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 1.85 by root, Sat Oct 28 01:40:30 2006 UTC vs.
Revision 1.116 by root, Wed Oct 3 21:27:51 2007 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
… …
61etc.), but can also be used to easily do operations in parallel that are 62etc.), 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 63normally 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 64on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 65concurrently.
65 66
66While this works on all types of file descriptors (for example sockets), 67While most of this works on all types of file descriptors (for
67using these functions on file descriptors that support nonblocking 68example sockets), using these functions on file descriptors that
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 69support nonblocking operation (again, sockets, pipes etc.) is very
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 70inefficient. Use an event loop for that (such as the L<Event|Event>
70fit into such an event loop itself. 71module): IO::AIO will naturally fit into such an event loop itself.
71 72
72In this version, a number of threads are started that execute your 73In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 74requests and signal their completion. You don't need thread support
74in perl, and the threads created by this module will not be visible 75in perl, and the threads created by this module will not be visible
75to perl. In the future, this module might make use of the native aio 76to perl. In the future, this module might make use of the native aio
… …
77not well-supported or restricted (GNU/Linux doesn't allow them on normal 78not well-supported or restricted (GNU/Linux doesn't allow them on normal
78files currently, for example), and they would only support aio_read and 79files currently, for example), and they would only support aio_read and
79aio_write, so the remaining functionality would have to be implemented 80aio_write, so the remaining functionality would have to be implemented
80using threads anyway. 81using threads anyway.
81 82
82Although the module will work with in the presence of other (Perl-) 83Although the module will work in the presence of other (Perl-) threads,
83threads, it is currently not reentrant in any way, so use appropriate 84it is currently not reentrant in any way, so use appropriate locking
84locking yourself, always call C<poll_cb> from within the same thread, or 85yourself, always call C<poll_cb> from within the same thread, or never
85never call C<poll_cb> (or other C<aio_> functions) recursively. 86call C<poll_cb> (or other C<aio_> functions) recursively.
87
88=head2 EXAMPLE
89
90This is a simple example that uses the Event module and loads
91F</etc/passwd> asynchronously:
92
93 use Fcntl;
94 use Event;
95 use IO::AIO;
96
97 # register the IO::AIO callback with Event
98 Event->io (fd => IO::AIO::poll_fileno,
99 poll => 'r',
100 cb => \&IO::AIO::poll_cb);
101
102 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = shift
105 or die "error while opening: $!";
106
107 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh;
109
110 # queue a request to read the file
111 my $contents;
112 aio_read $fh, 0, $size, $contents, 0, sub {
113 $_[0] == $size
114 or die "short read: $!";
115
116 close $fh;
117
118 # file contents now in $contents
119 print $contents;
120
121 # exit event loop and program
122 Event::unloop;
123 };
124 };
125
126 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc.
128
129 # process events as long as there are some:
130 Event::loop;
86 131
87=head1 REQUEST ANATOMY AND LIFETIME 132=head1 REQUEST ANATOMY AND LIFETIME
88 133
89Every C<aio_*> function creates a request. which is a C data structure not 134Every C<aio_*> function creates a request. which is a C data structure not
90directly visible to Perl. 135directly visible to Perl.
… …
132Request has reached the end of its lifetime and holds no resources anymore 177Request has reached the end of its lifetime and holds no resources anymore
133(except possibly for the Perl object, but its connection to the actual 178(except possibly for the Perl object, but its connection to the actual
134aio request is severed and calling its methods will either do nothing or 179aio request is severed and calling its methods will either do nothing or
135result in a runtime error). 180result in a runtime error).
136 181
182=back
183
137=cut 184=cut
138 185
139package IO::AIO; 186package IO::AIO;
140 187
141no warnings; 188no warnings;
142use strict 'vars'; 189use strict 'vars';
143 190
144use base 'Exporter'; 191use base 'Exporter';
145 192
146BEGIN { 193BEGIN {
147 our $VERSION = '2.0'; 194 our $VERSION = '2.5';
148 195
149 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
150 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 197 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
151 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
152 aio_copy aio_group aio_nop aio_mknod); 199 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
200 aio_chown aio_chmod aio_utime aio_truncate);
153 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
154 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
155 min_parallel max_parallel nreqs nready npending); 203 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs);
156 206
157 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
158 208
159 require XSLoader; 209 require XSLoader;
160 XSLoader::load ("IO::AIO", $VERSION); 210 XSLoader::load ("IO::AIO", $VERSION);
161} 211}
162 212
163=head1 FUNCTIONS 213=head1 FUNCTIONS
164 214
165=head2 AIO FUNCTIONS 215=head2 AIO REQUEST FUNCTIONS
166 216
167All the C<aio_*> calls are more or less thin wrappers around the syscall 217All the C<aio_*> calls are more or less thin wrappers around the syscall
168with the same name (sans C<aio_>). The arguments are similar or identical, 218with the same name (sans C<aio_>). The arguments are similar or identical,
169and they all accept an additional (and optional) C<$callback> argument 219and they all accept an additional (and optional) C<$callback> argument
170which must be a code reference. This code reference will get called with 220which must be a code reference. This code reference will get called with
… …
173syscall has been executed asynchronously. 223syscall has been executed asynchronously.
