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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.176 by root, Sun Jan 10 23:05:11 2010 UTC vs.
Revision 1.190 by root, Thu May 19 22:42:20 2011 UTC

… …
4 4
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", IO::AIO::O_RDONLY, 0, sub {
10 my $fh = shift 10 my $fh = shift
11 or die "/etc/passwd: $!"; 11 or die "/etc/passwd: $!";
12 ... 12 ...
13 }; 13 };
14 14
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76 76
77 # register the IO::AIO callback with EV 77 # register the IO::AIO callback with EV
78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
79 79
80 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
81 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
82 my $fh = shift 82 my $fh = shift
83 or die "error while opening: $!"; 83 or die "error while opening: $!";
84 84
85 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
86 my $size = -s $fh; 86 my $size = -s $fh;
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168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '3.5'; 173 our $VERSION = '3.8';
174 174
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
181 aio_chmod aio_utime aio_truncate 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs); 182 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs);
183 184
184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
186 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle idle_timeout
187 nreqs nready npending nthreads 188 nreqs nready npending nthreads
188 max_poll_time max_poll_reqs 189 max_poll_time max_poll_reqs
189 sendfile fadvise); 190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
190 192
191 push @AIO_REQ, qw(aio_busy); # not exported 193 push @AIO_REQ, qw(aio_busy); # not exported
192 194
193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
194 196
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239 aio_fdatasync $fh, $callback->($status) 241 aio_fdatasync $fh, $callback->($status)
240 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
241 aio_pathsync $path, $callback->($status) 243 aio_pathsync $path, $callback->($status)
242 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
243 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
244 aio_group $callback->(...) 248 aio_group $callback->(...)
245 aio_nop $callback->() 249 aio_nop $callback->()
246 250
247 $prev_pri = aioreq_pri [$pri] 251 $prev_pri = aioreq_pri [$pri]
248 aioreq_nice $pri_adjust 252 aioreq_nice $pri_adjust
… …
254 IO::AIO::max_poll_reqs $nreqs 258 IO::AIO::max_poll_reqs $nreqs
255 IO::AIO::max_poll_time $seconds 259 IO::AIO::max_poll_time $seconds
256 IO::AIO::min_parallel $nthreads 260 IO::AIO::min_parallel $nthreads
257 IO::AIO::max_parallel $nthreads 261 IO::AIO::max_parallel $nthreads
258 IO::AIO::max_idle $nthreads 262 IO::AIO::max_idle $nthreads
263 IO::AIO::idle_timeout $seconds
259 IO::AIO::max_outstanding $maxreqs 264 IO::AIO::max_outstanding $maxreqs
260 IO::AIO::nreqs 265 IO::AIO::nreqs
261 IO::AIO::nready 266 IO::AIO::nready
262 IO::AIO::npending 267 IO::AIO::npending
263 268
264 IO::AIO::sendfile $ofh, $ifh, $offset, $count 269 IO::AIO::sendfile $ofh, $ifh, $offset, $count
265 IO::AIO::fadvise $fh, $offset, $len, $advice 270 IO::AIO::fadvise $fh, $offset, $len, $advice
266 IO::AIO::mlockall $flags 271 IO::AIO::madvise $scalar, $offset, $length, $advice
272 IO::AIO::mprotect $scalar, $offset, $length, $protect
273 IO::AIO::munlock $scalar, $offset = 0, $length = undef
267 IO::AIO::munlockall 274 IO::AIO::munlockall
268 275
269=head2 AIO REQUEST FUNCTIONS 276=head2 AIO REQUEST FUNCTIONS
270 277
271All the C<aio_*> calls are more or less thin wrappers around the syscall 278All the C<aio_*> calls are more or less thin wrappers around the syscall
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352by the umask in effect then the request is being executed, so better never 359by the umask in effect then the request is being executed, so better never
353change the umask. 360change the umask.
354 361
355Example: 362Example:
356 363
357 aio_open "/etc/passwd", O_RDONLY, 0, sub { 364 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
358 if ($_[0]) { 365 if ($_[0]) {
359 print "open successful, fh is $_[0]\n"; 366 print "open successful, fh is $_[0]\n";
360 ... 367 ...
