 1038the C<poll_cb>). And in the callbacks of those requests, you can add
826itself finish. 1039further requests to the group. And only when all those requests have
1040finished will the the group itself finish.
827 1041
828=over 4 1042=over 4
829 1043
830=item add $grp ... 1044=item add $grp ...
831 1045
843itself. Useful when you queued a lot of events but got a result early. 1057itself. Useful when you queued a lot of events but got a result early.
844 1058
845=item $grp->result (...) 1059=item $grp->result (...)
846 1060
847Set the result value(s) that will be passed to the group callback when all 1061Set the result value(s) that will be passed to the group callback when all
848subrequests have finished and set thre groups errno to the current value 1062subrequests have finished and set the groups errno to the current value
849of errno (just like calling C<errno> without an error number). By default, 1063of errno (just like calling C<errno> without an error number). By default,
850no argument will be passed and errno is zero. 1064no argument will be passed and errno is zero.
851 1065
852=item $grp->errno ([$errno]) 1066=item $grp->errno ([$errno])
853 1067
864=item feed $grp $callback->($grp) 1078=item feed $grp $callback->($grp)
865 1079
866Sets a feeder/generator on this group: every group can have an attached 1080Sets a feeder/generator on this group: every group can have an attached
867generator that generates requests if idle. The idea behind this is that, 1081generator that generates requests if idle. The idea behind this is that,
868although you could just queue as many requests as you want in a group, 1082although you could just queue as many requests as you want in a group,
869this might starve other requests for a potentially long time. For 1083this might starve other requests for a potentially long time. For example,
870example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1084C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871requests, delaying any later requests for a long time. 1085delaying any later requests for a long time.
872 1086
873To avoid this, and allow incremental generation of requests, you can 1087To avoid this, and allow incremental generation of requests, you can
874instead a group and set a feeder on it that generates those requests. The 1088instead a group and set a feeder on it that generates those requests. The
875feed callback will be called whenever there are few enough (see C<limit>, 1089feed callback will be called whenever there are few enough (see C<limit>,
876below) requests active in the group itself and is expected to queue more 1090below) requests active in the group itself and is expected to queue more
880not impose any limits). 1094not impose any limits).
881 1095
882If the feed does not queue more requests when called, it will be 1096If the feed does not queue more requests when called, it will be
883automatically removed from the group. 1097automatically removed from the group.
884 1098
885If the feed limit is C<0>, it will be set to C<2> automatically. 1099If the feed limit is C<0> when this method is called, it will be set to
1100C<2> automatically.
886 1101
887Example: 1102Example:
888 1103
889 # stat all files in @files, but only ever use four aio requests concurrently: 1104 # stat all files in @files, but only ever use four aio requests concurrently:
890 1105
902Sets the feeder limit for the group: The feeder will be called whenever 1117Sets the feeder limit for the group: The feeder will be called whenever
903the group contains less than this many requests. 1118the group contains less than this many requests.
904 1119
905Setting the limit to C<0> will pause the feeding process. 1120Setting the limit to C<0> will pause the feeding process.
906 1121
1122The default value for the limit is C<0>, but note that setting a feeder
1123automatically bumps it up to C<2>.
1124
907=back 1125=back
908 1126
909=head2 SUPPORT FUNCTIONS 1127=head2 SUPPORT FUNCTIONS
910 1128
911=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1129=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
922See C<poll_cb> for an example. 1140See C<poll_cb> for an example.
923 1141
924=item IO::AIO::poll_cb 1142=item IO::AIO::poll_cb
925 1143
926Process some outstanding events on the result pipe. You have to call this 1144Process some outstanding events on the result pipe. You have to call this
927regularly. Returns the number of events processed. Returns immediately 1145regularly. Returns C<0> if all events could be processed, or C<-1> if it
1146returned earlier for whatever reason. Returns immediately when no events
928when no events are outstanding. The amount of events processed depends on 1147are outstanding. The amount of events processed depends on the settings of
929the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1148C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930 1149
931If not all requests were processed for whatever reason, the filehandle 1150If not all requests were processed for whatever reason, the filehandle
932will still be ready when C<poll_cb> returns. 1151will still be ready when C<poll_cb> returns, so normally you don't have to
1152do anything special to have it called later.
933 1153
934Example: Install an Event watcher that automatically calls 1154Example: Install an Event watcher that automatically calls
935IO::AIO::poll_cb with high priority: 1155IO::AIO::poll_cb with high priority:
936 1156
937 Event->io (fd => IO::AIO::poll_fileno, 1157 Event->io (fd => IO::AIO::poll_fileno,
971 poll => 'r', nice => 1, 1191 poll => 'r', nice => 1,
972 cb => &IO::AIO::poll_cb); 1192 cb => &IO::AIO::poll_cb);
973 1193
974=item IO::AIO::poll_wait 1194=item IO::AIO::poll_wait
975 1195
1196If there are any outstanding requests and none of them in the result
976Wait till the result filehandle becomes ready for reading (simply does a 1197phase, wait till the result filehandle becomes ready for reading (simply
977C<select> on the filehandle. This is useful if you want to synchronously 1198does a C<select> on the filehandle. This is useful if you want to
978wait for some requests to finish). 1199synchronously wait for some requests to finish).
979 1200
980See C<nreqs> for an example. 1201See C<nreqs> for an example.
981 1202
982=item IO::AIO::poll 1203=item IO::AIO::poll
983 1204
984Waits until some requests have been handled. 1205Waits until some requests have been handled.