174 224
175All functions expecting a filehandle keep a copy of the filehandle 225All functions expecting a filehandle keep a copy of the filehandle
176internally until the request has finished. 226internally until the request has finished.
177 227
178All requests return objects of type L<IO::AIO::REQ> that allow further 228All functions return request objects of type L<IO::AIO::REQ> that allow
179manipulation of those requests while they are in-flight. 229further manipulation of those requests while they are in-flight.
180 230
181The pathnames you pass to these routines I<must> be absolute and 231The pathnames you pass to these routines I<must> be absolute and
182encoded in byte form. The reason for the former is that at the time the 232encoded as octets. The reason for the former is that at the time the
183request is being executed, the current working directory could have 233request is being executed, the current working directory could have
184changed. Alternatively, you can make sure that you never change the 234changed. Alternatively, you can make sure that you never change the
185current working directory. 235current working directory anywhere in the program and then use relative
236paths.
186 237
187To encode pathnames to byte form, either make sure you either: a) 238To encode pathnames as octets, either make sure you either: a) always pass
188always pass in filenames you got from outside (command line, readdir 239in filenames you got from outside (command line, readdir etc.) without
189etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode 240tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode
190your pathnames to the locale (or other) encoding in effect in the user 241your pathnames to the locale (or other) encoding in effect in the user
191environment, d) use Glib::filename_from_unicode on unicode filenames or e) 242environment, d) use Glib::filename_from_unicode on unicode filenames or e)
192use something else. 243use something else to ensure your scalar has the correct contents.
244
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not.
193 247
194=over 4 248=over 4
195 249
196=item $prev_pri = aioreq_pri [$pri] 250=item $prev_pri = aioreq_pri [$pri]
197 251
… …
217 aio_read $_[0], ..., sub { 271 aio_read $_[0], ..., sub {
218 ... 272 ...
219 }; 273 };
220 }; 274 };
221 275
276
222=item aioreq_nice $pri_adjust 277=item aioreq_nice $pri_adjust
223 278
224Similar to C<aioreq_pri>, but subtracts the given value from the current 279Similar to C<aioreq_pri>, but subtracts the given value from the current
225priority, so effects are cumulative. 280priority, so the effect is cumulative.
281
226 282
227=item aio_open $pathname, $flags, $mode, $callback->($fh) 283=item aio_open $pathname, $flags, $mode, $callback->($fh)
228 284
229Asynchronously open or create a file and call the callback with a newly 285Asynchronously open or create a file and call the callback with a newly
230created filehandle for the file. 286created filehandle for the file.
… …
236list. They are the same as used by C<sysopen>. 292list. They are the same as used by C<sysopen>.
237 293
238Likewise, C<$mode> specifies the mode of the newly created file, if it 294Likewise, C<$mode> specifies the mode of the newly created file, if it
239didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 295didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
240except that it is mandatory (i.e. use C<0> if you don't create new files, 296except that it is mandatory (i.e. use C<0> if you don't create new files,
241and C<0666> or C<0777> if you do). 297and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
298by the umask in effect then the request is being executed, so better never
299change the umask.
242 300
243Example: 301Example:
244 302
245 aio_open "/etc/passwd", O_RDONLY, 0, sub { 303 aio_open "/etc/passwd", O_RDONLY, 0, sub {
246 if ($_[0]) { 304 if ($_[0]) {
… …
249 } else { 307 } else {
250 die "open failed: $!\n"; 308 die "open failed: $!\n";
251 } 309 }
252 }; 310 };
253 311
312
254=item aio_close $fh, $callback->($status) 313=item aio_close $fh, $callback->($status)
255 314
256Asynchronously close a file and call the callback with the result 315Asynchronously close a file and call the callback with the result
257code. I<WARNING:> although accepted, you should not pass in a perl 316code.
258filehandle here, as perl will likely close the file descriptor another
259time when the filehandle is destroyed. Normally, you can safely call perls
260C<close> or just let filehandles go out of scope.
261 317
262This is supposed to be a bug in the API, so that might change. It's 318Unlike the other functions operating on files, this function uses the
263therefore best to avoid this function. 319PerlIO layer to close the filehandle. The reason is that the PerlIO API
320insists on closing the underlying fd itself, no matter what, and doesn't
321allow modifications to the fd. Unfortunately, it is not clear that you can
322call PerlIO from different threads (actually, its quite clear that this
323won't work in some cases), so while it likely works perfectly with simple
324file handles (such as the ones created by C<aio_open>) it might fail in
325interesting ways for others.
326
327Having said that, aio_close tries to clean up the filehandle as much as
328possible before handing it to an io thread, and generally does work.
329
264 330
265=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 331=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
266 332
267=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 333=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
268 334
269Reads or writes C<length> bytes from the specified C<fh> and C<offset> 335Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
270into the scalar given by C<data> and offset C<dataoffset> and calls the 336into the scalar given by C<$data> and offset C<$dataoffset> and calls the
271callback without the actual number of bytes read (or -1 on error, just 337callback without the actual number of bytes read (or -1 on error, just
272like the syscall). 338like the syscall).