361 } else { 368 } else {
362 die "open failed: $!\n"; 369 die "open failed: $!\n";
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422reading at byte offset C<$in_offset>, and starts writing at the current 429reading at byte offset C<$in_offset>, and starts writing at the current
423file offset of C<$out_fh>. Because of that, it is not safe to issue more 430file offset of C<$out_fh>. Because of that, it is not safe to issue more
424than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 431than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
425other. 432other.
426 433
434Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
435are written, and there is no way to find out how many bytes have been read
436from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
437bytes written to C<$out_fh>. Only if the result value equals C<$length>
438one can assume that C<$length> bytes have been read.
439
440Unlike with other C<aio_> functions, it makes a lot of sense to use
441C<aio_sendfile> on non-blocking sockets, as long as one end (typically
442the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
443the socket I/O will be non-blocking. Note, however, that you can run into
444a trap where C<aio_sendfile> reads some data with readahead, then fails
445to write all data, and when the socket is ready the next time, the data
446in the cache is already lost, forcing C<aio_sendfile> to again hit the
447disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
448much better.
449
427This call tries to make use of a native C<sendfile> syscall to provide 450This call tries to make use of a native C<sendfile> syscall to provide
428zero-copy operation. For this to work, C<$out_fh> should refer to a 451zero-copy operation. For this to work, C<$out_fh> should refer to a
429socket, and C<$in_fh> should refer to an mmap'able file. 452socket, and C<$in_fh> should refer to an mmap'able file.
430 453
431If a native sendfile cannot be found or it fails with C<ENOSYS>, 454If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, 455C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
433it will be emulated, so you can call C<aio_sendfile> on any type of 456it will be emulated, so you can call C<aio_sendfile> on any type of
434filehandle regardless of the limitations of the operating system. 457filehandle regardless of the limitations of the operating system.
435
436Please note, however, that C<aio_sendfile> can read more bytes from
437C<$in_fh> than are written, and there is no way to find out how many
438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
439provides the number of bytes written to C<$out_fh>. Only if the result
440value equals C<$length> one can assume that C<$length> bytes have been
441read.
442 458
443 459
444=item aio_readahead $fh,$offset,$length, $callback->($retval) 460=item aio_readahead $fh,$offset,$length, $callback->($retval)
445 461
446C<aio_readahead> populates the page cache with data from a file so that 462C<aio_readahead> populates the page cache with data from a file so that
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468for an explanation. 484for an explanation.
469 485
470Currently, the stats are always 64-bit-stats, i.e. instead of returning an 486Currently, the stats are always 64-bit-stats, i.e. instead of returning an
471error when stat'ing a large file, the results will be silently truncated 487error when stat'ing a large file, the results will be silently truncated
472unless perl itself is compiled with large file support. 488unless perl itself is compiled with large file support.
489
490To help interpret the mode and dev/rdev stat values, IO::AIO offers the
491following constants and functions (if not implemented, the constants will
492be C<0> and the functions will either C<croak> or fall back on traditional
493behaviour).
494
495C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
496C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
497C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
473 498
474Example: Print the length of F</etc/passwd>: 499Example: Print the length of F</etc/passwd>:
475 500
476 aio_stat "/etc/passwd", sub { 501 aio_stat "/etc/passwd", sub {
477 $_[0] and die "stat failed: $!"; 502 $_[0] and die "stat failed: $!";
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579 604
580The only (POSIX-) portable way of calling this function is: 605The only (POSIX-) portable way of calling this function is:
581 606
582 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 607 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
583 608
609See C<aio_stat> for info about some potentially helpful extra constants
610and functions.
584 611
585=item aio_link $srcpath, $dstpath, $callback->($status) 612=item aio_link $srcpath, $dstpath, $callback->($status)
586 613
587Asynchronously create a new link to the existing object at C<$srcpath> at 614Asynchronously create a new link to the existing object at C<$srcpath> at
588the path C<$dstpath> and call the callback with the result code. 615the path C<$dstpath> and call the callback with the result code.
