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Revision 1.59 by root, Tue Feb 20 06:54:47 2018 UTC vs.
Revision 1.68 by root, Mon Sep 5 00:04:07 2022 UTC

221 IO::AIO::idle_timeout $seconds 221 IO::AIO::idle_timeout $seconds
222 IO::AIO::max_outstanding $maxreqs 222 IO::AIO::max_outstanding $maxreqs
223 IO::AIO::nreqs 223 IO::AIO::nreqs
224 IO::AIO::nready 224 IO::AIO::nready
225 IO::AIO::npending 225 IO::AIO::npending
226 IO::AIO::reinit
227
226 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 228 $nfd = IO::AIO::get_fdlimit
227 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 229 IO::AIO::min_fdlimit $nfd
228 230
229 IO::AIO::sendfile $ofh, $ifh, $offset, $count 231 IO::AIO::sendfile $ofh, $ifh, $offset, $count
230 IO::AIO::fadvise $fh, $offset, $len, $advice 232 IO::AIO::fadvise $fh, $offset, $len, $advice
233 IO::AIO::fexecve $fh, $argv, $envp
234
231 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 235 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
232 IO::AIO::munmap $scalar 236 IO::AIO::munmap $scalar
237 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
233 IO::AIO::madvise $scalar, $offset, $length, $advice 238 IO::AIO::madvise $scalar, $offset, $length, $advice
234 IO::AIO::mprotect $scalar, $offset, $length, $protect 239 IO::AIO::mprotect $scalar, $offset, $length, $protect
235 IO::AIO::munlock $scalar, $offset = 0, $length = undef 240 IO::AIO::munlock $scalar, $offset = 0, $length = undef
236 IO::AIO::munlockall 241 IO::AIO::munlockall
242
243 # stat extensions
244 $counter = IO::AIO::st_gen
245 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
246 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
247 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
248 $seconds = IO::AIO::st_btimesec
249 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
250
251 # very much unportable syscalls
252 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
253 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
254 IO::AIO::tee $r_fh, $w_fh, $length, $flags
255
256 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
257 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
258
259 $fh = IO::AIO::eventfd [$initval, [$flags]]
260 $fh = IO::AIO::memfd_create $pathname[, $flags]
261
262 $fh = IO::AIO::timerfd_create $clockid[, $flags]
263 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
264 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
265
266 $fh = IO::AIO::pidfd_open $pid[, $flags]
267 $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
268 $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
237 269
238 API NOTES 270 API NOTES
239 All the "aio_*" calls are more or less thin wrappers around the syscall 271 All the "aio_*" calls are more or less thin wrappers around the syscall
240 with the same name (sans "aio_"). The arguments are similar or 272 with the same name (sans "aio_"). The arguments are similar or
241 identical, and they all accept an additional (and optional) $callback 273 identical, and they all accept an additional (and optional) $callback
339 "O_APPEND"), the following POSIX and non-POSIX constants are 371 "O_APPEND"), the following POSIX and non-POSIX constants are
340 available (missing ones on your system are, as usual, 0): 372 available (missing ones on your system are, as usual, 0):
341 373
342 "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", 374 "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY",
343 "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", 375 "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY",
344 "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", and 376 "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", "O_TTY_INIT"
345 "O_TTY_INIT". 377 and "O_ACCMODE".
346 378
347 aio_close $fh, $callback->($status) 379 aio_close $fh, $callback->($status)
348 Asynchronously close a file and call the callback with the result 380 Asynchronously close a file and call the callback with the result
349 code. 381 code.
350 382
468 will be emulated by simply reading the data, which would have a 500 will be emulated by simply reading the data, which would have a
469 similar effect. 501 similar effect.
470 502
471 aio_stat $fh_or_path, $callback->($status) 503 aio_stat $fh_or_path, $callback->($status)
472 aio_lstat $fh, $callback->($status) 504 aio_lstat $fh, $callback->($status)
473 Works like perl's "stat" or "lstat" in void context. The callback 505 Works almost exactly like perl's "stat" or "lstat" in void context.