273 339
340If C<$offset> is undefined, then the current file descriptor offset will
341be used (and updated), otherwise the file descriptor offset will not be
342changed by these calls.
343
344If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
345
346If C<$dataoffset> is less than zero, it will be counted from the end of
347C<$data>.
348
274The C<$data> scalar I<MUST NOT> be modified in any way while the request 349The C<$data> scalar I<MUST NOT> be modified in any way while the request
275is outstanding. Modifying it can result in segfaults or WW3 (if the 350is outstanding. Modifying it can result in segfaults or World War III (if
276necessary/optional hardware is installed). 351the necessary/optional hardware is installed).
277 352
278Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 353Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
279offset C<0> within the scalar: 354offset C<0> within the scalar:
280 355
281 aio_read $fh, 7, 15, $buffer, 0, sub { 356 aio_read $fh, 7, 15, $buffer, 0, sub {
282 $_[0] > 0 or die "read error: $!"; 357 $_[0] > 0 or die "read error: $!";
283 print "read $_[0] bytes: <$buffer>\n"; 358 print "read $_[0] bytes: <$buffer>\n";
284 }; 359 };
360
285 361
286=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 362=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
287 363
288Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 364Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
289reading at byte offset C<$in_offset>, and starts writing at the current 365reading at byte offset C<$in_offset>, and starts writing at the current
… …
303C<$in_fh> than are written, and there is no way to find out how many 379C<$in_fh> than are written, and there is no way to find out how many
304bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 380bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
305provides the number of bytes written to C<$out_fh>. Only if the result 381provides the number of bytes written to C<$out_fh>. Only if the result
306value equals C<$length> one can assume that C<$length> bytes have been 382value equals C<$length> one can assume that C<$length> bytes have been
307read. 383read.
384
308 385
309=item aio_readahead $fh,$offset,$length, $callback->($retval) 386=item aio_readahead $fh,$offset,$length, $callback->($retval)
310 387
311C<aio_readahead> populates the page cache with data from a file so that 388C<aio_readahead> populates the page cache with data from a file so that
312subsequent reads from that file will not block on disk I/O. The C<$offset> 389subsequent reads from that file will not block on disk I/O. The C<$offset>
… …
318file. The current file offset of the file is left unchanged. 395file. The current file offset of the file is left unchanged.
319 396
320If that syscall doesn't exist (likely if your OS isn't Linux) it will be 397If that syscall doesn't exist (likely if your OS isn't Linux) it will be
321emulated by simply reading the data, which would have a similar effect. 398emulated by simply reading the data, which would have a similar effect.
322 399
400
323=item aio_stat $fh_or_path, $callback->($status) 401=item aio_stat $fh_or_path, $callback->($status)
324 402
325=item aio_lstat $fh, $callback->($status) 403=item aio_lstat $fh, $callback->($status)
326 404
327Works like perl's C<stat> or C<lstat> in void context. The callback will 405Works like perl's C<stat> or C<lstat> in void context. The callback will
… …
340 aio_stat "/etc/passwd", sub { 418 aio_stat "/etc/passwd", sub {
341 $_[0] and die "stat failed: $!"; 419 $_[0] and die "stat failed: $!";
342 print "size is ", -s _, "\n"; 420 print "size is ", -s _, "\n";
343 }; 421 };
344 422
423
424=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
425
426Works like perl's C<utime> function (including the special case of $atime
427and $mtime being undef). Fractional times are supported if the underlying
428syscalls support them.
429
430When called with a pathname, uses utimes(2) if available, otherwise
431utime(2). If called on a file descriptor, uses futimes(2) if available,
432otherwise returns ENOSYS, so this is not portable.
433
434Examples:
435
436 # set atime and mtime to current time (basically touch(1)):
437 aio_utime "path", undef, undef;
438 # set atime to current time and mtime to beginning of the epoch:
439 aio_utime "path", time, undef; # undef==0
440
441
442=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
443
444Works like perl's C<chown> function, except that C<undef> for either $uid
445or $gid is being interpreted as "do not change" (but -1 can also be used).
446
447Examples:
448
449 # same as "chown root path" in the shell:
450 aio_chown "path", 0, -1;
451 # same as above:
452 aio_chown "path", 0, undef;
453
454
455=item aio_truncate $fh_or_path, $offset, $callback->($status)
456
457Works like truncate(2) or ftruncate(2).
458
459
460=item aio_chmod $fh_or_path, $mode, $callback->($status)
461
462Works like perl's C<chmod> function.
463
464
345=item aio_unlink $pathname, $callback->($status) 465=item aio_unlink $pathname, $callback->($status)
346 466
347Asynchronously unlink (delete) a file and call the callback with the 467Asynchronously unlink (delete) a file and call the callback with the
348result code. 468result code.
349 469
470
350=item aio_mknod $path, $mode, $dev, $callback->($status) 471=item aio_mknod $path, $mode, $dev, $callback->($status)
351 472
473[EXPERIMENTAL]
474
352Asynchronously create a device node (or fifo). See mknod(2). 475Asynchronously create a device node (or fifo). See mknod(2).