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641 668
642=over 4 669=over 4
643 670
644=item IO::AIO::READDIR_DENTS 671=item IO::AIO::READDIR_DENTS
645 672
646When this flag is off, then the callback gets an arrayref with of names 673When this flag is off, then the callback gets an arrayref consisting of
647only (as with C<aio_readdir>), otherwise it gets an arrayref with 674names only (as with C<aio_readdir>), otherwise it gets an arrayref with
648C<[$name, $type, $inode]> arrayrefs, each describing a single directory 675C<[$name, $type, $inode]> arrayrefs, each describing a single directory
649entry in more detail. 676entry in more detail.
650 677
651C<$name> is the name of the entry. 678C<$name> is the name of the entry.
652 679
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1108as for C<aio_msync>, above, except for flags, which must be either 1135as for C<aio_msync>, above, except for flags, which must be either
1109C<0> (which reads all pages and ensures they are instantiated) or 1136C<0> (which reads all pages and ensures they are instantiated) or
1110C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1137C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1111writing an octet from it, which dirties the page). 1138writing an octet from it, which dirties the page).
1112 1139
1140=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1141
1142This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1143scalars.
1144
1145It reads in all the pages of the underlying storage into memory (if any)
1146and locks them, so they are not getting swapped/paged out or removed.
1147
1148If C<$length> is undefined, then the scalar will be locked till the end.
1149
1150On systems that do not implement C<mlock>, this function returns C<-1>
1151and sets errno to C<ENOSYS>.
1152
1153Note that the corresponding C<munlock> is synchronous and is
1154documented under L<MISCELLANEOUS FUNCTIONS>.
1155
1156Example: open a file, mmap and mlock it - both will be undone when
1157C<$data> gets destroyed.
1158
1159 open my $fh, "<", $path or die "$path: $!";
1160 my $data;
1161 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1162 aio_mlock $data; # mlock in background
1163
1164=item aio_mlockall $flags, $callback->($status)
1165
1166Calls the C<mlockall> function with the given C<$flags> (a combination of
1167C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1168
1169On systems that do not implement C<mlockall>, this function returns C<-1>
1170and sets errno to C<ENOSYS>.
1171
1172Note that the corresponding C<munlockall> is synchronous and is
1173documented under L<MISCELLANEOUS FUNCTIONS>.
1174
1175Example: asynchronously lock all current and future pages into memory.
1176
1177 aio_mlockall IO::AIO::MCL_FUTURE;
1178
1113=item aio_group $callback->(...) 1179=item aio_group $callback->(...)
1114 1180
1115This is a very special aio request: Instead of doing something, it is a 1181This is a very special aio request: Instead of doing something, it is a
1116container for other aio requests, which is useful if you want to bundle 1182container for other aio requests, which is useful if you want to bundle
1117many requests into a single, composite, request with a definite callback 1183many requests into a single, composite, request with a definite callback
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1460 1526
1461Under normal circumstances you don't need to call this function. 1527Under normal circumstances you don't need to call this function.
1462 1528
1463=item IO::AIO::max_idle $nthreads 1529=item IO::AIO::max_idle $nthreads
1464 1530
1465Limit the number of threads (default: 4) that are allowed to idle (i.e., 1531Limit the number of threads (default: 4) that are allowed to idle
1466threads that did not get a request to process within 10 seconds). That 1532(i.e., threads that did not get a request to process within the idle
1467means if a thread becomes idle while C<$nthreads> other threads are also 1533timeout (default: 10 seconds). That means if a thread becomes idle while
1468idle, it will free its resources and exit. 1534C<$nthreads> other threads are also idle, it will free its resources and
1535exit.
1469 1536
1470This is useful when you allow a large number of threads (e.g. 100 or 1000) 1537This is useful when you allow a large number of threads (e.g. 100 or 1000)
1471to allow for extremely high load situations, but want to free resources 1538to allow for extremely high load situations, but want to free resources
1472under normal circumstances (1000 threads can easily consume 30MB of RAM). 1539under normal circumstances (1000 threads can easily consume 30MB of RAM).