985 1206
1207Returns the number of requests processed, but is otherwise strictly
986Strictly equivalent to: 1208equivalent to:
987 1209
988 IO::AIO::poll_wait, IO::AIO::poll_cb 1210 IO::AIO::poll_wait, IO::AIO::poll_cb
989 if IO::AIO::nreqs;
990 1211
991=item IO::AIO::flush 1212=item IO::AIO::flush
992 1213
993Wait till all outstanding AIO requests have been handled. 1214Wait till all outstanding AIO requests have been handled.
994 1215
995Strictly equivalent to: 1216Strictly equivalent to:
996 1217
997 IO::AIO::poll_wait, IO::AIO::poll_cb 1218 IO::AIO::poll_wait, IO::AIO::poll_cb
998 while IO::AIO::nreqs; 1219 while IO::AIO::nreqs;
999 1220
1221=back
1222
1000=head3 CONTROLLING THE NUMBER OF THREADS 1223=head3 CONTROLLING THE NUMBER OF THREADS
1224
1225=over
1001 1226
1002=item IO::AIO::min_parallel $nthreads 1227=item IO::AIO::min_parallel $nthreads
1003 1228
1004Set the minimum number of AIO threads to C<$nthreads>. The current 1229Set the minimum number of AIO threads to C<$nthreads>. The current
1005default is C<8>, which means eight asynchronous operations can execute 1230default is C<8>, which means eight asynchronous operations can execute
1046 1271
1047The default is probably ok in most situations, especially if thread 1272The default is probably ok in most situations, especially if thread
1048creation is fast. If thread creation is very slow on your system you might 1273creation is fast. If thread creation is very slow on your system you might
1049want to use larger values. 1274want to use larger values.
1050 1275
1051=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1276=item IO::AIO::max_outstanding $maxreqs
1052 1277
1053This is a very bad function to use in interactive programs because it 1278This is a very bad function to use in interactive programs because it
1054blocks, and a bad way to reduce concurrency because it is inexact: Better 1279blocks, and a bad way to reduce concurrency because it is inexact: Better
1055use an C<aio_group> together with a feed callback. 1280use an C<aio_group> together with a feed callback.
1056 1281
1057Sets the maximum number of outstanding requests to C<$nreqs>. If you 1282Sets the maximum number of outstanding requests to C<$nreqs>. If you
1058to queue up more than this number of requests, the next call to the 1283do queue up more than this number of requests, the next call to the
1059C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1284C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060function will block until the limit is no longer exceeded. 1285function will block until the limit is no longer exceeded.
1061 1286
1062The default value is very large, so there is no practical limit on the 1287The default value is very large, so there is no practical limit on the
1063number of outstanding requests. 1288number of outstanding requests.
1064 1289
1065You can still queue as many requests as you want. Therefore, 1290You can still queue as many requests as you want. Therefore,
1066C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1291C<max_outstanding> is mainly useful in simple scripts (with low values) or
1067as a stop gap to shield against fatal memory overflow (with large values). 1292as a stop gap to shield against fatal memory overflow (with large values).
1068 1293
1294=back
1295
1069=head3 STATISTICAL INFORMATION 1296=head3 STATISTICAL INFORMATION
1297
1298=over
1070 1299
1071=item IO::AIO::nreqs 1300=item IO::AIO::nreqs
1072 1301
1073Returns the number of requests currently in the ready, execute or pending 1302Returns the number of requests currently in the ready, execute or pending
1074states (i.e. for which their callback has not been invoked yet). 1303states (i.e. for which their callback has not been invoked yet).
1090 1319
1091=back 1320=back
1092 1321
1093=cut 1322=cut
1094 1323
1095# support function to convert a fd into a perl filehandle
1096sub _fd2fh {
1097 return undef if $_[0] < 0;
1098
1099 # try to generate nice filehandles
1100 my $sym = "IO::AIO::fd#$_[0]";
1101 local *$sym;
1102
1103 open *$sym, "+<&=$_[0]" # usually works under any unix
1104 or open *$sym, "<&=$_[0]" # cygwin needs this
1105 or open *$sym, ">&=$_[0]" # or this
1106 or return undef;
1107
1108 *$sym
1109}
1110
1111min_parallel 8; 1324min_parallel 8;
1112 1325
1113END { 1326END { flush }
1114 min_parallel 1;
1115 flush;
1116};
1117 1327
11181; 13281;
1119 1329
1120=head2 FORK BEHAVIOUR 1330=head2 FORK BEHAVIOUR
1121 1331
1141bytes of memory. In addition, stat requests need a stat buffer (possibly 1351bytes of memory. In addition, stat requests need a stat buffer (possibly
1142a few hundred bytes), readdir requires a result buffer and so on. Perl 1352a few hundred bytes), readdir requires a result buffer and so on. Perl
1143scalars and other data passed into aio requests will also be locked and 1353scalars and other data passed into aio requests will also be locked and
1144will consume memory till the request has entered the done state. 1354will consume memory till the request has entered the done state.
1145 1355
1146This is now awfully much, so queuing lots of requests is not usually a 1356This is not awfully much, so queuing lots of requests is not usually a
1147problem. 1357problem.
1148 1358
1149Per-thread usage: 1359Per-thread usage:
1150 1360
1151In the execution phase, some aio requests require more memory for 1361In the execution phase, some aio requests require more memory for
1156 1366
1157Known bugs will be fixed in the next release. 1367Known bugs will be fixed in the next release.
1158 1368
1159=head1 SEE ALSO 1369=head1 SEE ALSO
1160 1370
1161L<Coro::AIO>. 1371L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1372more natural syntax.
1162 1373
1163=head1 AUTHOR 1374=head1 AUTHOR
1164 1375
1165 Marc Lehmann <schmorp@schmorp.de> 1376 Marc Lehmann <schmorp@schmorp.de>
1166 http://home.schmorp.de/ 1377 http://home.schmorp.de/

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