353 476
354The only portable (POSIX) way of calling this function is: 477The only (POSIX-) portable way of calling this function is:
355 478
356 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 479 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
480
357 481
358=item aio_link $srcpath, $dstpath, $callback->($status) 482=item aio_link $srcpath, $dstpath, $callback->($status)
359 483
360Asynchronously create a new link to the existing object at C<$srcpath> at 484Asynchronously create a new link to the existing object at C<$srcpath> at
361the path C<$dstpath> and call the callback with the result code. 485the path C<$dstpath> and call the callback with the result code.
362 486
487
363=item aio_symlink $srcpath, $dstpath, $callback->($status) 488=item aio_symlink $srcpath, $dstpath, $callback->($status)
364 489
365Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 490Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
366the path C<$dstpath> and call the callback with the result code. 491the path C<$dstpath> and call the callback with the result code.
367 492
493
494=item aio_readlink $path, $callback->($link)
495
496Asynchronously read the symlink specified by C<$path> and pass it to
497the callback. If an error occurs, nothing or undef gets passed to the
498callback.
499
500
368=item aio_rename $srcpath, $dstpath, $callback->($status) 501=item aio_rename $srcpath, $dstpath, $callback->($status)
369 502
370Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 503Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
371rename(2) and call the callback with the result code. 504rename(2) and call the callback with the result code.
372 505
506
507=item aio_mkdir $pathname, $mode, $callback->($status)
508
509Asynchronously mkdir (create) a directory and call the callback with
510the result code. C<$mode> will be modified by the umask at the time the
511request is executed, so do not change your umask.
512
513
373=item aio_rmdir $pathname, $callback->($status) 514=item aio_rmdir $pathname, $callback->($status)
374 515
375Asynchronously rmdir (delete) a directory and call the callback with the 516Asynchronously rmdir (delete) a directory and call the callback with the
376result code. 517result code.
518
377 519
378=item aio_readdir $pathname, $callback->($entries) 520=item aio_readdir $pathname, $callback->($entries)
379 521
380Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 522Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
381directory (i.e. opendir + readdir + closedir). The entries will not be 523directory (i.e. opendir + readdir + closedir). The entries will not be
382sorted, and will B<NOT> include the C<.> and C<..> entries. 524sorted, and will B<NOT> include the C<.> and C<..> entries.
383 525
384The callback a single argument which is either C<undef> or an array-ref 526The callback a single argument which is either C<undef> or an array-ref
385with the filenames. 527with the filenames.
528
529
530=item aio_load $path, $data, $callback->($status)
531
532This is a composite request that tries to fully load the given file into
533memory. Status is the same as with aio_read.
534
535=cut
536
537sub aio_load($$;$) {
538 aio_block {
539 my ($path, undef, $cb) = @_;
540 my $data = \$_[1];
541
542 my $pri = aioreq_pri;
543 my $grp = aio_group $cb;
544
545 aioreq_pri $pri;
546 add $grp aio_open $path, O_RDONLY, 0, sub {
547 my $fh = shift
548 or return $grp->result (-1);
549
550 aioreq_pri $pri;
551 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552 $grp->result ($_[0]);
553 };
554 };
555
556 $grp
557 }
558}
386 559
387=item aio_copy $srcpath, $dstpath, $callback->($status) 560=item aio_copy $srcpath, $dstpath, $callback->($status)
388 561
389Try to copy the I<file> (directories not supported as either source or 562Try to copy the I<file> (directories not supported as either source or
390destination) from C<$srcpath> to C<$dstpath> and call the callback with 563destination) from C<$srcpath> to C<$dstpath> and call the callback with
… …
400errors are being ignored. 573errors are being ignored.
401 574
402=cut 575=cut
403 576
404sub aio_copy($$;$) { 577sub aio_copy($$;$) {
578 aio_block {
405 my ($src, $dst, $cb) = @_; 579 my ($src, $dst, $cb) = @_;
406 580
407 my $pri = aioreq_pri; 581 my $pri = aioreq_pri;
408 my $grp = aio_group $cb; 582 my $grp = aio_group $cb;
409 583
410 aioreq_pri $pri; 584 aioreq_pri $pri;
411 add $grp aio_open $src, O_RDONLY, 0, sub { 585 add $grp aio_open $src, O_RDONLY, 0, sub {
412 if (my $src_fh = $_[0]) { 586 if (my $src_fh = $_[0]) {
413 my @stat = stat $src_fh; 587 my @stat = stat $src_fh;
414 588
415 aioreq_pri $pri; 589 aioreq_pri $pri;
416 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 590 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
417 if (my $dst_fh = $_[0]) { 591 if (my $dst_fh = $_[0]) {
418 aioreq_pri $pri; 592 aioreq_pri $pri;
419 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 593 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
420 if ($_[0] == $stat[7]) { 594 if ($_[0] == $stat[7]) {
421 $grp->result (0); 595 $grp->result (0);
422 close $src_fh; 596 close $src_fh;
423 597
424 # those should not normally block. should. should. 598 # those should not normally block. should. should.
