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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.181 by root, Tue May 4 21:14:01 2010 UTC vs.
Revision 1.193 by root, Thu May 26 04:15:37 2011 UTC

… …
168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '3.65'; 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
… …
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, $length = undef
267 IO::AIO::munlockall 274 IO::AIO::munlockall
268 275
269=head2 AIO REQUEST FUNCTIONS 276=head2 AIO REQUEST FUNCTIONS
270 277
271All the C<aio_*> calls are more or less thin wrappers around the syscall 278All the C<aio_*> calls are more or less thin wrappers around the syscall
… …
422reading at byte offset C<$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
… …
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: $!";
… …
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.
… …
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
… …
665systems that do not deliver the inode information. 692systems that do not deliver the inode information.
666 693
667=item IO::AIO::READDIR_DIRS_FIRST 694=item IO::AIO::READDIR_DIRS_FIRST
668 695
669When this flag is set, then the names will be returned in an order where 696When this flag is set, then the names will be returned in an order where
670likely directories come first. This is useful when you need to quickly 697likely directories come first, in optimal stat order. This is useful when
671find directories, or you want to find all directories while avoiding to 698you need to quickly find directories, or you want to find all directories
672stat() each entry. 699while avoiding to stat() each entry.
673 700
674If the system returns type information in readdir, then this is used 701If the system returns type information in readdir, then this is used
675to find directories directly. Otherwise, likely directories are files 702to find directories directly. Otherwise, likely directories are names
676beginning with ".", or otherwise files with no dots, of which files with 703beginning with ".", or otherwise names with no dots, of which names with
677short names are tried first. 704short names are tried first.
678 705
679=item IO::AIO::READDIR_STAT_ORDER 706=item IO::AIO::READDIR_STAT_ORDER
680 707
681When this flag is set, then the names will be returned in an order 708When this flag is set, then the names will be returned in an order
… …
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
… …
1340 1406
1341See C<poll_cb> for an example. 1407See C<poll_cb> for an example.
1342 1408
1343=item IO::AIO::poll_cb 1409=item IO::AIO::poll_cb
1344 1410
1345Process some outstanding events on the result pipe. You have to call this 1411Process some outstanding events on the result pipe. You have to call
1346regularly. Returns C<0> if all events could be processed, or C<-1> if it 1412this regularly. Returns C<0> if all events could be processed (or there
1347returned earlier for whatever reason. Returns immediately when no events 1413were no events to process), or C<-1> if it returned earlier for whatever
1348are outstanding. The amount of events processed depends on the settings of 1414reason. Returns immediately when no events are outstanding. The amount of
1349C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1415events processed depends on the settings of C<IO::AIO::max_poll_req> and
1416C<IO::AIO::max_poll_time>.
1350 1417
1351If not all requests were processed for whatever reason, the filehandle 1418If not all requests were processed for whatever reason, the filehandle
1352will still be ready when C<poll_cb> returns, so normally you don't have to 1419will still be ready when C<poll_cb> returns, so normally you don't have to
1353do anything special to have it called later. 1420do anything special to have it called later.
1421
1422Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1423ready, it can be beneficial to call this function from loops which submit
1424a lot of requests, to make sure the results get processed when they become
1425available and not just when the loop is finished and the event loop takes
1426over again. This function returns very fast when there are no outstanding
1427requests.
1354 1428
1355Example: Install an Event watcher that automatically calls 1429Example: Install an Event watcher that automatically calls
1356IO::AIO::poll_cb with high priority (more examples can be found in the 1430IO::AIO::poll_cb with high priority (more examples can be found in the
1357SYNOPSIS section, at the top of this document): 1431SYNOPSIS section, at the top of this document):
1358 1432
… …
1460 1534
1461Under normal circumstances you don't need to call this function. 1535Under normal circumstances you don't need to call this function.