474 will be called after the stat and the results will be available 506 The callback will be called after the stat and the results will be
475 using "stat _" or "-s _" etc... 507 available using "stat _" or "-s _" and other tests (with the
508 exception of "-B" and "-T").
476 509
477 The pathname passed to "aio_stat" must be absolute. See API NOTES, 510 The pathname passed to "aio_stat" must be absolute. See API NOTES,
478 above, for an explanation. 511 above, for an explanation.
479 512
480 Currently, the stats are always 64-bit-stats, i.e. instead of 513 Currently, the stats are always 64-bit-stats, i.e. instead of
488 back on traditional behaviour). 521 back on traditional behaviour).
489 522
490 "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", 523 "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG",
491 "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", 524 "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t",
492 "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". 525 "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor".
526
527 To access higher resolution stat timestamps, see "SUBSECOND STAT
528 TIME ACCESS".
493 529
494 Example: Print the length of /etc/passwd: 530 Example: Print the length of /etc/passwd:
495 531
496 aio_stat "/etc/passwd", sub { 532 aio_stat "/etc/passwd", sub {
497 $_[0] and die "stat failed: $!"; 533 $_[0] and die "stat failed: $!";
544 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 580 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
545 Works like perl's "utime" function (including the special case of 581 Works like perl's "utime" function (including the special case of
546 $atime and $mtime being undef). Fractional times are supported if 582 $atime and $mtime being undef). Fractional times are supported if
547 the underlying syscalls support them. 583 the underlying syscalls support them.
548 584
549 When called with a pathname, uses utimes(2) if available, otherwise 585 When called with a pathname, uses utimensat(2) or utimes(2) if
550 utime(2). If called on a file descriptor, uses futimes(2) if 586 available, otherwise utime(2). If called on a file descriptor, uses
551 available, otherwise returns ENOSYS, so this is not portable. 587 futimens(2) or futimes(2) if available, otherwise returns ENOSYS, so
588 this is not portable.
552 589
553 Examples: 590 Examples:
554 591
555 # set atime and mtime to current time (basically touch(1)): 592 # set atime and mtime to current time (basically touch(1)):
556 aio_utime "path", undef, undef; 593 aio_utime "path", undef, undef;
686 The flags are a combination of the following constants, ORed 723 The flags are a combination of the following constants, ORed
687 together (the flags will also be passed to the callback, possibly 724 together (the flags will also be passed to the callback, possibly
688 modified): 725 modified):
689 726
690 IO::AIO::READDIR_DENTS 727 IO::AIO::READDIR_DENTS
691 When this flag is off, then the callback gets an arrayref 728 Normally the callback gets an arrayref consisting of names only
692 consisting of names only (as with "aio_readdir"), otherwise it 729 (as with "aio_readdir"). If this flag is set, then the callback
693 gets an arrayref with "[$name, $type, $inode]" arrayrefs, each 730 gets an arrayref with "[$name, $type, $inode]" arrayrefs, each
694 describing a single directory entry in more detail. 731 describing a single directory entry in more detail:
695 732
696 $name is the name of the entry. 733 $name is the name of the entry.
697 734
698 $type is one of the "IO::AIO::DT_xxx" constants: 735 $type is one of the "IO::AIO::DT_xxx" constants:
699 736
700 "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", 737 "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR",
701 "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", 738 "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG",
702 "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". 739 "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT".
703 740
704 "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If 741 "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If
705 you need to know, you have to run stat yourself. Also, for speed 742 you need to know, you have to run stat yourself. Also, for
706 reasons, the $type scalars are read-only: you can not modify 743 speed/memory reasons, the $type scalars are read-only: you must
707 them. 744 not modify them.
708 745
709 $inode is the inode number (which might not be exact on systems 746 $inode is the inode number (which might not be exact on systems
710 with 64 bit inode numbers and 32 bit perls). This field has 747 with 64 bit inode numbers and 32 bit perls). This field has
711 unspecified content on systems that do not deliver the inode 748 unspecified content on systems that do not deliver the inode
712 information. 749 information.
724 of which names with short names are tried first. 761 of which names with short names are tried first.