425 utime $stat[8], $stat[9], $dst; 599 utime $stat[8], $stat[9], $dst;
426 chmod $stat[2] & 07777, $dst_fh; 600 chmod $stat[2] & 07777, $dst_fh;
427 chown $stat[4], $stat[5], $dst_fh; 601 chown $stat[4], $stat[5], $dst_fh;
428 close $dst_fh; 602 close $dst_fh;
429 } else { 603 } else {
430 $grp->result (-1); 604 $grp->result (-1);
431 close $src_fh; 605 close $src_fh;
432 close $dst_fh; 606 close $dst_fh;
433 607
434 aioreq $pri; 608 aioreq $pri;
435 add $grp aio_unlink $dst; 609 add $grp aio_unlink $dst;
610 }
436 } 611 };
612 } else {
613 $grp->result (-1);
437 }; 614 }
438 } else {
439 $grp->result (-1);
440 } 615 },
616
617 } else {
618 $grp->result (-1);
441 }, 619 }
442
443 } else {
444 $grp->result (-1);
445 } 620 };
621
622 $grp
446 }; 623 }
447
448 $grp
449} 624}
450 625
451=item aio_move $srcpath, $dstpath, $callback->($status) 626=item aio_move $srcpath, $dstpath, $callback->($status)
452 627
453Try to move the I<file> (directories not supported as either source or 628Try to move the I<file> (directories not supported as either source or
… …
459that is successful, unlinking the C<$srcpath>. 634that is successful, unlinking the C<$srcpath>.
460 635
461=cut 636=cut
462 637
463sub aio_move($$;$) { 638sub aio_move($$;$) {
639 aio_block {
464 my ($src, $dst, $cb) = @_; 640 my ($src, $dst, $cb) = @_;
465 641
466 my $pri = aioreq_pri; 642 my $pri = aioreq_pri;
467 my $grp = aio_group $cb; 643 my $grp = aio_group $cb;
468 644
469 aioreq_pri $pri; 645 aioreq_pri $pri;
470 add $grp aio_rename $src, $dst, sub { 646 add $grp aio_rename $src, $dst, sub {
471 if ($_[0] && $! == EXDEV) { 647 if ($_[0] && $! == EXDEV) {
472 aioreq_pri $pri; 648 aioreq_pri $pri;
473 add $grp aio_copy $src, $dst, sub { 649 add $grp aio_copy $src, $dst, sub {
650 $grp->result ($_[0]);
651
652 if (!$_[0]) {
653 aioreq_pri $pri;
654 add $grp aio_unlink $src;
655 }
656 };
657 } else {
474 $grp->result ($_[0]); 658 $grp->result ($_[0]);
475
476 if (!$_[0]) {
477 aioreq_pri $pri;
478 add $grp aio_unlink $src;
479 }
480 }; 659 }
481 } else {
482 $grp->result ($_[0]);
483 } 660 };
661
662 $grp
484 }; 663 }
485
486 $grp
487} 664}
488 665
489=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 666=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
490 667
491Scans a directory (similar to C<aio_readdir>) but additionally tries to 668Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
538as those tend to return 0 or 1 as link counts, which disables the 715as those tend to return 0 or 1 as link counts, which disables the
539directory counting heuristic. 716directory counting heuristic.
540 717
541=cut 718=cut
542 719
543sub aio_scandir($$$) { 720sub aio_scandir($$;$) {
721 aio_block {
544 my ($path, $maxreq, $cb) = @_; 722 my ($path, $maxreq, $cb) = @_;
545 723
546 my $pri = aioreq_pri; 724 my $pri = aioreq_pri;
547 725
548 my $grp = aio_group $cb; 726 my $grp = aio_group $cb;
549 727
550 $maxreq = 4 if $maxreq <= 0; 728 $maxreq = 4 if $maxreq <= 0;
551 729
552 # stat once 730 # stat once
553 aioreq_pri $pri;
554 add $grp aio_stat $path, sub {
555 return $grp->result () if $_[0];
556 my $now = time;
557 my $hash1 = join ":", (stat _)[0,1,3,7,9];
558
559 # read the directory entries
560 aioreq_pri $pri; 731 aioreq_pri $pri;
561 add $grp aio_readdir $path, sub { 732 add $grp aio_stat $path, sub {
562 my $entries = shift
563 or return $grp->result (); 733 return $grp->result () if $_[0];
734 my $now = time;
735 my $hash1 = join ":", (stat _)[0,1,3,7,9];
564 736
565 # stat the dir another time 737 # read the directory entries
566 aioreq_pri $pri; 738 aioreq_pri $pri;
739 add $grp aio_readdir $path, sub {
740 my $entries = shift
741 or return $grp->result ();
742
743 # stat the dir another time
744 aioreq_pri $pri;
567 add $grp aio_stat $path, sub { 745 add $grp aio_stat $path, sub {
568 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 746 my $hash2 = join ":", (stat _)[0,1,3,7,9];
569 747
570 my $ndirs; 748 my $ndirs;
571 749
572 # take the slow route if anything looks fishy 750 # take the slow route if anything looks fishy
573 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 751 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
574 $ndirs = -1; 752 $ndirs = -1;
575 } else { 753 } else {
576 # if nlink == 2, we are finished 754 # if nlink == 2, we are finished
577 # on non-posix-fs's, we rely on nlink < 2 755 # on non-posix-fs's, we rely on nlink < 2
578 $ndirs = (stat _)[3] - 2 756 $ndirs = (stat _)[3] - 2