1462 1536
1463=item IO::AIO::max_idle $nthreads 1537=item IO::AIO::max_idle $nthreads
1464 1538
1465Limit the number of threads (default: 4) that are allowed to idle (i.e., 1539Limit the number of threads (default: 4) that are allowed to idle
1466threads that did not get a request to process within 10 seconds). That 1540(i.e., threads that did not get a request to process within the idle
1467means if a thread becomes idle while C<$nthreads> other threads are also 1541timeout (default: 10 seconds). That means if a thread becomes idle while
1468idle, it will free its resources and exit. 1542C<$nthreads> other threads are also idle, it will free its resources and
1543exit.
1469 1544
1470This is useful when you allow a large number of threads (e.g. 100 or 1000) 1545This 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 1546to allow for extremely high load situations, but want to free resources
1472under normal circumstances (1000 threads can easily consume 30MB of RAM). 1547under normal circumstances (1000 threads can easily consume 30MB of RAM).
1473 1548
1474The default is probably ok in most situations, especially if thread 1549The default is probably ok in most situations, especially if thread
1475creation is fast. If thread creation is very slow on your system you might 1550creation is fast. If thread creation is very slow on your system you might
1476want to use larger values. 1551want to use larger values.
1552
1553=item IO::AIO::idle_timeout $seconds
1554
1555Sets the minimum idle timeout (default 10) after which worker threads are
1556allowed to exit. SEe C<IO::AIO::max_idle>.
1477 1557
1478=item IO::AIO::max_outstanding $maxreqs 1558=item IO::AIO::max_outstanding $maxreqs
1479 1559
1480This is a very bad function to use in interactive programs because it 1560This 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 1561blocks, and a bad way to reduce concurrency because it is inexact: Better
… …
1537 1617
1538Returns the number of bytes copied, or C<-1> on error. 1618Returns the number of bytes copied, or C<-1> on error.
1539 1619
1540=item IO::AIO::fadvise $fh, $offset, $len, $advice 1620=item IO::AIO::fadvise $fh, $offset, $len, $advice
1541 1621
1542Simply calls the C<posix_fadvise> function (see it's 1622Simply calls the C<posix_fadvise> function (see its
1543manpage for details). The following advice constants are 1623manpage for details). The following advice constants are
1544avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1624avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1545C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1625C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1546C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1626C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1547 1627
1548On systems that do not implement C<posix_fadvise>, this function returns 1628On systems that do not implement C<posix_fadvise>, this function returns
1549ENOSYS, otherwise the return value of C<posix_fadvise>. 1629ENOSYS, otherwise the return value of C<posix_fadvise>.
1630
1631=item IO::AIO::madvise $scalar, $offset, $len, $advice
1632
1633Simply calls the C<posix_madvise> function (see its
1634manpage for details). The following advice constants are
1635avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1636C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1637
1638On systems that do not implement C<posix_madvise>, this function returns
1639ENOSYS, otherwise the return value of C<posix_madvise>.
1640
1641=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1642
1643Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1644$scalar (see its manpage for details). The following protect
1645constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1646C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1647
1648On systems that do not implement C<mprotect>, this function returns
1649ENOSYS, otherwise the return value of C<mprotect>.
1550 1650
1551=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1651=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1552 1652
1553Memory-maps a file (or anonymous memory range) and attaches it to the 1653Memory-maps a file (or anonymous memory range) and attaches it to the
1554given C<$scalar>, which will act like a string scalar. 1654given C<$scalar>, which will act like a string scalar.
… …
1600 1700
1601=item IO::AIO::munmap $scalar 1701=item IO::AIO::munmap $scalar
1602 1702
1603Removes a previous mmap and undefines the C<$scalar>. 1703Removes a previous mmap and undefines the C<$scalar>.
1604 1704
1605=item IO::AIO::mlockall $flags 1705=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1606 1706
1607Calls the C<mlockall> function with the given C<$flags> (a combination of 1707Calls the C<munlock> function, undoing the effects of a previous
1608C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>). 1708C<aio_mlock> call (see its description for details).
1609
1610On systems that do not implement C<mlockall>, this function returns
1611ENOSYS, otherwise the return value of C<mlockall>.
1612 1709
1613=item IO::AIO::munlockall 1710=item IO::AIO::munlockall
1614 1711
1615Calls the C<munlockall> function. 1712Calls the C<munlockall> function.
1616 1713

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