725 762
726 IO::AIO::READDIR_STAT_ORDER 763 IO::AIO::READDIR_STAT_ORDER
727 When this flag is set, then the names will be returned in an 764 When this flag is set, then the names will be returned in an
728 order suitable for stat()'ing each one. That is, when you plan 765 order suitable for stat()'ing each one. That is, when you plan
729 to stat() all files in the given directory, then the returned 766 to stat() most or all files in the given directory, then the
730 order will likely be fastest. 767 returned order will likely be faster.
731 768
732 If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are 769 If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are
733 specified, then the likely dirs come first, resulting in a less 770 specified, then the likely dirs come first, resulting in a less
734 optimal stat order. 771 optimal stat order for stat'ing all entries, but likely a more
772 optimal order for finding subdirectories.
735 773
736 IO::AIO::READDIR_FOUND_UNKNOWN 774 IO::AIO::READDIR_FOUND_UNKNOWN
737 This flag should not be set when calling "aio_readdirx". 775 This flag should not be set when calling "aio_readdirx".
738 Instead, it is being set by "aio_readdirx", when any of the 776 Instead, it is being set by "aio_readdirx", when any of the
739 $type's found were "IO::AIO::DT_UNKNOWN". The absence of this 777 $type's found were "IO::AIO::DT_UNKNOWN". The absence of this
880 So in general, you should only use these calls for things that do 918 So in general, you should only use these calls for things that do
881 (filesystem) I/O, not for things that wait for other events 919 (filesystem) I/O, not for things that wait for other events
882 (network, other processes), although if you are careful and know 920 (network, other processes), although if you are careful and know
883 what you are doing, you still can. 921 what you are doing, you still can.
884 922
885 The following constants are available (missing ones are, as usual 923 The following constants are available and can be used for normal
886 0): 924 "ioctl" and "fcntl" as well (missing ones are, as usual 0):
887 925
888 "F_DUPFD_CLOEXEC", 926 "F_DUPFD_CLOEXEC",
889 927
890 "F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW", 928 "F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW",
891 929
892 "FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE", 930 "FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE",
893 "FIDEDUPERANGE". 931 "FIDEDUPERANGE".
932
933 "F_ADD_SEALS", "F_GET_SEALS", "F_SEAL_SEAL", "F_SEAL_SHRINK",
934 "F_SEAL_GROW" and "F_SEAL_WRITE".
894 935
895 "FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION", 936 "FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION",
896 "FS_IOC_SETVERSION", "FS_IOC_FIEMAP". 937 "FS_IOC_SETVERSION", "FS_IOC_FIEMAP".
897 938
898 "FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR", 939 "FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR",
1009 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1050 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1010 aio_mlock $data; # mlock in background 1051 aio_mlock $data; # mlock in background
1011 1052
1012 aio_mlockall $flags, $callback->($status) 1053 aio_mlockall $flags, $callback->($status)
1013 Calls the "mlockall" function with the given $flags (a combination 1054 Calls the "mlockall" function with the given $flags (a combination
1014 of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). 1055 of "IO::AIO::MCL_CURRENT", "IO::AIO::MCL_FUTURE" and
1056 "IO::AIO::MCL_ONFAULT").
1015 1057
1016 On systems that do not implement "mlockall", this function returns 1058 On systems that do not implement "mlockall", this function returns
1017 -1 and sets errno to "ENOSYS". 1059 -1 and sets errno to "ENOSYS". Similarly, flag combinations not
1060 supported by the system result in a return value of -1 with errno
1061 being set to "EINVAL".
1018 1062
1019 Note that the corresponding "munlockall" is synchronous and is 1063 Note that the corresponding "munlockall" is synchronous and is
1020 documented under "MISCELLANEOUS FUNCTIONS". 1064 documented under "MISCELLANEOUS FUNCTIONS".
1021 1065
1022 Example: asynchronously lock all current and future pages into 1066 Example: asynchronously lock all current and future pages into
1211 fails the request with "ENOENT", there is often no need for error 1255 fails the request with "ENOENT", there is often no need for error
1212 checking in the "aio_wd" callback, as future requests using the 1256 checking in the "aio_wd" callback, as future requests using the
1213 value will fail in the expected way. 1257 value will fail in the expected way.