579 or return $grp->result ([], $entries); 757 or return $grp->result ([], $entries);
580 } 758 }
581 759
582 # sort into likely dirs and likely nondirs 760 # sort into likely dirs and likely nondirs
583 # dirs == files without ".", short entries first 761 # dirs == files without ".", short entries first
584 $entries = [map $_->[0], 762 $entries = [map $_->[0],
585 sort { $b->[1] cmp $a->[1] } 763 sort { $b->[1] cmp $a->[1] }
586 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 764 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
587 @$entries]; 765 @$entries];
588 766
589 my (@dirs, @nondirs); 767 my (@dirs, @nondirs);
590 768
591 my $statgrp = add $grp aio_group sub { 769 my $statgrp = add $grp aio_group sub {
592 $grp->result (\@dirs, \@nondirs); 770 $grp->result (\@dirs, \@nondirs);
593 }; 771 };
594 772
595 limit $statgrp $maxreq; 773 limit $statgrp $maxreq;
596 feed $statgrp sub { 774 feed $statgrp sub {
597 return unless @$entries; 775 return unless @$entries;
598 my $entry = pop @$entries; 776 my $entry = pop @$entries;
599 777
600 aioreq_pri $pri; 778 aioreq_pri $pri;
601 add $statgrp aio_stat "$path/$entry/.", sub { 779 add $statgrp aio_stat "$path/$entry/.", sub {
602 if ($_[0] < 0) { 780 if ($_[0] < 0) {
603 push @nondirs, $entry; 781 push @nondirs, $entry;
604 } else { 782 } else {
605 # need to check for real directory 783 # need to check for real directory
606 aioreq_pri $pri; 784 aioreq_pri $pri;
607 add $statgrp aio_lstat "$path/$entry", sub { 785 add $statgrp aio_lstat "$path/$entry", sub {
608 if (-d _) { 786 if (-d _) {
609 push @dirs, $entry; 787 push @dirs, $entry;
610 788
611 unless (--$ndirs) { 789 unless (--$ndirs) {
612 push @nondirs, @$entries; 790 push @nondirs, @$entries;
613 feed $statgrp; 791 feed $statgrp;
792 }
793 } else {
794 push @nondirs, $entry;
614 } 795 }
615 } else {
616 push @nondirs, $entry;
617 } 796 }
618 } 797 }
619 } 798 };
620 }; 799 };
621 }; 800 };
622 }; 801 };
623 }; 802 };
803
804 $grp
624 }; 805 }
806}
625 807
808=item aio_rmtree $path, $callback->($status)
809
810Delete a directory tree starting (and including) C<$path>, return the
811status of the final C<rmdir> only. This is a composite request that
812uses C<aio_scandir> to recurse into and rmdir directories, and unlink
813everything else.
814
815=cut
816
817sub aio_rmtree;
818sub aio_rmtree($;$) {
819 aio_block {
820 my ($path, $cb) = @_;
821
822 my $pri = aioreq_pri;
823 my $grp = aio_group $cb;
824
825 aioreq_pri $pri;
826 add $grp aio_scandir $path, 0, sub {
827 my ($dirs, $nondirs) = @_;
828
829 my $dirgrp = aio_group sub {
830 add $grp aio_rmdir $path, sub {
831 $grp->result ($_[0]);
832 };
833 };
834
835 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
836 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
837
838 add $grp $dirgrp;
839 };
840
626 $grp 841 $grp
842 }
627} 843}
628 844
629=item aio_fsync $fh, $callback->($status) 845=item aio_fsync $fh, $callback->($status)
630 846
631Asynchronously call fsync on the given filehandle and call the callback 847Asynchronously call fsync on the given filehandle and call the callback
… …
845 1061
846=back 1062=back
847 1063
848=head2 SUPPORT FUNCTIONS 1064=head2 SUPPORT FUNCTIONS
849 1065
1066=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1067
850=over 4 1068=over 4
851 1069
852=item $fileno = IO::AIO::poll_fileno 1070=item $fileno = IO::AIO::poll_fileno
853 1071
854Return the I<request result pipe file descriptor>. This filehandle must be 1072Return the I<request result pipe file descriptor>. This filehandle must be
… …
858 1076
859See C<poll_cb> for an example. 1077See C<poll_cb> for an example.
860 1078
861=item IO::AIO::poll_cb 1079=item IO::AIO::poll_cb
862 1080
863Process all outstanding events on the result pipe. You have to call this 1081Process some outstanding events on the result pipe. You have to call this
864regularly. Returns the number of events processed. Returns immediately 1082regularly. Returns the number of events processed. Returns immediately
865when no events are outstanding. 1083when no events are outstanding. The amount of events processed depends on
1084the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
866 1085
867If not all requests were processed for whatever reason, the filehandle 1086If not all requests were processed for whatever reason, the filehandle
868will still be ready when C<poll_cb> returns. 1087will still be ready when C<poll_cb> returns.
