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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.283 by root, Tue Feb 20 06:05:19 2018 UTC vs.
Revision 1.306 by root, Wed Oct 16 09:11:35 2019 UTC

171use common::sense; 171use common::sense;
172 172
173use base 'Exporter'; 173use base 'Exporter';
174 174
175BEGIN { 175BEGIN {
176 our $VERSION = 4.4; 176 our $VERSION = 4.73;
177 177
178 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close 178 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
179 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 179 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
193 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
194 nreqs nready npending nthreads 194 nreqs nready npending nthreads
195 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
196 sendfile fadvise madvise 196 sendfile fadvise madvise
197 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall);
198 198
199 push @AIO_REQ, qw(aio_busy); # not exported 199 push @AIO_REQ, qw(aio_busy); # not exported
200 200
201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
202 202
278 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
279 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
280 IO::AIO::nreqs 280 IO::AIO::nreqs
281 IO::AIO::nready 281 IO::AIO::nready
282 IO::AIO::npending 282 IO::AIO::npending
283 IO::AIO::reinit
284
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 285 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 286 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
285 287
286 IO::AIO::sendfile $ofh, $ifh, $offset, $count 288 IO::AIO::sendfile $ofh, $ifh, $offset, $count
287 IO::AIO::fadvise $fh, $offset, $len, $advice 289 IO::AIO::fadvise $fh, $offset, $len, $advice
290
288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 291 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289 IO::AIO::munmap $scalar 292 IO::AIO::munmap $scalar
293 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
290 IO::AIO::madvise $scalar, $offset, $length, $advice 294 IO::AIO::madvise $scalar, $offset, $length, $advice
291 IO::AIO::mprotect $scalar, $offset, $length, $protect 295 IO::AIO::mprotect $scalar, $offset, $length, $protect
292 IO::AIO::munlock $scalar, $offset = 0, $length = undef 296 IO::AIO::munlock $scalar, $offset = 0, $length = undef
293 IO::AIO::munlockall 297 IO::AIO::munlockall
298
299 # stat extensions
300 $counter = IO::AIO::st_gen
301 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
302 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
303 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
304 $seconds = IO::AIO::st_btimesec
305 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
306
307 # very much unportable syscalls
308 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
309 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
310 IO::AIO::tee $r_fh, $w_fh, $length, $flags
311 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
312 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
313 $fh = IO::AIO::memfd_create $pathname[, $flags]
314 $fh = IO::AIO::eventfd [$initval, [$flags]]
315 $fh = IO::AIO::timerfd_create $clockid[, $flags]
316 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
317 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
294 318
295=head2 API NOTES 319=head2 API NOTES
296 320
297All the C<aio_*> calls are more or less thin wrappers around the syscall 321All the C<aio_*> calls are more or less thin wrappers around the syscall
298with the same name (sans C<aio_>). The arguments are similar or identical, 322with the same name (sans C<aio_>). The arguments are similar or identical,
404following POSIX and non-POSIX constants are available (missing ones on 428following POSIX and non-POSIX constants are available (missing ones on
405your system are, as usual, C<0>): 429your system are, as usual, C<0>):
406 430
407C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 431C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
408C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 432C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
409C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. 433C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
410 434
411 435
412=item aio_close $fh, $callback->($status) 436=item aio_close $fh, $callback->($status)
413 437
414Asynchronously close a file and call the callback with the result 438Asynchronously close a file and call the callback with the result
540 564
541=item aio_stat $fh_or_path, $callback->($status) 565=item aio_stat $fh_or_path, $callback->($status)
542 566
543=item aio_lstat $fh, $callback->($status) 567=item aio_lstat $fh, $callback->($status)
544 568
545Works like perl's C<stat> or C<lstat> in void context. The callback will 569Works almost exactly like perl's C<stat> or C<lstat> in void context. The
546be called after the stat and the results will be available using C<stat _> 570callback will be called after the stat and the results will be available
547or C<-s _> etc... 571using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
572and C<-T>).
548 573
549The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 574The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
550for an explanation. 575for an explanation.
551 576
552Currently, the stats are always 64-bit-stats, i.e. instead of returning an 577Currently, the stats are always 64-bit-stats, i.e. instead of returning an
559behaviour). 584behaviour).
560 585
561C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 586C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
562C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 587C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
563C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 588C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
589
590To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
591ACCESS>.