1214 1258
1215 IO::AIO::CWD 1259 IO::AIO::CWD
1216 This is a compiletime constant (object) that represents the process 1260 This is a compile time constant (object) that represents the process
1217 current working directory. 1261 current working directory.
1218 1262
1219 Specifying this object as working directory object for a pathname is 1263 Specifying this object as working directory object for a pathname is
1220 as if the pathname would be specified directly, without a directory 1264 as if the pathname would be specified directly, without a directory
1221 object. For example, these calls are functionally identical: 1265 object. For example, these calls are functionally identical:
1446 Strictly equivalent to: 1490 Strictly equivalent to:
1447 1491
1448 IO::AIO::poll_wait, IO::AIO::poll_cb 1492 IO::AIO::poll_wait, IO::AIO::poll_cb
1449 while IO::AIO::nreqs; 1493 while IO::AIO::nreqs;
1450 1494
1495 This function can be useful at program aborts, to make sure
1496 outstanding I/O has been done ("IO::AIO" uses an "END" block which
1497 already calls this function on normal exits), or when you are merely
1498 using "IO::AIO" for its more advanced functions, rather than for
1499 async I/O, e.g.:
1500
1501 my ($dirs, $nondirs);
1502 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1503 IO::AIO::flush;
1504 # $dirs, $nondirs are now set
1505
1451 IO::AIO::max_poll_reqs $nreqs 1506 IO::AIO::max_poll_reqs $nreqs
1452 IO::AIO::max_poll_time $seconds 1507 IO::AIO::max_poll_time $seconds
1453 These set the maximum number of requests (default 0, meaning 1508 These set the maximum number of requests (default 0, meaning
1454 infinity) that are being processed by "IO::AIO::poll_cb" in one 1509 infinity) that are being processed by "IO::AIO::poll_cb" in one
1455 call, respectively the maximum amount of time (default 0, meaning 1510 call, respectively the maximum amount of time (default 0, meaning
1544 no longer exceeded. 1599 no longer exceeded.
1545 1600
1546 In other words, this setting does not enforce a queue limit, but can 1601 In other words, this setting does not enforce a queue limit, but can
1547 be used to make poll functions block if the limit is exceeded. 1602 be used to make poll functions block if the limit is exceeded.
1548 1603
1549 This is a very bad function to use in interactive programs because 1604 This is a bad function to use in interactive programs because it
1550 it blocks, and a bad way to reduce concurrency because it is 1605 blocks, and a bad way to reduce concurrency because it is inexact.
1551 inexact: Better use an "aio_group" together with a feed callback. 1606 If you need to issue many requests without being able to call a poll
1607 function on demand, it is better to use an "aio_group" together with
1608 a feed callback.
1552 1609
1553 Its main use is in scripts without an event loop - when you want to 1610 Its main use is in scripts without an event loop - when you want to
1554 stat a lot of files, you can write something like this: 1611 stat a lot of files, you can write something like this:
1555 1612
1556 IO::AIO::max_outstanding 32; 1613 IO::AIO::max_outstanding 32;
1561 } 1618 }
1562 1619
1563 IO::AIO::flush; 1620 IO::AIO::flush;
1564 1621
1565 The call to "poll_cb" inside the loop will normally return 1622 The call to "poll_cb" inside the loop will normally return
1566 instantly, but as soon as more thna 32 reqeusts are in-flight, it 1623 instantly, allowing the loop to progress, but as soon as more than
1567 will block until some requests have been handled. This keeps the 1624 32 requests are in-flight, it will block until some requests have
1568 loop from pushing a large number of "aio_stat" requests onto the 1625 been handled. This keeps the loop from pushing a large number of
1569 queue. 1626 "aio_stat" requests onto the queue (which, with many paths to stat,
1627 can use up a lot of memory).
1570 1628
1571 The default value for "max_outstanding" is very large, so there is 1629 The default value for "max_outstanding" is very large, so there is
1572 no practical limit on the number of outstanding requests. 1630 no practical limit on the number of outstanding requests.