869 1088
870Example: Install an Event watcher that automatically calls 1089Example: Install an Event watcher that automatically calls
… …
872 1091
873 Event->io (fd => IO::AIO::poll_fileno, 1092 Event->io (fd => IO::AIO::poll_fileno,
874 poll => 'r', async => 1, 1093 poll => 'r', async => 1,
875 cb => \&IO::AIO::poll_cb); 1094 cb => \&IO::AIO::poll_cb);
876 1095
877=item IO::AIO::poll_some $max_requests 1096=item IO::AIO::max_poll_reqs $nreqs
878 1097
879Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1098=item IO::AIO::max_poll_time $seconds
880at a time.
881 1099
882Useful if you want to ensure some level of interactiveness when perl is 1100These set the maximum number of requests (default C<0>, meaning infinity)
883not fast enough to process all requests in time. 1101that are being processed by C<IO::AIO::poll_cb> in one call, respectively
1102the maximum amount of time (default C<0>, meaning infinity) spent in
1103C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
1104of time C<poll_cb> is allowed to use).
1105
1106Setting C<max_poll_time> to a non-zero value creates an overhead of one
1107syscall per request processed, which is not normally a problem unless your
1108callbacks are really really fast or your OS is really really slow (I am
1109not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1110
1111Setting these is useful if you want to ensure some level of
1112interactiveness when perl is not fast enough to process all requests in
1113time.
1114
1115For interactive programs, values such as C<0.01> to C<0.1> should be fine.
884 1116
885Example: Install an Event watcher that automatically calls 1117Example: Install an Event watcher that automatically calls
886IO::AIO::poll_some with low priority, to ensure that other parts of the 1118IO::AIO::poll_cb with low priority, to ensure that other parts of the
887program get the CPU sometimes even under high AIO load. 1119program get the CPU sometimes even under high AIO load.
888 1120
1121 # try not to spend much more than 0.1s in poll_cb
1122 IO::AIO::max_poll_time 0.1;
1123
1124 # use a low priority so other tasks have priority
889 Event->io (fd => IO::AIO::poll_fileno, 1125 Event->io (fd => IO::AIO::poll_fileno,
890 poll => 'r', nice => 1, 1126 poll => 'r', nice => 1,
891 cb => sub { IO::AIO::poll_some 256 }); 1127 cb => &IO::AIO::poll_cb);
892 1128
893=item IO::AIO::poll_wait 1129=item IO::AIO::poll_wait
894 1130
1131If there are any outstanding requests and none of them in the result
895Wait till the result filehandle becomes ready for reading (simply does a 1132phase, wait till the result filehandle becomes ready for reading (simply
896C<select> on the filehandle. This is useful if you want to synchronously wait 1133does a C<select> on the filehandle. This is useful if you want to
897for some requests to finish). 1134synchronously wait for some requests to finish).
898 1135
899See C<nreqs> for an example. 1136See C<nreqs> for an example.
900 1137
1138=item IO::AIO::poll
1139
1140Waits until some requests have been handled.
1141
1142Returns the number of requests processed, but is otherwise strictly
1143equivalent to:
1144
1145 IO::AIO::poll_wait, IO::AIO::poll_cb
1146
901=item IO::AIO::nreqs 1147=item IO::AIO::flush
902 1148
903Returns the number of requests currently in the ready, execute or pending 1149Wait till all outstanding AIO requests have been handled.
904states (i.e. for which their callback has not been invoked yet).
905 1150
906Example: wait till there are no outstanding requests anymore: 1151Strictly equivalent to:
907 1152
908 IO::AIO::poll_wait, IO::AIO::poll_cb 1153 IO::AIO::poll_wait, IO::AIO::poll_cb
909 while IO::AIO::nreqs; 1154 while IO::AIO::nreqs;
910 1155
911=item IO::AIO::nready 1156=back
912 1157
913Returns the number of requests currently in the ready state (not yet 1158=head3 CONTROLLING THE NUMBER OF THREADS
914executed).
915 1159
916=item IO::AIO::npending 1160=over
917
918Returns the number of requests currently in the pending state (executed,
919but not yet processed by poll_cb).
920
921=item IO::AIO::flush
922
923Wait till all outstanding AIO requests have been handled.
924
925Strictly equivalent to:
926
927 IO::AIO::poll_wait, IO::AIO::poll_cb
928 while IO::AIO::nreqs;
929
930=item IO::AIO::poll
931
932Waits until some requests have been handled.
933
934Strictly equivalent to:
935
936 IO::AIO::poll_wait, IO::AIO::poll_cb
937 if IO::AIO::nreqs;
938 1161
939=item IO::AIO::min_parallel $nthreads 1162=item IO::AIO::min_parallel $nthreads
940 1163
941Set the minimum number of AIO threads to C<$nthreads>. The current 1164Set the minimum number of AIO threads to C<$nthreads>. The current
942default is C<8>, which means eight asynchronous operations can execute 1165default is C<8>, which means eight asynchronous operations can execute
943concurrently at any one time (the number of outstanding requests, 1166concurrently at any one time (the number of outstanding requests,
944however, is unlimited). 1167however, is unlimited).
945 1168
946IO::AIO starts threads only on demand, when an AIO request is queued and 1169IO::AIO starts threads only on demand, when an AIO request is queued and
947no free thread exists. 1170no free thread exists. Please note that queueing up a hundred requests can
1171create demand for a hundred threads, even if it turns out that everything
1172is in the cache and could have been processed faster by a single thread.