564 592
565Example: Print the length of F</etc/passwd>: 593Example: Print the length of F</etc/passwd>:
566 594
567 aio_stat "/etc/passwd", sub { 595 aio_stat "/etc/passwd", sub {
568 $_[0] and die "stat failed: $!"; 596 $_[0] and die "stat failed: $!";
618 646
619Works like perl's C<utime> function (including the special case of $atime 647Works like perl's C<utime> function (including the special case of $atime
620and $mtime being undef). Fractional times are supported if the underlying 648and $mtime being undef). Fractional times are supported if the underlying
621syscalls support them. 649syscalls support them.
622 650
623When called with a pathname, uses utimes(2) if available, otherwise 651When called with a pathname, uses utimensat(2) or utimes(2) if available,
624utime(2). If called on a file descriptor, uses futimes(2) if available, 652otherwise utime(2). If called on a file descriptor, uses futimens(2)
625otherwise returns ENOSYS, so this is not portable. 653or futimes(2) if available, otherwise returns ENOSYS, so this is not
654portable.
626 655
627Examples: 656Examples:
628 657
629 # set atime and mtime to current time (basically touch(1)): 658 # set atime and mtime to current time (basically touch(1)):
630 aio_utime "path", undef, undef; 659 aio_utime "path", undef, undef;
789 818
790=over 4 819=over 4
791 820
792=item IO::AIO::READDIR_DENTS 821=item IO::AIO::READDIR_DENTS
793 822
794When this flag is off, then the callback gets an arrayref consisting of 823Normally the callback gets an arrayref consisting of names only (as
795names only (as with C<aio_readdir>), otherwise it gets an arrayref with 824with C<aio_readdir>). If this flag is set, then the callback gets an
796C<[$name, $type, $inode]> arrayrefs, each describing a single directory 825arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
797entry in more detail. 826single directory entry in more detail:
798 827
799C<$name> is the name of the entry. 828C<$name> is the name of the entry.
800 829
801C<$type> is one of the C<IO::AIO::DT_xxx> constants: 830C<$type> is one of the C<IO::AIO::DT_xxx> constants:
802 831
803C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 832C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
804C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 833C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
805C<IO::AIO::DT_WHT>. 834C<IO::AIO::DT_WHT>.
806 835
807C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 836C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
808know, you have to run stat yourself. Also, for speed reasons, the C<$type> 837to know, you have to run stat yourself. Also, for speed/memory reasons,
809scalars are read-only: you can not modify them. 838the C<$type> scalars are read-only: you must not modify them.
810 839
811C<$inode> is the inode number (which might not be exact on systems with 64 840C<$inode> is the inode number (which might not be exact on systems with 64
812bit inode numbers and 32 bit perls). This field has unspecified content on 841bit inode numbers and 32 bit perls). This field has unspecified content on
813systems that do not deliver the inode information. 842systems that do not deliver the inode information.
814 843
825short names are tried first. 854short names are tried first.
826 855
827=item IO::AIO::READDIR_STAT_ORDER 856=item IO::AIO::READDIR_STAT_ORDER
828 857
829When this flag is set, then the names will be returned in an order 858When this flag is set, then the names will be returned in an order
830suitable for stat()'ing each one. That is, when you plan to stat() 859suitable for stat()'ing each one. That is, when you plan to stat() most or
831all files in the given directory, then the returned order will likely 860all files in the given directory, then the returned order will likely be
832be fastest. 861faster.
833 862
834If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 863If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
835the likely dirs come first, resulting in a less optimal stat order. 864then the likely dirs come first, resulting in a less optimal stat order
865for stat'ing all entries, but likely a more optimal order for finding
866subdirectories.