1573 1631
1574 STATISTICAL INFORMATION 1632 STATISTICAL INFORMATION
1588 1646
1589 IO::AIO::npending 1647 IO::AIO::npending
1590 Returns the number of requests currently in the pending state 1648 Returns the number of requests currently in the pending state
1591 (executed, but not yet processed by poll_cb). 1649 (executed, but not yet processed by poll_cb).
1592 1650
1651 SUBSECOND STAT TIME ACCESS
1652 Both "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" functions can
1653 generally find access/modification and change times with subsecond time
1654 accuracy of the system supports it, but perl's built-in functions only
1655 return the integer part.
1656
1657 The following functions return the timestamps of the most recent stat
1658 with subsecond precision on most systems and work both after
1659 "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" calls. Their return
1660 value is only meaningful after a successful "stat"/"lstat" call, or
1661 during/after a successful "aio_stat"/"aio_lstat" callback.
1662
1663 This is similar to the Time::HiRes "stat" functions, but can return full
1664 resolution without rounding and work with standard perl "stat",
1665 alleviating the need to call the special "Time::HiRes" functions, which
1666 do not act like their perl counterparts.
1667
1668 On operating systems or file systems where subsecond time resolution is
1669 not supported or could not be detected, a fractional part of 0 is
1670 returned, so it is always safe to call these functions.
1671
1672 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime,
1673 IO::AIO::st_btime
1674 Return the access, modication, change or birth time, respectively,
1675 including fractional part. Due to the limited precision of floating
1676 point, the accuracy on most platforms is only a bit better than
1677 milliseconds for times around now - see the *nsec* function family,
1678 below, for full accuracy.
1679
1680 File birth time is only available when the OS and perl support it
1681 (on FreeBSD and NetBSD at the time of this writing, although support
1682 is adaptive, so if your OS/perl gains support, IO::AIO can take
1683 advantage of it). On systems where it isn't available, 0 is
1684 currently returned, but this might change to "undef" in a future
1685 version.
1686
1687 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
1688 Returns access, modification, change and birth time all in one go,
1689 and maybe more times in the future version.
1690
1691 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec,
1692 IO::AIO::st_ctimensec, IO::AIO::st_btimensec
1693 Return the fractional access, modifcation, change or birth time, in
1694 nanoseconds, as an integer in the range 0 to 999999999.
1695
1696 Note that no accessors are provided for access, modification and
1697 change times - you need to get those from "stat _" if required ("int
1698 IO::AIO::st_atime" and so on will *not* generally give you the
1699 correct value).
1700
1701 $seconds = IO::AIO::st_btimesec
1702 The (integral) seconds part of the file birth time, if available.
1703
1704 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
1705 Like the functions above, but returns all four times in one go (and
1706 maybe more in future versions).
1707
1708 $counter = IO::AIO::st_gen
1709 Returns the generation counter (in practice this is just a random
1710 number) of the file. This is only available on platforms which have
1711 this member in their "struct stat" (most BSDs at the time of this
1712 writing) and generally only to the root usert. If unsupported, 0 is
1713 returned, but this might change to "undef" in a future version.
1714
1715 Example: print the high resolution modification time of /etc, using
1716 "stat", and "IO::AIO::aio_stat".
1717
1718 if (stat "/etc") {
1719 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
1720 }
1721
1722 IO::AIO::aio_stat "/etc", sub {
1723 $_[0]
1724 and return;
1725
1726 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
1727 };
1728
1729 IO::AIO::flush;
1730
1731 Output of the awbove on my system, showing reduced and full accuracy:
1732
1733 stat(/etc) mtime: 1534043702.020808
1734 aio_stat(/etc) mtime: 1534043702.020807792
1735
1593 MISCELLANEOUS FUNCTIONS 1736 MISCELLANEOUS FUNCTIONS
1594 IO::AIO implements some functions that are useful when you want to use 1737 IO::AIO implements some functions that are useful when you want to use
1595 some "Advanced I/O" function not available to in Perl, without going the 1738 some "Advanced I/O" function not available to in Perl, without going the
1596 "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" 1739 "Asynchronous I/O" route. Many of these have an asynchronous "aio_*"
1597 counterpart. 1740 counterpart.