948 1173
949It is recommended to keep the number of threads relatively low, as some 1174It is recommended to keep the number of threads relatively low, as some
950Linux kernel versions will scale negatively with the number of threads 1175Linux kernel versions will scale negatively with the number of threads
951(higher parallelity => MUCH higher latency). With current Linux 2.6 1176(higher parallelity => MUCH higher latency). With current Linux 2.6
952versions, 4-32 threads should be fine. 1177versions, 4-32 threads should be fine.
… …
966This module automatically runs C<max_parallel 0> at program end, to ensure 1191This module automatically runs C<max_parallel 0> at program end, to ensure
967that all threads are killed and that there are no outstanding requests. 1192that all threads are killed and that there are no outstanding requests.
968 1193
969Under normal circumstances you don't need to call this function. 1194Under normal circumstances you don't need to call this function.
970 1195
1196=item IO::AIO::max_idle $nthreads
1197
1198Limit the number of threads (default: 4) that are allowed to idle (i.e.,
1199threads that did not get a request to process within 10 seconds). That
1200means if a thread becomes idle while C<$nthreads> other threads are also
1201idle, it will free its resources and exit.
1202
1203This is useful when you allow a large number of threads (e.g. 100 or 1000)
1204to allow for extremely high load situations, but want to free resources
1205under normal circumstances (1000 threads can easily consume 30MB of RAM).
1206
1207The default is probably ok in most situations, especially if thread
1208creation is fast. If thread creation is very slow on your system you might
1209want to use larger values.
1210
971=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1211=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
972 1212
973This is a very bad function to use in interactive programs because it 1213This is a very bad function to use in interactive programs because it
974blocks, and a bad way to reduce concurrency because it is inexact: Better 1214blocks, and a bad way to reduce concurrency because it is inexact: Better
975use an C<aio_group> together with a feed callback. 1215use an C<aio_group> together with a feed callback.
976 1216
977Sets the maximum number of outstanding requests to C<$nreqs>. If you 1217Sets the maximum number of outstanding requests to C<$nreqs>. If you
978to queue up more than this number of requests, the next call to the 1218do queue up more than this number of requests, the next call to the
979C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1219C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
980function will block until the limit is no longer exceeded. 1220function will block until the limit is no longer exceeded.
981 1221
982The default value is very large, so there is no practical limit on the 1222The default value is very large, so there is no practical limit on the
983number of outstanding requests. 1223number of outstanding requests.
… …
986C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1226C<max_oustsanding> is mainly useful in simple scripts (with low values) or
987as a stop gap to shield against fatal memory overflow (with large values). 1227as a stop gap to shield against fatal memory overflow (with large values).
988 1228
989=back 1229=back
990 1230
1231=head3 STATISTICAL INFORMATION
1232
1233=over
1234
1235=item IO::AIO::nreqs
1236
1237Returns the number of requests currently in the ready, execute or pending
1238states (i.e. for which their callback has not been invoked yet).
1239
1240Example: wait till there are no outstanding requests anymore:
1241
1242 IO::AIO::poll_wait, IO::AIO::poll_cb
1243 while IO::AIO::nreqs;
1244
1245=item IO::AIO::nready
1246
1247Returns the number of requests currently in the ready state (not yet
1248executed).
1249
1250=item IO::AIO::npending
1251
1252Returns the number of requests currently in the pending state (executed,
1253but not yet processed by poll_cb).
1254
1255=back
1256
991=cut 1257=cut
992 1258
993# support function to convert a fd into a perl filehandle
994sub _fd2fh {
995 return undef if $_[0] < 0;
996
997 # try to generate nice filehandles
998 my $sym = "IO::AIO::fd#$_[0]";
999 local *$sym;
1000
1001 open *$sym, "+<&=$_[0]" # usually works under any unix
1002 or open *$sym, "<&=$_[0]" # cygwin needs this
1003 or open *$sym, ">&=$_[0]" # or this
1004 or return undef;
1005
1006 *$sym
1007}
1008
1009min_parallel 8; 1259min_parallel 8;
1010 1260
1011END { 1261END { flush }
1012 min_parallel 1;
1013 flush;
1014};
1015 1262
10161; 12631;
1017 1264
1018=head2 FORK BEHAVIOUR 1265=head2 FORK BEHAVIOUR
1019 1266
… …
1039bytes of memory. In addition, stat requests need a stat buffer (possibly 1286bytes of memory. In addition, stat requests need a stat buffer (possibly
1040a few hundred bytes), readdir requires a result buffer and so on. Perl 1287a few hundred bytes), readdir requires a result buffer and so on. Perl
1041scalars and other data passed into aio requests will also be locked and 1288scalars and other data passed into aio requests will also be locked and
1042will consume memory till the request has entered the done state. 1289will consume memory till the request has entered the done state.
1043 1290
1044This is now awfully much, so queuing lots of requests is not usually a 1291This is not awfully much, so queuing lots of requests is not usually a
1045problem. 1292problem.
1046 1293
1047Per-thread usage: 1294Per-thread usage:
1048 1295
1049In the execution phase, some aio requests require more memory for 1296In the execution phase, some aio requests require more memory for

Diff Legend

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