836 867
837=item IO::AIO::READDIR_FOUND_UNKNOWN 868=item IO::AIO::READDIR_FOUND_UNKNOWN
838 869
839This flag should not be set when calling C<aio_readdirx>. Instead, it 870This flag should not be set when calling C<aio_readdirx>. Instead, it
840is being set by C<aio_readdirx>, when any of the C<$type>'s found were 871is being set by C<aio_readdirx>, when any of the C<$type>'s found were
1101 aioreq_pri $pri; 1132 aioreq_pri $pri;
1102 add $grp aio_stat $wd, sub { 1133 add $grp aio_stat $wd, sub {
1103 return $grp->result () if $_[0]; 1134 return $grp->result () if $_[0];
1104 my $now = time; 1135 my $now = time;
1105 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1136 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1137 my $rdxflags = READDIR_DIRS_FIRST;
1138
1139 if ((stat _)[3] < 2) {
1140 # at least one non-POSIX filesystem exists
1141 # that returns useful DT_type values: btrfs,
1142 # so optimise for this here by requesting dents
1143 $rdxflags |= READDIR_DENTS;
1144 }
1106 1145
1107 # read the directory entries 1146 # read the directory entries
1108 aioreq_pri $pri; 1147 aioreq_pri $pri;
1109 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1148 add $grp aio_readdirx $wd, $rdxflags, sub {
1110 my $entries = shift 1149 my ($entries, $flags) = @_
1111 or return $grp->result (); 1150 or return $grp->result ();
1151
1152 if ($rdxflags & READDIR_DENTS) {
1153 # if we requested type values, see if we can use them directly.
1154
1155 # if there were any DT_UNKNOWN entries then we assume we
1156 # don't know. alternatively, we could assume that if we get
1157 # one DT_DIR, then all directories are indeed marked with
1158 # DT_DIR, but this seems not required for btrfs, and this
1159 # is basically the "btrfs can't get it's act together" code
1160 # branch.
1161 unless ($flags & READDIR_FOUND_UNKNOWN) {
1162 # now we have valid DT_ information for all entries,
1163 # so use it as an optimisation without further stat's.
1164 # they must also all be at the beginning of @$entries
1165 # by now.
1166
1167 my $dirs;
1168
1169 if (@$entries) {
1170 for (0 .. $#$entries) {
1171 if ($entries->[$_][1] != DT_DIR) {
1172 # splice out directories
1173 $dirs = [splice @$entries, 0, $_];
1174 last;
1175 }
1176 }
1177
1178 # if we didn't find any non-dir, then all entries are dirs
1179 unless ($dirs) {
1180 ($dirs, $entries) = ($entries, []);
1181 }
1182 } else {
1183 # directory is empty, so there are no sbdirs
1184 $dirs = [];
1185 }
1186
1187 # either splice'd the directories out or the dir was empty.
1188 # convert dents to filenames
1189 $_ = $_->[0] for @$dirs;
1190 $_ = $_->[0] for @$entries;
1191
1192 return $grp->result ($dirs, $entries);
1193 }
1194
1195 # cannot use, so return to our old ways
1196 # by pretending we only scanned for names.
1197 $_ = $_->[0] for @$entries;
1198 }
1112 1199
1113 # stat the dir another time 1200 # stat the dir another time
1114 aioreq_pri $pri; 1201 aioreq_pri $pri;
1115 add $grp aio_stat $wd, sub { 1202 add $grp aio_stat $wd, sub {
1116 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1203 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1222So in general, you should only use these calls for things that do 1309So in general, you should only use these calls for things that do
1223(filesystem) I/O, not for things that wait for other events (network, 1310(filesystem) I/O, not for things that wait for other events (network,
1224other processes), although if you are careful and know what you are doing, 1311other processes), although if you are careful and know what you are doing,
1225you still can. 1312you still can.
1226 1313
1227The following constants are available (missing ones are, as usual C<0>): 1314The following constants are available and can be used for normal C<ioctl>
1315and C<fcntl> as well (missing ones are, as usual C<0>):
1228 1316
1229C<F_DUPFD_CLOEXEC>, 1317C<F_DUPFD_CLOEXEC>,
1230 1318
1231C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1319C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1232 1320
1233C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1321C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1322
1323C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1324C<F_SEAL_WRITE>.
1234 1325
1235C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1326C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1236C<FS_IOC_FIEMAP>. 1327C<FS_IOC_FIEMAP>.
1237 1328
1238C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1329C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1377 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1468 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1378 aio_mlock $data; # mlock in background 1469 aio_mlock $data; # mlock in background
1379 1470
1380=item aio_mlockall $flags, $callback->($status) 1471=item aio_mlockall $flags, $callback->($status)
1381 1472
1382Calls the C<mlockall> function with the given C<$flags> (a combination of 1473Calls the C<mlockall> function with the given C<$flags> (a
1383C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1474combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1475C<IO::AIO::MCL_ONFAULT>).