1598 1741
1742 $retval = IO::AIO::fexecve $fh, $argv, $envp
1743 A more-or-less direct equivalent to the POSIX "fexecve" functions,
1744 which allows you to specify the program to be executed via a file
1745 descriptor (or handle). Returns -1 and sets errno to "ENOSYS" if not
1746 available.
1747
1599 $numfd = IO::AIO::get_fdlimit 1748 $numfd = IO::AIO::get_fdlimit
1600 This function is *EXPERIMENTAL* and subject to change.
1601
1602 Tries to find the current file descriptor limit and returns it, or 1749 Tries to find the current file descriptor limit and returns it, or
1603 "undef" and sets $! in case of an error. The limit is one larger 1750 "undef" and sets $! in case of an error. The limit is one larger
1604 than the highest valid file descriptor number. 1751 than the highest valid file descriptor number.
1605 1752
1606 IO::AIO::min_fdlimit [$numfd] 1753 IO::AIO::min_fdlimit [$numfd]
1607 This function is *EXPERIMENTAL* and subject to change.
1608
1609 Try to increase the current file descriptor limit(s) to at least 1754 Try to increase the current file descriptor limit(s) to at least
1610 $numfd by changing the soft or hard file descriptor resource limit. 1755 $numfd by changing the soft or hard file descriptor resource limit.
1611 If $numfd is missing, it will try to set a very high limit, although 1756 If $numfd is missing, it will try to set a very high limit, although
1612 this is not recommended when you know the actual minimum that you 1757 this is not recommended when you know the actual minimum that you
1613 require. 1758 require.
1700 not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to 1845 not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to
1701 "MAP_ANON" if your system only provides this constant), 1846 "MAP_ANON" if your system only provides this constant),
1702 "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", 1847 "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE",
1703 "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", 1848 "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK",
1704 "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", 1849 "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN",
1705 "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or 1850 "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_STACK",
1706 "IO::AIO::MAP_STACK". 1851 "IO::AIO::MAP_FIXED_NOREPLACE", "IO::AIO::MAP_SHARED_VALIDATE",
1852 "IO::AIO::MAP_SYNC" or "IO::AIO::MAP_UNINITIALIZED".
1707 1853
1708 If $fh is "undef", then a file descriptor of -1 is passed. 1854 If $fh is "undef", then a file descriptor of -1 is passed.
1709 1855
1710 $offset is the offset from the start of the file - it generally must 1856 $offset is the offset from the start of the file - it generally must
1711 be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. 1857 be a multiple of "IO::AIO::PAGESIZE" and defaults to 0.
1723 1869
1724 my $fast_md5 = md5 $data; 1870 my $fast_md5 = md5 $data;
1725 1871
1726 IO::AIO::munmap $scalar 1872 IO::AIO::munmap $scalar
1727 Removes a previous mmap and undefines the $scalar. 1873 Removes a previous mmap and undefines the $scalar.
1874
1875 IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[,
1876 $new_address = 0]
1877 Calls the Linux-specific mremap(2) system call. The $scalar must
1878 have been mapped by "IO::AIO::mmap", and $flags must currently
1879 either be 0 or "IO::AIO::MREMAP_MAYMOVE".
1880
1881 Returns true if successful, and false otherwise. If the underlying
1882 mmapped region has changed address, then the true value has the
1883 numerical value 1, otherwise it has the numerical value 0:
1884
1885 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
1886 or die "mremap: $!";
1887
1888 if ($success*1) {
1889 warn "scalar has chanegd address in memory\n";
1890 }
1891
1892 "IO::AIO::MREMAP_FIXED" and the $new_address argument are currently
1893 implemented, but not supported and might go away in a future
1894 version.
1895
1896 On systems where this call is not supported or is not emulated, this
1897 call returns falls and sets $! to "ENOSYS".
1898
1899 IO::AIO::mlockall $flags
1900 Calls the "eio_mlockall_sync" function, which is like
1901 "aio_mlockall", but is blocking.