1473 1540
1474The default is probably ok in most situations, especially if thread 1541The default is probably ok in most situations, especially if thread
1475creation is fast. If thread creation is very slow on your system you might 1542creation is fast. If thread creation is very slow on your system you might
1476want to use larger values. 1543want to use larger values.
1544
1545=item IO::AIO::idle_timeout $seconds
1546
1547Sets the minimum idle timeout (default 10) after which worker threads are
1548allowed to exit. SEe C<IO::AIO::max_idle>.
1477 1549
1478=item IO::AIO::max_outstanding $maxreqs 1550=item IO::AIO::max_outstanding $maxreqs
1479 1551
1480This is a very bad function to use in interactive programs because it 1552This is a very bad function to use in interactive programs because it
1481blocks, and a bad way to reduce concurrency because it is inexact: Better 1553blocks, and a bad way to reduce concurrency because it is inexact: Better
… …
1537 1609
1538Returns the number of bytes copied, or C<-1> on error. 1610Returns the number of bytes copied, or C<-1> on error.
1539 1611
1540=item IO::AIO::fadvise $fh, $offset, $len, $advice 1612=item IO::AIO::fadvise $fh, $offset, $len, $advice
1541 1613
1542Simply calls the C<posix_fadvise> function (see it's 1614Simply calls the C<posix_fadvise> function (see its
1543manpage for details). The following advice constants are 1615manpage for details). The following advice constants are
1544avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1616avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1545C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1617C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1546C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1618C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1547 1619
1548On systems that do not implement C<posix_fadvise>, this function returns 1620On systems that do not implement C<posix_fadvise>, this function returns
1549ENOSYS, otherwise the return value of C<posix_fadvise>. 1621ENOSYS, otherwise the return value of C<posix_fadvise>.
1622
1623=item IO::AIO::madvise $scalar, $offset, $len, $advice
1624
1625Simply calls the C<posix_madvise> function (see its
1626manpage for details). The following advice constants are
1627avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1628C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1629
1630On systems that do not implement C<posix_madvise>, this function returns
1631ENOSYS, otherwise the return value of C<posix_madvise>.
1632
1633=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1634
1635Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1636$scalar (see its manpage for details). The following protect
1637constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1638C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1639
1640On systems that do not implement C<mprotect>, this function returns
1641ENOSYS, otherwise the return value of C<mprotect>.
1550 1642
1551=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1643=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1552 1644
1553Memory-maps a file (or anonymous memory range) and attaches it to the 1645Memory-maps a file (or anonymous memory range) and attaches it to the
1554given C<$scalar>, which will act like a string scalar. 1646given C<$scalar>, which will act like a string scalar.
… …
1580C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 1672C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1581C<IO::AIO::MAP_NONBLOCK> 1673C<IO::AIO::MAP_NONBLOCK>
1582 1674
1583If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 1675If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1584 1676
1677C<$offset> is the offset from the start of the file - it generally must be
1678a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1679
1680Example:
1681
1682 use Digest::MD5;
1683 use IO::AIO;
1684
1685 open my $fh, "<verybigfile"
1686 or die "$!";
1687
1688 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1689 or die "verybigfile: $!";
1690
1691 my $fast_md5 = md5 $data;
1692
1585=item IO::AIO::munmap $scalar 1693=item IO::AIO::munmap $scalar
1586 1694
1587Removes a previous mmap and undefines the C<$scalar>. 1695Removes a previous mmap and undefines the C<$scalar>.
1588 1696
1589=item IO::AIO::mlockall $flags 1697=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1590 1698
1591Calls the C<mlockall> function with the given C<$flags> (a combination of 1699Calls the C<munlock> function, undoing the effects of a previous
1592C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>). 1700C<aio_mlock> call (see its description for details).
1593
1594On systems that do not implement C<mlockall>, this function returns
1595ENOSYS, otherwise the return value of C<mlockall>.
1596 1701
1597=item IO::AIO::munlockall 1702=item IO::AIO::munlockall
1598 1703
1599Calls the C<munlockall> function. 1704Calls the C<munlockall> function.
1600 1705

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