1384 1476
1385On systems that do not implement C<mlockall>, this function returns C<-1> 1477On systems that do not implement C<mlockall>, this function returns C<-1>
1386and sets errno to C<ENOSYS>. 1478and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1479by the system result in a return value of C<-1> with errno being set to
1480C<EINVAL>.
1387 1481
1388Note that the corresponding C<munlockall> is synchronous and is 1482Note that the corresponding C<munlockall> is synchronous and is
1389documented under L<MISCELLANEOUS FUNCTIONS>. 1483documented under L<MISCELLANEOUS FUNCTIONS>.
1390 1484
1391Example: asynchronously lock all current and future pages into memory. 1485Example: asynchronously lock all current and future pages into memory.
1585C<aio_wd> callback, as future requests using the value will fail in the 1679C<aio_wd> callback, as future requests using the value will fail in the
1586expected way. 1680expected way.
1587 1681
1588=item IO::AIO::CWD 1682=item IO::AIO::CWD
1589 1683
1590This is a compiletime constant (object) that represents the process 1684This is a compile time constant (object) that represents the process
1591current working directory. 1685current working directory.
1592 1686
1593Specifying this object as working directory object for a pathname is as if 1687Specifying this object as working directory object for a pathname is as if
1594the pathname would be specified directly, without a directory object. For 1688the pathname would be specified directly, without a directory object. For
1595example, these calls are functionally identical: 1689example, these calls are functionally identical:
1776The default value for the limit is C<0>, but note that setting a feeder 1870The default value for the limit is C<0>, but note that setting a feeder
1777automatically bumps it up to C<2>. 1871automatically bumps it up to C<2>.
1778 1872
1779=back 1873=back
1780 1874
1875
1781=head2 SUPPORT FUNCTIONS 1876=head2 SUPPORT FUNCTIONS
1782 1877
1783=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1878=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1784 1879
1785=over 4 1880=over 4
1850Strictly equivalent to: 1945Strictly equivalent to:
1851 1946
1852 IO::AIO::poll_wait, IO::AIO::poll_cb 1947 IO::AIO::poll_wait, IO::AIO::poll_cb
1853 while IO::AIO::nreqs; 1948 while IO::AIO::nreqs;
1854 1949
1950This function can be useful at program aborts, to make sure outstanding
1951I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1952this function on normal exits), or when you are merely using C<IO::AIO>
1953for its more advanced functions, rather than for async I/O, e.g.:
1954
1955 my ($dirs, $nondirs);
1956 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1957 IO::AIO::flush;
1958 # $dirs, $nondirs are now set
1959
1855=item IO::AIO::max_poll_reqs $nreqs 1960=item IO::AIO::max_poll_reqs $nreqs
1856 1961
1857=item IO::AIO::max_poll_time $seconds 1962=item IO::AIO::max_poll_time $seconds
1858 1963
1859These set the maximum number of requests (default C<0>, meaning infinity) 1964These set the maximum number of requests (default C<0>, meaning infinity)
1885 poll => 'r', nice => 1, 1990 poll => 'r', nice => 1,
1886 cb => &IO::AIO::poll_cb); 1991 cb => &IO::AIO::poll_cb);
1887 1992
1888=back 1993=back
1889 1994
1995
1890=head3 CONTROLLING THE NUMBER OF THREADS 1996=head3 CONTROLLING THE NUMBER OF THREADS
1891 1997
1892=over 1998=over
1893 1999
1894=item IO::AIO::min_parallel $nthreads 2000=item IO::AIO::min_parallel $nthreads
1981The default value for C<max_outstanding> is very large, so there is no 2087The default value for C<max_outstanding> is very large, so there is no
1982practical limit on the number of outstanding requests. 2088practical limit on the number of outstanding requests.
1983 2089
1984=back 2090=back
1985 2091
2092
1986=head3 STATISTICAL INFORMATION 2093=head3 STATISTICAL INFORMATION
1987 2094
1988=over 2095=over
1989 2096
1990=item IO::AIO::nreqs 2097=item IO::AIO::nreqs
2006 2113
2007Returns the number of requests currently in the pending state (executed, 2114Returns the number of requests currently in the pending state (executed,
2008but not yet processed by poll_cb). 2115but not yet processed by poll_cb).