1728 1902
1729 IO::AIO::munlock $scalar, $offset = 0, $length = undef 1903 IO::AIO::munlock $scalar, $offset = 0, $length = undef
1730 Calls the "munlock" function, undoing the effects of a previous 1904 Calls the "munlock" function, undoing the effects of a previous
1731 "aio_mlock" call (see its description for details). 1905 "aio_mlock" call (see its description for details).
1732 1906
1733 IO::AIO::munlockall 1907 IO::AIO::munlockall
1734 Calls the "munlockall" function. 1908 Calls the "munlockall" function.
1735 1909
1736 On systems that do not implement "munlockall", this function returns 1910 On systems that do not implement "munlockall", this function returns
1737 ENOSYS, otherwise the return value of "munlockall". 1911 ENOSYS, otherwise the return value of "munlockall".
1912
1913 $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
1914 Uses the GNU/Linux accept4(2) syscall, if available, to accept a
1915 socket and return the new file handle on success, or sets $! and
1916 returns "undef" on error.
1917
1918 The remote name of the new socket will be stored in $sockaddr, which
1919 will be extended to allow for at least $sockaddr_maxlen octets. If
1920 the socket name does not fit into $sockaddr_maxlen octets, this is
1921 signaled by returning a longer string in $sockaddr, which might or
1922 might not be truncated.
1923
1924 To accept name-less sockets, use "undef" for $sockaddr and 0 for
1925 $sockaddr_maxlen.
1926
1927 The main reasons to use this syscall rather than portable accept(2)
1928 are that you can specify "SOCK_NONBLOCK" and/or "SOCK_CLOEXEC" flags
1929 and you can accept name-less sockets by specifying 0 for
1930 $sockaddr_maxlen, which is sadly not possible with perl's interface
1931 to "accept".
1738 1932
1739 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 1933 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
1740 Calls the GNU/Linux splice(2) syscall, if available. If $r_off or 1934 Calls the GNU/Linux splice(2) syscall, if available. If $r_off or
1741 $w_off are "undef", then "NULL" is passed for these, otherwise they 1935 $w_off are "undef", then "NULL" is passed for these, otherwise they
1742 should be the file offset. 1936 should be the file offset.
1783 Example: create a pipe race-free w.r.t. threads and fork: 1977 Example: create a pipe race-free w.r.t. threads and fork:
1784 1978
1785 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC 1979 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
1786 or die "pipe2: $!\n"; 1980 or die "pipe2: $!\n";
1787 1981
1982 $fh = IO::AIO::memfd_create $pathname[, $flags]
1983 This is a direct interface to the Linux memfd_create(2) system call.
1984 The (unhelpful) default for $flags is 0, but your default should be
1985 "IO::AIO::MFD_CLOEXEC".
1986
1987 On success, the new memfd filehandle is returned, otherwise returns
1988 "undef". If the memfd_create syscall is missing, fails with
1989 "ENOSYS".
1990
1991 Please refer to memfd_create(2) for more info on this call.
1992
1993 The following $flags values are available: "IO::AIO::MFD_CLOEXEC",
1994 "IO::AIO::MFD_ALLOW_SEALING", "IO::AIO::MFD_HUGETLB",
1995 "IO::AIO::MFD_HUGETLB_2MB" and "IO::AIO::MFD_HUGETLB_1GB".
1996
1997 Example: create a new memfd.
1998
1999 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2000 or die "memfd_create: $!\n";
2001
2002 $fh = IO::AIO::pidfd_open $pid[, $flags]
2003 This is an interface to the Linux pidfd_open(2) system call. The
2004 default for $flags is 0.
2005
2006 On success, a new pidfd filehandle is returned (that is already set
2007 to close-on-exec), otherwise returns "undef". If the syscall is
2008 missing, fails with "ENOSYS".
2009
2010 Example: open pid 6341 as pidfd.
2011
2012 my $fh = IO::AIO::pidfd_open 6341
2013 or die "pidfd_open: $!\n";
2014
2015 $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[,
2016 $flags]]
2017 This is an interface to the Linux pidfd_send_signal system call. The
2018 default for $siginfo is "undef" and the default for $flags is 0.
2019
2020 Returns the system call status. If the syscall is missing, fails
2021 with "ENOSYS".
2022
2023 When specified, $siginfo must be a reference to a hash with one or
2024 more of the following members:
2025
2026 code - the "si_code" member
2027 pid - the "si_pid" member
2028 uid - the "si_uid" member
2029 value_int - the "si_value.sival_int" member
2030 value_ptr - the "si_value.sival_ptr" member, specified as an integer
2031
2032 Example: send a SIGKILL to the specified process.
2033
2034 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2035 and die "pidfd_send_signal: $!\n";
2036
2037 Example: send a SIGKILL to the specified process with extra data.
2038
2039 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2040 and die "pidfd_send_signal: $!\n";
2041
2042 $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2043 This is an interface to the Linux pidfd_getfd system call. The
2044 default for $flags is 0.
2045
2046 On success, returns a dup'ed copy of the target file descriptor
2047 (specified as an integer) returned (that is already set to
2048 close-on-exec), otherwise returns "undef". If the syscall is
2049 missing, fails with "ENOSYS".
2050
2051 Example: get a copy of standard error of another process and print
2052 soemthing to it.
2053
2054 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2055 or die "pidfd_getfd: $!\n";
2056 print $errfh "stderr\n";
2057
1788 $fh = IO::AIO::eventfd [$initval, [$flags]] 2058 $fh = IO::AIO::eventfd [$initval, [$flags]]
1789 This is a direct interface to the Linux eventfd(2) system call. The 2059 This is a direct interface to the Linux eventfd(2) system call. The
1790 (unhelpful) defaults for $initval and $flags are 0 for both. 2060 (unhelpful) defaults for $initval and $flags are 0 for both.
1791 2061
1792 On success, the new eventfd filehandle is returned, otherwise 2062 On success, the new eventfd filehandle is returned, otherwise
1799 "IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and 2069 "IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and
1800 "IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30). 2070 "IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30).
1801 2071
1802 Example: create a new eventfd filehandle: 2072 Example: create a new eventfd filehandle:
1803 2073
1804 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC 2074 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
1805 or die "eventfd: $!\n"; 2075 or die "eventfd: $!\n";
1806 2076
1807 $fh = IO::AIO::timerfd_create $clockid[, $flags] 2077 $fh = IO::AIO::timerfd_create $clockid[, $flags]
1808 This is a direct interface to the Linux timerfd_create(2) system 2078 This is a direct interface to the Linux timerfd_create(2) system
1809 call. The (unhelpful) default for $flags is 0. 2079 call. The (unhelpful) default for $flags is 0, but your default
2080 should be "IO::AIO::TFD_CLOEXEC".
1810 2081
1811 On success, the new timerfd filehandle is returned, otherwise 2082 On success, the new timerfd filehandle is returned, otherwise
1812 returns "undef". If the eventfd syscall is missing, fails with 2083 returns "undef". If the timerfd_create syscall is missing, fails
1813 "ENOSYS". 2084 with "ENOSYS".
1814 2085
1815 Please refer to timerfd_create(2) for more info on this call. 2086 Please refer to timerfd_create(2) for more info on this call.
1816 2087
1817 The following $clockid values are available: 2088 The following $clockid values are available:
1818 "IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC" 2089 "IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC"
1961 I am not sure anything can be done about this, so this is considered a 2232 I am not sure anything can be done about this, so this is considered a
1962 known issue, rather than a bug. 2233 known issue, rather than a bug.
1963 2234
1964SEE ALSO 2235SEE ALSO
1965 AnyEvent::AIO for easy integration into event loops, Coro::AIO for a 2236 AnyEvent::AIO for easy integration into event loops, Coro::AIO for a
1966 more natural syntax. 2237 more natural syntax and IO::FDPass for file descriptor passing.
1967 2238
1968AUTHOR 2239AUTHOR
1969 Marc Lehmann <schmorp@schmorp.de> 2240 Marc Lehmann <schmorp@schmorp.de>
1970 http://home.schmorp.de/ 2241 http://home.schmorp.de/
1971 2242

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