2009 2116
2010=back 2117=back
2118
2119
2120=head3 SUBSECOND STAT TIME ACCESS
2121
2122Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2123generally find access/modification and change times with subsecond time
2124accuracy of the system supports it, but perl's built-in functions only
2125return the integer part.
2126
2127The following functions return the timestamps of the most recent
2128stat with subsecond precision on most systems and work both after
2129C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2130value is only meaningful after a successful C<stat>/C<lstat> call, or
2131during/after a successful C<aio_stat>/C<aio_lstat> callback.
2132
2133This is similar to the L<Time::HiRes> C<stat> functions, but can return
2134full resolution without rounding and work with standard perl C<stat>,
2135alleviating the need to call the special C<Time::HiRes> functions, which
2136do not act like their perl counterparts.
2137
2138On operating systems or file systems where subsecond time resolution is
2139not supported or could not be detected, a fractional part of C<0> is
2140returned, so it is always safe to call these functions.
2141
2142=over 4
2143
2144=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2145
2146Return the access, modication, change or birth time, respectively,
2147including fractional part. Due to the limited precision of floating point,
2148the accuracy on most platforms is only a bit better than milliseconds
2149for times around now - see the I<nsec> function family, below, for full
2150accuracy.
2151
2152File birth time is only available when the OS and perl support it (on
2153FreeBSD and NetBSD at the time of this writing, although support is
2154adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2155it). On systems where it isn't available, C<0> is currently returned, but
2156this might change to C<undef> in a future version.
2157
2158=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2159
2160Returns access, modification, change and birth time all in one go, and
2161maybe more times in the future version.
2162
2163=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2164
2165Return the fractional access, modifcation, change or birth time, in nanoseconds,
2166as an integer in the range C<0> to C<999999999>.
2167
2168Note that no accessors are provided for access, modification and
2169change times - you need to get those from C<stat _> if required (C<int
2170IO::AIO::st_atime> and so on will I<not> generally give you the correct
2171value).
2172
2173=item $seconds = IO::AIO::st_btimesec
2174
2175The (integral) seconds part of the file birth time, if available.
2176
2177=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2178
2179Like the functions above, but returns all four times in one go (and maybe
2180more in future versions).
2181
2182=item $counter = IO::AIO::st_gen
2183
2184Returns the generation counter (in practice this is just a random number)
2185of the file. This is only available on platforms which have this member in
2186their C<struct stat> (most BSDs at the time of this writing) and generally
2187only to the root usert. If unsupported, C<0> is returned, but this might
2188change to C<undef> in a future version.
2189
2190=back
2191
2192Example: print the high resolution modification time of F</etc>, using
2193C<stat>, and C<IO::AIO::aio_stat>.
2194
2195 if (stat "/etc") {
2196 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2197 }
2198
2199 IO::AIO::aio_stat "/etc", sub {
2200 $_[0]
2201 and return;
2202
2203 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2204 };
2205
2206 IO::AIO::flush;
2207
2208Output of the awbove on my system, showing reduced and full accuracy:
2209
2210 stat(/etc) mtime: 1534043702.020808
2211 aio_stat(/etc) mtime: 1534043702.020807792
2212
2011 2213
2012=head3 MISCELLANEOUS FUNCTIONS 2214=head3 MISCELLANEOUS FUNCTIONS
2013 2215
2014IO::AIO implements some functions that are useful when you want to use 2216IO::AIO implements some functions that are useful when you want to use
2015some "Advanced I/O" function not available to in Perl, without going the 2217some "Advanced I/O" function not available to in Perl, without going the
2156 2358
2157=item IO::AIO::munmap $scalar 2359=item IO::AIO::munmap $scalar
2158 2360
2159Removes a previous mmap and undefines the C<$scalar>. 2361Removes a previous mmap and undefines the C<$scalar>.
2160 2362
2363=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2364
2365Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2366been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2367C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2368
2369Returns true if successful, and false otherwise. If the underlying mmapped
2370region has changed address, then the true value has the numerical value
2371C<1>, otherwise it has the numerical value C<0>:
2372
2373 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2374 or die "mremap: $!";
2375
2376 if ($success*1) {
2377 warn "scalar has chanegd address in memory\n";
2378 }
2379
2380C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2381implemented, but not supported and might go away in a future version.
2382
2383On systems where this call is not supported or is not emulated, this call
2384returns falls and sets C<$!> to C<ENOSYS>.
2385
2386=item IO::AIO::mlockall $flags
2387
2388Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2389but is blocking.
2390
2161=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2391=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2162 2392
2163Calls the C<munlock> function, undoing the effects of a previous 2393Calls the C<munlock> function, undoing the effects of a previous
2164C<aio_mlock> call (see its description for details). 2394C<aio_mlock> call (see its description for details).
2165 2395
2167 2397
2168Calls the C<munlockall> function. 2398Calls the C<munlockall> function.
2169 2399
2170On systems that do not implement C<munlockall>, this function returns 2400On systems that do not implement C<munlockall>, this function returns
2171ENOSYS, otherwise the return value of C<munlockall>. 2401ENOSYS, otherwise the return value of C<munlockall>.
2402
2403=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2404
2405Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2406and return the new file handle on success, or sets C<$!> and returns
2407C<undef> on error.
2408
2409The remote name of the new socket will be stored in C<$sockaddr>, which
2410will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2411socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2412by returning a longer string in C<$sockaddr>, which might or might not be
2413truncated.
2414
2415To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2416C<$sockaddr_maxlen>.
2417
2418The main reasons to use this syscall rather than portable C«accept(2)>
2419are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2420flags and you can accept name-less sockets by specifying C<0> for
2421C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2422C<accept>.
2172 2423
2173=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2424=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2174 2425
2175Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2426Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2176C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2427C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2220Example: create a pipe race-free w.r.t. threads and fork: 2471Example: create a pipe race-free w.r.t. threads and fork:
2221 2472
2222 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC 2473 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2223 or die "pipe2: $!\n"; 2474 or die "pipe2: $!\n";
2224 2475
2476=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2477
2478This is a direct interface to the Linux L<memfd_create(2)> system
2479call. The (unhelpful) default for C<$flags> is C<0>, but your default
2480should be C<IO::AIO::MFD_CLOEXEC>.
2481
2482On success, the new memfd filehandle is returned, otherwise returns
2483C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2484
2485Please refer to L<memfd_create(2)> for more info on this call.
2486
2487The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2488C<IO::AIO::MFD_ALLOW_SEALING> and C<IO::AIO::MFD_HUGETLB>.
2489
2490Example: create a new memfd.
2491
2492 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2493 or die "m,emfd_create: $!\n";
2225=item $fh = IO::AIO::eventfd [$initval, [$flags]] 2494=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2226 2495
2227This is a direct interface to the Linux L<eventfd(2)> system call. The 2496This is a direct interface to the Linux L<eventfd(2)> system call. The
2228(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both. 2497(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2229 2498
2235The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>, 2504The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2236C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30). 2505C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2237 2506
2238Example: create a new eventfd filehandle: 2507Example: create a new eventfd filehandle:
2239 2508
2240 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC 2509 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2241 or die "eventfd: $!\n"; 2510 or die "eventfd: $!\n";
2242 2511
2243=item $fh = IO::AIO::timerfd_create $clockid[, $flags] 2512=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2244 2513
2245This is a direct interface to the Linux L<timerfd_create(2)> system call. The 2514This is a direct interface to the Linux L<timerfd_create(2)> system
2246(unhelpful) default for C<$flags> is C<0>. 2515call. The (unhelpful) default for C<$flags> is C<0>, but your default
2516should be C<IO::AIO::TFD_CLOEXEC>.
2247 2517
2248On success, the new timerfd filehandle is returned, otherwise returns 2518On success, the new timerfd filehandle is returned, otherwise returns
2249C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>. 2519C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2250 2520
2251Please refer to L<timerfd_create(2)> for more info on this call. 2521Please refer to L<timerfd_create(2)> for more info on this call.
2252 2522
2253The following C<$clockid> values are 2523The following C<$clockid> values are
2254available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC> 2524available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2420known issue, rather than a bug. 2690known issue, rather than a bug.
2421 2691
2422=head1 SEE ALSO 2692=head1 SEE ALSO
2423 2693
2424L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2694L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2425more natural syntax. 2695more natural syntax and L<IO::FDPass> for file descriptor passing.
2426 2696
2427=head1 AUTHOR 2697=head1 AUTHOR
2428 2698
2429 Marc Lehmann <schmorp@schmorp.de> 2699 Marc Lehmann <schmorp@schmorp.de>
2430 http://home.schmorp.de/ 2700 http://home.schmorp.de/

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